Animal Co-ordination, Control And Homeostatis Flashcards
What is a hormone?
Chemical messages produced by endocrine glands and released directly into the blood stream
How does the hormone get to the target organ?
Hormone produced from gland
Diffuses into blood
Blood carries hormone to target organ
Pituitary gland
Produces many hormones
Regulates body conditions
Thyroid gland
Produces thyroxine
Regulating metabolic rate + heart rate
Adrenal gland
Produces adrenaline
Fight or flight
Ovaries
Produces oestrogen
Menstrual cycle
Testes
Produces testosterone
Controls puberty + sperm production
Pancreas
Produces insulin
Regulates blood glucose levels
What does adrenaline do?
Increases heart rate + blood pressure
Because heart muscles contract more rapidly
Increases blood flow to the muscles
Stimulates liver changing glycogen into glucose
(Raises blood sugar levels)
Negative feedback
Body detects level above/below normal level, triggering response, bringing levels back to normal
Negative feedback regulates…
Thyroxine levels
What happens when thyroxine levels are low?
- stimulates TRH production in hypothalamus
- stimulates pituitary gland, realising TSH
- TSH stimulates thyroid gland to release thyroxine
- thyroxine levels increase
What happens when thyroxine levels are too high?
TRH production in hypothalamus is inhibited
Reducing production of TSH
Thyroxine levels decrease to normal level
What happens day 1-5 of menstrual cycle?
Menstruation happens
Lining of uterus breaks down
Because of low levels oestrogen and progesterone
What happens day 5-14 of menstrual cycle?
Uterus lining starts to thicken
Because of oestrogen
What happens day 14 of menstrual cycle?
LH surge stimulates ovulation
What happens day 14-25 of menstrual cycle?
If no fertilised egg has landed on uterus, spongy layer breaks down again
The cycle restarts
Role of FSH
Made in pituitary gland
Helps egg mature before ovulation
Role of oestrogen
Made in ovaries
Causes uterus lining to thicken
Role of LH
Made in pituitary gland
LH surge stimulates ovulation
Role of progesterone
Made in corpus luteum
Maintains lining of uterus
What’s ovulation?
Ovary releases egg
Contraception methods
Hormone (combined pill)
Contraceptive patch
Condom
Diaphram
What does the combined pill + contraceptive patch do?
Releases hormones (oestrogen+progesterone), preventing ovulation
Thickens mucus around the cervix
Prevents sperm reaching the vagina
What does a condom do?
Prevents fertilisation + pregnancy
What does a diaphragm do?
Silicone dome which covers the cervix
Keeping sperm out of he uterus
Success rate for hormonal contraception
99%
Success rate for condom
98%
Success rate for diaphragm
92% - 96%
Cons of hormonal contraception
Headaches
Acne
STI’s
What does ART stand for?
Assisted reproductive technology
Clomifene therapy
Infertile women take the hormone
Causing FSH and LH production, stimulating ovulation
IVF (in vitro fertilisation)
FSH + LH given before egg collection (stimulate egg production)
Egg is collected and fertilised w/ sperm in a lab
Embryo transferred back into uterus
Homeostasis
Maintaining constant internal environment
How can you control blood glucose levels?
Insulin
Glucagon
What do you add if blood glucose levels are too HIGH?
Insulin
What do you add if blood glucose levels are too LOW?
Glucagon
How does insulin balance blood glucose levels?
Pancreas produces insulin
Insulin causes cells to remove glucose form the blood
Liver converts glucose into glycogen + stores it
Homeostasis took place
How does glucagon balance blood glucose levels?
Pancreas releases glucagon into bloodstream
Glucagon triggers liver cells
Converting glycogen stores into glucose
Glucose released into the blood
Diabetes type 1
Pancreas doesn’t work properly
Lack on insulin produced
Diabetes type 2
Pancreas doesn’t produce enough insulin
Symptom of diabetes
Thirsty
Hunger
Fatigue
Urination
Loss of weight
Treatment for type 1 diabetes
Insulin injection before meals
Treatment for type 2 diabetes
Balanced diet
Exercise
What’s the correlation between obesity and type 2 diabetes?
People whom are obese are more likely to become diabetic
What is classed obese?
BMI = over 30
BMI
Mass / (height)2