Topic 7- Animal Coordination, Control And Homeostasis Flashcards
(100 cards)
Hormones
Chemicals released directly into the blood affecting particular cells in target organs to control organs/cells need for constant adjustment.
What system is involved in the secretion of hormones?
The endocrine system
What glands produce hormones?
Endocrine glands
Examples of endocrine glands
The pituitary gland Thyroid gland Adrenal glands Ovaries Testes Pancreas
Pituitary gland
Location and function
Located in brain
master gland
Produce many hormones regulating body conditions and acting on other glands to release hormones that bring about change.
Thyroid gland
What does it produce?
THYROXINE (controlling metabolism, heart rate, temperature)
Ovaries
What do they produce?
OESTROGEN (involved in menstrual cycle)
Testes
What does it produce?
TESTOSTERONE (controls puberty and sperm production)
Adrenal glands
What does it produce?
ADRENALINE (prepares body for ‘fight or flight’ response)
pancreas
What does it produce?
INSULIN (regulates blood glucose levels)
Difference between hormones and neurones
Neurones = fast while hormones = slow action
Neurones= short time while hormones= long lasting
Neurones act on precise area while hormones act in a general area
Where are adrenal glands located?
Just above kidneys.
How does adrenaline prepare your body for, ‘flight/fight’?
Binds to specific heart receptors, causing heart muscle to contract more frequently w more force so heart rate/blood pressure increase.
Increases blood flow to muscles (more oxygen/glucose for respiration)
Also binds to receptors in liver, causing liver to break down glycogen stores and release glucose, increasing blood glucose level
What does your brain do when it detects a stressful situation
Sends nervous impulses to the adrenal glands which secrete adrenaline.
How does the body uses negative feedback systems?
When it detects a substance level has gone above/below the normal level, it triggers a response to bring the level back to normal again.
Metabolic rate
The speed at which chemical reactions in the body occur.
What happens when your blood thyroxine level is lower than normal?
The hypothalamus is stimulated to release THYROTROPIN RELEASING HORMONE.
What does thyrotropin releasing hormone do?
Stimulates the pituitary gland to produce thyroid stimulating hormone which stimulates the thyroid gland to release thyroxine so the thyroxine level rises back to normal.
What happens when the blood thyroxine levels are higher than normal?
TRH production in the hypothalamus is inhibited .
The menstrual cycle
The monthly sequence of events in which the female body releases an egg and prepares the uterus in case the egg is fertilised.
Stage 1 of menstrual cycle
Uterus lining breaks down and is released
Uterus lining
Endometrium
Stage 2 of menstrual cycle
Uterus lining is repaired (day 4 to 14)
Until becomes spongy layer of blood vessels ready for fertilised egg to implant there.
Stage 3 of menstrual cycle
Egg develops and is released from ovary
Ovulation
Day 14