Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Chapter 15-homeostasis > Flashcards

Chapter 15-homeostasis Flashcards

1
Q

Where core body temp is monitored?

A

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Type of cell that detects change in temp?

A

Thermoreceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Homeostatic mechanism that works to restore changes in temp to normal range?

A

Negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Responses that conserve heat?

A
  • contraction of erector pili muscles
  • curling up
  • vasoconstriction of arterioles near skin surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Behavioural response to decrease in temp?

A

Curling up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How large, thin ears help control body temp?

A

Large SA to lose heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How ears that move forwards and backwards help control temp?

A

Increases air movement over skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define homeostasis?

A

Maintaining stable internal environment within narrow limits even though environment is changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How negative feedback used to control blood glucose conc?

A
  • B cells detect increase in blood glucose conc
  • B cells in pancreas secrete insulin
  • increases uptake of glucose by effector cells. Enters through glucose transport proteins
  • glucose converted to glycogen by glycogenesis
  • inc use of glucose in respiration
  • if lower glucose conc, alpha cells in pancreases release glucagon
  • increased conversion of glycogen to glucose by glycogenolysis
  • increase covers on of other compounds like amino acids + lipids to glucose by gluconeogeneis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Role of ATP in cell?

A
  • phosphate removed by hydrolysis to release 30kJmol-1 energy
  • energy released used for metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How endotherm prevents temp decreasing when external temp decreases?

A
  • thermoreceptors stimulated by decrease in external temp
  • impulses sent to hypothalamus through sensory neurones
  • vasoconstriction of arterioles to reduce heat loss. Prevent heat Loss by conduction
  • shivering. Involuntary muscle spasms to generate heat
  • erector pili muscles contract to raise hairs/ fur to trap insulating layer of air
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why described as endotherm?

A

-generate heat from metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why more difficult for bees to maintain body temp than mammals? Both endotherms

A
  • insects smaller + have larger SA:V ratio
  • greater rate of heat loss
  • mammals + birds have thicker insulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Animals that are able to regulate + maintain core body temperature within narrow limits?

A

Endotherm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Increase in diameter of lumen of arterioles to allow more bloods to flow through?

A

Vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hormone that increases metabolic rate so generates heat?

A

Adrenaline

17
Q

Why are receptors + effectors important in homeostasis?

A
  • body needs sensory receptors to monitor changes in external environment
  • effectors respond to these changes + restore to original balance
18
Q

Why effective homeostasis depends on negative rather than positive feedback systems?

A
  • in (-) f.s , when change takes place, systems in body act to return situation to normal. They inhibit change
  • in (+) f.s, when change takes place, systems in body act to reinforce the change
  • in homeostasis, body seeks to maintain dynamic equilibrium. If there is a change, the need is to inhibit it + return things to original state
  • possible with (-) but it (+)
19
Q

What is an ectotherm?

A

Animals that use heat from their surroundings to warm their bodies so their core body temp is heavily dependent on environment

20
Q

Example of ectotherm?

A
  • lizards

- locusts

21
Q

Give example of ectotherm warming up though radiation?

A
  • basks in sun

- gains heat by radiation from sunlight

22
Q

Give example of ectotherm warming up though conduction?

A

Presses against hot earth.

Gains heat by conduction

23
Q

Give example of ectotherm warming up though convection?

A

Ectotherm stands up as high as if can off the ground

Will lose heat by convection currents in air around it

24
Q

Give example of ectotherm warming up though evaporation?

A
  • wallows in mud or water

- loses heat by evaporation of water from surface of skin

25
Q

Why control of internal temp so important to ectotherms + endotherms?

A
  • reactions of respiration are controlled by enzymes + have optimum temp
  • if temp too low, reactions are v. Slow.
  • not enough energy for muscle contraction for movement
  • if temp too high, enzymes denature
  • cells of body die which can lead to death
26
Q

How evaporation of water in thermoregulatioj differs between ectotherms + endotherms?

A
  • ectotherms don’t sweat. Cool down using evaporation of water only if they wallow or submerge in water
  • when emerge from water or mud, they cool down as water evaporates from skin surface
  • endotherms sweat as core body temp increases
  • evaporation of water in sweat lowers skin surface temp which lowers temp of blood by conduction
27
Q

Difference in role of peripheral temp receptors + temp receptors in hypothalamus?

A
  • peripheral temp receptors are in skin + detect changes in surface temp
  • receptors in hypothalamus detect blood temp within body
  • peripheral receptors respond to environmental stimuli while receptors in hypothalamus respond directly to changes in core temp
28
Q

Why endotherms in hot climates pale?

A

-pale colours reflect light + therefore heat so decreased amount of heat absorbed from sunlight

29
Q

Why would you expect endotherms that live in cold climates to be dark coloured?

A

-dark colours absorb more heat +therefore help increase body temp

30
Q

Not many endotherms in cold climates are acc dark. Why?

A
  • cold places have lots of ice + snow
  • dark colours show up against the white
  • makes animals more visible to predators
31
Q

Describe how arterioles under the skin helps control temperature?

A
  • impulses sent to muscle
  • muscles in arterioles contract
  • lumen of arteriole constrict
  • reduces blood flow to capillaries under skin
  • reduces heat by evaporation
32
Q

does secretion of adrenaline generate heat?

A

no

33
Q

Why is it more difficult for moths and bublebees to maintain their body temp than mammals?

A
  • have large SA:V ratio

- lose heat very quickly

Biology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions