Lab 1—The Back

1) What are the parts of a typical vertebra?

BodyTransverse Processes (2)Spinous ProcessArticular Processes (4)Vertebral ForamenPedicleLamina

2) What distinguishes vertebrae from different regions of the body?

Cervical vertebrae have holes in the transverse processes for the vertebral artery; thoracic vertebrae have articular facets for costovertebral joints with the ribs. Lumbar vertebrae generally have a proportionately larger vertebral body and are lacking the aforementioned diagnostic identifiers.

3) How many vertebrae are in the different body regions?

7 Cervical (C1—Atlas, elevation of head; C2—Axis, rotation of head)12 Thoracic (C7 and T1 have prominent spinous processes)5 Lumbar (L1 can be difficult to distinguish from T12)5 Sacral (fused—Sacrum)4 Coccyx (fused—Coccyx)

4) What is meant by the term "nerve"?  Ramus? Root?

A nerve is a bundle of fibers that carries messages between the CNS and the PNS. Each spinal nerve consists of fibers from a dorsal and a ventral root which join to create the nerve at the intervertebral foramen. (A dorsal root is afferent; ventral is efferent.) Lateral to the nerves are the rami, the ventral ramus innervates the anterior of the body and superficial back muscles; the dorsal ramus innervates the deep muscles of the back.

5) Which muscles comprise the "superficial" muscles of the back?

Trapezius, Latissimus Dorsi, Rhomboid Major & Minor, Levator Scapulae(The trapezius is innervated by the spinal accessory nerve CN XI)

The "intermediate" layer of muscles? 

Serratus posterior superior and Serratus posterior inferior

The "deep" muscles?Erector Spinae group (lateral to medial):

Iliocostalis, Longissimus, SpinalisTransversospinalis group (superficial to deep):

Semispinalis, Multifidius, Ratores

Are there differences in the function of these groups?

Superficial muscles are responsible for supporting the back, neck, and scapula. The intermediate muscles function in assisting respiration, and the deep muscles are responsible for supporting and erecting the spine.

Are there differences in their innervation?

Deep muscles are innervated by the dorsal rami, superficial and intermediate muscles by the ventral rami. (Each ramus carries all four fiber types—GSA, GSE, GVA, GVE)

How will you be able to distinguish one muscle from another?

Shape, position, insertions, origins, fiber direction

Lab 2—Breast and Thoracic Wall

1) What is meant by the term "spinal nerve"?

A spinal nerve is a nerve that originates from the spinal cord at the union of pure dorsal and ventral roots, as opposed to a nerve branching off more distally in the body.

2) Where is a nerve formed?

A nerve is formed where it leaves the spinal cord at the union of its dorsal and ventral roots, often associated with passage through the intervertebral foramen.

3) What type of fiber is found in a ventral root?  A dorsal root?

Dorsal roots are made of afferent fibers, ventral roots are made of efferent fibers.

4) What are the coverings of the spinal cord? 

The SC is covered by three specialized layers of fascia known as the meninges. The outermost layer is called the dura and is fairly tough. The next layer is the arachnoid and is thinner and spider-looking. The innermost layer is the pia and

cannot easily be seen except for the attachments between the SC and the dura. There are several real and potential spaces. The outermost space (outside the spinal cord between the vertebrae and the dura) is the epidural space, the next is the subdural (between the dura and the arachnoid) which is a potential space, the last is the subarachnoid space (between the arachnoid and the pia) which is also a real space. Cerebrospinal fluid (CSF) is contained primarily in the subarachnoid space (i.e. the largest space within the dura).

5) What is the cauda equina?

The cauda equina is the “tail of the spinal cord”; it begins where the body of the spinal cord ends, leaving the lower lumbar and sacral nerve roots of the spinal cord to continue down until they join together and exit the vertebral column. NOTE: The cauda equina runs WITHIN the subarachnoid space between the dura and the pia.

6) What are the denticulate ligaments?  What are they comprised of?

The denticulate ligaments are the attachments of the spinal fibers to the arachnoid and dura mater. They are extensions of pia mater. There are approximately 21 on each side of the spinal cord.

7) What is the conus medullaris?  Where does it terminate in the adult? What is the clinical importance of this?

The conus medullaris is the end of the body of the spinal cord. It terminates at the level of L1-L2, thus spinal taps into the subarachnoid space are done at the level of L3-L4 to avoid piercing the spinal cord itself. NOTE: The needle of a spinal tap may intercalate itself between the spinal roots of the cauda equina but is unlikely to damage them.

8) What type of bone forms the body of a vertebra?  The neural arch?

The vertebral body is formed by spongy (inside) and cancellous bone (outside). The neural arch is formed by compact bone.

9) What type of joint is formed by the vertebral bodies and the intervening intervertebral discs?

These joints are not synovial and thus they fall into the class of joints known as synarthroses. Because they have ligament attachments they are further known as syndesmoses. Because a fibrocartilaginous disk is interposed between the bones of these joints, they are further known as symphyses.

10) What type of joint is a zygapophyseal joint?  A costotransverse joint?A zygapophyseal joint is a synovial joint found between two vertebrae that allows the spine to flex. A costotransverse joint is a synovial joint found between vertebrae and their corresponding ribs.

Lab 3—Thoracic Body Wall

1) Where does a spinal nerve "begin"?

A spinal nerve begins at the union of its dorsal and ventral roots as it leaves the intervertebral foramen.

2) What type of joint is found between the head of a rib and the body of avertebra?  What is the name of this joint?

It is a synovial, costovertebral joint.

3) Which ribs are known as "floating ribs"?  Why?

Ribs 11-12 are called floating ribs because they are not attached to the sternum.

4) Where is milk stored in a lactating breast?

Milk is stored in the lactiferous sinuses.

5) What is the function of the retromammary space?

The main function of the retromammary space is to allow the breast some degree of movement and isolation of infection from the chest.

6) What major vein is found in the deltopectoral triangle? Where does this vein drain into?

The major vein found in the deltopectoral triangle is the cephalic vein, and it drains into the axillary vein.

7) What artery is the internal thoracic artery a direct branch of?  Do you know another artery that also arises from this larger artery?

The internal thoracic artery is a branch of the subclavian on both the right and left sides. Other arteries that are branches of the subclavian are the vertebral artery, thyrocervical trunk, costocervical trunk, dorsal scapular artery, and the axillary artery.

8) Where do the intercostal veins, arteries and nerves lie in relation to the ribs?  Why is this location important clinically?

Intercostal veins, arteries and nerves run along the underside of their associated rib in the intercostal space. This is clinically important because, in order to avoid damaging vessels, chest tubes need to be inserted into the bottom of the intercostal space, along the top surface of the inferior rib.

9) Why are the medial and lateral pectoral nerves so named?

They are named due to their positions relative to the brachial plexus. However, the medial pectoral nerve pierces the pectoralis minor LATERAL to the lateral pectoral nerve, which runs between the pectoralis major and minor. Both nerves innervate both muscles.

10) How will you identify/distinguish between the external and internalintercostal muscles?

External intercostals fibers run from the superiolateral to inferiomedial (i.e. “hands in pockets”); the internal intercostals run from the inferiolateral to the superiomedial (i.e. “hands on hips”).

Lab 4—Abdominal Body Wall

1) How many types of nerve fibers would you find in the beginning of a spinal nerve?

All four types: GSA & GVA from the dorsal root; GSE & GVE from the ventral root.

2) Which fibers comprise the Autonomic Nervous System? Why?

By definition, autonomic nervous fibers are composed of GVE, and they have sympathetic and parasympathetic components.

3) Where are the first cell bodies of sympathetic nerve fibers located? Where are the second cell bodies located?

The first cell bodies of the sympathetic nerve fibers are located in the intermediolateral column (grey matter) of the spinal cord between T1 and L2. The postganglionic cell bodies and synapses are located in the sympathetic chain ganglia or in the prevertebral ganglia (sympathetic plexi).

4) What is a "splanchnic" nerve?  How many are there?

The sympathetic thoracic splanchnic nerves go directly to hollow organs IN THE ABDOMEN without first synapsising [sic] [*editor’s note—what a great word! C.G.] in the paravertebral ganglia (sympathetic chain). There is a greater, lesser, least, and lumbar splanchnic nerve. These primarily innervate the foregut, midgut, hindgut, and the pelvis, respectively. NOTE: The pelvic splanchics have NOTHING to do with the sympathetic thoracic splanchnics. They are a completely different system that functions in parallel with the thoracic splanchnics. The pelvic splanchnics are parasympathetic nerves to the gut, analogous in function to the vagus nerves, which innervate the hindgut distal to the left colic flexure. (The vagus, of course, provide parasympathetic innervation to the gut proximal to the left colic flexure, as well as to the heart and other important organs.)

5) What comprises the inguinal ligament?

The inguinal ligament is composed of the aponeurosis of the external obliques.

6) Which muscles/aponeurosis/fascia contribute to the coverings of thespermatic cord?

From superficial to deep: external obliques (external spermatic fascia), internal obliques (cremaster), and fascia transversalis (internal spermatic fascia). NOTE: The transversus abdominus DOES NOT contribute to the spermatic cord.FURTHER NOTE: The transverses abdominus DOES contribute to the conjoint tendon, along with the internal obliques. The conjoint tendon is attached directly to the pubic bone.

7) What nerve(s) carry sensation from the scrotum?  the labia?

Sensation from the scrotum is carried from the ilioinguinal nerve, the genital branch of the genital femoral nerve, the perineal branch of the pudendal nerve, and the perineal branch of the posterior femoral cutaneous nerves. The labia are embrologically homologous to the scrotom and thus have similar innervations.

8) What is/are the "root value/s" of the ilioinguinal nerve? The iliohypogastric nerve?

Both are L1, and innervate the skin and muscles of the lower abdominal wall and thigh, although the ilioinguinal additionally innervates the scrotum.

9) What are the boundaries of the inguinal triangle?

The inferior epigastric medially, the inguinal ligament inferiorly, and the rectus abdominus medially.

10) What is the difference between a "direct" and an "indirect" inguinalhernia?

Direct hernias pass through the abdominal wall (within the borders of the inguinal triangle) while indirect hernias pass through the inguinal canal from the deep ring to the superficial ring.

Lab 5—Pleura, Lungs and Middle Mediastinum

1) What are the plural cavities?  What is the difference between visceral and parietal plurae?

The plural cavities are the spaces in the thorax where the lungs are. The visceral pleurae covers the lungs, the parietal plurae covers the thorax. Together with the intervening serous fluid they create a nearly frictionless surface so that the lungs can expand properly.

2) Into which "space" would you insert a needle for aspiration during a "plural tap" (thoracocentesis)? Why?

7-9th intercostals, the level of the costodiaphragmatic recess.

3) What is meant by the "root" of the lung?

The “root” or hilus of the lung is the location where the bronchi and blood vessels enter the lung.

4) What nerve would provide preganglionic parasympathetic fibers to thelungs?

The vagus nerve.

5) What is in a white ramus communicans?

A white ramus communicans is where preganglionic sympathetic nerves enter the paravertebral ganglia (sympathetic chain).

6) What is the root value of the Greater Splanchnic nerve?  What is the primary type of fiber in this nerve?  What other type of nerve fibers would be there?  Which ones would not? Why?

Roots: T5-9, Lesser T10-11, Least T12, Lumbar L1-2The Greater Splanchnic nerve is primarily GVE because it is autonomic. However there is also GVA present because GVA fibers carry impulses back to the CNS while primarily following GVE paths [*editor’s note—thx Amar Patel my man. Word. C.G.]. There are probably no GSA or GSE fibers present because the Greater Splanchnic does not innervate skeletal muscle.

7) From which arteries do lung tissue receive oxygenated blood?  Where do these arise from?

Lung tissue receives oxygenated blood from the bronchial arteries which arise directly from the descending aorta.

8) What is the function of the azygos sytem of veins? What does the wordazygos mean?

The azygos system of veins serve to drain the vessels of the thorax into the SVC and IVC. In addition they can provide a shunt from the IVC to the SVC or the reverse. Azygos means “unpaired”. Vagus means “wandering”. And duodenum means “twelve finger-breadths”. Thank you, Dr. Laitman.

9) One of my favorite nerves in the body is the Left Recurrent Laryngeal nerve.  When you see it try to understand the reason for its most unusual location and path.

The Left Recurrent Laryngeal wraps around the aorta b/c it was pulled down during development.

10) Which main bronchus has a more vertical path to the lung?  What isthe clinical significance of this?

The right main stem bronchus takes a more vertical pat into the lung, and thus aspirated items are more likely to enter the right rather than left lung

11) What are "bronchopulmonary" segments?  What is their importance?

Bronchopulmonary segements are defined by the bronchi and their successive divisions. They are important because each part of the lung is supplied by a superior bronchus, thus they define the segments that are supplied by their origin.

Lab 6—Superior Mediastinum

1) Why are arteries called "coronary" arteries and veins "cardiac" veins?

The coronary arteries originate at the aorta and run in the coronary sulcus around the top of the heart, hence the latin root “cor” for crown. The cardiac veins originate lower at the right atrium and give off primarily longitudinal branches.

2) Can you describe the path of blood flow through the heart in a late term fetus?  In an adult?

Blood enters the RA via the superior and inferior vena cava and is then mostly shunted through the foramen ovale to the left atrium then the LV and aorta. Some blood does go to the RV and then the lungs but there is a further shunt through the ductus artiosus to the aorta from the pulmonary arteries

3) What structure is prominent in the anterior part of the superior mediastinum in an infant but only remains as a fatty mass in an adult?

The thymus. Important in fetal radiography. It will appear as a shadow in the upper thorax of a healthy infant.

4) Are there differences between the right and left main bronchi?  What are they?

Yes. The right main bronchus is shorter, and wider, and more vertical. In addition the right has three branches while the left has two.

5) What and where is the "carina"?

It is the bifurcation of the trachea into the main stem bronchi. Often indicated in CT scans.

6) Can you identify on - cross section or CT  - the great vessels, trachea and esophagus?

Really important! The trachea will be a central structure, often circular or D-shaped, that appears as a dark or empty space on a transverse CT. The esophagus is an elongated or pinched structure always located posterior to the trachea and occasionally slightly lateral as well. The great vessels are generally more difficult, but the aorta can always be visualized easily. Practice on WEBCT - GROSS ANATOMY - INTERACTIVE MODULES - THORAX.

7) What is the "primary" type of nerve fiber that you will find in the vagus nerve in the middle of the thorax?

The vagus nerve is a parasympathetic nerve and thus primarily carries preganglionic parasympathetic GVE fibers.

8) What type of muscle fiber comprises the distal portion of the esophagus?  What nerve will innervate the esophagus? What type of nerve fiber would innervate the distal esophagus?

The esophagus is comprised of smooth muscle and thus is innervated by GVA and GVE. The proximal esophagus is innervated parasympathetically by the recurrent laryngeal nerves whereas the distal esophagus is innervated by the vagus.

9) What forms the posterior aspect of tracheal rings?

The trachealis muscle—a smooth muscle tissue.

10) What are the different "splanchnic" nerves?  What are their root values?What are the primary fiber types in each?  What other type of fiber would you also find in them?  What type(s) would you NOT expect to find? Why?

Roots: Greater T5-9, Lesser T10-11, Least T12, Lumbar L1-2The sympathetic splanchnic nerves are primarily GVE because they are autonomic. However there is also GVA present because GVA fibers carry impulses back to the CNS while primarily following GVE paths. There are probably no GSA or GSE fibers present because the splanchnics do not innervate skeletal muscle. [And remember, the pelvic splanchnics are a different system (parasympathetic gut) and thus the above discussion does not apply.]

Labs 7&8—Heart Dissection and Chambers

1) Can you position the heart in anatomical position? What structures will you see anteriorly or posteriorly? If you see a heart placed on a tray (e.g., as you may see in a practical) will you know your orientation?

The apex of the left ventricle is situated anterior and inferiorly towards the left of the thorax. The left and right atria constitute the base of the heart and are situated towards the posterior thoracic wall, with the left atrium touching the esophagus which runs behind it.

2) What is meant when one says that the "right coronary artery is dominant" in a patient?

Occasionally the posterior descending branch of the right coronary artery will elongate through the coronary sulcus, completely circumnavigating the heart, and supply blood to the atrioventricular tissue usually supplied by the left circumflex branch of the left coronary artery. (*Editor’s note: thx my man scott. You rock. CG)

3) Do you understand what is meant by an "end" artery? Why are coronary arteries called "functional" end arteries? What is the clinical implication of this?

End arteries are so called because they don’t anastomose with any other vessels. The coronary arteries are functional end arteries because even though there is some anastomosis, it is not sufficient to perfuse the heart in the event of a blockage. Clinically this means that if there is a stenosis or occlusion of either coronary artery an MI will occur.

4) When do the coronary arteries fill with blood – during "systole" or "diastole"?  What is the anatomical basis for this?

During systole the coronary arteries are blocked by the semilunar cusps of the open aortic valve, thus they fill during diastole when the aortic valve closes.

5) What is the "skeleton" of the heart?

The skeleton of the heart refers to a structure of dense fibrous connective tissue that stiffens the heart around the atrioventricular orifices and origins of the pulmonary trunk and aorta to keep them from distorting during ventricular contraction, as well as serving as an attachment site for the pectinate and cardiac muscle fibers of the heart valves.

6) Start thinking about cardiac pain.  Where is the usual area of "referred pain" from the heart?  Why?  Where else can cardiac pain be perceived? Why?  Make sure that you are starting to understand what is meant by a dermatome, and which ones relate to heart pain.

The heart is innervated by GVA nerves with root values of T1-T5 and C4 whose cell bodies are found in the DRG along with those of GSA fibers that innervate dermatomes in the jaw, neck, shoulders and upper chest. Thus, referred cardiac pain might be felt in these areas.

7) What comprises the "conduction system" of the heart?

The conduction system begins with specialized cardiac muscle fibers (NOT nerves) in the SA node located in the superior region of the right atrium near the entrance of the SVC. The impulse travels from the SA node through fibers to the AV node located in the interatrial septum, near the entrance of the coronary sinus. From there the impulse travels along the atrioventricular bundle through the membranous part of the interventricular septum, where it splits into left and right bundle branches. The right bundle branch fibers travel in the septomarginal trabecula (moderator band!), carrying the impulse to the anterior and septal papillary muscles of the right ventricle. The left bundle branch fibers carry the impulse to the papillary muscles of the left ventricle.

8) What and where is the "fossa ovalis"? What was it embryologically? What was its embryologic function?

The fossa ovalis is located in the interatrial septum. Embrologically it was once the foramen ovale which served to shunt oxygenated blood from the right atrium to the left atrium. After birth when the pressure in the LV increased the septum was forced closed and eventually fused shut.

9) Please review the "borders" of the heart and be familiar with their appearance in PA radiographic views.  Please also make sure that you can visualize the heart and great vessels on CT scans.

WEBCT - GROSS ANATOMY - INTERACTIVE MODULES – THORAX and ABDOMEN

Get busy if you haven’t done this already. And, let me know if you want to go over them with someone, because I love these.

10) Please review the valves of the heart and the mechanism that operatesthem.  Which valves work via pressure differences, which via muscular actions?

The aortic and pulmonary valves work via pressure differences (open during systole—ventricular contraction, closed during diastole—atrial contraction), while those between the atria and the ventricles (i.e. the tricuspid and the mitral) operate via direct muscular actions.

Lab 9—Abdomen

1) What is the role of a structure such as the Greater Omentum?

The greater omentum serves to support and protect the structures of the abdomen and in the event of an ulcer facilitates the healing process.

2) Can you find the "portal triad"? What structures comprise this?

The portal triad consists of the portal vein, proper hepatic artery and common bile duct. It runs in the hepatoduodenal ligament of the lesser omentum, from the liver-gallbladder junction to the duodenum.

3) Do you understand what is meant by the terms "intraperitoneal", "primarily retroperitoneal", "secondarily retroperitoneal", "extraperitoneal"? Can you give an example of each?

Intraperitoneal refers to structures that are completely encased in peritoneum, i.e. the liver, gallbladder, spleen, stomach, 1st part of duodenum, jejunum, ileum, transverse colon, sigmoid colon and (usually) the appendix.

Primary retroperitoneal refers to structures that have always been retroperitoneal, such as the kidneys, adrenal glands, aorta, IVC and testes.

Secondary retroperitoneal refers to structures that were once intraperitoneal but become retroperitoneal, such as the 2-4th parts of the duodenum, cecum, ascending and descending colon, rectum and pancreas

Extraperitoneal refers to structures outside the peritoneum but not posterior or dorsal to it, such as the bladder, prostate, seminal vesicles, uterus and ovaries.

4) Review the path of the alimentary tract from proximal to distal. It will be important for you to know the correct order of structures.

Mouth, esophagus, cardiac sphincter, stomach, pyloric sphincter, duodenum (4 parts), jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anus.

5) What are the subdivisions of the "small" intestine? Which are intraperitoneal, which retroperitomeal?

The small intestine is composed of the duodenum, jejunum and ileum. The first part of the duodenum is intraperitoneal, the 2-4th parts are secondarily retroperitoneal, and the jejunum and ileum are both intraperitoneal.

6) What are the subdivisions of the "large" intestine? Which are intraperitoneal, which retroperitoneal?

The large intestine is composed of the cecum, ascending, transverse, descending, and sigmoid colon. The transverse and sigmoid colons are intraperitoneal; the cecum, ascending and descending colons are secondary retroperitoneal.

7) What is a "mesentery"?  What is "The" Mesentery?

A mesentery is a double layer of peritoneum. “The Mesentery” is the mesentery that supports the small intestine and through which the blood supply runs to the small intestine from the SMA and IMA.

8) What are the paracolic "gutters"?  What is their clinical significance?

The paracolic gutters are found on either side of both the ascending and descending colon and are cilincally significant because for substances such as fluids can “drain” down them.

9) Where would you experience "early" pain from appendicitis? Why?  What do we generally mean when we say "early pain" from a structure?  What do we mean when we say "late pain"?

Early, or visceral, appendicitis pain would be felt near the umbilicus as referred pain. Late pain will be felt as a result of irritation of a somatically innervated structure such as the body wall and will correspond with the actual location of inflammation.

10) In your preparation, please go over the autonomic (sympathetic and parasympathetic) innervation to the abdomen.

Parasympathetic: vagus from distal esophagus to left colic flecture, pelvic splanchnics distal to left colic flecture.

Sympathetic: greater, lesser, least and lumbar (thoracic) splanchnics.

Lab 10—Unpaired Aortic Vessels

1) What are the three "unpaired" vessels off of the abdominal aorta?

Celiac Trunk, Superior Mesenteric Artery, and Inferior Mesenteric Artery. Median sacral gets an acknowledgement as well.

2) What other direct branches, besides the great unpaired ones, arise from the abdominal aorta?

There are also the Renals, medial suprarenals, inferior phrenics, testicular/ovarian, and lumbars (1-4).

3) What vertebral levels do the major abdominal, aortic branches correspond to?

Celiac trunk T12, SMA L1, IMA L3.

4) What do aortic branches from different parts of the aorta (e.g., ventral, lateral) do?  Is there any organization to aortic branches that can aid you in understanding their functions (i.e, which structures do they supply with blood)?

Ventral branches tend to be major vessels such as the celiac trunk, SMA, and IMA which supply the gut and unpaired organs such as the liver. More lateral branches tend to supply specific paired organs such as the kidneys.

5) What arteries supply the Diaphragm?  Where do they arise from?

Superior and Inferior phrenics, Musculophrenic and Pericardiacophrenic. The inferior phrenics arise from the abdominal aorta, superior phrenics arise from the thoracic aorta, and the musculophrenic and pericardiacophrenic are branches of the internal thoracic artery.

6) What arteries supply the suprarenal glands?  Where do they arise from?

The suprarenal glands are supplied by the superior, medial and inferior suprarenals. The superior suprarenals arise from the inferior phrenics, the medial suprarenals arise directly from the abdominal aorta, and the inferior suprarenals arise from the renal arteries.

7) What is the difference between the hepatic veins and the portal vein?

The portal vein carries blood from all of the digestive organs into the liver for filtering, while the hepatic veins carry blood away from the liver into the systemic IVC circulation.

8) What is the "portal triad"?  Where is it?

The portal triad refers to the portal vein, proper hepatic artery and bile duct, which run in the hepatoduodenal ligament.

9) What is meant by the "marginal" artery?  Where is it located?  What is its clinical significance?

The marginal artery is located circling the inside of the Mesentery and connects the vessels carrying blood to the vasa recta. Clinically it is significant because it is supplied by both the SMA and IMA and thus is a major route of collateral circulation in the event of blockage.

10) Observe the left renal vein.  What is special about it?

The left renal vein is important because it drains much of the left part of the abdomen. It functions as a direct extension of the IVC, giving off branches on the left side that are paralleled by the IVC on the right.

Lab 11—Gastrointestinal Tract and Unpaired Abdominal Organs

1) Can you identify the gross regions of the stomach, e.g., pyloric antrum, canal, sphincter, cardiac orifice, fundus?

2) What are the "vasa recta"?  Are they different in appearance between structures such as the jejunum and ileum?  If so, what is (are) the difference(s)?

The vasa recta are the straight veins that run off of the arcades in the Mesentery. They are longer when running into the jejunum and become shorter as you follow the gut distally towards the ileum.

3) What is meant by the "bare area" of the liver?  What are the coronary ligaments?  Why are they called "coronary"?

The bare area of the liver is so named because there is no peritoneum lying in this area and thus the liver is in direct contact with the diaphragm. The coronary ligaments are the result of the reflection of the peritoneum in this area and thus encircle or “crown” the bare area.

4) Try to trace the route of bile passage.  Where is bile made? Where is it stored?

Bile is made in the liver. It flows into the hepatic duct, which then becomes the common bile duct when it is joined by the cystic duct. There it goes into the duodenum, or is sent back through the cystic duct to the gall bladder for storage.

5) Note the location of the IVC dorsal to the portal vein.  This position is important clinically, and we will discuss this next week.

It is clinically important because in the event of high portal hypertension the IVC and portal vein can anastomose to create an alternate route.

6) What are the main tributaries of the portal vein?

The SMV and the Splenic Vein

7) What is the difference between the portal veins and the hepatic veins?

Portal veins carry unfiltered blood to the liver from the portal system; hepatic veins carry filtered blood from the liver to the systemic circulation.

8)  Make sure that you are familiar with the autonomic innervation of adominal viscera and where visceral pain may be perceived.  Where would you likely feel biliary colic?  Why?

Biliary colic would likely be felt as referred pain in dermatomes from T7-9 because GVA cell bodies from the abdominal viscera will interact with GSA cell bodies from the T7-9 dermatomes in the DRG.

9) What nerve would carry preganglionic parasympathetic fibers to the gallbladder?

The parasympathetic fibers to the gallbladder will be supplied by the vagus nerve as will all organs proximal to the left colic flexure.

10) Why is it often said that the liver can be divided into segments similar to those of the lung?  What is meant by this?

Similarly to the lung, the liver is supplied by increasingly small subdivisions.

Lab 12—Posterior Abdominal Wall

1) What is meant by a "portal" system?  What is "The Hepato-Portal" system?

A portal system is a system which allows an alternate passage of blood between two capillary beds distinct from systemic circulation. The hepato-portal system drains the blood from the digestive organs into the liver for filtration before entering systemic circulation.

2) What is the function of the Azygos System of Veins? What two major vessels does the azygos vein connect?

The azygos drains the thorax, and also connects the IVC and SVC.

3) Where do the kidneys develop embryologically?  The suprarenals?

Embryologically the kidneys develop near the pelvis and migrate upwards during development, while the suprarenals develop at their mature vertebral levels.

4) Review the vasculature of the kidney and suprarenal glands. Note that they come from different sources.  From what artery does the kidney receive blood?  What is

special about this artery? Why are there frequently multiple renal arteries? What arteries provide the suprarenals with blood? Where do they arise from?

The kidneys receive blood from the renal arteries, which give off the inferior suprarenal arteries and branch to each segment of the kidney. There can be multiple renal arteries if they do not deteriorate during the embryological upward migration of the kidneys. The suprarenals are supplied by the superior (inferior phrenics) medial (aorta) and inferior (renal) suprarenal arteries.

5) What are the root values of the nerves that you will be encountering in lab today?

Subcostal (T12), Iliohypogastric (L1), Ilioinguinal (L1), Genital Femoral (L1-L2), Lateral Cutaneous (L2-L3), Obdurator (L2-L4), Femoral (L2-L4)

6) You will see some very large nerves for the first time today. What is the function of the obturator nerve?  What is its root value?

The obdurator supplies innervation to the thigh and arises from L2-L4.

7) What is the function of the femoral nerve?  Where is it going?

The femoral nerve supplies innervation to the thigh, hip and knee joints

8) Review the anatomy, blood supply and innervation of the diaphragm.  What type of muscle comprises most of the Diaphragm?

The diaphragm is innervated primarily by the phrenic nerves (GSE) as most fibers are skeletal muscle. Blood to the diaphragm comes from the superior and inferior phrenic arteries off the aorta, and the musculophrenic and pericardiacophrenic arteries from the internal thoracic artery.

9) What is a diaphragmatic hernia?

A diaphragmatic hernia is a protrusion of abdominal contents through the diaphragm, commonly through the esophageal hiatus.

10) Identify the large muscles of the posterior abdominal wall (i.e.,the transversus abdominus, the psoas major and the quadratus lumborum). What is the major role of the combined muscle known as the "iliopsoas"? See if you can identify these muscles on radiograms and CT scans.

The iliopsoas muscle is involved in flexion of the thigh, as is the iliacus. Muscles are tricky on transverse CT scans; I’ve found that they are rarely what you expect them to be.

Lab 13

1) What does the word "pelvis" mean? What is the "true" pelvis? The "false" pelvis?

Means Bowl. The pelvis is a bony ring, interposed between the movable vertebrae of the vertebral column which it supports, and the lower limbs upon which it rests. It is composed of 4 bones: two hip bones laterally and anteriorly (ilium, ischium and pubis) and the sacrum and coccys posteriorly. The true pelvis is that part of the pelvic cavity which is situated below and behind the pelvic brim. It is the location of the pelvic viscera (bladder, uterus, ovaries). The false pelvis is the expanded portion of the cavity situated above and in front of the pelvic brim. Location for abdominal viscera (sigmoid colon and ileum)

2) What are some of the key differences between a male and female bony pelvis?

The most noticeable difference is that the pubic arch is wider and more rounded than in the male where it is an angle rather than an arch. Also the female superior aperture of the true pelvis is larger and more oval. The inferior aperture is also larger and the coccyx is more movable (helps during birth).

3) What are the boundaries of the ischioanal (ischiorectal) fossa? What important structures run in the lateral wall of the fossa? What is the clinical importance of this?BoundariesAnterior Superficial transverse perineal muscle (Transversus perineial superficialis)Inferior perineal membrane of the UGDPosteriorGluteus MaximusSacrotuberous LigamentLateralTuberosity of the ischiumObturator internusMedialLevator aniSphincter ani externusSuperiorLevator aniInferiorSkin

On the lateral wall (alcock’s cnal) we can fin the internal pudendal artery and vein and the pudendal nerve (S2-S4)

4) What is meant by the lesser and greater sciatic foramina? Also, note the location of the sciatic nerve and the posterior cutaneous nerve of the thigh.

The foramens are formed whne the sacrospinous ligament crosses over the sacrotuberosity ligament. The lesser sciatic foramen, which lies inferior to the pelvic floor (and the greater sciatic), provides communication between the gluteal region and the perineum. The sciatic nerve (L4-S3) forms on the anterior surface of the piriformis muscle and leaves the pelvic cavity through the greater sciatic foramen inferior to the piriformis. It passes though the gluteal region where it divides into its two major branches, the common fibular nerve (peroneal, dorsal) and the tibial nerve (ventral)

5) What are meant by the terms "urogenital triangle", "anal triangle" "urogenital diaphragm" and "pelvic diaphragm"? Start to learn the components of these diaphragms. Also, what is a “diaphragm”?

The perineum lies inferior to the pelvic floor between the lower limbs. Its margin is formed by the pelvic outlet, like a diamond shape. An imaginary line between the ischial tuberosities divides the perineum into two triangular regionsUrogenital triangle contains the roots of the external genitalia and, in women, the openings of the urethra and the vagina. In men, the distal part of the urethra is enclosed in the erectile tissues. Posteriorly there is the Anal triangle that contains the anal aperture. The pelvic diaphragm is composed of muscles fibers of the levator ani (iliococcygeus, pubococcygeus, puborectalis) and coccygeus, spanning the area underneath the true pelvis. It is important in providing support for the pelvic viscera and in the maintenance of continence as part of the urinary and anal sphicters.

6) What is an erectile "body"? How many erectile bodies comprise the penis? The clitoris? What is the major anatomical difference between the penis and the clitoris?

The penis is comprised of two sets of erectile structures. Two corpus cavernosa and one corpus spongiosa. The clitoris is only comprised of corpus cavernosa

7) What type of muscle is the uterus comprised of? The urinary bladder?

Smooth muscle

8) Make sure that you are able to identify muscles such as the bulbospongiousus and ischiocavernosus in both males and females. Where are they located?

The bulbospongiousus muscle is covering the corpus spongiousum on both male and female (the corpus spongiosum and bulbourethral glans/ bulbs of the vestibule and greater vestibular glans). Basically is down the middle in the urogential triangle superficial pouch, with and opening in the middle for women genitalia. The ischiovaernosus is covering the corpus carvenosum on the lateral edges of the triangle.

9) From what nerves do the pelvic viscera receive their sympathetic innervation? Parasympathetic innervation?

Sympathetic Lesser and Lumbar splanchnics

Parasympathetic Pelvic Splanchnics

Lab 14

1)What is the danger of putting a sharp instrument leading from the vagina into the posterior fornix?

Perforating into the rectaluterine pouch

2) How many parts of the urethra are there in the male? In the female?

Female 1

Male 4Preprostatic Urethra (internal urethral sphincter)Prostatic urethraMembranous urethra (external urethral sphincter)Spongy urethra (erectile tissue, corpus spongiosum)

3) What is the anatomical basis for women being particularly susceptible to Urinary Tract Infections (UTIs)?

The bacteria that causes urinary tract infections are normally found in the lower intestine. The trouble starts when they move into the urethra and up into the bladder. In both men and women E coli. Leaving the body through the rectum can sometimes reenter through the urethra. If they succeed in reaching the bladder, they can settle and multiply. Since a woman’s urethra is far shorter than a man’s, bacteria invading a woman’s urinary tract have a much shorter trip and a far better chance of getting established.

4) What is the anatomical basis for an ectopic pregnancy?

The infundibulum and the frimbrae are both intraperitoneal

5) If the ovarian artery is blocked, could the ovary still have a blood supply? If yes, how? If not, why not?Yes there is collateral circulation with the uterine artery from the internal iliac

6) Review the regions of the uterus. Know what the external os, cervix, fundus, etc. are.

7) Make sure that you see, and understand, what the broad ligament, mesosalpinx and mesometrium are. Can you identify them in the cadaver?

The broad ligament is the wide fold of peritoneum that connects the sides of the uterus to the walls and floor of the pelvis. It is made out of three parts: Mesometrium- the mesentery of the uterus. Mesosalpinx- the part that surrounds the uterine tube. Mesovarium- the part that surrounds the ovary.

8) Review the composition of the pelvic and urogenital diaphragms. What are the differences between males and females?

The pelvic diaphragm is the floor of the pelvis and it is composed of the levitor ani muscles (pubococcygeus, iliococcygeus, puborectalis) and the coccygeal muscle.The urogenital diaphragm (UGD) is the layer that separates the deep perineal sac from the upper pelvis. It has the External Sphincter urethra muscle.Deep transverse perineal muscleCompressor urethrae (in women)Sphincter urethro-vaginalis (women)Membranous urethra (men)Bulbourethral glands (men)

9) What constitutes the fixed part of the penis and the mobile part of the penis? What and where are the ischiocavernosus and bulbospongiosus muscles in the male and in the female? What type of muscles are these? What type of nerve fibers innervate these muscles?

The fixed part or root of the penis consists of the two crura, which are proximal parts of the corpora cavernosa attached to the pubic arch, and the bulb of the penis, which is the proximal part of the corpus spongiosum anchored to the perineal membrane.The mobile part or body of the penis , which is covered entirely by skin, is formed by the tethering of the two proximal free parts of the corpus cavernosa and the related free part of the corpus spongiosum. The ischiocavernosus muscle is located over the corpus cavernosum tissue and the bulbospongiosus muscle is overlaying the corpus spongiosum tissue. There are skeletal muscles innervated by GSE and GSA from the pudendal nerves. (S2-S4)

10) Please make sure that you have seen, and are familiar with, the pudendal nerve and its course from the greater sciatic foramen through the lateral wall of the ischioanal fossa (i.e., in the pudendal canal). How many branches does the pudendal normally have? What is the first branch off of the pudendal nerve, and where does it course? What are the other branches? Where will you find them?

Branches of the pudendal nerve areInferior anal (rectal)Perineal (travels in the perennial canal and gives off the scrotal branches)Dorsal nerve of the penis

Lab 15

1) What is meant by the term "rotator cuff"? What muscles and tendons form this?

The rotator cuff is an anatomical term given to the group of muscles and their tendons that act to stabilize the shoulder.

Muscles:

Supraspinatus- abducts, suprascapular nerve (C5), tendon to greater tubercleInfraspinatus- laterally rotates, Suprascapular nerve (C5-C6) tendon to greater tubercleTeres Minor- laterally rotates, Axillary Nerve (C5-C6) tendon to greater tubercleSubscapularis- medially rotates the humerus, subscapular nerve (C5-C6) tendon to lesser tubercle

2) Read about the path of the suprascapular nerve and artery in relation to the suprascapular ligament. We will show you this in prosections.

The suprascapular notch is converted to a foramen by the superior transverse scapular ligament. This is the route through which structures pass between the base of the neck

and the posterior scapular region. The suprascapular nerve passes through the foramen underneath the ligament while the artery travels over the ligament.

3) What are meant by the terms flexion, extension, abduction, adduction, medal and lateral rotation?

4) What muscle (s) are responsible for abducting the humerus?

Supraspinatus, deltoid, serratus anterior

5) What arteries comprise the anastomotic network around the scapula?

Intercostal (thoracic aorta), dorsal scapular (subclavian), suprascapular (TCT), transverse cervical (TCT), circumfelex (subscapular)

6) Identify the superficial veins. Where is a frequent location for the administration of material via a venipuncture?

Cephalic vein- drains anterolateral portion of the arm from dorsal venous network of the hand into the axillary v. after crossing over the deltoidpectoral triangle.

Basilic vein- drains anteromedial portion of the arm from dorsal network of the hand into axiallary.

Median cubital vein (commonly used for venipuncture) joins cephalic and basilic at the level of the elbow

Median vein of forearm- ascends in the forearm between the cephalic and the basilic veins to join the basilic in the cubital fossa

Perforating veins- form communications between deep and superficial veins.

7) What are the borders of the axilla? What are the major contents?BORDERS

Apex of the axilla – entrance from neck to axilla; lies between the 1st rib, clavicle, and superior edge of the subscapularis

Base of the axilla – formed by concave skin, cutaneous tissue, and axillary fascia extending from the arm to the thoracic wall

Anterior wall – formed by pectoralis major and minor and the pectoral and clavipectoral fascia associated with them

Posterior wall – formed chiefly by the scapula and subscapularis on its anterior surface and inferiorly by the teres major and latissimus dorsi

Medial wall – formed by the thoracic wall (1st to 4th ribs and intercostal muscles) and the overlying serratus anterior

Lateral wall – narrow bony wall formed by the intertubercular groove of the humerus

CONTENTS (vessels and nerves going to and from the upper limb)

Nerves – Brachial plexusVessels – Axillary artery and its branches; Axillary vein and its branches; Five major groups of axillary lymph nodes (apical, pectoral, subscapular, humeral, and central)

8) What is the axillary artery a direct continuation of? Where does the axillary artery begin? What does it divide into?

Subclavian. Begins after the dorsal scapular at the lateral border of the 1st rib and ends at the inferior border of the teres major to become the brachial artery. It divides into superior thoracic, thoracoacromial, lateral thoracic, subscapular, anterior circumflex humeral, posterior circumflex humeral

9) What is the brachial plexus? Where does it begin? What root values contribute to the plexus?

1)Brachial plexus (L. Braid) is the major network of nerves supplying the upper limb. It is formed by union of anterior primary rami of C5 through C8 nerves and the greater part of the anterior ramus of the T1 nerve. Roots of the brachial plexus are located in the posterior triangle of the neck (defined in question #2 of Lab I above) and emerge from the scalene hiatus (triangular gap bounded by the anterior and middle scalene muscles and the 1st rib to which the muscles attach) to form three trunks:

Superior: C5 and C6Middle: C7Interior: C8 and T1

10) Can you identify the "M" configuration of the lower part of the plexus? What are the major nerves that arise from it? What are their root values? What muscles do they innervate? What regions of skin do they carry sensation from?

The M is formed by the Musculocutaneous-Median-Ulna nerves.

Musculocutaneous (C5-C7) Innervates all the flexors of the arm (Coracobrachialis, Biceps Brachii, the grater part of the brachioradialis) Lateral skin of the forearmMedian (C5-T1) Innervates the flexors of the forearm and the hand. Forearm it has two branches. The Anterior intersseous nerve (all except the ulnar half of the flexor digitorium profundus ) and the palmar cutaneous nerve. In the hand it has: the recurrent

branch that goes to the thenar compartment (opponens pollicis, abductor pollicis brevis, flexor pollicis brevis). Digital cutaneous, the common palmar and the proper palmar. First and second lumbricals. Palmar skin of digist 1,2,3 and ½ of 4 and the tips of the dorsal part of the digits.Ulna (C8-T1) innervates the ½ medial of the flexor digitorium profundus Flexor carpi ulnaris. In the hand it innervates the hypothenar muscles (opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis) Adductor pollicis 3 and 4 lumbrical muscles, dosal (4) and palmar (3) interossei muscles, palmaris brevis. The skin of digist 5 and ½ of 4 and their dorsal part.

Lab 16

1) The brachioradialis muscle is a flexor of the forearm. What evidence is there to suggest that evolutionarily it might have functioned as an extensor?

Even though it is a flexor muscle of the arm, the brachioradialis is located in the posteolateral compartment of the forearm and is thus innervated by the radial nerve, a nerve known to primarly innervate the extensor muscles in the forearm

2) Where would you take an arterial pulse in the arm? Where would you place a stethescope when taking blood pressure? Why?

Brachial artery. Place stethoscope over the cubital fossa. After occluding the artery, the pressure is released and systolic pressure is recorded as the pressre at which blood first heard to spurt in the artery. Diastolic pressure is indicated by an absence of sound made by blood flowing though the artery.

3) What type of joints are the proximal, middle and distal radio-ulnar joints?

4) What is the relationship of the ulnar nerve to the distal portion of the humerus?

5) Which nerve (s) lie deep to the flexor retinaculum within the carpal tunnel? Which nerve (s) lie superficial to the retinaculum?

6) Where does the tendon of the profundus muscle insert? Where does the tendon of the superficialis insert? Where do the tendons of the lumbrical muscles insert? What do these muscles do?

7) What is meant by terms "extrinsic" and "intrinsic" muscles of the hand?

8) What nerve(s) carry sensation from the dorsum of the hand? The palmar surface of the hand?

9) How many carpal bones are there? What are their names (yes, I expect you to know them)?

10) What are the thenar muscles?

11) Make sure that you can trace the course of the axillary artery, its continuation, and branches into and throughout the arm, forearm and hand.

Lab 17

1) How many muscles will move the thumb?

2) What is meant by the term "anatomical snuff box"? What forms its borders? What is its main "component"?

3) What is meant by the term "synergistic muscle activity"? Could you give an example of this?

4) What are the functions of the lumbrical muscles? What are their innervations? What common clinicopathology of the hand are these muscles involved in?

5) Review the sensory innervation of both the dorsum and palmar surfaces of the hand.

6) The shoulder joint is classified as what general type of joint? Be able to compare/contrast it to another similarly structured joint in the body.

Lab 18

1) Before you begin, orient yourself to the bony anatomy pf the pelvis and lower limb bones.

2) What are the three large thigh compartments? What nerves innervate these compartments? What are their root values?

3) What is the function(s) of the anterior (antero-lateral) compartment of muscles? What muscle largely comprises this group? What is its innervation?

4) Trace the path of those nerves from the posterior abdominal wall that travel into the lower extremity. Make sure you can identify the path of these nerves.

5) What is the function(s) of the muscles of the medial compartment? What muscles comprise this group? What are their innervations?

6) What is the femoral sheath? Where is it located? What is found in the sheath; what lies outside it?

7) Review the axes of motion of the three major joints (hip, knee, ankle) of the lower extremity. Start thinking functionally. What muscles groups will move the hip? What muscle groups will move the knee joint?

8) What is meant by the terms flexion, extension, abduction, adduction, lateral and medial rotation?