Chapter 21 EXAM

Question 1

The smallest arterial branches are __ and from there blood moves into ____.

Answer 1

Arterioles

Capillaries

Question 2

What takes place at the capillaries?

Answer 2

Diffusion between blood and interstitial fluid

Question 3

From capillaries, blood enters sm ___ which unite to form larger ____ and return blood to the heart.

Answer 3

Venules

Veins

Question 4

What are the 3 layers in a blood vessel?

Answer 4

Tunica intima
Tunica media
Tunica externa

Question 5

The tunica intima is the inner layer of a vessel. It is made up of what fibers?

Answer 5

Endothelial lining and surrounding layer of connective tissue

Question 6

In arteries, the outer margin of the tunica intima contains a thick layer of elastic fibers called what?

Answer 6

Internal elastic membrane

Question 7

The ___ ___ is the middle layer of a vessel and is made up of concentric sheets of smooth muscle tissue in a framework of loos connective tissue.

Answer 7

Tunica media

Question 8

The external elastic membrane separates what?

Answer 8

The tunica media fr the tunica externa

Question 9

The tunica extrerna is the outer layer of a vessel that forms what?

Answer 9

Connective tissue sheath

Question 10

In ____, the tunica externa contains collagen fibers w/scattered bands of elastic fibers

Answer 10

Arteries

Question 11

In ___, the tunica externa is generally thicker than the tunica media & contains networks of elastic fibers & bundles of smooth muscle cells.

Answer 11

Veins

Question 12

T or F: The walls of arteries & veins are too thick to allow diffusion.

Answer 12

True

Question 13

What are vasa vasorum?

Answer 13

Sm arteries & veins that supply smooth muscle cells & fibroblasts of tunica media & tunica externa in lg vessels

Question 14

Which contains more smooth muscle and elastic fibers; an artery or a vein?

Answer 14

Artery

Question 15

When a/an ____ constricts its endothelium is thrown into folds giving it a pleated appearance.

Answer 15

Artery

Question 16

What is it in a vain that prevents backflow of blood into the capillaries?

Answer 16

Valves

Question 17

Vasoconstriction of arterial smooth muscle is caused by stimulation of what division of the ANS?

Answer 17

Sympathetic division

Question 18

What 3 things about the circulatory sys do vasoconstriction or vasodilation affect?

Answer 18

Afterload on the heart
Peripheral BP
Capillary blood flow

Question 19

Elastic arteries are also known as conducting arteries. Why?

Answer 19

B/c they carry lg vols of blood away from the heart

Question 20

What happens to BP & elastic arteries during ventricular systole?

Answer 20

BP rises & arteries expand as stroke vol is ejected

Question 21

What happens to BP & elastic fibers during ventricular diastole?

Answer 21

BP falls & arteries return to their original size

Question 22

What is the name given to arteries that distribute blood to the bodies skeletal muscles and internal organs?

Answer 22

Muscular or distribution arteries

Question 23

Superficial arteries are important as ___ ___.

Answer 23

Pressure Points

Question 24

When local arterial pressure exceeds the capacity of elastic components of the tunics an ___ occurs.

Answer 24

Aneurysm

Question 25

What are the 3 components of a fenestrated capillary?

Answer 25

Pores Endothelial cells Basement membrane

Question 26

What are the 2 components of a continuous capillary?

Answer 26

Endothelial cells | Basement membrane

Question 27

What 3 components make up and arteriole?

Answer 27

Smooth Muscle Endothelium Basement membrane

Question 28

What are the 2 components of a venule?

Answer 28

Tunica externa | Endothelium

Question 29

What are the only vessels that allow for exchange between blood and surrounding interstitial fluid?

Answer 29

Capillaries

Question 30

Which capillaries have the following characteristics: - In all tissues except epithelia & cartilage - Permit water, sm solutes & lipid soluble material to diffuse into interstitial fluid - Prevent loss of blood cells & plasma proteins

Answer 30

Continuous Capillaries

Question 31

What is bulk transport?

Answer 31

Mvmt of materials by endo- or exocytosis at the inner endothelial surface

Question 32

___ ___ contain windows or pores that penetrate the endothelial lining,

Answer 32

Fenestrated capillaries

Question 33

What is the purpose of the pores on fenestrated capillaries?

Answer 33

Rapid exchange of water & solutes between plasma & interstitial fluid

Question 34

____ resemble fenestrated capillaries that are flattened and irregular shape.

Answer 34

Sinusoids

Question 35

What type of capillary has the following characteristics: - Gaps between adjacent endothelial cells - Thin or absent basement membrane - Permit free exchange of water & solutes as lg as plasma proteins

Answer 35

Sinusoidal Capillaries

Question 36

____ function not as individual units but rather as part of an interconnected network called a bed or plexus.

Answer 36

Capillaries

Question 37

What do capillaries empty into?

Answer 37

Venules

Question 38

The entrance to each capillary is guarded by what?

Answer 38

Precapillary sphincter

Question 39

The passageway that forms the entrance to capillaries fr arterioles or the exit to venules is known as what?

Answer 39

Metarteriole or precapillary arteriole

Question 40

In between metarterioles, are passageways that resemble typical capillaries in structure and are called what?

Answer 40

Thoroughfare channels

Question 41

More than one artery may supply a capillary bed. The multiple arteries are known as ___.

Answer 41

Collaterals

Question 42

The fusion of 2 collateral arteries that supply a capillary bed is an example of ___ ___.

Answer 42

Arterial anastomosis

Question 43

___ ___ are direct connections between arterioles and venues.

Answer 43

Arteriovenous Anastomoses

Question 44

What occurs when an arteriovenous anastomoses are dilated?

Answer 44

Blood bypasses the capillary bed and flows directly into venous circulation

Question 45

The pattern of blood flow through an arteriovenous anastomoses is regulated by ___ innervation under the ctrl of the cardiovascular centers of the ___ ___.

Answer 45

Sympathetic | Medulla Oblongata

Question 46

What is angiogenesis and what directs it?

Answer 46

Formation of new blood vessels | Vascular endothelial growth factor (VEGF)

Question 47

The cycling of contraction & relaxation of smooth muscles that changes blood flow through capillary beds is called ____.

Answer 47

Vasomotion

Question 48

What controls vasomotor?

Answer 48

Changes in concentrations of chemicals & dissolved gasses in interstitial fluids

Question 49

The smallest venous vessels w/an internal diameter of 20 um are ___.

Answer 49

Venules

Question 50

Medium-sized veins are comparable to ___ ___ ranging in size fr __ - __ mm.

Answer 50

Muscular arteries | 2-9mm

Question 51

___ ___ include the superior & inferior venae cavae & their tributaries within the abdominopelvic & thoracic cavities.

Answer 51

Large veins

Question 52

What are valves?

Answer 52

Folds of tunica intima that prevent backflow in the venous system

Question 53

Define venous return.

Answer 53

Rate of blood flow back to the heart

Question 54

The relationship between the vol of blood contained in a vessel and BP is known as what?

Answer 54

Capacitance of a blood vessel

Question 55

Vessels which expand easily & can accommodate lg changes in blood vol are known as ___ vessels.

Answer 55

Capacitance

Question 56

The constriction of veins in what 3 organs can redistribute a significant portion of blood vol?

Answer 56

Liver Skin Lungs

Question 57

The amt of blood that can be shifted fr veins in the liver, skin and lungs to general circulation is called the ___ ___.

Answer 57

Venous reserve

Question 58

Describe a pressure gradient as it relates to blood vessels.

Answer 58

The difference in pressure fr one end of the vessel to the other

Question 59

What term is given to BP within the capillary walls?

Answer 59

Capillary hydrostatic pressure

Question 60

Venous pressure is what?

Answer 60

BP within the venous system

Question 61

What term describes the resistance of the entire cardiovascular system?

Answer 61

Total Peripheral Resistance

Question 62

What 3 factors affect the total peripheral resistance?

Answer 62

Vascular resistance Blood Viscosity Turbulence

Question 63

What 2 factors affect vascular resistance?

Answer 63

Vessel length | Vessel diameter

Question 64

___ is the resistance to flow caused by interactions among molecules and suspended materials within a liquid.

Answer 64

Viscosity

Question 65

High flow rates, irregular surfaces & sudden changes in vessel diameter upset smooth blood flow by creating eddies & swirls. This phenomenon is know as what?

Answer 65

Turbulence

Question 66

The vol of blood flowing per unit of time through a vessel or grp of vessels is know as what?

Answer 66

Blood flow

Question 67

The hydrostatic pressure in the arterial system is called ___ ___.

Answer 67

Blood Pressure

Question 68

The term describing the pressure difference between the base of the ascending aorta & the entrance to the right atria is ___ ___.

Answer 68

Circulatory pressure

Question 69

Define hydrostatic pressure.

Answer 69

Pressure exerted by a liquid in response to an applied force

Question 70

Define peripheral resistance.

Answer 70

The resistance in the arterial system

Question 71

As arteries branch their total cross sectional area increases affecting BP how?

Answer 71

Causing it to fall rapidly

Question 72

As the total cross-sectional area of the vessels increases from the aorta toward the capillaries the velocity of blood flow does what?

Answer 72

Decreases

Question 73

The peak BP measured during ventricular systole is called ___ ___.

Answer 73

Systolic pressure

Question 74

The minimum BP at the end of ventricular diastole is called ___ ___.

Answer 74

Diastolic pressure

Question 75

Pulse pressure is the difference between what and what?

Answer 75

Systolic and Diastolic pressure

Question 76

How do we calculate mean arterial pressure?

Answer 76

Add 1/3 of the pulse pressure to diastolic pressure

Question 77

What is the effect of HTN on the heart?

Answer 77

Increases workload Ventricular enlargement Greater demand for O2 Possible ischemia

Question 78

As systolic pressure climbs arterial walls stretch to accommodate ventricular systole but when diastole begins, BP falls & arteries recoil. This phenomenon is called what?

Answer 78

Elastic rebound

Question 79

Explain respiratory pump.

Answer 79

Changes in thoracic pressure due to inhalation and exhalation assists in moving blood in the venous system

Question 80

Define diffusion.

Answer 80

Net mvmt of ions or molecules fr an area of higher concentration to an area of lower concentration

Question 81

What are 3 variables that make diffusion occur most rapidly?

Answer 81

Short distances Lg concentration gradient Ions or molecules are small

Question 82

___ is the removal of solutes as a solution flows across a porous membrane.

Answer 82

Filtration

Question 83

What occurs during capillary filtration?

Answer 83

Water & sm solutes are forced across a capillary wall leaving larger solutes & suspended proteins in the blood stream

Question 84

Filtration takes place at what part of a capillary and why?

Answer 84

Primarily at the arterial end b/c hydrostatic pressure is highest

Question 85

The term used to describe the diffusion of water across a selectively permeable membrane is what?

Answer 85

Osmosis

Question 86

The presence of suspended proteins that cannot cross capillary walls creates an osmotic pressure called __ __ __ pressure.

Answer 86

Blood Colloid Osmotic

Question 87

What are the 4 functions of the mvmt of water out of capillaries, through peripheral tissues & back in bloodstream via lymphatic sys?

Answer 87

1. Constant comms between plasma & interstitial fluid 2. Accelerates distribution of nutrients, hormones, dissolved gasses 3. Transport of insoluble lipids & tissue proteins that can't cross capillary walls 4. Flushing action that carries bacterial toxins & other chemicals

Question 88

What is net hydrostatic pressure?

Answer 88

Difference between pressure inside capillary walls & hydrostatic pressure

Question 89

Net ___ ___ pressure tends to push water & solutes out of capillaries & into interstitial fluid.

Answer 89

Capillary Hydrostatic

Question 90

What does net capillary colloid osmotic pressure do to water & solutes?

Answer 90

Tends to pull them into a capillary fr interstitial fluid

Question 91

The net filtration pressure (NFP) is the different between what and what?

Answer 91

Net hydrostatic pressure and net osmotic pressure

Question 92

When net filtration pressure is positive what will fluid tend to do?

Answer 92

Move out of capillaries into interstitial fluid

Question 93

When net filtration pressure is negative what will fluid tend to do?

Answer 93

Move into capillaries (reabsorption)