Blood Vessels - Chapter 19

? from Mastering: What vein is formed from the union of the anterior tibial vein and posterior tibial vein?

Popliteal vein

Arterial anastomoses

Provide alternate pathways (collateral channels) Common in joints, brain, heart, kidney, spleen

Muscular arteries give rise to...

... arterioles

Elastic arteries give rise to...

... muscular arteries

All capillary endothelial cells are joined by...

... tight junctions with gaps called intracellular clefts Allow passage of fluids and small solutes

What is another name for arterioles?

Resistance vessels/arteries

3 Walls of Blood Vessels (except capillaries)

Tunica intima Tunica media Tunica externa

Hemorrhoids

Varicose veins surrounding anus Can happen in pregnancy

2 types of vessels in capillary beds

Vascular shunt (metarteriole-thoroughfare channel) True capillaries

Varicose veins

Venous valves that become leaky = blood can backflow Usually veins closer to surface of skin Causes: standing a lot, obesity, pregnant More of cosmetic problem, some pain Can be hereditary

Venous anastomoses

Why veins don't get blocked much = have a ton of them

Blood vessels

Work with lymphatic system

? from Mastering: Which description most accurately describes the functions of the superior and inferior venae cave? a) The superior vena cava primarily drains oxygen-poor blood from the body above the diaphragm, while the inferior vena cava drains oxygen-poor blood from areas below the diaphragm. b) The superior vena cava brings oxygen-rich blood to the right atrium, while the inferior vena cava brings oxygen-rich blood from the organs below the diaphragm to the right ventricle. c) The superior vena cava primarily drains oxygen-rich blood from the right lung, while the inferior vena cava drains oxygen-poor blood from the organs of the body. d) The superior vena cava brings oxygen-rich blood to the heart, while the inferior vena cava carries oxygen-poor blood away from the heart.

a) The superior vena cava primarily drains oxygen-poor blood from the body above the diaphragm, while the inferior vena cava drains oxygen-poor blood from areas below the diaphragm.

? from Mastering: Which of the following would decrease peripheral resistance to blood flow? a) anemia b) atherosclerosis c) increasing blood vessel length d) vasoconstriction

a) anemia

Which of the following will lower blood pressure? a) atrial natriuretic peptide (ANP) b) aldosterone c) angiotensin II d) antidiuretic hormone (ADH)

a) atrial natriuretic peptide (ANP)

? from Mastering: Which of the following would be interrupted in the indirect renal mechanism if angiotensin converting enzyme (ACE) is blocked from performing its job? a) conversion of angiotensin I into angiotensin II b) sympathetic nervous system activity c) conversion of angiotensin I from angiotensinogen d) release of renin from the kidneys

a) conversion of angiotensin I into angiotensin II

? from Mastering: In local autoregulation of blood flow, usually low oxygen levels cause vasodilation. Which tissue shows the opposite pattern? a) lungs b) skeletal muscles c) liver d) heart

a) lungs

? from Mastering: In which of the following blood vessels would you expect to find the LEAST amount of carbon dioxide? a) pulmonary vein b) venae cava c) pulmonary artery d) aorta

a) pulmonary vein

Why is it important that blood pressure drop to lower levels as it reaches the capillary beds? a) because capillaries actually are high-pressure vessels b) because capillaries are fragile and extremely permeable c) because capillaries depend on the lower pressure to prevent fluid exchange between the capillaries and the tissue fluid d) because capillaries actually need a higher blood pressure for filtration activities

b) because capillaries are fragile and extremely permeable

? from Mastering: What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries? a) hydrostatic pressure in interstitial fluid (HPif) b) osmotic pressure in capillary (OPc) c) hydrostatic pressure in a capillary (HPc) d) osmotic pressure in interstitial fluid (OPif)

b) osmotic pressure in capillary (OPc)

? from Mastering: In the capillaries, hydrostatic pressure (HP) is exerted by __________. blood pressure proteins in the blood

blood pressure

? from Mastering: Toxic substances absorbed by the digestive system put stress on the liver because all of the blood from the digestive organs is drained by the __________. a) inferior vena cava b) suprarenal veins c) hepatic portal vein d) abdominal aorta

c) hepatic portal vein

? from Mastering: What is the main function of the pulmonary circuit? a) to provide nutrients to the lung tissues b) to release oxygen from the blood c) to oxygenate the blood d) to provide oxygen to the lung tissues

c) to oxygenate the blood

? from Mastering: The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________. interstitial fluid; capillary capillary; interstitial fluid

capillary; interstitial fluid

? from Mastering: Which statement best describes blood flow through the pulmonary veins? a) Pulmonary veins take oxygen-poor blood to the lungs, where the blood can become oxygenated. b) Pulmonary veins bring oxygen-poor blood from lung capillaries toward the heart. c) Pulmonary veins take oxygen-rich blood to the organs and tissues of the body and then back to the heart. d) Pulmonary veins carry oxygen-rich blood from lung capillaries to the heart.

d) Pulmonary veins carry oxygen-rich blood from lung capillaries to the heart.

? from Mastering: From what artery does the right common carotid artery arise? a) external carotid artery b) aortic arch c) internal carotid artery d) brachiocephalic trunk

d) brachiocephalic trunk

? from Mastering: Vasomotion because of changes in pH or CO2 levels would be a result of __________? a) angiotensin regulation b) renal mechanisms c) baroreceptor reflexes d) chemoreceptor reflexes

d) chemoreceptor reflexes

? from Mastering: Which of these responses is NOT a response consistent with a drop in mean arterial pressure? a) secretion of aldosterone b) release of renin from the kidneys c) increased thirst d) increased filtration by the kidneys

d) increased filtration by the kidneys

? from Mastering: Which net pressure draws fluid into the capillary? net osmotic pressure net hydrostatic pressure

net osmotic pressure

? from Mastering: What is the value for the net filtration pressure (NFP) at the arteriolar end of the capillary? 1 mm Hg 10 mm Hg 26 mm Hg 35 mm Hg

10 mm Hg

True capillaries

10 to 100 exchange vessels per capillary bed Precapillary sphincters = when closed, blood will flow almost directly through capillary bed

How much blood is held in pulmonary blood vessels?

12%

How much blood is held in systemic arteries and arterioles?

15%

How much blood vessel is in one pound of fat?

3.5 miles

? from Mastering: Which of the following would reflect the typical net hydrostatic pressure (HP) at the arterial end of the capillary? 12 mm Hg 1 mm Hg 34 mm Hg

34 mm Hg

How much blood is held in capillaries?

5%

How much blood vessel is in one pound of muscle?

6.5 miles

How much blood is held in systemic veins and venules?

60%

How many miles of blood vessels do we have?

60,000-100,000 miles = can circle Earth several times

? from Mastering: Assume a person is experiencing a hemorrhage and the HPc has dropped to 23 mm Hg at the arteriole end of the capillary. Calculate net filtration pressure (NFP) at the arteriole end of the capillary. -8 mm Hg -2 mm Hg 2 mm Hg 10 mm Hg

-2 mm Hg

? from Mastering: Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues? lipid-soluble substances proteins carbon dioxide oxygen

proteins

? from Mastering: The colloid osmotic pressure in the capillary is caused by __________. blood pressure proteins in the blood

proteins in the blood

? from Mastering: Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary? venous arterial

venous

Elastic arteries

Around the heart = biggest arteries = thick walls, large lumen AKA conducting arteries EX: Aorta Lots of elastin and some smooth muscle Expands with heart pressure and squeezes to help move blood = stretch/recoil property

Vasa vasorum

Blood vessels that are found and supply large blood vessels EX: aorta

Another name for veins

Capacitance vessels

Veins

Carries deoxygenated blood to the heart EXCEPTIONS: pulmonary artery and umbilical arteries Formed when venules converge Have all tunics but much thinner walled AKA capacitance vessels = hold a lot of blood Histology = collapse on itself

Arteries

Carry oxygenated blood away from heart EXCEPTIONS: pulmonary artery and umbilical arteries

? from Mastering: Which artery branches into the common hepatic artery, splenic artery, and left gastric artery?

Celiac trunk

Venules

Come off capillary bed = merge together to form larger veins Exchange and are permeable Little bit of smooth muscle BP lower than aorta

3 Types of Capillaries

Continous capillaries Fenestrated capillaries Sinusoidal capillaries

3 Places with no capillaries

Cornea and lens Epithelial tissue Cartilage

Muscular arteries

Deliver blood to body organs AKA distributing arteries Size = pinkie to pencil lead Thickest tunica media = more smooth muscle and less elastin Big role in vasoconstriction/vasodilation = Control BP

Capillaries

Does actual exchange of nutrients, gases, waste, hormones 1 cell thick = microscopic = only single RBC can pass through at a time Snuggle up to every cell in body (with exceptions)

3 groups of Arteries

Elastic arteries Muscular arteries Arterioles

Microcirculation

Flow of blood through capillary bed

Continous capillaries

Found in skin (lower layers), muscles, lungs, and CNS Most common capillary and least permeable Has pericytes Vesicles carry fluid across endothelial cells Form blood brain​ barrier with only tight junctions around entire perimeter on brain capillary endothelial cells

Fenestrated capillaries

Has holes in it that allow more permeability Found in areas of active filtration (kidney) and absorption (small intestine) and areas of endocrine hormone secretion (endocrine glands) Holes usually covered by thin diaphragm In some digestive organs, the number of holes increases during active absorption of nutrients

Tunica intima

Innermost layer that is "intimate" with blood Endothelium = simple squamous epithelium that lines all vessels = 1 cell thick

Vascular anastomoses

Interconnections between pathways = multiple ways to get blood to a location

Capillary bed

Interwoven network of capillaries between arterioles and venules

Adaptations to ensure veins return blood to heart

Large diameter lumens offer little resistance Venous valves = prevent backflow = infoldings of tunica media Venous sinuses = enlarged area = EX: coronary sinus and dural sinuses

Arteriovenous anastomoses

Little shunts from arterial to venous side = direct path straight through capillary

BP in veins is _______ than arteries

Lower = so adaptations ensure return of blood to heart

Vascular shunt

Metarteriole-thoroughfare channel Starts with terminal arteriole, metarteriole, thoroughfare channel, and postcapillary venule

Sinusoidal capillaries

Most permeable or leaky with very large holes and intracellular clefts Not a lot of tight junctions Incomplete basement membrane Found in liver, spleen, bone marrow, and adrenal medulla Allows large molecules and cells to pass across walls Macrophages extends and catches "prey"

Tunica externa

Outermost layer of wall AKA Tunica adventitia Lots of collagen fibers to anchor walls and to surroudning​ tissues

What is another name for elastic arteries?

Conducting arteries

Tunica media

Middle layer composed mostly of smooth muscle and sheets of elastin Vasoconstriction/Vasodilation = changing lumen diameter Fattest layer Changes BP/ blood flow

Arterioles

Smallest of artery types Bigger arterioles have all 3 tunics but smallest ones only have 2 tunics Not all named Different networking in each person Control blood flow to capillary beds by changing diameter AKA resistance vessels/arteries = change resistance to blood flow

Pericytes

Special spidery cells with branches that wrap around capillaries to stabilize them Helps to control permeability = what goes in/out

9 arterial pressure points to take pulse

Superficial temporal artery Facial artery Common carotid artery Radial artery Brachial artery Femoral artery Popliteal artery Posterior tibial artery Dorsal pedal artery

? from Mastering: Which of the following is NOT one of the ways that angiotensin II increases arterial blood pressure? a) Angiotensin II triggers the sensation of thirst. b) Angiotensin II prompts the release of antidiuretic hormone (ADH). c) Angiotensin II stimulates the secretion of aldosterone. d) Angiotensin II promotes vasodilation that decreases peripheral resistance.

d) Angiotensin II promotes vasodilation that decreases peripheral resistance.

How much blood is held in the heart?

8%

? from Mastering: Which of the following hormonal effects is mismatched? a) Angiotensin increases peripheral resistance by causing vessel diameter changes. b) Atrial natriuretic protein decreases blood volume by affecting blood vessel diameter. c) Epinephrine decreases peripheral resistance by affecting blood vessel diameter. d) Aldosterone increases blood pressure by affecting blood volume.

c) Epinephrine decreases peripheral resistance by affecting blood vessel diameter.

? from Mastering: Which of the following is NOT a capillary transport mechanism? a) movement through intracellular clefts or fenestrations b) diffusion through the endothelial cell membrane c) bulk flow d) transport via vesicles or caveolae

c) bulk flow

All blood vessels contain...

A lumen and a wall

What is another name for muscular arteries?

Distributing arteries