Animal Coordination, Control and Hormones Flashcards
Hormone definition
Chemical released directly into blood
Controls things in organs and cells that need constant adjustment
Produced in the endocrine glands
Pituitary gland facts
Produced many hormones that regulate body conditions
“Master gland” as hormones released act on other glands
Thyroid gland facts
Produced thyroxine
Controls metabolism, heart rate and temperature
Ovaries facts
Female only
Produced oestrogen involved in menstrual cycle
Adrenal glands facts
Produces adrenaline
Prepares body for “fight and flight” responses
Testes facts
Produces testosterone
Controls livery and sperm production in males
Pancreas facts
Produced insulin
Regulates blood glucose levels
Differences between hormones and neurones
Slower action
Act for a long time
Act in a more general way / larger area
Adrenaline facts
Hormone released by adrenal glands
Prepares body for “fight or flight response”
How adrenaline increases heart rate, blood pressure and rate of respiration
Binds to specific receptors in the heart, causing heart muscles to contract more frequently and harder
Also increased blood flow to muscles, so cells receive more oxygen and glucose for respiration
How adrenaline increases blood glucose levels
Adrenaline binds receptors in liver
Causes liver to break down glycogen stores to release glucose into the blood
How metabolism is regulated using negative feedback
When blood thyroxine level is lower than normal, hypothalamus releases TRH (thyrotropin)
TRH stimulates pituitary gland to release TSH (thyroid stimulating hormone)
TSH stimulates thyroid gland to release thyroxine so blood thyroxine levels become normal
If blood thyroxine levels are higher than normal, release of TRH then TSH then thyroxine falls
Menstrual cycle Stage 1
Day 1
Lining of uterus breaks down and is released
Menstrual cycle Stage 2
Day 4 to 14
Uterus lining is repaired, until it becomes a thick spongy layer full of blood vessels, ready for a fertilised egg
Menstrual cycle Stage 3
Day 14
Egg develops and is released from ovary (ovulation)
Menstrual cycle Stage 4
Day 14 to 28
Lining is maintained until day 28
If no ferris tied egg has landed, menstrual cycle restarts
FSH facts
follicle-stimulating hormone
Released by pituitary gland
Causes a follicle to mature in ovaries
Stimulates oestrogen production
follicle definition
egg cell and it’s surrounding cells
Oestrogen facts
Released by ovaries
Causes uterus lining to thicken and grow
High level stimulates LH surge