The Endocrine System II (Lecture 15)

Question 1

What is the average human body temperature?

Answer 1

37C

Question 2

______ is a decrease in body temperature whereas ______ is a increase in body temperature

Answer 2

Hypothermia, hyperthermia

Question 3

What is thermoregulation?

Answer 3

Rate of heat production in the body = Rate of heat loss of body

Question 4

True or False: Heat production is a byproduct of metabolism

Answer 4

true

Question 5

What two ways can muscle activity effect heat pridcution

Answer 5

muscle contractions, shivering

Question 6

What are the 3 ways that food can affect thermogenesis.

Answer 6

Digestion, absorption, and storage of food

Question 7

True or False: Most of the heat produced in the body is generated deep in organs

Answer 7

True

Question 8

What are the 2 ways in how the rate that heat is lost is determined by?

Answer 8

Rate that heat is conducted from the body core to the skin

Rate that heat is transferred from the skin to the surroundings

Question 9

What are the two things that act as a insulator to the body?

Answer 9

Skin and fat of the subcutaneous tissue

Fat conducts heat one third as readily as other tissues

Question 10

True or False: Blood flow to skin from the body core provides heat transfer

Answer 10

True

Question 11

As temperature decreases, ______ is more prevalent but as temperature increases ______ is more prevalent.

Answer 11

Vasoconstriction, Vasodilation

Question 12

The control of heat conduction to the skin is by the ______.

Answer 12

SNS

Question 13

What are the 3 mechanisms of heat transfer?

Answer 13

Radiation
Thermal energy through electromagnetic waves

Conduction
Thermal energy through contact

Evaporation
Insensible water loss
Sweating

Convection
Heat transfer by movement of fluid or air

Question 14

True or False: Clothing decreases the flow of convection air current

Answer 14

True

Question 15

True or False: Clothing when wet makes high conductivity of water increases the rate of heat transmission through cloth by 20X.

Answer 15

True

Question 16

Where is the intergrating thermoregulatory center

Answer 16

Hypothalamus

Question 17

Where are thermoreceptors found

Answer 17

Central: found in CNS (hypothalamus)
Input about the core temperature

Peripheral: found in PNS (mainly skin)

Question 18

What are the effectors?

Answer 18

Sweat glands

Muscles
Skeletal muscles
Smooth muscle of cutaneous blood vessels

Question 19

True or False: Internal body temperature stays relatively stable in regards to atmospheric temperature change.

Answer 19

True (x^3)

Question 20

Increasing body temperature results in?

Answer 20

Cutaneous vasodilation

Increased blood flow to skin, causing heat loss

Question 21

Decreasing body temperature results in?

Answer 21

Cutaneous vasoconstriction

Decreased blood flow to skin, causing heat retention

Question 22

What is the negative feedback loop of thermoregulation in response to cold enviroment?

Answer 22

Thermoreceptors detect change

signal sent to integration centre

sweat glands decrease while vasoconstrction increses (limiting blood flow) and therefore reduces heat loss

In muscle, shivering occurs, which increases heat generation

all of this increases body temperature

Question 23

What can generate heat if an organism does not have shivering thermogenesis?

Answer 23

Brown fat

Question 24

_______ million sweat glands located in the skin throughout the body of humans

Answer 24

About 2.5

Question 25

True or False: 1 degree C increase in body temperature causes enough sweating to remove 10X the basal rate of body heat production

Answer 25

True

Question 26

What are the most common type of sweat glands and where are they primarily located?

Answer 26

Eccine, Concentrated in forehead, palms of hands, soles of feet (active at birth)

Question 27

What glands empty into hair follicles, active at puberty and located in armpit and genital region?

Answer 27

Apocrine

Question 28

True or False: As sympathetic activity increases, sweat production increases

Answer 28

True

Question 29

Eccrine sweat glands produce a primary secretion of mainly ______.

Answer 29

water, Na2+, Cl-

Question 30

True or False: Na2+ and Cl- are reabsorbed in the duct and water follows the same direction by osmosis through eccrine sweat glands.

Answer 30

True

Question 31

Apocrine sweat glands produce sweat containing ______.

Answer 31

Na2+, Cl- as well as proteins and fatty acids

Question 32

True or False: The protein and fatty acids secreted on the skin surface providing nutrients for bacterial growth

Answer 32

True

Question 33

Exposure to heat for several hours a day will allow for development of increased tolerance to hot or humid conditions in _______

Answer 33

1-3 weeks

Question 34

True or False: No significant loss of Na2+ and Cl- in the sweat of a person that is unacclimated to heat.

Answer 34

False, significant losse

Question 35

Unacclimated person seldom produces more than ______ of sweat/hour.

Answer 35

1L

Question 36

True or False: Acclimatized person to hot weather can increase sweat production to 2 -3 L/hour

Answer 36

True

Question 37

True or False: Acclimatization can remove heat from the body at a rate of more than 2 times the normal basal rates

Answer 37

False, 10x

Question 38

Effects of acclimatization are due to increased secretion of ______ by the adrenal glands.

Answer 38

Aldosterone

Question 39

During fever white blood cells secrete ______.

Answer 39

pyroxenes

Question 40

______ are chemicals that induce fever through actions on the thermoregulatory centre

Answer 40

Pyroxenes

Question 41

True or False: During fever the body temperatures set point increases.

Answer 41

True