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BIOL 221 Lecture Notes - Lecture 3: Vasa Vasorum, Extracellular Fluid, Elastic Fiber

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peachbeetle258
10 Feb 2020
School
Towson University
Department
Biology
Course
BIOL 221
Professor
Ellen Lathrop-Davis

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Document Summary

Arteries always carry blood away from the heart regardless of the oxygen levels of the blood in them. The largest arteries leaving the ventricles are elastic arteries, also called conducting arteries. These vessels branch to form muscular, or distributing, arteries. Continued branching leads to smaller arteries and eventually to smaller artery-like vessels called arterioles. Arterioles branch to form capillaries, sites of exchange of materials between plasma (of blood) and interstitial fluid (in tissues). After exchanging solutes, the capillaries join together to form small vessels called venules. Venules join together to form veins; veins return blood to heart regardless of the oxygen content. Elastic arteries include the aorta and its major branches (e. g. , brachiocephalic artery, femoral artery) as well as the pulmonary trunk. These large vessels have a very thick tunica externa with a well- developed vasa vasorum. They are also called conducting arteries because they carry blood rapidly away from the heart. Fluctuations in pressure are highest in elastic arteries.

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Related Questions

1. Which of the following is the correct sequence of bloodflow?

a. heart --> atery --> arteriole --> capillary -->vein --> venule --> heart

b. heart --> vein --> venule --> capillary -->arteriole --> artery --> heart

c. heart --> artery --> arteriole --> capillary -->venule --> vein --> heart

d. heart --> artery --> venule --> capillary -->arteriole --> vein --> heart

e. heart--> artery --> capillary --> arteriole -->venule --> vein --> heart

2. What are the functions of the elastic fibers that are foundin the walls of ateries? (there may be more than one answer)

Select one or more:

a. they allow the artery to stretch and then recoil back to itsoriginal shape as blood is forcegully pumped from the heart intothe arteries

b. they allow arteries to lengthen as the volume of blood in thearteries increase

c. they help maintain a steady blood pressure during thedifferent phases of heart contraction

d. they smooth out the walls of the arteries to preventturbulent blood flow

3. Which of the following are functions of the lymphatic system?(there may be more than one answer)

Select one or more:

a. help fight infections and cancer

b. allows excess interstitial fluid (fluid found between thecells in your tissues) to get dumped back into your blood

c. brings large molecules from fat digestion into thebloodstream so that they can be processed and stored

d. all of the above are functions of the lymphatic system

4. Which of the following blood vessels bring newly oxygenatedblood from the blood vessels in the lungs back to the heart so thatthe heart can pump it to the rest of the body?

Select one:

a. aorta

b. inferior vena cava

c. pulmonary vein

d. pulmonary artery

5. Which of the following mechanisms help blood fight gravity sothat, for instance, it can return from blood vessels in your feetback into your heart? (there may be more than one answer)

Select one or more:

a. breathing allows the pressure in your chest to decrease andallow blood to flow up towards your heart

b. as you walk, the skeletal muscles in your legs contract andsqueeze the veins; since veins have valves, blood flows up anddoesn't backflow back down

c. the force of blood flowing out of the heart and into thearteries pushes all of the blood along, causing blood to return tothe heart

d. precapillary sphincters open to allow blood to flow backtowards the heart

6. The tricuspid and bicuspid/mitral valves prevent backflow ofblood from the atria into the ventricles.

Select one:

True

False

7. The following sequence represents the correct order of bloodflow through the heart:

inferior and superior vena cava --> right atrium --> rightventricle --> pulmonary artery --> lungs --> pulmonaryvein --> left atrium --> left ventricle --> aorta

Select one:

True

False

8. Capillaries are as wide as one red blood cell.

Select one:

True

False

9. The purpose of the coronary arteries is to bring oxygenatedblood to the walls of the heart so that the muscles in the heartwalls can contract.

Select one:

True

False

10. Vasodilation refers to the narrowing of blood vessels.

Select one:

True

False

True of False: Freshwater environments have a higher concentration of oxygen than saltwater environments.

QUESTION 2 If the difference in partial pressure of gas on either side of the barrier to diffusion is 0, which of these events will occur?

The area for gas exchange will increase to accommodate this similarity.

The constant for diffusion will decrease.

The rate of diffusion will be 0.

The distance thickness of the barrier to diffusion will also be 0.

QUESTION 3 On the x-axis of the oxygen–hemoglobin equilibrium curve is the partial pressure of oxygen in tissues. Which type of blood is most likely to be represented by the right-hand side of the axis? (Hint: the oxygen-hemoglobin equilibrium curve is figure 45.14 in your book on pg 913)

blood found in the left ventricle

blood found in the right atrium

blood found in the superior vena cava

blood found in the inferior vena cava

QUESTION 4 Which of these is an example of pulmonary circulation?

Blood is pumped from the right ventricle to the lungs.

Blood is pumped from the left ventricle to the aorta.

Blood is pumped from the aorta to the cardiac vein.

Blood is pumped from the inferior vena cava to the right atrium.

QUESTION 5 O2 will diffuse from blood to tissue faster in response to which of the following conditions?

an increase in the PO2 of the tissue

a decrease in the PO2 of the tissue

an increase in the thickness of the capillary wall

a decrease in the surface area of the capillary

QUESTION 6 Which of the following promotes oxygen release from hemoglobin?

a decrease in temperature

a decrease in carbon dioxide levels

a decrease in pH

a decrease in carbonic anhydrase

QUESTION 7 How does the medulla oblongata sense the amount of carbon dioxide in the blood?

A. Carbonic anhydrase produced by cells performing cellular respiration is exported and travels though the blood, and binds to a receptor on the medullary respiratory center, which causes a signal amplification resulting in a change in gene expression which results in the production of proteins that will cause the diaphragm to contract

B. CO2 produced by cells performing cellular respiration reacts with blood plasma for form an acid, which increases the pH of the blood, which causes the medullary respiratory center to contract the diaphragm

C. CO2 produced by cells performing cellular respiration reacts with blood plasma for form an acid, which decreases the pH of the blood, which causes the medullary respiratory center to contract the diaphragm

D. A and B

E. A and C

QUESTION 8 Which of the following parts of the lung are considered "dead space"? A. The alveoli B. The trachea C. The bronchi D. B and C E. All of the above

QUESTION 9 Which of the following blood vessels have the thinnest walls?

arteries

arterioles

capillaries

venules

veins

QUESTION 10 How does the interstitial fluid return to the bloodstream?

A. Interstitial fluid flows into the capillary where the osmotic pressure driving fluid into the bloodstream is greater than the blood pressure driving fluid out of the blood

B. Interstitial fluid flows into the capillary where the blood pressure driving fluid into the bloodstream is greater than the osmotic pressure driving fluid out of the blood

C. Interstitial fluid leaves the tissue via lymphatic ducts and travels through the lymphatic system, which returns the fluid to the veins. D. A and C

E. B and C

QUESTION 11 True or False: When an electrocardiogram (EKG or ECG) shows a flat line (aka asystole), medical personnel will restart the heart using a defibrillator.