Homeostasis

Question 1

Define homeostasis

Answer 1

• Process where the body’s organ systems, tissues, and cells work and how their functions are integrated to regulate the body’s internal environment
• It is a dynamic state
• Condition in which the body’s internal environment remains relatively constant, within physiological limits.
• any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body.

Question 2

stressors may be internal/external/both
(Choose)

Answer 2

Both

Question 3

_______ is responsible for maintaining homeostasis by regulating most processes that affect the body’s internal environment

Answer 3

Hypothalamus

Question 4

What processes affect the body’s internal environment? (10)

Answer 4

• blood pressure
• heart rate
• strength of contractions of the cardiac muscle tissues
• respiration
• digestion
• body temperature
• thirst and fluid balance
• interaction of the nervous system and endocrine system
• appetite and food intake
• sleep-wake cycles

Question 5

Where is hypothalamus located

Answer 5

Within the diencephalon (not necessary probably)

Middle of the brain in a diagram

Question 6

Describe the sequence of the homeostasis process (3functions)

Answer 6

Stimulus -> receptor -> effector-> stimulus

Question 7

What is the homeostasis state (normal) for:

a) blood pH
b) Blood pressure
c) body temperature

Answer 7

a) 7.4
b) 139 mmHg
c) 37degrees i think? Ion remember

Question 8

What feedback mechanisms are used to control homeostasis?

Answer 8

Positive and negative

Question 9

Explain positive and negative feedback loops

Answer 9

Positive - feedback serves to intensify a response until an endpoint is reached
Negative - feedback serves to reduce an excessive response and keep a variable within the normal range

Question 10

State 4 physiological adjustments that happen during physical activity and exposure to extreme environments

Answer 10

• increase metabolism
• adjust cardiovascular and respiratory responses to ensure a supply of oxygen
• clear metabolic by-products (eg CO2)
• regulate body temperature to prevent hyperthermia/hypothermia

Question 11

Physiological regulation and integration is done by what systems?

Answer 11

Nervous and endocrine

Question 12

What basic components make up feedback mechanisms

Answer 12

• A receptor (such as nerve endings in the skin that sense temperature)
• A control centre (duch as the hypothalamus)
• An effector (such as shivering if your body temperature drops sharply)

Question 13

the production of body heat is proportional to metabolic rate. There are several factors that can affect this, such as: (7)

Answer 13

exercise
hormones
nervous system
body temperature
ingestion of food
age
sex differences

Question 14

Heat can be transferred away from body via what (4)

Answer 14

conduction, convection, radiation and evaporation

Question 15

Name the medical condition that occurs when there is too much heat production and too little heat loss in the body.

Answer 15

hyperthermia

Question 16

at what body temperature is it considered hyperthermia

Answer 16

at above 39 degree Celcius

Question 17

explain conduction when talking about the heat transfer in the body

Answer 17

heat generated deep in your body can be conducted through tissue to the body’s surface and to the clothing air or water that is in direct contact with your skin

Question 18

explain convection when talking about the heat transfer in the body

Answer 18

convection involves moving heat from one place to another by the motion of air or water. For example, blood transfers heat by convection from the deep body tissues to the skin

Question 19

explain radiation when talking about the heat transfer in the body

Answer 19

radiation is the transfer of energy waves that are sent out from one object and absorbed by another. For example, solar energy from direct sunlight can be reflected from snow, sand or water to help warm a person.

Question 20

explain evaporation when talking about the heat transfer in the body

Answer 20

Evaporative cooling is the conversion of sweat from liquid to water vapor. This is the main way for the body to lose heat during exercise

Question 21

what is non-shivering thermogenesis

Answer 21

Process by which the body generates heat in response to cold temperature exposure without shivering

Question 22

explain shivering

Answer 22

When exposed to cold, the hypothalamus triggers rapid, small muscle contractions, which increase metabolic activity and produce heat as a byproduct.

Question 23

sweat production over an area of skin depends on what

Answer 23

• the density (the number of sweat glands per cm^2 of skin surface)
• the amount of sweat per gland

Question 24

what is the difference between acclimatization and acclimation

Answer 24

acclimatization is a natural adaptation while acclimation is acclimatization in an artificial environment

Question 25

How many days of exercising in hot environment does it take for heat acclimatization to take place

Answer 25

10-14days

Question 26

what chronic adaptations to exercise can improve exercise performance in heat

Answer 26

- increased plasma volume - earlier onset of sweating (and at a lower core temperature) - a more dilute sweat composition (electrolyte loss reduced) - reduced rate of muscle glycogen use - decreased psychological perception of effort

Question 27

For how long are the benefits of heat acclimatization retained after returning to a cooler environment

Answer 27

about a week

Question 28

after how long will the benefits of heat acclimatization be lost after returning to a cooler environment

Answer 28

about 3 weeks

Question 29

What improvements do you get from heat acclimatization

Answer 29

- maximal oxygen consumption - lactate threshold - thermotolerance