Chapter 14: Metabolic Rate and Temperature Regulation

Question 1

_________ - is total energy expenditure of the body, per unit time.

Answer 1

metabolic rate

Question 2

_____________ - is used as an accepted and standard way of measuring an individual’s metabolic rate.

Answer 2

Basal Metabolic Rate (BMR)

Question 3

__________ - metabolic rate measured under standard conditions, with the body in a quiet, resting, and fasting condition.

Answer 3

basal state

Question 4

_________ - provides a baseline measurement of a person’s metabolic rate.

Answer 4

Basal Metabolic Rate

Question 5

What are the Three factors affect BMR?

Answer 5

1. Physical size
2. Age
3. Gender

Question 6

What are the Three main factors that affect BMR?

Answer 6

i. Activity level of the nervous system
ii. Blood levels of several hormones
iii. Body temperature

Question 7

___________ - Factors that increase heat production by the tissues (in the body).

Answer 7

“Calorigenic Effects”

Question 8

______________ - means heat production due to ingestion of food which increases the metabolic rate for 1-3 hours after eating.

Answer 8

Food-induced thermogenesis

Question 9

____________ - is the factor that increases metabolic rate the most.

Answer 9

Exercise (or muscle activity)

Question 10

______________ - is an organism that can maintain body temperature at a relatively constant level.

Answer 10

Warm-blooded homeotherm

Question 11

____________ - organism sets its body temperature based on the ambient temperature.

Answer 11

Cold-blooded

Question 12

____________ - is usually a few degrees lower than the core ____________ .

Answer 12

Skin temperature

body temperature

Question 13

Internal temperature drops slightly during ______ and a bit higher during _______ hours.

Answer 13

sleep

waking

Question 14

What are the two factors that regulate the total heat content of the body?

Answer 14

1. Total heat production by body
2. Total heat loss from body

Question 15

What are the mechanisms of the body to produce heat?

Answer 15

1. Shivering Thermogenesis
2. Non-shivering Thermogenesis

Question 16

______________ - General skeletal muscle contraction, in response to the body becoming too cold. Production of heat increases several folds within seconds, due to increased muscle contraction.

Answer 16

Shivering Thermogenesis

Question 17

______________ - Due to increased secretion of epinephrine and thyroid. Most common and effective in infants compared with adults.

Answer 17

Non-shivering Thermogenesis

Question 18

What are the 4 main mechanisms to lose heat?

Answer 18

1. Radiation
2. Conduction
3. Convection
4. Evaporation

Question 19

_________ - Heat transfer in the form of electromagnetic waves. Rate of heat loss by radiation increases, as the temperature difference between the two environments increase.

Answer 19

Radiation

Question 20

Exchange of heat by transfer of thermal energy, during collisions between adjacent molecules. Heat is exchanged between body and another medium (environment) when the two come in direct contact.

Answer 20

Conduction

Question 21

__________ - Means exchange of heat between body and another environment (air or fluid) as the air/fluid that is heated moves away and a new mass replaces it.

Answer 21

Convection

Question 22

___________ - Heat is the form of energy used to drive the evaporation process which takes place from the skin surface, as well as the surface of the respiratory tract.

Answer 22

Evaporation

Question 23

__________ - is an important thermoregulatory center.

Answer 23

hypothalamus

Question 24

___________ - detects changes in body temperature and sends the info to different brain centers via ascending pathways.

Answer 24

thermoreceptor

Question 25

What are the two types of thermoreceptors?

Answer 25

1. Central 2. Peripheral

Question 26

\_\_\_\_\_\_\_\_\_\_\_\_ - Located in the hypothalamus and visceral organs. Responsible for detecting changes in body core temperature.

Answer 26

Central Thermoreceptors

Question 27

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ - Located in the Skin, nasal and oral cavities. Report changes of temperature in the periphery.

Answer 27

Peripheral Thermoreceptors

Question 28

What are the two sub-types of peripheral thermoreceptors?

Answer 28

Cold and Warm receptors

Question 29

What are the responses of Hypothalamus that results to heat loss?

Answer 29

* Vasodilation * Sweating * Decreased muscle tone

Question 30

What are the responses of Hypothalamus that results to heat production ?

Answer 30

* Vasoconstriction * Increased BMR * Shivering * Decreased sweating (therefore, lower evaporative heat loss) * Increased secretion of thyroid hormone

Question 31

\_\_\_\_\_\_\_\_\_\_ - When body temperature increases (above physiological levels) abnormally.

Answer 31

Hyperthermia

Question 32

What are the causes of Hyperthermia?

Answer 32

1. fever 2. exercise 3. unusual heat retention or inability to lose heat.

Question 33

\_\_\_\_\_\_\_\_\_\_\_ - is located in the hypothalamus and is affected during fever, infection and overactivity of immune cells.

Answer 33

set point

Question 34

\_\_\_\_\_\_\_\_\_\_\_\_ - Mainly due to loss of fluid, as a result of sweating too much or, in some cases, excessive vasodilation of cutaneous blood vessels.

Answer 34

Heat exhaustion

Question 35

\_\_\_\_\_\_\_\_\_\_ - Heat loss system is failing (or has failed), thus, body temperature rises to very high levels. This may result in collapse, unconsciousness (for a long period of time), seizures and even death.

Answer 35

Heat Stroke