Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology Year 2 > Homeostatis > Flashcards

Homeostatis Flashcards

(62 cards)

Start Studying
1
Q

homeostasis

A

the ability of an organism to maintain a constant internal environment

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

what is thermoregulation

A

the control of the internal body temperature.

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

why do organisms heat up and cool down

A

Exo chemical reactants
Latent heat of evaporation
Radiation
Convection
Conduction

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

what are ectotherms

A

Use their surroundings to warm their bodies
Core body temperature is dependent on environment
Live in water and don’t need to thermoregulate
High heat capacity means temp of environment does not change

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

endotherms

A

Endotherms:
Rely on their metabolic processes to warm up and they usually maintain a stable core body temperature
Have adaptations which enable them to maintain their body temperature and take advantage of warmth from the environment
Metabolic rate is higher than ectotherms.

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

which one, ednotherms or ectothers cannot control body temp and how have they overcome this

A

ectotherms
they have overcome this by behavuoural and physiological responses

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

examples of behavioural response

A

Bask in the sun, orientating their bodies so that maximum surface area is exposed towards the sun
Through conduction, they can increase their body temperature by pressing their bodies against the warm ground.
Cool down by preventing their core temperature reaching a point where enzymes begin to denature
To cool down they shelter from the sun by seeking shade or hiding

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

physiological response

A

Dark colours absorb more radiation than light
Alter their heart rate to increase or decrease the metabolic rate and to affect the warming or cooling across the body surfaces

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

What detects temperature of the blood in the body surfaces?

A

Temperature receptors in the hypthalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

waya to cool down

A
  • vasodilation
  • increased sweating
  • reducing insulating layers of hair or feathers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

explain vasodilation

A

arterioles constrict
less blood able to flow
minimises heat which can radiate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

increasing sweat

A

sweat glands reduce secretion of sweat

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

reducing insulating effect of hair or feathers

A

hair erector muscles relax
hiar lie flat
avoids trapping insulating layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ways to warm up

A

Vasoconstriction
Decreased sweating
Rasing body hair or feathers
Shivering

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

vasoconstriction

A

arterioles constrict
atriovenous shunt vessels dilate
little blood flow
little radiation takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

decreased sweating

A

core temp falls
sweating decrease
sweat production stops
reduces cooling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

raising body hair

A

erector pili misicles contract
traps insulin layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

shivering

A

muscles contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the 2 control centres to control thermolregulation in the hypothalamus

A

heat loss
heat gain centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

heat loss centre

A

Activated when the temperature of the blood flowing through the hypothalamus increases, sends impulses through autonomic motor neurons to effectors triggering response to lower core temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

heat gain centre

A

Activated when the temperature of the blood flow through the hypothalamus decreases, it sends impulses through the autonomic nervous system to effectors in the skin and muscles which triggers responses that act to raise the core temp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is excretion

A

removal of waste products pf metabolism from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the main metabolic waste products in mammals

A

co2
bile bigments
nitrogenous waste (urea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
function of the liver
- breaks down amino acid into urea - detoxfies the blood - stores glycogen - makes bile
26
structure of the liver
hepatic artery hepatic vein hepatic portal vein bile duct hepatocytes liver lobules sinusoids kuppfer cells
27
function of the hepatic artery
to deliver oxygenated blood to the liver aorta------liver
28
function of the hepatic vein
take deoxygenated blood away from the liver, allows amino acids to enter liver ---- heart
29
function of the hepatic portal vein
allows harmful substances to be removed from liver and broken down intestine --- liver
30
function of the bile duct
takes bile from liver to the gall bladder
31
liver lobules and hepatocytes
specialised epithelial cells which is made up of hepatocytes which divide and replicate
32
what connects the hepatic artery and hepatic portal vein
sinusoids
33
what converts toxic substances into less harmful substances
blood moves through sinusoids and hepatocytes convert
34
what are kupfer cells
attach to walls of sinusioids and break down red bloood cells and remove bacteria
35
carbohydrate metabolisim
bgc levels increase insulin rise hepatocytes stimulated to convert glucose into glycogen
36
deamination
amino group removed from an amino acid and ammonia and organic ions are produced
37
reaction of liver converting amino acids into urea
ornithine cycle
38
detoxification
the liver detoxifies harmful toxins and make them harmless
39
what is the 2 important roles of the kidney
osmoregulation excretion they filter nitrogenous waste products out of the blood, urea they maintain the water balance and PH of the blood and hence the tissue fluid which surrounds all the cells
40
production and release of urine
nephrons act as a filtering unit and the liquid produced by the kidney tubules is urine urine passes out the kidneys down ureters and is collected in the bladder, the sphincter opens the bladder and urine passes out down the urethra
41
Main 3 areas of a kidney
cortex medulla pelvis
42
cortex
dark outer layer filter of blood capillary network which carries blood from renal artery to nephron
43
medulla
light colour tubules of nephron which forms pyramids of kidney and cd
44
pelvis
where urine is collected
45
Nephron
filters blood, removes nitrogenous wastes and balances mineral ions and water
46
structure of nephron: Bowmans capsule
contains glomerulus, more blood goes in than leaves due to ultrafiltration
47
structure of nephron: proximal convoluted tubule
found in cortex coiled region after the bowman's capsule covered with microvilli to increase SA many mitochondria to provide ATP GLUCOSE, AMINOACIDS, VITAMINS, HORMONES move from filtrate back into blood via active transport
48
structure of nephron: loop of Henle
creates region of high solute conc in tissue fluid in the medulla broken down into: ascending limb which is medulla to cortex descending limb which is the context to medulla
49
structure of nephron Distal convoluted tubule
ADH
50
structure of nephron: collecting duct
urine passes down cd through medulla to pelvis
51
ultrafiltration
to remove nitrogenous waste and osmoregulation of the blood
52
where does ultrafiltration take place and process
Bowmans capsule - blood enters through the afferent arterioles which splits into capillaries forming the glomerulus, this causes a high hydrostatic pressures of the blood. - small molecules such as water urea etc are forced out which forms glomerulus filtrate. - fluid passes through the basement membrane which along with the capillary acts as sieve - podocytes within the Bowmans capsule act as an additional filter.
53
what is the process of selective reabsorption
In the proximal convoluted tubule (PCT), loop of Henle and the distal convoluted tubule (DCT), useful substances are reabsorbed, passing out of the nephron and back into the capillaries. Glucose is reabsorbed in the PCT by active transport and facilitated diffusion. Water is reabsorbed in the loop of Henle, DCT and collecting duct by osmosis. The remaining filtrate is urine, containing excess water, excess salts and urea. This passes from the collecting duct to the bladder via the ureter.
54
what is the adaptations of the pct
many mitochondria to provide atp and many microvilli to increase sa
55
loop of Henle process to control the movement of ions and allow water to be reabsorbed.
The ascending limb is permeable to ions but impermeable to water, sodium ions are actively pumped into the medulla. This lowers the water potential of the medulla, causing water to move out of the nephron by osmosis from the descending limb (which is permeable to water but not ions). As water moves out of the nephron, the filtrate becomes more concentrated. This causes sodium ions to move out of the nephron at the start of the ascending limb, down their concentration gradient by facilitated diffusion. This lowers the water potential of the medulla even further, causing water to move out of the DCT and collecting duct by osmosis. Water that has moved into the medulla eventually moves into the capillary
56
dct
balances the water needs of the body many mitochondria to carry out active transport
57
cd
urine
58
function of adh
controls water content of our urine by increasing the reabsorption of water from cd
59
negative feedback mechanism of adh
Osmoreceptors in the hypothalamus detect a drop in blood water potential. The hypothalamus signals to the posterior pituitary gland to secrete ADH. ADH causes the walls of the DCT and collecting duct to become more permeable to water (by the incorporation of more aquaporins into the membranes of the cells that line these parts of the nephron). More water moves by osmosis out of the DCT/collecting duct and reabsorbed into the bloodstream, increasing its water potential. A smaller volume of concentrated urine is produced.
60
mechanisim of adh action
1. vesicles in cell lining of the collecting duct fuse with cell surface membranes of medulla 2. membranes contain aquaporins which make it more permeable to water 3. this allows water to move out of the tubule cells into blood capillary via osmosis
61
go over urine and testing
62
kidney failures

Biology Year 2 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions