Topic 7 - Animal Coordination, Control and Homeostasis Flashcards
What is a hormone?
A chemical messenger sent in the blood
What is an endocrine gland?
A gland that produces a hormone
Name 6 endocrine glands and the hormones they produce:
- Pituitary Gland: Many hormones
- Thyroid Gland: Thyroxine
- Pancreas: Insulin
- Adrenal Glands: Adrenalin
- Ovaries: Oestrogen
- Testes: Testosterone
What are the three differences between neurones and hormones?
- Neurones are very fast, hormones are slower
- Neurones last a short time, hormones last a long time
- Neurones are very specific to an area, hormones are more general
What does adrenalin prepare you for?
‘Fight or Flight’
How does adrenalin work?
- Binds to receptors on heart, causing more constrictions, so heart rate and blood pressure increase
- Binds to receptors on liver, causing glycogen to break down into glucose, increasing blood sugar levels
What is the purpose of a negative feedback system?
To keep the amount of a hormone in the blood at the correct/safe level
What does thyroxine regulate?
Metabolism
How does thyroxine work?
- When it is at a low level, the hypothalamus is stimulated to produce TRH
- TRH stimulates the pituitary to release TSH
- TSH stimulates the thyroid to release thyroxine
- When the level of thyroxine is too high, the hypothalamus’ production of TRH is inhibited
How long is the menstrual cycle?
28 days
How many stages are in the menstrual cycle?
4
How long does each stage of the menstrual cycle last?
- Stage 1: Day 1 - Day 4
- Stage 2: Day 4 - Day 14
- Stage 3: Day 14
- Stage 4: Day 14 - Day 28
What 4 hormones control the menstrual cycle?
- FSH
- LH
- Oestrogen
- Progesterone
How can infertility be controlled?
- Clomifene therapy: Causing more FSH and LH to be produced, causing ovulation
- IVF: Collecting eggs and fertilising them in the lab, before putting them back into the woman
What are the hormonal methods of contraception?
- Taking oestrogen every day to prevent egg maturation
- Taking progesterone stops sperm reaching the egg
- Contraceptive pill (oestrogen and progesterone)
- Contraceptive injection (progesterone)
What are the physical barrier methods of contraception?
- Male Condom
- Female Condom
- Diaphragm
What is homeostasis?
Maintaining a constant internal environment
Give 3 examples of homeostasis:
- Osmoregulation
- Thermoregulation
- Blood glucose regulation
What 2 hormones control blood glucose levels?
- Insulin
- Glucagon
How are blood glucose levels controlled?
- If it is too high, insulin is added, which makes the liver turn glucose into glycogen
- If it is too low, glucagon is added, which makes the liver turn glycogen into glucose
What is the main difference between type 1 and type 2 diabetes?
- Type 1 is caused by a lack of insulin
- Type 2 is caused by a resistance to insulin
How can type 1 diabetes be treated?
- Insulin therapy
- Taking regular exercise
What is the correlation between obesity and type 2 diabetes?
People who are obese (BMI > 30) are at higher risk of type 2 diabetes
How can type 2 diabetes be treated?
- Healthy diet
- Regular exercise
- Losing weight
