Circulation and Short-Term Blood Pressure Regulation

Question 1

innermost layer

Contains endothelium: runs uninterrupted through entire cardiovascular system

Answer 1

Tunica intima

Question 2

present only in arteries

Answer 2

Internal, external elastic lamina

Question 3

contains smooth muscle fibers (vasoconstriction)

Answer 3

tunica media

Question 4

connective tissue that stabilizes blood vessels

Answer 4

tunica external

Question 5

need to handle___ amounts of pressure from the ____.

Have ____ walls, smaller ___ than ____.

Answer 5

• Structure Function of Arteries*
  large
  heart

thicker
lumens
veins

Question 6

2 Types of arteries:

Answer 6

Elastic

Muscular

Question 7

A.k.a. conducting arteries

Includes the aorta and its principal branches

Have large lumens to collect large volumes of blood from the heart

Answer 7

Elastic arteries

Question 8

A.k.a. distributing arteries

Have the largest tunica media of any blood vessel type; possess a great ability to vasoconstrict

Branch extensively to deliver blood to arterioles throughout the body

Answer 8

Muscular Arteries

Question 9

smallest artery type

Answer 9

arterioles

Question 10

Arterioles (2)

Answer 10

1. larger

2. Tinniest

Question 11

Still contain all three tunics

Resemble small muscular arteries

Answer 11

Larger

Question 12

Simply endothelium surrounded by 1-2 fiber layers of smooth muscle

Answer 12

Tinniest

Question 13

arterioles that change their diameter to allow more or less blood flow

Answer 13

resistance vessels

Question 14

adjust blood flow based on specific demands of local tissue

E.g., increased NO release during exercise

Answer 14

metabolic responses

Question 15

occur reflexively within smooth muscle of tunica media

E.g., increased pressure causes contraction

Answer 15

myogenic responses

Question 16

Smallest blood vessel type, so erythrocytes flow in single file

site of __ and ___ exchange: Only tunica intimate is present and is permeable

Answer 16

capillaries

gas
nutrient

Question 17

3 types of capillaries

Answer 17

Continuous
fenestrated
Sinusoid

Question 18

Most common type

Lining does not contain pores

Exchange occurs through intercellular clefts and pinocytic vessels

Answer 18

Continuous

Question 19

Endothelial cells dotted with pores

More readily allows passage of fluid and larger molecules

Answer 19

fenestrated

Question 20

Have larger fenestrations and a discontinuous basement membrane
Allow movement of entire cells through barrier

Answer 20

Sinusoid

Question 21

Delivers blood to capillary bed

Answer 21

terminal arteriole

Question 22

Bands of smooth muscle that encircle each true capillary at its origin from a metarteriole

Answer 22

Pre capillary sphincter

Question 23

Arises from the terminal arteriole

Answer 23

Metateriole

Question 24

Vessels of exchange: branch off the metarteriole, converge upon the thoroughfare channel

Answer 24

True capillaries

Question 25

Arises from the metarteriole; returns blood to postcapillary venule

Answer 25

Thoroughfare channel

Question 26

Directly connects the terminal arteriole to the postcapillary venule

Answer 26

Vascular shunt

Question 27

Drains blood away from capillary bed

Answer 27

postcapullary venule

Question 28

smallest of vessels carrying blood back to the heart

Have all three tunics, but very thin

Answer 28

Venules

Question 29

Failure of venous valves, allowing blood to pool in peripheral veins of legs

Answer 29

Varicose Veins

Question 30

Principles of Hemodynamics

Answer 30

1. Blood Flow (F)
2. Blood Pressure (BP or P)
3. resistance

Question 31

Volume of blood moving through a vessel, tissue, organ or entire circulation per unit of time

Answer 31

Blood flow

Question 32

Force exerted onto a given area of the vessel wall by the blood contained within it, measured in mm Hg

Answer 32

Blood pressure

Question 33

Friction encountered by blood, impeding its flow

Answer 33

resistance

Question 34

assists venous return

During contraction, bulging muscles compress veins, forcing blood back towards the heart

Answer 34

Muscular Pump

Question 35

also assists

During inspiration, intrathoracic pressure decreases, drawing blood towards the thoracic cavity

Answer 35

Respiratory pump

Question 36

Monitor oxygen, carbon dioxide, hydrogen ion contents of blood
Objective: change cardiac output and blood pressure to meet varying metabolic needs of body

Answer 36

Chemoreceptors

Question 37

Cerebral cortex and hypothalamus also relay information

Communicate with the limbic system; cause of physical manifestation of emotions

Answer 37

Higher Brain centers

Question 38

Anti-diuretic hormone (ADH): a.k.a. vasopressin; causes vasoconstriction
Thromboxane and serotonin: cause vasoconstriction
Epinephrine and norepinephrine: cause vasoconstriction

Answer 38

endocrine factors

Question 39

Blood vessels ___ and ____ due to loss of ____, decreased vessel compliance and accumulation of fatty deposits (plaques)

Stiffened blood vessels cause heightened MAP, which further stiffens blood vessels vicious cycle

Increased risk of ____

Cardio-protective estrogen effects are lost in post-menopausal women

Answer 39

Aging Effects on Circulation

stiffen
narrow
elasticity

myocardial infarction (MI)