B11 Hormonal Control Flashcards
What is a hormone
A chemical substance that helps to regulate a process innthe body
What does the hormone insulin do
Controls your blood glucose
What does the hormone adrenaline do
Prepares your body for fight or flight
How do hormones travel around the body
The blood carries hormones to target organs where it produces an effect
How do the effects of hormone differ from electrical impulses from the nervous systerm
Hormones can act rapidly, but compared to the neevous system, the effects are slower, but longer lasting
What is the endocrine system
The collection of glands that produce hormones
Why do we need to regulate blood sugar
Glucose is used in respiration in cells to carry out many functions
Why is it important that there is not too much sugar in the blood
Water would leave the cells by osmosis
Why is it important that there is not too little sugar in the blood
There would not be enough respiration
What does the pancreas do in the process of controlling blood sugar level
It controls and monitors the level of glucose in the blood using insulin and glucagon
How do insulin make your blood sugar drop
Your blood sugar increases after eating a meal
Your pancreas secretes insulin
Insulin allows glucose to move from your blood into your cells
Glucose also may be converted into glycogen ( insoluble carbohydrate )
Glycogen is stored in the liver and muscles ( this can be converted into glucose if needed )
If glycogen stores are full then glucose is converted into lipids and stored ( can lead to obesity )
How does glucagon increase your blood sugar level
If you dont eat your blood sugar drops Pancreas secretes glucagon Glucagon tells the liver to break down glycogen into goucose Glucose is released into the bloodstream Blood sugar returns to normal
Type 1 diabetes how, who
Pancreas can’t make insulin or caused by an infection but mostly genetic
Effects young people
Type 2 diabetes how, who
Body stops responding to insulin, caused by unhealthy diet
Usually in later age with obesity
What is a negative feedback loop
It helps maintain a steady state in the body
If a factor increases inside the body, a change takes place to restore it to normal
A negative feedback response opposes a change
What is thyroxine
(Made from iodine in your diet ) from the thyroid gland
Stimulates the basal metabolic rate
Plays an important role in growth and development
What is adrenaline
Produced by adrenal glands in times of fear and stress
Increases heart rate and boosts delivery of oxygen and glucose to the brain and muscles
Prepares the body for fight or flight
Once danger has gone, levels return to normal
No negative feedback loop required
What is the negative feedback loop when there is a fall in thyroxine levels
Fall in thyroxine in the blood
Pituitary gland produces more TSH ( thyroid stimulating hormone )
Thyroid gland produces more thyroxine
Normal thyroxine levels
What is the negative feedback loop for a rise in thyroxine levels
Rise in thyroxine in the blood
Pituitary gland produces less TSH
Thyroid gland produces less thyroxine
Normal thyroxine levels
What is the male primary sex characteristic
The testes 🍆
What is the female primary sex characteristic
The Ovaries
What is the main male reproductive hormone and what secondary sex characteristics does it cause ( 9 )
Testorerone:
- Growth spurt
- Pubic hair
- Underarm hair
- Facial hair
- Larynx grows and voice breaks
- External genitalia and the skin around it darken
- Testes grow and become active
- Shoulders and chest broaden
- Muscles develop and brain matures
What is are the main female reproductive hormones and what secondary sex characteristics does it cause ( 10 )
Oestrogen, progesterone Oestrogen causes: 1. Growth spurt 2. Hair under the arms 3. Pubic hair 4. Breasts develop 5. External genitalia grow and skin darkens 6. Female pattern of fat is deposited on the hips, buttocks and thighs 7. Brain matures 8. Mature eggs form every month in the ovaries 9. Uterus grows and becomes active 10. Menstruation ( period ) begins
What two hormones does the pituitary gland produce for females and what are they important for
They are involved in fertility Follicle Stimulating Hormone ( FSH ): causes egg in ovary to mature Luteinizing Hormone ( LH ): stimulates release of the egg at ovulation
How long does the menstruation cycle last for
28 days
What hormones control the menstruation cycle
FSH
LH
Oestrogen
Progesterone
What is the function of progesterone and where is it made
( made in the ovaries, same as oestrogen )
maintains the lining of the uterus ready for pregnancy, if there is no pregnancy then it drops and uterus lining goes
What are the 3 main events in menstruation
Menstruation ( days 1 - 6 )- uterus lining down, blood and cells are lost
Proliferation ( days 6 - 13 )- repair of uterus lining
Ovulation ( day 14 )- release of egg from the ovary
What changes are there in the body for days 6 - 13 of the menstrual cycle
Proliferation
Eggs begin to develop in the ovaries
Uterus lining repairs
FSH causes: new egg to develop, oestrogen release
Oestrogen released causes: a stop in FSH production ( stops eggs producing ), starts LH release, thickens uterus lining
What changes are there in the body for day 14 of the menstrual cycle
Ovulation
Follicle releases the egg in ovary
Uterues lining remains thick
High LH level: causes follicle to burst and release egg into the oviduct
What happens in the ovaries from days 1 - 15
1 - 6: immature eggs
6 - 13: New eggs starts to develop in growing follicle
14: Egg releases from follicle
After 15: Empty follicle becomes corpus luteum ( yellow body ) and egg dies
If pregnancy occurs, what happens to the levels of Oestrogen and Progesterone
They both remain at high levels
This is to maintain the uterus lining, so menstruation does not occur
What is IVF
In Vitro Fertilisatio is a method for generating fertilised embryos outside the body
What are reasons for infertility
Problems with male and female reproductive system ( e.g polycystic ovaries )
Obesity
Eating disorders
Age
What is lack of ovulation
Some women do not mame enough FSH to stimulate maturation kf eggs in ovaries
Artificial FSH can be given as fertility drug, also stimulates oestrogen production
Artificial LH can be given to trigger ovulation
Women who suffer from this can be treated and can go on to have children naturally
When can IVF be used
Fallopian tubes are damaged
A donor is required
No obvious cause for infertility
Man produces little sperm
Steps for IVF
- Fertility drugs are used to make lots of eggs mature at same time fkr collection
- Eggs are collected and placed in special solution in petri dish
- Sample of semen collected and the sperm and eggs are mixed in petri dish
- Eggs are checked to make sure they have been fertilised and early embryos are developing properly
- When fertilised egs have formed tiny balls of cells, 1 or 2 are placed in womb of mother. Then at least one baby will grow and develop successfully
Disadvantages of IVF
Expensive
Not always successful
If sperm is provided by donor, it is nkt father’s biological child
Health risks for mother
Emotionall and physically stressful
Ethical issues for eggs if woman dies, relationship breaks or they change their mind because eggs could be used for stem cells
Advantages of IVF
Gives infertile people the chance to have a baby
Donor sperm from younger man keeps up success rate
Can be collected and stored or fertilised and stored
How does the pill work and positives and negatives
Contains lows doses of Oestrogen and Progerone, innibit release of FSH from pituitary gland, so no eggs mature. Hormones stop uterus lining developing, preventing implantation. Also make cervix mucus thick to prevent sperm getting through
Positive: easy to use
Negative: slight raised blood pressure, chance of thrombosis and breast cancer
How does the implant work and positives and negatives
Small tube under skin, slowly releases progesterone
Positives: 99.95% effective
Negative: only lasts about 12 weeks
How does the condom work and positives and negatives
Latex sheath placed over penis, collects semen and prevents semen from fertilising egg
Positive: no side effects, can protect against some STDs
Negative: easy to break
How does the patch work and positives and negatives
Contains mixure of oestrogen and progesterone, released into blood stream
Positive: effective
Negative: can cause skin irritation
How do intrautrine devices work and positives and negatives
Small structures inserted into uterus by doctor, stop egg from growing ( hostile environment )
Positives: very effective
Negative: can cause infections
How do spermicides work and positives and negatives
Chemicals that kill or disable sperm
Positives: readily available
Negatives: not good at preventing pregnancy
How does abstainance work and positives and negatives
People dont have sex when there is a chance of getting pregnant
Positive: no side effects
Negative: unreliable
