Chapter 5B

Question 1

The 5 main types of blood vessels are arteries, A, capillaries, B, and veins.

Answer 1

A arterioles
B venules

Question 2

1. Arteries carry blood away from the X to other organs. Large, elastic arteries leave the
   X and divide into medium-sized, muscular arteries that branch out into the various
   regions of the body

Answer 2

heart
heart

Question 3

Medium-sized arteries then divide into small arteries, which in turn divide into still
smaller arteries called X

Answer 3

arterioles

Question 4

As the arterioles enter a tissue, they branch into numerous tiny vessels called X

Answer 4

capillaries

Question 5

The thin walls of capillaries allow the exchange of substances between the blood and
body tissues. Groups of capillaries within a tissue re-unite to form small veins called
X. These in turn merge to form progressively larger blood vessels called veins.

Answer 5

venules

Question 6

X are the blood vessels that convey blood from the tissues back to the heart

Answer 6

Veins

Question 7

The wall of a blood vessel consists of three structural layers or tunics:

• Tunica X or intima: epithelial inner lining
• Tunica B: middle layer consisting of smooth muscle and elastic connective tissue
• Tunica C or adventitia: connective tissue outer covering

Answer 7

X interna
B media
C externa

Question 8

…. membrane (collagen fibers) and an ….. elastic …. (elastic fibers)
separates tunica interna and media.

Answer 8

Basement
internal elastic lamina

Question 9

Interna: forms the inner lining of a blood vessel and is in direct contact with the blood as it
flows through the lumen. It is a thin layer of flattened cells that lines the inner surface of the
entire cardiovascular system: X

Answer 9

endothelium.

Question 10

Media: is a muscular and connective tissue layer that displays the greatest variation among the
different vessel types.

Primary role of the smooth muscle cells (SMCs) is to regulate thediameter of the lumen:

SMCs contraction narrows lumen diameter: A
SMCs relaxation increases lumen diameter: B

Answer 10

A vasoconstriction
B vasodilation

Question 11

Externa: consists of elastic and X fibers. It contains numerous nerves and, especially in
larger vessels, tiny blood vessels that supply the tissue of the vessel wall (vasa vasorum). It also
helps anchor the vessels to surrounding tissues.

Answer 11

collagen

Question 12

Unlike arteries, veins contain X that ensure blood flows in only one
direction (arteries don’t require valves because pressure from the heart is so
strong that blood is only able to flow in one direction).

Answer 12

valves

Question 13

True/false: the capillaries are composed of a layer of only two endothelial cells and a basement membrane.

Answer 13

false, single layer of endothelial cells +basement membr

Question 14

True/false: capillaries lack both a tunica media and a tunica externa

Answer 14

true

Question 15

Precapillary sphincters regulate the flow of blood through capillary X: when the
precapillary sphincters are relaxed (open), blood flows into the capillaries, when contract
(close or partially close), blood flow through the capillaries ceases or decreases.

Answer 15

beds

Question 16

Typically, blood flows intermittently through capillaries due to:

1. vasomotion: what is this?
2. and the precapillary sphincters

Answer 16

alternating contraction and relaxation of the smooth muscle of metarterioles

Question 17

The body contains three different types of capillaries:

Continuous capillaries
Fenestrated capillaries
Sinusoids capillaries

explain

Answer 17

continous: with a continuous plasma membrane (only interrupted by clefts)
Fenestrated: plasma membrane has many fenestrations (small pores)
Sinusoid: are wider than other capillaries: more fenestrations and clefts

Question 18

Substances enter and leave capillaries by three basic mechanisms:

1. X
2. Transcytosis
3. Bulk flow

Answer 18

Simple diffusion

Question 19

Simple diffusion: most important method for solute exchange. It is the
mechanism for many substances: X, CO2, glucose, amino acids, and hormones

Answer 19

O2

Question 20

Transcytosis: substances in blood plasma become enclosed within tiny pinocytic
X and enter the endothelial cell from the lumen side and exit on the
other side by exocytosis. Mechanims for large, lipid-insoluble molecules

Answer 20

vesicles

Question 21

Bulk flow: large numbers of ions, molecules, or particles in a fluid move
together in the same direction occurs from an area of higher/lower pressure to an
area of higher/lower pressure, and it continues as long as a pressure difference exists.

Answer 21

higher to lower

Question 22

Bulk flow is important for regulation of the relative volumes of blood and
interstitial fluid.

• Pressure-driven movement of fluid and solutes from blood capillaries into
  interstitial fluid is called filtration.
• Pressure-driven movement from interstitial fluid into blood capillaries is
  called ….

Answer 22

reabsorption

Question 23

Blood hydrostatic pressure (BHP): the pressure generated by the pumping action of
the heart “pushes” fluid out of capillaries into interstitial fluid: promotes
filtration/reabsorption.

Answer 23

filtration

Question 24

Blood colloid osmotic pressure (BCOP): is a force caused by the colloidal suspension
of large proteins. The effect of BCOP is to “pull” fluid from interstitial
spaces into capillaries: promote filtration/reabsorption.

Answer 24

reabsorption

Question 25

The balance of the Blood hydrostatic pressure (BHP) and the Blood colloid osmotic pressure (BCOP)is called the .... (NFP). This determines whether the volumes of blood and interstitial fluid remain steady or change.

Answer 25

net filtration pressure

Question 26

Starling’s law of the capillaries = the volume of fluid and solutes reabsorbed normally is exactly as large as the volume filtered (equilibrium) true/false

Answer 26

false: the volume of fluid and solutes reabsorbed normally is almost as large as the volume filtered. Its a near equilibrium

Question 27

At the arterial end of a capillary, there is a net inward/outward pressure and fluid moves in/out of the capillary into interstitial spaces (filtration).

Answer 27

outward, out

Question 28

At the venous end of a capillary, there is a net inward/outward pressure, and fluid moves in/out of the capillary from tissue spaces (reabsorption)

Answer 28

inward, in

Question 29

On average, about 85% of the fluid filtered out of capillaries is reabsorbed. (!) * The excess filtered fluid and the few plasma proteins that do escape from blood into interstitial fluid enter ..... capillaries.

Answer 29

lymphatic

Question 30

If filtration greatly excedes reabsorption, the result is X: an abnormal increase in interstitial fluid volumen.

Answer 30

edema

Question 31

As lymph drains into the junction of the jugular and subclavian veins in the upper thorax, these materials return to the blood.

Answer 31

ok

Question 32

Total blood flow is the same as...... : the volume of blood that circulates through blood vessels each minute.

Answer 32

cardiac output (CO)

Question 32

Hemodynamics refers to the X involved in circulating blood throughout the body

Answer 32

forces

Question 33

How the cardiac output becomes distributed into circulatory routes depends on two more factors: 1. the X difference that drives the blood flow through a tissue (high to low, the greater the difference, the greater the flow) 2. the resistance to blood flow in specific blood vessels (the higher the resistence, the smaller the blood flow)

Answer 33

pressure

Question 34

Vascular resistance is the opposition to blood flow due to friction between blood and the walls of blood vessels. Vascular resistance depends on: 1. Blood viscosity 2. Total blood vessel length 3. Size of the blood vessel lumen (vessel radius) which is the main determinant of resistance? (!)

Answer 34

3. size of the blood vessel lumen

Question 35

Contraction of the X generates blood pressure

Answer 35

ventricles

Question 36

true/false * BP rises and falls with each heartbeat in blood vessels leading to capillaries

Answer 36

true

Question 37

true/false BP is lowest in the aorta and large systemic arteries.

Answer 37

false, highest

Question 38

As blood leaves the aorta and flows through the systemic circulation, its pressure falls progressively as the distance from the left ventricle increases. true/false

Answer 38

true

Question 39

* Systolic blood pressure (SBP): lowest/highest pressure attained in arteries during systole. * Diastolic blood pressure (DBP): lowest/highest arterial pressure during diastole Blood pressure is measured with a sphygmomanometer.

Answer 39

highest, lowest

Question 40

BP is mainly determined by cardiac output, X, and vascular resistance

Answer 40

blood volume

Question 41

Several interconnected negative feedback systems control blood pressure by adjusting: * heart rate: + heart rate, + blood pressure * stroke volume: + stroke volumen, + blood pressure * blood volume: + blood volume, + blood pressure * systemic vascular resistance: + systemic vascular resistance, + blood pressure

Answer 41

mkay

Question 42

Mechanisms to adjust blood pressure: Systemic blood pressure: 1. Neural regulation 2. Hormonal regulation And Local flux regulation: 3. Xregulation

Answer 42

Auto

Question 43

The cardiovascular (CV) center receives input from higher brain centers. Then, it provides output to the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS) to regulate heart and X (vasoconstriction)

Answer 43

blood vessels

Question 44

Xreceptors (pressure-sensitive sensory receptors), are located in the aorta, internal carotid arteries, and other large arteries in the neck and chest. * They send impulses to the cardiovascular center to help regulate blood pressure.

Answer 44

Baro

Question 45

The two most important baroreceptor reflexes are: Carotid sinus reflex: baroreceptors in the wall of the carotid sinuses help regulate blood pressure in the X. 2. Aortic reflex: baroreceptors in the wall of the ascending aorta and arch of the aorta regulate systemic X

Answer 45

brain blood pressure

Question 46

When blood pressure falls, - Increases sympathetic and decreases parasympathetic stimulation (vasoconstriction) - increased secretion of epinephrine and norepinephrine Consequence: ....

Answer 46

the heart beats faster

Question 47

When an increase in pressure is detected, 1. Decreases sympathetic and increases parasympathetic stimulation 2. heart rate and force of contraction decreases

Answer 47

ok

Question 48

carotid bodies descent from and aortic bodies, (they're veins? its a bit unclear)

Answer 48

ok

Question 49

chemoreceptors detect: hypoxia (Low X) * High X: hypercapnia * High X: acidosis

Answer 49

O2 CO2 H+

Question 50

Chemoreceptors provide input to the vasomotor center in the brain stem, but also to the X center (also in the brain stem) to adjust the rate of breathing In response, the CV center increases sympathetic stimulation to arterioles and veins, producing vasoX and an in/decrease in blood pressure.

Answer 50

respiratory constriction increase

Question 51

Renin secreted by kidney in/decreases blood pressure through Angiotensin II and aldosterone.

Answer 51

increases

Question 52

Antidiuretic hormone (ADH) produced by the hypothalamus in/decreases blood pressure

Answer 52

increases

Question 53

Atrial natriuretic peptide (ANP) released by cells in the atria of the heart in/decreases blood pressure.

Answer 53

decreases

Question 54

Vasodilators produce X dilation of arterioles and relaxation of precapillary sphincters: increases blood flow into capillary networks. * Vasoconstrictors have the opposite effect.

Answer 54

local

Question 55

Two types of stimuli cause autoregulatory changes: 1. Physical changes: warming promotes vasodilation, cooling vasoconstriction. 2. X: white blood cells, platelets, smooth muscle fibers, macrophages, and endothelial cells release a wide variety of X that alter blood-vessel diameter

Answer 55

Chemicals

Question 56

Vasodilating chemicals: K+, H+, lactic acid, and adenosine, ..... Tissue trauma or inflammation causes release of kinins and histamine.

Answer 56

nitric oxide

Question 57

Vasoconstrictors chemicals: thromboxane A2, superoxide radicals, serotonin (from platelets), and endothelins (from endothelial cells)

Answer 57

k

Question 58

Do O2 levels autoregulate blood pressure too?

Answer 58

yes

Question 59

In response to low O2: * The walls of blood vessels in the systemic/pulmonary circulation dilate: restores the normal O2 level. * The walls of blood vessels in the systemic/pulmonary circulation constrict: ensures that blood mostly bypasses poorly ventilated alveoli and flows to better-ventilated areas of the lung.

Answer 59

systemic, pulmonary

Question 60

The venous system can accommodate a large volume of blood at relatively low pressures: high capacitance. * This feature permits the veins to hold a very high percentage of the blood in circulation: blood X (nearly 3/4 of all blood)

Answer 60

reservoir

Question 61

Venoconstriction reduces/increases the volume of blood in reservoirs and allows a greater blood volume to flow to skeletal muscles, where it is needed most. * Venoconstriction is controlled by the cardiovascular center in the brain stem. When needed, it sends a larger number of sympathetic impulses to veins.

Answer 61

reduces

Question 62

Several mechanisms ensure venous retourn: 1. Gravity: blood from veins above the heart (head and neck) returns to the heart simply by "flowing downhill”. 2. Preassure gradient: it occurs due to the pressure generated by contractions of the heart’s left ventricle: the pressure difference from venules (averaging about 16 mmHg) to the right ventricle (0 mmHg), although small, normally is sufficient to cause venous return to the heart. 3. X 4. Respiratory pump Moreover, one-way valves inside veins that allow for blood flow, toward the heart, in a forward direction.

Answer 62

Skeletal muscle pump