⭐️SB7- Animal Coordination, Control And Homeostasis Flashcards
What is metabolic rate?
Rate at which energy stored in food is transferred by all reactions that happen in the body
What is resting metabolic rate?
Metabolic rate that’s measured when the body’s at rest, in a warm room long after a meal
Name a hormone that effects metabolic rate
Thyroxine as it changes how certain cells work e.g. causing heart cells to contract more strongly
Where is thyroxine released from?
The thyroid gland
What’s negative feedback?
When an action directly triggers an opposite response
How is control of thyroxine level in the blood an example of negative feedback?
As an increase in thyroxine concentration directly causes a change that brings about a decrease in the amount of thyroxine released into the blood
What is homeostasis?
The constant maintenance of internal conditions to maintain optimal conditions for cellular reactions.
What are hormones?
Chemical messengers that take time to get around the body and are transported by the blood to their target organs
What processes require transfer of energy when the body is at rest?
Respiration, digestion, heart rate, mitosis e.c.t
How are thyroxine and metabolism linked?
It is produced when metabolism needs to be higher
What hormone does the hypothalamus make?
TRH
What hormone does the pituitary gland make?
TSH
What does TRH do?
It triggers the pituitary gland to make TSH
What does TSH do?
It triggers the thyroid gland to release thyroxine which goes to its target organs
What hormone do the adrenal glands release and where are they located?
Adrenalin, glands located above the kidneys
What are the three target organs of adrenaline?
The liver, the heart and the blood vessels
What does adrenaline do to the liver?
Causes breakdown of glycogen and when broken down, glucose molecules are released into the body for respiration
What does adrenaline do to the heart?
Causes the heart muscles to rapidly contract, increasing heart rate and pressure of blood flow
What does adrenaline do to the blood vessels?
Either widens the diameter to increase blood flow
Or narrows the diameter to reduce blood flow to muscles increasing blood pressure
Why is it important for adrenaline to trigger liver cells into changing glycogen to glucose?
As it increases blood sugar concentration and can then be used in respiration as energy
How long in a menstrual cycle cycle?
28 days
What happens at the start of the menstrual cycle?
Menstruation that lasts from 3-7 days
What is FSH?
A hormone produced just after menstruation, by the pituitary gland.
What does FSH do?
Matures the edges in the ovaries and stimulates the follicles to produce oestrogen
When does ovulation occur?
Day 13-15
When is a woman most likely to get pregnant?
After the ovary releases the egg in ovulation : between day 16-20 of her cycle
What does increasing oestrogen after being triggered by FSH cause?
The LH hormone surges causing the dominant follicle to rupture and releasing a mature egg from the ovary into the Fallopian tube
What happens to the empty follicle after the LH surge causes the egg to be released?
Progesterone is produced by the follicle inside the ovary
What does progesterone cause?
Further build up in the lining of the womb in preparation for a fertilised egg
What happens at the end of the cycle if the egg isn’t fertilised?
The follicle shrinks, progesterone decreases causing the uterus lining to break down and shed and menstruation starts again
For oestrogen:
Where is it produced?
When is it produced?
What does it trigger?
- produces by the follicles in the ovaries
- at around the middle of the menstrual cycle
- triggers the LH hormone to surge and inhibits FSH
How does a diaphragm or cap prevent fertilisation?
As it’s placed over the cervix and prevents sperm entering the vagina
How does the hormone pill prevent fertilisation?
It releases hormones to prevent ovulation and thickens mucus at the cervix making it hard for sperm to pass through
Why does the pill have a lot of oestrogen?
Use knowledge of hormones to explain
As oestrogen inhibits FSH so no eggs will be matured
What is IVF?
Invetro fertilisation which stands for fertilisation in a Petri dish
When may a couple find it hard to have children?
When a woman is Lowe on oestrogen, when there’s a lack of FSH, if the male has a low sperm count e. c.t
What is Assisted Reproductive Technique? (ART)
A technique that uses hormones and other techniques to increase chances of getting pregnant
Name some ART techniques
Clomifene therapy and IVF
What is clomifene therapy?
A drug that helps increase the concentration of FSH and LH in the blood for women that rarely or never release an egg in the menstrual cycle
What problems can IVF overcome?
Blocked oviducts in the woman, low sperm count for makes
What are the steps to IVF?
- Egg follicle maturation stimulated by hormones
- Egg cell released by follicles taken from ovary
- Sperm cells taken from man
- Egg and sperm combined in Petri dish
- If fertilised, one/two embryos placed in uterus
For LH,
Where is it produced?
When is it produced?
What does it trigger?
Produced in the pituitary gland, middle of the cycle around day 14 and triggers ovulation by causing the dominant follicle to rupture releasing a mature egg
For progesterone,
Where is it produced?
When is it produced?
What does it trigger?
Made by the empty follicle around day 22 of the cycle, causes the uterus lining to thicken in preparation for the fertilised egg
What can urine tests do?
Test for pregnancy and diseases like diabetes