Topic 7 - Animal Coordination, Control & Homeostatsis Flashcards
Hormones
- Chemical Messenger
- Stimulates a process to occur
- Secreted by glands
Endocrine Glands:
- Pituitary Gland (Brain)
- Thyroid Gland (Throat)
- Pancreas (Centre of Bod)
- Adrenal Gland (On top of Kidneys)
- Testes
- Ovaries
How Hormones are Transported:
- Hormones travel through blood to target cell
- They bind to cell’s receptors
How does adrenalin prepare the body for fight or flight
- increased heart rate
- increased blood pressure
- increased blood flow to the muscles
- raised blood sugar levels
How does thyroxine controls metabolic rate as an example of negative feedback?
- Low levels of thyroxine stimulates production of TRH in hypothalamus
- This causes release of TSH from the pituitary gland
- TSH acts on the thyroid to produce thyroxine
- When thyroxine levels are normal thyroxine inhibits the release of TRH and the production of TSH
Menstrual Cycle: Stage 1
- Day 1-7, Menstruation
↑FSH ↓Oestrogen
Menstrual Cycle: Stage 2
- Day 7-14, Uterus Rebuilding
↑LH ↓Progesterone
Menstrual Cycle: Stage 3
Day 14, Ovulation
↑Oestrogen ↓FSH ↓LH
Menstrual Cycle: Stage 4
Day 14-28, Uterus Maintained
↑Progesterone ↓FSH ↓LH
How does hormonal contraception influence the menstrual cycle and prevent pregnancy?
- Pill contained Progesterone
- Uterus is maintained, no ovulation, no egg is fertilised
Factors of Barrier Contraception:
+ Prevents STIs
+ Immediate effectiveness
- Can break
- Can be hard to apply
Factors of Hormonal Contraception:
+ Provide long-lasting protection
+ Very effective
- Doesn’t protect against STIs
- Has side effects like irregular vaginal bleeding
Hormones in IVF:
- Ovarian stimulation
- Triggers ovulation
Hormones in Clomifene therapy
- Ovulation stimulation
- Timing intercourse
Why is homeostasis important?
- Ensures reactions in the body cells can function
Why is homeostasis important specifically for thermoregulation?
- So enzymes can function in metabolism
Why is homeostasis important specifically for osmoregulation?
- Uneven water:salt ratio can cause cells to burst or shrivel
What is the role of the dermis?
- Allows for vasodilation and constriction
What is the role of the epidermis?
- Acts as a protective barrier
What is the role of the hypothalamus?
- Regulates temperature with negative feedback
- Acts as a thermostat
Why is shivering a feature of thermoregulation?
- Muscles contract, so respiration (an exothermic reaction) takes place, which releases heat energy
Why is vasoconstriction a feature of thermoregulation?
- When cold, vessels narrow to prevent heat energy emissions from blood to skin
Why is vasodilation a feature of thermoregulation?
- When hot, blood vessels expand to allow blood to emit heat from the skin
How does insulin control blood glucose level?
When BG is HIGH:
- Insulin binds to cells to cause blood to be absorbed
- The glucose in blood is converted to glycogen
How does glucagon control blood glucose level?
When BG is LOW:
- Stimulates cells to breakdown glycogen into glucose
Type 1 Diabetes:
- what is it
- how its controlled
- Pancreas cannot produce insulin
- Inject insulin, exercise and diet
Type 2 Diabetes:
- what is it
- how its controlled
- Insulin cannot bind to cells
- Low sugar diet and exercise
Correlation between BMI and Type 2 Diabetes:
Higher BMI, higher Type 2 Diabetes chance
Correlation between waist:hip ratio and Type 2 Diabetes:
The bigger the circumference of the waist relative to the hip, the higher chance of getting Type 2 Diabetes
Ultrafilteration
- Occurs between Glomerulus and Bowman’s Capsules
Filters molecules like: - Urea
- Glucose
- Water
- Salts
And forms a filtrate
Reabsorption - Water
- Collecting Duct reabsorbs water due to osmosis (water:salt concentration)
Reabsorption - Glucose
- Proximal convoluted tubule causes reabsorption in order to regulate blood glucose levels
Kidney Function:
- Filter blood to remove waste and excess substances
Ureters Function:
- Transport urine from the kidneys to the bladder using muscle contractions.
Bladder Function:
- Store urine until it’s ready to be expelled from the body during urination.
Urethra Function:
Carry urine from the bladder to outside the body during urination
ADH
- Higher ADH causes higher permeability in collecting ducts for water. allowing for more reabsorption
Kidney Dialysis
- Artificial method of filtering the blood with a machine out of the body
- Machine contains glucose and salt concentration similar to that in the blood
Organ Donation advantages:
- Freedom
- Less restricted diet
- Cheaper then kidney dialysis
- Long term
Organ Donation disadvantages:
- Immune response can occur
- Immunosuppressant drugs may be used
- Not enough donors
What creates urea?
- Excess amino acids in the liver
