Chapter 23: Circulation

Chapter 23: CirculationNEW AIM: How have different organisms evolved to perform circulation?

Circulatory system- system of internal transport

Q. What needs to be transported?

- oxygen, RBC’s- carbon dioxide- nutrients- waste products of metabolism

(CO2 to lungs, urea and other waste to kidneys)

- hormones- body defense substances like antibodies and WBC- temp. regulation (heat transfer)

Q. When would an organism not need a CS?When every cell is in contact with the outside world and get what it needs (nutrients, etc…) and can get rid of waste.


Circulatory system1. must reach EVERY cell

a. capillaries

- tiny blood vessels - within a few cells of every cell

b. interstitial fluid- “pond” b/w capillaries and tissue cells

Fig. 23.1A

Fig. 23.1B

- Site of diffusion; one cell width in diameter

Nutrients and wastes diffusing between the capillaries (top), interstitial fluid (blue) and tissue cells (bottom).


Circulatory system

a. Porifera

2. Many animals do not have a true circulatory system

- Circulation achieved by flagellated collar cells circulating sea water through the pores up and out through the osculum.


Circulatory system

a. Cnidaria


Fig. 23.2A

Use GV cavity as “circulatory system”



Circulatory system

a. Cnidaria


b. Platyhelminthes (phylum)

Planaria - tiny (3-12mm) freshwater flat worm

Fig. 23.2A

Use GV cavity as “circulatory system”


Circulatory system3. Two basic true circulatory systems have evolved

a. Open circulatory system

Fig. 23.2B




Fig. 23.2B

i. many invertebrates- mollusks (phylum containing snails, clams, squids etc…)- arthropods

ii. open ended vessels

iii. blood and interstitial fluid are the same




Fig. 23.2B



iii. blood and interstitial fluid are the same – called hemolymph

iv. grasshopper

Hemolymph is moved toward the abdomen/tail end by rhythmic muscle contractions and enters the pores of tubular heart. Pores have a one way valve so hemolymph cannot flow back into body cavity, but is forced through open-ended tubes to maintain circulation when hearts pump.




Fig. 23.2B




iv. grasshopper

Reminder, circulatory system NOT used for transport of gases (O2, CO2) as tracheal system will do this.




Fig. 23.2B




iv. grasshopper

It is much like a fish tank where the tubular hearts would be like the filter in that is sucks water from the tank and puts it back in. The tank would be the body cavity.




Fig. 23.2B




iv. grasshopper

Less efficient as oxygen, nutrients and waste products like CO2 are constantly mixed in the coelum (body cavity), but costs less ATP to move fluid due to lower hydrostatic pressure.

Advantages and Disadvantages




b. Closed circulatory systemi. Blood confined to vesselsii. Three types of vessels

- arteries

iii. Earthworm (Annelida)

- aortic arches “heart”

- dorsal/ventral vessels

(cardiovascular system)

- veins- capillaries

Fig. 23.2C

- Peristalsis moves blood through vessels in combination with hearts pumping




- arteries

iii. Earthworm (Annelida)

- aortic arches “heart”

- dorsal/ventral vessels



- Peristalsis moves blood through vessels in combination with hearts pumping

The dorsal blood vessels are responsible for carrying blood to the front of the earthworm’s body. The ventral blood vessels are responsible for carrying blood to the back of the earthworm’s body.




- arteries

iii. Fish

- two chamber heart

- follow the path of blood



Fig. 23.2C




- arteries

iii. Fish

- two chamber heart

- follow the path of blood



Fig. 23.2C



c. Compare the CVS of fish and mammals

i. Fish- single circuit- heart sees only oxygen poor blood- blood helped along by movement

Fig. 23.3




Fig. 23.3




Fig. 23.3

ii. Mammals (and birds – convergent evo)

- dual circuit (pulmonary and systemic)

- two pumps in one (double circulation)

- Compare flow rate - right side O2 poor, left side O2 rich

- Follow flow pathQ. Why do endotherms need a greater flow rate?

- 4 chamber heart

Endotherms use 10X as much energy as equal size ectotherm – circ system must deliver 10X as much fuel and O2 and remove 10X as much waste.



d. Mammals and birds evolved not from fish, but from reptiles. Hypothesize the number of chambers in a reptilian heart?

iii. Amphibians and some reptiles

- Have a three chambered heart (2 atria and one ventricle) where blood mixes in the ventricle and is sent to the pulmonary and systemic circuits. Less efficient than birds and mammals.


The Human Circulatory System

1. Hearta. Size?

d. Explain the purpose of valves

Fig. 23.4

b. location?c. composition?

- compare walls of atria to those of ventricles.

Alternative valve names







2. Follow the flowa. Start at RV

c. R,L PA to lungs

d. Lungs to LA via pulm. veins

Fig. 23.4

b. RV to R,L pulmonary artery through semilunar valve

- O2 and CO2 exchange in lung cap.

e. LA to LV through AV valve

f. LV to aorta through SL valve





c. R,L PA to lungs


Fig. 23.4




g. Arteries branch off aorta north to head and armsh. Aorta heads south where arteries branch to abdominal organs an legs







c. R,L PA to lungs


Fig. 23.4




g. Arteries branch off aorta north to head and armsh. Aorta heads south where arteries branch to abdominal organs an legs



2. Follow the flowi. Arteries ->

Fig. 23.4

l. SVC and IFC empty into RA

Arterioles -> Capillary beds ->

Venules -> Veins

k. Lower body to inferior vena cava

(exchange O2/CO2/nutrients/etc..)

j. Upper body veins drain into superior vena cava





Fig. 23.4

l. SVC and IFC empty into RA


Venules -> Veins






m. RA to RV through AV valve


Fig. 23.4

l. SVC and IVC empty into RA

Q. Explain why the wall of the LV is thicker than that of the RV?


Venules -> Veins





3. Structure-function of blood vesselsa. capillaries

Fig. 23.5

i. thin wallsii. simple squamous wrapped in LCT (loose connective tissue)

iii. smooth inner surface




- same epithelium

Fig. 23.5

i. thicker walls

b. Arteries and veins

i. thin wallsii. simple squamous wrapped in LCT


- layer of smooth muscle- thicker in arteries




- same epithelium

Fig. 23.5

i. thicker walls








- same epithelium

Fig. 23.5

i. thicker walls





- outer layer of elastic conn. tissue




- same epithelium

Fig. 23.5

i. thicker walls









- same epithelium

Fig. 23.5

i. thicker walls





- Needs to be thicker as they receive high pressure blood from the heart.

http://ebsco.smartimagebase.com/generateexhibit.php?ID=14555&TC=&A=1189





- same epithelium

Fig. 23.5

i. thicker walls





- outer layer of elastic conn. tissue to recoil after expanding

c. Many veins have valves to maintain unidirectional flow http://ebsco.smartimagebase.com/generateexhibit.php?ID=14555&TC=&A=1189





- same epithelium

Fig. 23.9B

i. thicker walls






c. Many veins have valves






- same epithelium

Fig. 23.5

i. thicker walls






c. Many veins have valves





4. Rhythmic Heart Contractiona. Cardiac cycle

ii. Two phases

- heart at rest- diastolic

i Complete sequence of filling and pumping heart

http://library.med.utah.edu/kw/pharm/hyper_heart1.html

- AV valves open- SL valves closed- all chambers fill with blood

Fig. 23.6




4. Rhythmic Heart Contractiona. Cardiac cycle

ii. Two phases

- atria contract- systolic

i Complete sequence of filling and pumping heart


- ventricles fill-up- ventricles contract

- AV valves slam shut (“lub”)- SL valves open- blood enters atria

- SL valves close (“dub”)b. Heart murmur

Fig. 23.6

- Occurs when a valve leaks a bit, you can hear a faint ”swish” with a stethoscope.

“lub”

“dub”




5. Keeping the Rhythma. Sinoatrial node (SA) node

- heart’s natural pacemaker- generates an electrical signal

- travels through atria to AV node

Fig. 23.7

- Called Perkinje fibers



5. Keeping the Rhythmb. Atrioventricular (AV) node

- .1 sec delay after receiving signal- sends new electrical signal to ventricles

- ventricles contract

Fig. 23.7



5. Keeping the Rhythm

* Conclusion: heart will beat at an extrinisic rate of 60-100 beats per minute if removed from body all by itself (Indiana Jones and the temple of doom), typically faster than normal. The brain has control over the rate at which it beats….next slide

Fig. 23.7




Vagus nerve (X – 10th – cranial nerve)

Fig. 23.7

Innervates the SA node and send signals to slow it down

Sympathetic cardiac nerve (spinal nerves)Innervates the SA node and send signals to speed up

HormonesEx. Andrenaline (epinephrine)

- Speed up SA node




Fig. 23.7

The 12 cranial nerves



5. Keeping the Rhythmb. Electrocardiogram (ECG)

- electrical signal of heart generates electrical signal in skin

Fig. 23.7



5. Keeping the Rhythmb. Electrocardiogram (ECG)

- electrical signal of heart generates electrical signal in skin



6. Failure of the heart’s pacemakera. Artificial pacemaker

- tiny electronic device inserted near AV node to control heart rate

Chapter 21: Nutrition and Digestion

Milestone Questions

AIM: How do animals obtain nutrition?

1. Compare an open to a closed circulatory system.

2. How is the circulatory system of fish different than mammals and birds?

3. Blood returning to the mammalian heart from the pulmonary vein will drain first into…

4. Why do we call certain vessels arteries and others veins?

5. Blood draining into the aorta was just in the…



Atherosclerosisa. Chronic CV disease

7. Cardiovascular Disease

- plaques develop on inner walls of arteries due to diet/genetics blocking blood flow

- A blood clots that form elsewhere in the CV system and breaks off, getting trapped in small vessels (thromboembolism)

- These are also sites of irregular blood clot formation that can lead to a thromboembolism of the heart (heart attack) or brain (stroke).

Fig. 23.8B

b. Leading cause of heart attack and stroke

-Thrombo = blood clot-Embolism = lodging of a traveling mass (embolus) in a blood vessel



Atherosclerosisa. Chronic CV disease


Fig. 23.8B

Naturally selected under condition of vitamin C deficiency?



Heart Attack (myocardial infarction)a. Coronary arteries

- blockage- 1/3rd people die immediately

- survivors have impaired ability to pump blood; cardiac muscle does not regenerate well and is replaced with inelastic scar tissue.

- leading cause of death in US


Fig. 23.8Ahttp://www.healthcentral.com/cholesterol/understanding-cholesterol-13-115.html



Strokea. Rapid loss of brain function

- caused by disturbance in blood vessels in brain – either a blockage or a burst.


- Neurons being serviced by this vessel die; neurons do not regenerate.

Aneurysm – swelling of a blood vessel caused by weakening of the vessel walls. The larger the aneurysm the more likely it will burst.




Atherosclerosisc. Treatment

- drugs to lower cholesterol (LDL; low density lipoprotein) levels in bloods

Ex. Statins

Lovastatin

- Class of drugs that inhibit HMG-CoA reductase

In 1971, Akira Endo, a Japanese biochemist working for the pharmaceutical company Sankyo, began the search for a cholesterol-lowering drug. Research had already shown that cholesterol is mostly manufactured by the body in the liver, using an enzyme known as HMG-CoA reductase.[4] Endo and his team reasoned that certain microorganisms may produce inhibitors of the enzyme to defend themselves against other organisms, as mevalonate is a precursor of many substances required by organisms for the maintenance of their cell wall (ergosterol) or cytoskeleton (isoprenoids).[46] The first agent they identified was mevastatin (ML-236B), a molecule produced by the fungus Penicillium citrinum.





angioplasty

Insert a device containing a balloon on the end and inflate the balloon thereby pushing the plaque out of the way.

Invasive (surgical) solution:





- angioplasty - stenting

Perform the angioplasty with an expandable mesh that will be left in place to hold the vessel open and keep the plaque out of the way.






- angioplasty - stenting- coronary bypass

Run a vein from the leg between aorta or some other local artery to a point past the blockage assuring blood flow to the downstream region.






Not so successful as we can synthesize cholesterol as shown and therefore our body maintains its programmed homeostatic level.

What about diet?

Vitamin C?

Linus Pauling thought so….



8. Blood Pressure

- keeps blood moving through system – heart pumps blood into arteries and arteries will swell and rebound aiding in the movement of the blood.- pulse

b. Two different pressures- systolic pressure

c. What determines blood pressure?

a. Force exerted on walls of blood vessels

- diastolic pressure

- cardiac output- resistance to blood flow imposed by narrow opening of arterioles

Fig. 23.9A- friction in capillaries- Clogged arteries



9. Measuring Blood Pressure

b. Average “normal” blood pressure

120/80 (in mmHg)

a. Measure pressure on arterial walls

What do these numbers mean?

Sphygmomanometer – blood pressure cuff used to measure blood pressure

Blood pressure is measured with a sphygmomanometer and a stethoscope. When the cuff is inflated, it will cut off blood flow to the arm as shown.





120/80


Fig. 23.9A


The medical worker will slowly decrease the pressure in the cuff…





120/80


Fig. 23.9A


When the pressure in the cuff falls below the pressure exerted by the heart on the arteries when it pumps, blood will move past the cuff and be heard. This is the systolic pressure as it is the pressure exerted during the systolic (pumping) phase of the cardiac cycle = 120mm Hg in this case.





120/80


Fig. 23.9A


Nothing is heard when the heart is not beating (diastolic phase of the cardiac cycle) since the pressure in the arteries is lower. Therefore it is only heard when the heart beats at this time.





120/80


Fig. 23.9A


The pressure in the cuff will be lowered even further until blood flow is no longer heard indicating a smooth, continuous flow of blood = the diastolic or resting pressure (80mm Hg in this case).





120/80


Fig. 23.9A


Top number is systolic pressure.

Bottom number is diastolic pressure.




i. High blood pressure

- persistent systolic pressure > 140

ii. Affects 25% of population

c. Hypertension

and/or

- weakens heart and blood vessels

- diastolic pressure > 90

iii. “silent killer”

- heart failure, heart attack, stroke, kidney failure, vision loss - promotes plaque formation

iv. Risk factors- age, race, family history, excess weight, inactivity, Tobacco use, excessive alcohol, stress, sleep apnea, etc…

Chapter 23: CirculationNEW: How have different organisms evolved to perform circulation?



v. How can we control hypertension?

- diet

c. Hypertension

- exercise

- avoid smoking

- avoid excess alcohol

- Medication to lower the pressure




Renin-Angiotensin-aldosterone system

c. Hypertension

Regulates blood pressure and water (fluid) balance in the body.




Antihypertensive drugs

c. Hypertension

1. Diuretics2. Adrenergic Receptor inhibitors

1. Beta blockers and alpha blockers3. Calcium channel blockers4. Renin inhibitors5. ACE (angiotensin-converting enzyme) inhibitors6. Angiotensin II receptor inhibitors7. Aldosterone receptor inhibitors8. Vasodilators9. Alpha-2 agonists



10. How does our body regulate blood pressure and blood distribution?

b. Constrict smooth muscles within capillary beds

a. Constrict smooth muscles in arterioles leading to capillaries (vasoconstriction)

Fig. 23.11

Predict what would happen in blood capillary beds of the digestive tract before and after eating.



10. How does our body regulate blood pressure and blood distribution?

b. Constrict smooth muscles within capillary beds

a. Constrict smooth muscles in arterioles leading to capillaries (vasoconstriction)

Fig. 23.11

After eating, the sphincter muscles leading to the capillaries of the jejunum would relax allowing maximum blood to enter the jejunum so as to pick up the maximum amount of nutrients.



11. How are substances transferred through capillary walls?

b. Endocytosis/Exocytosis

a. Simple or Facilitated Diffusion through membranes

Fig. 23.12A

- Small solutes (O2, CO2, monomers, etc…)

- larger substances – endocytose on inside and exocytose to interstitial fluid



11. How are substances transferred through capillary walls?

Fig. 23.12B

c. Leakage – capillaries are leaking as the cells they are made of are not tightly attached to each other. Therefore, substances smaller than cells can diffuse (passive) out of the blood directly into the interstitial fluid without going through a cell. Also, the pressure exerted by the heart/arteries recoiling can push (active) these substances out between the cells as well.



12. What exactly is…blood?

Fig. 23.12B

a. How much blood in an average human? 4 to 6 L (1 to 1.5 gallons)

b. Two main components



12. What exactly is…blood?

Fig. 23.12B

a. How much blood in an average human? 4 to 6 L (1 to 1.5 gallons)


90%

albumin



12. What exactly is…blood?a. How much blood in an average human? 4 to 6 L (1 to 1.5 gallons)




13. Structure-function of the Red Blood Cell (RBC)

Fig. 23.14

a. RBC = erythrocytes (Gr erythros, red)

b. 25 to 50 billion in blood

c. Describe their shape (structure)?

d. How does this structure fit its function?

- small biconcave disks

- large surface area for O2 diffusion

- pack 250 million hemoglobins per cell, no nucleus to take up space, no mitochondria to use up oxygen being carried. These cells have no reason to divide or make new protein. This is all being done in the bone marrow.

- no nuclei

- no mitochondria ???



13. Structure-function of the Red Blood Cell (RBC)e. Site of production?

i. Bone marrow of large bones

pelvis, sternum, ribs, vertebrae, ends of upper humerus and femur

ii. How RBC production is regulated

- erythropoietin (EPO)

EPO is a glycoprotein hormone secreted by the kidneys when blood oxygen levels are low, which signals hematopoetic stems cells in the bone marrow to undergo mitosis and make more RBC’s



13. Structure-function of the Red Blood Cell (RBC)e. Site of production?

i. Bone marrow of large bones

pelvis, sternum, ribs, vertebrae, ends of upper humerus and femur

ii. Predict how RBC production is regulated

- erythropoietin (EPO)

EPO is used as an illegal “performance-enhancing drug”.

The athlete will have more RBC’s circulating and will therefore carry more oxygen to muscle cells for cell respiration thereby generating more ATP – dangerous as blood thickens and can cause heart failure and death.



13. Structure-function of the Red Blood Cell (RBC)f. Life span of an RBC

i. 120 days (3-4 months)

iii. At what rate are they dying and being replaced?

~2,000,000 per second

ii. Broken down and recycled by spleen and liver – only the heme is discarded as bilirubin – secreted with bile by the liver (the iron/amino acids are saved and recycled)



13. Structure-function of the Red Blood Cell (RBC)g. anemia

i. A qualitative or quantitative deficiency of hemoglobin

ii. SOME Causes

- excessive blood loss

- reduced oxygen carrying capacity

- sickle cell anemia (genetic)

1. pernicious anemia

- Caused by an impaired absorption of vitamin B-12 by intestines, which is needed to make thymine (nitrogenous base of DNA nucleotides).

- Vitamin/mineral deficiency





ii. SOME Causes




- pernicious anemia

- impaired absorption of vitamin B-12 by intestines


- therefore DNA replication is inhibited resulting in the inhibition of mitosis resulting in fewer, larger RBC’s made





ii. SOME Causes




1. pernicious anemia

- impaired absorption of vitamin B-12 by intestines


2. iron deficiency (most common cause)- especially women due to blood loss during menstration

- needed for thymine biosynthesis No iron, no carrying O2 by hemoglobin



14. What about those White Blood Cells (WBC’s)?a. White blood cell = leukocyte (Gr leukos, white)

i. Help defend the body

- prevent cancer

ii. Five major types

- fight infections (pathogens)

B and T cells

Function of each will be discussed with the immune system. Just now the types for now.





- prevent cancer



iii. Where would you predict they spend most of their time?

- interstitial fluid

- lymphatic tissue





- prevent cancer





- lymphatic tissue

The Lymph System

Substances like water, salts, etc… that diffuse or are pushed out at the capillary beds need to reenter the blood stream. This is accomplished by the lymphatic system.





- prevent cancer





- lymphatic tissue

The Lymph System

The fluid entering the lymphatic system is now called lymph and will enter at lymphatic capillaries. On its way back to the blood stream it will pass through lymph nodes that contain lots of WBCs, which will destroy any foreign items in the lymph like bacteria and viruses. The lymph will enter back into the circulatory system at the vena cava.


The Lymph System

Know the various lymph system organs.





- prevent cancer

ii. Five major types (already discussed)



- interstitial fluid in tissues

- lymphatic tissue

iv. Predict where white blood cells are produced...

- Same place as the RBC’s…bone marrow – all blood cells are made in the bone marrow.



15. What happens when you bust a blood vessel?a. Blood clotting (coagulation)

1. Vessel gets damaged.

Fig. 23.16

2. Damaged cells release chemicals that make platelets “sticky”

3. Platelets will stick to damaged site serving as the initial “plug”, but this is not enough.




4. Stuck Platelets and damaged cells will release a protein called tissue factor or factor III (it’s a kinase), which can start what is known as the coagulation cascade…

Fig. 23.16

Tissue factor



15. What happens when you bust a blood vessel?a. Blood clotting (coagulation or thrombosis)

Fig. 23.16

5. Coagulation cascade

There are many proteins already in your blood in an inactive form that are involved in forming blood clots…tissue factor will do what?

Clotting needs to be fast, you can’t wait for the proteins to be made/secreted, and they obviously need to be inactive (proenzymes) until needed…

It will begin their activation (next slide) - phosphorylation



15. What happens when you bust a blood vessel?

The coagulation cascade is shown to the right (do not memorize), just understand the concept.


Each protein is typically called a “factor” with a roman numeral after it like Factor XII or Factor XI.

The activated form typically has an “a” after it like Factor XIIa means activated Factor XII.

Hirudin (secreted by leeches – hirudinae) inhibits thrombin



15. What happens when you bust a blood vessel?

Now look at where it says trauma, lets follow this pathway:


1. Trauma (vessel damage) will result in the activation of Factor VII to VIIa

2. Factor VIIa will bind with tissue factor (released from damaged cell and platelets) to activate Factor X to Xa

3. Factor Xa will activate the protein prothrombin to thrombin.

4.Thrombin will activate fibrinogen to fibrin

5. Fibrin is a fibrous, web-like protein that will stick to the platelets like spiderman’s web and lock them in place




Fig. 23.16

iv. Cofactors needed for clotting factors to function properly

- Ca++

- Vitamin K (made by intestinal bacteria)



15. What happens when you bust a blood vessel?b. Hemophilia

i. group of genetic disorders that impair body's ability to control

blood clotting. - Hemophilia A

- most common form

- Hemophilia B

- Hemophilia C

- lack of Factor VIII

- lack of Factor IX

- lack of Factor XI

- Sex-linked, genes for factors are on the X chromosome

Why is hemophilia more common in males?



15. What happens when you bust a blood vessel?c. Thrombosis

i. Formation of a thrombus (blood clot) within a blood vessel. -Causes

* The composition of the blood (hypercoagulability) * Quality of the vessel wall (endothelial cell injury) * Nature of the blood flow

- obstructs blood flow

- ThromboembolismThrombus = blood clot

Embolism = when an object migrates from one part of body and causes blockage of a blood vessel in another part.



16. Leukemiaa. Cancer of white blood cells

b. Occurs in bone marrow

i. displaces normal bone marrow cells- reduced RBC’s and platelets

- normal WBC’s suppressed or dysfunctional

- anemia and impaired clotting

- suppressed immune system

c. Fatal if not treated

i. Radiation and chemotherapy

ii. Bone marrow transplantiii. Stem cell treatment



17. Fetal Blood Flowa. Maternal blood supplies fetus with nutrients and O2 and takes away fetal waste. This happens by diffusion through the placenta.

b. Compare hemoglobin in the fetus to hemoglobin in the mother.

Why would a fetus need a different form of hemoglobin than the mother?It is all about affinity for oxygen. Fetal hemoglobin has a higher affinity. If it didn’t, the oxygen would not move from mom to fetus. The fetus also has 50% more hemoglobin in its blood. The delta (δ) gene is turned off in you and I, while the β gene is turned on.

Recall that hemoglobin is an example of quartanary structure, and is composed of four polypeptide chains: 2 α and 2 β in us, and 2 α and 2 δ in a fetus.



17. Fetal Blood Flowc. Fetal circulation

- Umbilical vein (because it is moving towards the heart) is carrying oxygen/nutrient rich blood to the fetus.

- Follow the blood flow in the diagram:

1. Umbilical vein

2. Through liver to inferior vena cava

3. To right atrium of heart



17. Fetal Blood Flowc. Fetal circulation

- The fetal heart has a hole (foramen ovale) between the atria…why?

- Normally, the blood goes from RA to RV and to lungs, but fetal lungs are non-functional and do not need as much blood.

- Much of the blood flows into the LA, bypassing the lungs so that it can get to the cells in the rest of the body more quickly and efficiently!!

- The foramen ovale closes up at birth.



17. Fetal Blood Flowc. Ductus Arteriosus

- A small shunt (passageway) connecting the pulmonary artery to the aorta further splitting the oxygenated blood from the placenta to both the body and lungs.



17. Fetal Blood FlowReview

1. Fetal hemoglobin2. Foramen Ovale3. Ductus Arteriosus

Chapter 21: Nutrition and Digestion

Milestone Questions

AIM: How do animals obtain nutrition?

1. What does a blood pressure of 120/80 mean?

2. Identify one surgical treatment of artherosclerosis.

3. What is the function of have a hole (foramen ovale) between atria in an infant heart?

4. Identify the three major cellular components of blood.

5. The Renin-Angiotensin-aldosterone system is involved in regulating…

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Chapter 23: Circulation