Topic 7 - Animal coodination, control and homeostasis Flashcards
Where are hormones produced
In endocrine glands which release into blood stream
What is the general role of hormones in the body
They control things in organs and cells that need constant adjustment
How are hormones transported around the body
They are chemical messengers released directly into the blood
What is produced by the pituitary gland
Produces many hormones that regulate body conditions
Master gland as hormones created act on other glands directing them to release hormones which create change
What is produced by the Thyroid gland
Produces thyroxine- regulate metabolism heart rate and temperature
What is produced by the Ovaries
Oestrogen- controls mentrual cycle
What is produced by the Adrenal Gland
Adrenaline- prepare body for fight or flight
What is produced by the Testes
Testosterone- controls puberty and sperm production in males
What is produced by the Pancreas
Insulin which regulates blood glucose concentration
How does adrenaline prepare body for fight or flight
Activates processed that increase supply of oxygen and glucose to cells by binding to receptors in heart and liver to increase blood pressure glucose concentration and respiration
What does your brain send in stressful situation
nervous impulses to adrenal gland to secrete adrenaline
What is a metabolic rate
The speed chemical reactions occur in the body
What is the effect of thyroxine on metabollic rate? and a negative feedback system
When thyroxine level is too LOW, hypothalamus releases TRH which stmulate the pitauitary gland making TSH which stimulates the release of thyroxine to get level in blood back to normal
If too HIGH the release or TRH from the hypothalamus is inhibited, which reduces production of TSH so blood thyroxine level falls
What is a negative feedback system
When body detects level of substance has gone above of below the normal it triggers a response to bring it back down to normal again. eg Thyroxine
What happens in the menstrual cycle
Stage 1- menstruation - Lining of uterus breaks down and is released
Stage 2- uterus lining is repaired (4-14) becomes thick layer of blood vessels
Stage 3- day 14 is ovulation egg released from ovary
Stage 4- lining (endometrium) is maintained until day 28 if no fertilised egg landed on uterus by then lining breaks down
What does Oestrogen do in the menstrual cycle
Causes uterus lining to thicken and grow
high level stimulates LH surge
What does progesterone do
released by corpus luteum after ovulation it maintains lining of uterus
when low level lining breaks down
How can barrier methods be used as contraception
condoms stop the sperm meeting the egg and fertilising it.