Chapter 29

Question 1

What is angiogenesis?

Answer 1

-development of blood vessles

Question 2

What are the functions of arteries, veins, and capillaries?

Answer 2

• arteries: conduct blood away from the heart
• veins: conduct blood toward the heart
• capillaries: small vessels that permit gas, nutrient, and waste exchange

Question 3

What kinds of arteries are there?

Answer 3

• elastic
• muscular
• arterioles

Question 4

What are the characteristics of all the different types of arteries?

Answer 4

• elastic: stretch and recoil without causing harm; accommodates blood that is forced out of the heart
• muscular: distributing arteries; carry blood to specific organs; smaller than elastic; thick muscular layer
• arterioles: resistance vessels; smallest arteries; divert blood to a specific area

Question 5

What are examples of the different types of arteries?

Answer 5

• elastic: aorta and major branches; pulmonary arteries
• muscular: brachial artery, gastric artery, and superior mesenteric artery
• arterioles: not individually named

Question 6

What are metarterioles?

Answer 6

-a vessel that connects an arteriole to a venule

Question 7

What are precapillary sphincters? Function?

Answer 7

• smooth muscle cells that wrap around the entrance to a capillary
• increase or decrease blood flow to a capillary bed by dilation or constriction

Question 8

What is a capillary?

Answer 8

• primary exchange vessels
• where the transfer of nutrients, gases, and waste occurs
• microscopic vessels
• carries blood from arterioles to venules

Question 9

What kinds of capillaries are there?

Answer 9

• continuous capillaries
• fenestrated capillaries
• sinusoids

Question 10

What are characteristics of continuous capillaries? Location?

Answer 10

• have a continuous lining of endothelial cells
• have small openings in the walls called intercellular clefts
• found in skeletal muscle, lungs, and connective tissue

Question 11

What are characteristics of fenestrated capillaries? Location?

Answer 11

• have intercellular clefts
• also have small holes called fenestrations
• found in endocrine glands, kidneys, and small intestine

Question 12

What are characteristics of sinusoids? Location? Function?

Answer 12

• incomplete basement membrane
• wider lumen
• large fenestrations
• found in bone marrow, liver, and lymph nodes
• allow blood cells to migrate

Question 13

What are the characteristics of a vein?

Answer 13

• carries blood toward the heart
• receives blood from venules
• becomes larger towards the heart
• can stretch greatly
• maintains blood pressure

Question 14

What is a venous sinus? Location?

Answer 14

• venous structure that contains no smooth muscle cells

- in dural venous sinuses of the brain and coronary sinus of the heart

Question 15

What is a venule?

Answer 15

• small diameter

- receives blood from metarterioles

Question 16

What types of tissues make up vessels? Function?

Answer 16

• endothelial tissue: smooth inside layer containing holes
• collagen fibers: protein strands that strengthen and provide support
• elastic fibers: allow for recoil after distention and maintains passive tension
• smooth muscle tissue: involuntary muscle that constricts or dilates blood vessels

Question 17

What is unique about capillaries?

Answer 17

• they only have endothelium

- they only have tunica intima

Question 18

What are the layers of a blood vessels?

Answer 18

• tunica externa
• tunica media
• tunica intima

Question 19

What makes up each layer of a blood vessel?

Answer 19

• tunica externa: fibrous connective tissue; prevents tearing
• tunica media: smooth muscle and elastic fibers
• tunica intima: endothelium and basement membrane

Question 20

How does the thickness of each layer compare in an artery and a vein?

Answer 20

• tunica externa: thickest layer of veins; thinner than arteries
• tunica media: very thick in arteries; much thinner in veins
• tunica intima: smooth in arteries; valves in veins

Question 21

What are vasa vasorum?

Answer 21

• little vessels that supply the arteries

- they run in the tunica externa

Question 22

What layer forms the valves in the veins?

Answer 22

-tunica intima

Question 23

What is a portal system? Examples?

Answer 23

• blood passes through two consecutive capillary beds before returning to the heart
• hypophyseal portal system between hypothalamus and anterior pituitary
• hepatic portal system between the intestines and the liver

Question 24

What is vascular anastomosis? Purpose?

Answer 24

• connection of blood vessels from one to another

- provides an alternate route for blood flow which may bypass a blocked vessel

Question 25

What is the Circle of Willis?

Answer 25

-the circle in the brain that allows for alternate blood flow incase the original gets cut off

Question 26

Where do most people have strokes?

Answer 26

• in the anterior communicating artery

- 2mm long

Question 27

What is the hepatic portal system?

Answer 27

• veins from the spleen, stomach, pancreas, bladder, and intestines do not pour their blood directly into the inferior vena cava
• they send their blood to the liver via the hepatic portal vein
• after the liver processes the blood, it is drained into the IVC via hepatic veins

Question 28

What is the purpose of the hepatic portal system?

Answer 28

• excess glucose is removed and stored in the liver

- toxic molecules can be detoxified before blood is distributed

Question 29

What veins are involved in the hepatic portal system?

Answer 29

• hepatic portal veins: splenic vein, superior mesenteric vein, and inferior mesenteric vein
• hepatic veins

Question 30

How is fetal circulation different than circulation after birth?

Answer 30

• the fetus receives oxygen and nutrients from maternal blood
• placenta acts as the lungs and digestive system for the fetus
• umbilical arteries, umbilical vein, and ductus venosus go in close proximity to the maternal blood

Question 31

Which vessels contain oxygenated blood?

Answer 31

-umbilical vein

Question 32

Which vessels contain deoxygenated blood?

Answer 32

-umbilical arteries

Question 33

What is the foramen ovale? Function? Another name?

Answer 33

• opening in the septum between right and left atria
• allows blood to bypass the right ventricle to bypass the lungs
• becomes the fossa ovalis

Question 34

What is the ductus arteriosis? Function? Another name?

Answer 34

• a small vessel connecting the pulmonary trunk with the aorta
• bypasses the lungs
• becomes ligamentum arteriosum

Question 35

What is the ductus venosus? Function? Another name?

Answer 35

• continuation of the umbilical vein
• drains into the inferior vena cava
• works as a way for blood to bypass the liver
• becomes ligamentum venosum

Question 36

What are the changes in circulation at birth?

Answer 36

• cutting the umbilical cord severs the umbilical arteries and vein
• the ductus venosus becomes ligamentum venosum which is a fibrous cord
• the forament ovale will close and become the fossa ovalis
• the ductus arteriosis contracts and becomes the ligamentum arteriosum