Physio 17

Question 1

What is one of the primary functions of blood flow to the skin?

Answer 1

Determining heat loss from the body

Question 2

How does blood flow to the skin contribute to maintaining homeostasis?

Answer 2

By controlling body temperature

Question 3

What is the crucial role of adequate blood plasma delivery to the kidneys?

Answer 3

Allowing the excretion of waste products

Question 4

Besides waste excretion, what other vital function of the kidneys is dependent on adequate blood plasma flow?

Answer 4

Regulation of body fluid volumes and electrolytes

Question 5

What does the phrase “extreme degrees of local blood flow control” imply?

Answer 5

Individual organs can tightly adjust their own blood supply.

Question 6

The control of blood flow to the skin is primarily linked to:

a) Metabolic demand
b) Excretion of waste
c) Thermoregulation
d) Oxygen delivery

Answer 6

Thermoregulation

Question 7

What are some of the specific needs of the tissues for blood flow?

Answer 7

1. Delivery of oxygen to the tissues.
2. Delivery of other nutrients, such as glucose, amino acids, and fatty acids.
3. Removal of carbon dioxide from the tissues.
4. Removal of hydrogen ions from the tissues.
5. Maintenance of proper concentrations of other ions in the tissues.
6. Transport of various hormones and other substances to the different tissues.

Question 8

One of the most fundamental principles of circulatory function is the ability of each
tissue to control its own local blood flow in proportion to its _____?

Answer 8

metabolic needs

Question 9

Thyroid and adrenal glands have blood flows in the range of?

Answer 9

Several hundred ml/min per 100 g of tissue

Question 10

What is the total blood flow through the liver?

Answer 10

1350 ml/min

Question 11

The blood flow per 100 g of liver tissue is approximately?

Answer 11

95 ml/min

Question 12

Chapter 17 highlights an “extremely large blood flow” through which organ?

Answer 12

Kidney

Question 13

What is the primary reason for the very high blood flow through the kidneys?

Answer 13

To cleanse the blood of waste products

Question 14

Despite constituting a large percentage of total body mass, inactive muscles have a relatively:

a) Very high total blood flow
b) Very low total blood flow
c) Blood flow similar to the liver
d) Blood flow exceeding that of the kidneys

Answer 14

Very low total blood flow

Question 15

What is the blood flow per 100 g of inactive muscle tissue?

Answer 15

4 ml/min

Question 16

During heavy exercise, the metabolic activity of muscles can increase by more than?

Answer 16

60-fold

Question 17

During heavy exercise, the total blood flow to the body’s muscles can increase up to?

Answer 17

16,000 ml/min

Question 18

The blood flow per 100 g of muscle tissue during heavy exercise can reach as high as?

Answer 18

80 ml/min

Question 19

Blood flow of of inactive muscles of the body

Answer 19

750 ml/min

Question 20

2 phases of local blood flow

Answer 20

1. acute control
2. long-term control

Question 21

T/F. Maintaining a very large blood flow through all tissues at all times would be an efficient way for the body to operate

Answer 21

False

Question 22

True or False: Blood flow to each tissue is generally regulated to match the tissue’s requirements closely.

Answer 22

True

Question 23

True or False: Blood flow to tissues is usually maintained at a level significantly higher than what is minimally required.

Answer 23

False

Question 24

True or False: For tissues where oxygen delivery is paramount, blood flow is controlled to be just slightly above the level needed for full oxygenation.

Answer 24

True

Question 25

True or False: By precisely controlling local blood flow, the workload on the heart is minimized.

Answer 25

True

Question 26

True or False: Maintaining blood flow at the minimal required level helps prevent both tissue deficiency and unnecessary cardiac workload.

Answer 26

True

Question 27

Achieved by rapid changes in local vasodilation or vasoconstriction of the arterioles to provide very rapid maintenance of appropriate local tissue blood flow

Answer 27

Acute control

Question 28

Slow, controlled changes in flow over a period of days, weeks, or even months that provide better control of the blood flow in to the needs of the tissues.

Answer 28

Long-term control

Question 29

A result of an increase or decrease in the physical sizes and numbers of actual blood vessels supplying the tissues

Answer 29

Long-term control

Question 30

Increase in metabolism up to eight times normal increases the blood flow acutely about ___________.

Answer 30

fourfold

Question 31

One of the most necessary of the metabolic nutrients

Answer 31

Oxygen

Question 32

Whenever the availability of oxygen to the tissues decreases, such as:

Answer 32

1. at high alti tude at the top of a high mountain 2. in pneumonia 3. carbon monoxide poisoning 4. cyanide poisoning

Question 33

Two basic theories for the regulation of local blood flow

Answer 33

1. vasodilator theory 2. oxygen lack theory

Question 34

Give at least three vasodilator substances

Answer 34

1. adenosine 2. carbon dioxide 3. adenosine phosphate compounds 4. histamine 5. potassium ions 6. hydrogen ions

Question 35

Believed to diffuse through the tissues to the precapillary sphincters, metarterioles, and arterioles to cause dilation

Answer 35

Vasodilator substances

Question 36

Vasodilator substances may be released from the tissue in response to?

Answer 36

oxygen deficiency

Question 37

An increased rate of metabolism in a tissue leads to?

Answer 37

A greater rate of formation of vasodilator substances.

Question 38

The vasodilator substances, once formed, are believed to act on which blood vessels to cause dilation?

Answer 38

Precapillary sphincters, metarterioles, and arterioles.

Question 39

The release of vasodilator substances from tissue can be a response to?

Answer 39

Oxygen deficiency

Question 40

Which two substances are released due to decreased oxygen availability that cause vasodilation?

Answer 40

Adenosine and lactic acid

Question 41

When blood flow is reduced and cell metabolism continues, the concentration of which substances tends to increase in the tissues?

Answer 41

Vasodilator metabolites like carbon dioxide, lactic acid, and potassium ions.

Question 42

Many physiologists consider which substance to be an important local vasodilator for controlling local blood flow?

Answer 42

Adenosine.

Question 43

Minute quantities of adenosine are released from heart muscle cells when?

Answer 43

Coronary blood flow becomes too little.

Question 44

The release of adenosine in the heart leads to?

Answer 44

Local vasodilation in the heart.

Question 45

Increased metabolic activity in the heart leads to increased utilization of?

Answer 45

Oxygen

Question 46

Decreased oxygen concentration in heart muscle cells due to increased metabolism leads to the degradation of?

Answer 46

Adenosine triphosphate

Question 47

The vasodilator theory primarily explain?

Answer 47

Acute local regulation of blood flow

Question 48

Also called as oxygen lack theory

Answer 48

Nutrient lack theory

Question 49

Under special conditions, it has been shown that lack of _____ in the perfusing blood can cause local tissue vasodilation.

Answer 49

glucose

Question 50

Vasodilation occurs in the vitamin deficiency disease _____, in which the patient has deficiencies of the vitamin B substances thiamine, niacin, and riboflavin.

Answer 50

beriberi

Question 51

Beriberi is associated with deficiencies of which vitamin B substances?

Answer 51

Thiamine, niacin, and riboflavin

Question 52

In beriberi, the peripheral vascular blood flow often increases by how much?

Answer 52

Twofold to threefold

Question 53

A deficiency in thiamine, niacin, and riboflavin might lead to diminished?

Answer 53

Smooth muscle contractile ability

Question 54

T/F. Control of local blood flow is solely dependent on oxygen availability

Answer 54

False

Question 55

Lack of essential nutrients can potentially influence local blood vessel diameter. a) True b) False

Answer 55

True