Topic 7- Animal coordination, control and homeostasis Flashcards
1
Q
What are hormones and where are they secreted from and where do they travel?
A
- Chemical messengers
- Secreted from endocrine glands
- Target organs through the blood stream
2
Q
What are the 6 ( need to know) endocrine glands?
A
- Pituitary
- Thyroid
- Pancreas
- Adrenal
- Ovaries
- Testes
3
Q
What is the purpose and effects of adrenaline and where is it secreted from?
A
- Fight or flight
- Adrenal glands
- Increases blood pressure ( to muscles)
- Increases heart rate ( to muscles)
- Increases glucose levels in blood stream from liver
- Reduces blood flow to gut ( prevents digestion)
- Widens airways, increased breathing rate
4
Q
Where is TRH ( Thyrotropin releasing hormone) secreted, why and what does it do?
A
- Hypothalamus (For metabolism)
- When there are low levels of thryoxine
- Stimulates TSH to be secreted from pituitary gland
5
Q
Where is TSH (thyroid stimulating hormone) secreted and what does it do?
A
- Pituitary gland
- Stimulates thyroxine to be secreted from the thyroid gland
6
Q
What happens when there are normal/high levels of thyroxine
A
- Inhibits production of TRH and TSH
7
Q
What does thyroxine do?
A
- Controls metabolic rate
8
Q
Where and does FSH do in the preovulatory phase?
A
- Pituitary gland
- Stimulates follicle to mature egg
- stimulates the secretion of oestrogen from the follicles
9
Q
Where and does oestrogen do in the preovulatory phase?
A
- From Follicles
- Builds the lining of the uterus for fertilisation
- Stimulates LH secretion from the pituitary gland
- Inhibits FSH
10
Q
Where and what does LH (luteinezing hormone) do in the postovulatory phase?
A
- Stimulates follicle to release egg (ovulation)
- Empty follicle (yellow body) secretes progesterone and oestrogen
11
Q
Where and does progesterone do in the postovulatory phase?
A
- From the yellow body (corpus luteum)
- Maintains uterus lining
- Inhibits LH
12
Q
Which two hormones spike together in the middle of the cycle?
A
- LH
- Oestrogen
13
Q
What happens if there is no fertilisation?
A
- Oestrogen and progesterone levels decrease
- Lining sheds causing bleeding
- FSH levels increase
14
Q
How is IVF done?
A
- Mother given lots of FSH and LH to mature many eggs
- Sperm is used to fertilise in lab
- Placed into mothers womb
15
Q
What are the positives to IVF?
A
- Allow those struggling with conception to have children
16
Q
What are the negatives to IVF?
A
- Mentally demanding
- Costly
- Low success rates
- Women can have multiple children ( triplets) dangerous
17
Q
How do hormonal contraceptives affect the hormonal cycle?
A
The pill- inhibit FSH production to stop eggs maturing
- implant, skin patch, injection- Produce progesterone (inhibits FSH and LH)
18
Q
What are the positives to the pill?
A
- Effective
- Easy to use
19
Q
What are the negatives to the pill?
A
- Has to be used daily
- Side effects (increase risk of blood clots and breast cancer)
- Doesn’t protect against STI’s
20
Q
What is clomifene and why is it used?
A
- Drug containing lots of FSH
- Women who produce less FSH use it to stimulate the follicles for egg to mature
21
Q
What are the positives to skin patches, implant or injections?
A
- Last a long time
22
Q
What are the negatives to skin patches, implant or injections?
A
- Side effects
- Don’t protect against STI’s
23
Q
Are barrier or hormonal contraceptives better?
A
- Hormonal are more effective (6-12 /100 pregnancies annually compared to 18+/100)
- Hormonal doesn’t protect against STI’s
24
Q
Why is thermoregulation important?
A
- The human body should be around 37 degrees celsius
- Can slow or denature enzymes
25
What is the importance of osmoregulation?
- Can cause cells to become turgid and burst (if too much water)
- Cells can loose water and shrivel (if too much salt)
- Most fluids are made with water (urine, phlegm)
26
What happens when we are too hot?
- Vasodilation, blood vessels widen to allow flow to skin
- Sweat gland produces sweat ( evaporates with heat)
- Hair erector muscles relax (prevent heat being trapped)
27
What happens when we are too cold?
- Vasoconstriction, blood vessels constrict to prevent blood flow to skin
- Hair erector muscles contract, hairs trap a layers of air as an insulator
- Swat glands stop producing water
28
What is glucose stored as?
Glycogen
29
Where is glucose stored (mostly)?
- Liver
- Muscles
30
What happens when glucose levels are high in the bloodstream?
- Pancreas secretes INSULIN
- insulin causes the body to absorb glucose
- For cells to respire
31
What happens when glucose levels are low in the bloodstream?
- Pancreas releases GLUCAGON
- causes glycogen in liver (muscles) to be broken down into glucose
- And released in the blood stream
32
What are metabolic rest (thyroxine) and glucose levels examples of?
- Negative feedback loop
33
What is vasodilation?
- Arterials near the skin surface dilate,
- too hot
- Loose heat through skin
- Face goes red
34
What is vasoconstriction?
- Arterials near the skin surface constrict
- too cold
- Blood flows further away from the face as to not loose heat
- Face goes blue
35
What is the hypothalamus' role in thermoregulation?
- detects if the temperature is too far from normal 37 degrees
36
What is the sweat glands role in thermoregulation?
-Sweat glands in dermis secrete water onto epidermis
-Epidermis uses heat to evaporate water
37
What and where does the hormone that controls osmoregulation come from?
- ADH
- Hypothalamus
38
What brings blood to the kidneys?
- renal arteries
39
How and why do renal arteries cause high pressure?
- Narrow when exiting the kidney
- Causes high pressure
- Forces smaller molecules (glucose, urea, water)
- Into the nephron
40
Where does nephron absorb small molecules, and what is its purpose?
- Glomerulus (bundle of blood vessels)
- Bowmans capsule ( large SA, enters nephron)
- Stops cells and proteins entering the nephron
41
What happens to the small molecules that are absorbed into the nephron?
- Travel down the nephrons tubules
- Active reabsorption
42
Where is glucose reabsorbed from the kidney?
- Proximal Convoluted tubule
- (before loop)
43
Where is salt and water reabsorbed from the kidney?
- Loop of henle
44
How are the small molecules reabsorbed actively in the kindey?
- Nephron surrounded by cappilaries
45
What happens when there is little water in the body
- ADH released from hypothalamus
- Causes collecting ducts walls to become more permeable
- Allows more water to be reabsorbed into cells
46
What about urine indicates low water levels in the body
- Less urine
- high urea concentration
- yellow urine (acidic)
47
What happens if there is lots of water in the body (kidney)?
- ADH is inhibited
- Collecting duct walls less permeable
- Less water reabsorbed
48
Treatment for kidney failure?
-Dialysis
-Kidney transplant
49
How does dialysis work?
-Dialysis fluid contains similar concentration of glucose,l amino acids and ions as blood (no net movement) (unless patient is too high or low)
-Blood passes through a tube with a partially permeable membrane
-Allows small molecules (especially urea) to leave body
50
Problems with dialysis?
-Fluid needs to be replenished
-Time consuming
-Can cuase infections and blood clots
-Expenisve
51
Problems with kidney transplant?
-Kidney rejected
-Imunnosuppresents hieghten suseptibility to other diseases
-Not enough donors
