Cardiovascular SystemChapter 13

Objectives:1. Identify structures and functions

of the cardiovascular system.2. Trace the flow of blood through

the body.

Coverings of the Heart

• Pericardium: (?)1.Visceral (?)pericardium (“epicardium”(?))

– Innermost layer– Covers the heart

2.Parietal (?)pericardium– Outer layer of visceral pericardium– Forms inner lining of fibrous pericardium

3.Fibrous (?)pericardium– Dense connective tissue attached to central

portion of diaphragm, posterior of sternum, vertebral column, and large blood vessels attached to heart

Pericardial Cavity

• Space between parietal and visceral pericardium layers

• Filled with serous fluid to reduce friction between the membranes as the heart moves

Wall of the Heart

1. Epicardium– Outer layer– Corresponds to visceral pericardium– Protects heart by reducing friction

2. Myocardium– Thick, middle layer– Consists mostly of cardiac muscle tissue that

pumps blood out of the heart chambers3. Endocardium

– Inner layer– Epithelium and connective tissue

Heart Chambers & Valves

• ????• Four hollow chambers:

– Upper chambers = atria (atrium)– Lower chambers = ventricles

• Atria– Thin walls– Receive blood returning to the heart

• Ventricles– Receive blood from the atria– Contract to force blood out of the heart into

the arteries

Heart Chambers & Valves, continued…..• Left atrium and ventricle are separated

from the right atrium and ventricle by a solid, wall-like septum.

• Atrioventricular valves – separate ???1. Tricuspid valve

• on the right• “3 cusps”

2. Bicuspid valve (“mitral valve”) • on the left• “2 cusps”

– Allows blood to flow ONLY from atrium to ventricular – no backflow

Heart Chambers & Valves, continued…..

• Right atrium receives blood from:– Superior vena cava (???)– Inferior vena cava (???)– Coronary sinus – small vein that drains blood

from the myocardium• Right ventricle

– Thinner muscular wall than the left ventricle– Only has to pump blood to the lungs

• Blood leaves the ventricle through the pulmonary valve, and enters the pulmonary trunk, which divides into the left and right pulmonary arteries.

Heart Chambers & Valves, continued…..• Left atrium receives blood from the lungs

through 4 pulmonary veins.• Blood leaves the left ventricle through the

aortic valve, into the aorta.• Ventricular wall is thicker than that of the

right ventricle – has to pump blood to the rest of the body

Sketch & Label the Valves

Label the Exterior Heart

Label the Interior Heart

Add to Your Labeled Diagrams

1. Color the areas that contain oxygenated blood red.

2. Color the areas that contain unoxygenated blood blue. (***WHAT COLOR IS UNOXYGENATED BLOOD, REALLY?)

3. Add arrows to indicate the direction of blood through the whole system.

4. Write in the areas each blood vessel is going to or coming from (i.e., lungs, body, heart muscle).

Blood Supply to the Heart

• Coronary arteries– Supply oxygenated blood to the heart muscle– The first 2 branches off the aorta, right beside

the aortic valve– These are tiny!

• Cardiac veins– Return blood from the myocardium to the

coronary sinus.– What is the coronary sinus?

Blood Vessels

• Arteries → arterioles → capillaries → venules → veins → ???

• Gas exchange between the blood and body tissues occurs in which blood vessels?

• Arteries are under relative high pressure.• Veins have valves that prevent a backflow

of blood.

Paths of Circulation

• Two major pathways:1. Pulmonary circuit - lungs2. Systemic circuit – body and heart

• BOTH pathways have the 5 types of blood vessels.

• The pulmonary circuit starts when blood is pumped out of the __________, and ends when blood returns to the _______.

• The systemic circuit starts when blood is pumped out of the __________, and ends when blood returns to the _______.

Arterial System

• Aorta– Largest diameter artery– Exits the left ventricle (1. ascending aorta)– Curves over the top and to the left of the heart

(2. aortic arch)– 3. Descending aorta gradually moves

medially(?) until it lies directly in front of the vertebral column• Descending aorta ABOVE the diaphragm: 4. thoracic

aorta• BELOW the diaphragm: 5. abdominal aorta

For this next part, you will need:

1. Handout to label as we go.2. Add this chart to your notes *****:

Portion of Aorta Major Branches General Regions or Organs Supplied

Major Arteries of the Ascending Aorta

• Right and left coronary arteries

Major Arteries of the Aortic Arch

1. Brachiocephalic artery2. Left common carotid artery3. Left subclavian artery

Major Arteries of the Descending Aorta

• Bronchial artery

Major Arteries of the Thoracic Aorta

1. Pericardial artery2. Esophageal artery3. Mediastinal artery4. Posterior intercostal artery

Major Arteries of the Abdominal Aorta

1. Celiac artery ( gives rise to gastric, splenic, and hepatic arteries)

2. Phrenic artery3. Superior mesenteric artery4. Suprarenal arteries5. Renal arteries6. Gonadal arteries7. Inferior mesenteric artery8. Lumbar arteries9. Middle sacral artery10.Common iliac arteries

Arteries to the Neck, Head, and Brain

• These branch off the subclavian and common carotid arteries.

1.Vertebral arteries– branch off the subclavian arteries – pass through the transverse foramina of the

cervical vertebrae– Enter the skull through the foramen magnum– Supply blood to the vertebrae and their

ligaments and muscles

Arteries to the Neck, Head, and Brain, continued…..

2. Thyrocervical arteries– short vessels that branch off the subclavian

arteries– give off branches to the thyroid gland,

parathyroid glands, larynx, trachea, esophagus, and pharynx

Arteries to the Neck, Head, and Brain, continued…..

3. Left and right common carotid arteries diverge into internal and external carotid arteries– External carotid artery goes up the side of the

head giving off branches to structures in the neck, face, jaw, and base of the skull

– Internal carotid artery follows a deeper course along the pharynx to the base of the skull• Provides the major blood supply to the brain

Arteries to the Shoulder and Upper Limb• After the subclavian artery pass between

the clavicle and the 1st rib, it becomes the axillary artery, which then becomes the brachial artery.

• A deep brachial artery branches off the brachial artery and curves around the humerus to supply the triceps brachii.

• At the elbow, the brachial artery branches into radial and ulnar arteries. They rejoin at the wrist.

• Which artery is used for taking a pulse?

Arteries to the Pelvis and Lower Limb

• Common iliac arteries divide into internal and external arteries.– Internal supplies pelvic muscles and organs– External supplies lower limbs – becomes the

femoral artery• Femoral artery supplies muscles and

tissues of the thigh area.• As it approaches the knee, it becomes the

popliteal artery, supplying the knee joint and muscles in the thigh and calf.

Arteries to the Pelvis and Lower Limb, continued…..• Popliteal artery branches into:

– Anterior tibial artery– Posterior tibial artery

• Anterior tibial artery:– Passes between tibia and fibula– Supplies skin and muscles in anterior and

lateral parts of leg– Becomes the dorsalis pedis artery (???)

• Posterior tibial artery:– Descends beneath the calf muscle– Supplies skin, muscles, and other tissues of

the leg

Venous System

• MOST veins follow closely along their same-named arteries. (example: brachial artery and brachial vein)

• Notable differences:– Aorta vs. vena cava– Internal and external carotid arteries vs.

internal and external jugular veins