B5 Homeostasis and response Flashcards
What is homeostasis?
The ability for an organism to regulate internal conditions even if outside conditions change. For example, water levels and temperature.
What makes up the Nervous System?
CNS and PNS.
What is a receptor?
Something which reacts to a stimulus e.g. a hot stove.
What is an effector?
Something that causes you to react to the stimulus e.g. moving your hand away.
What is a reflex arc?
A signal which bypasses the brain and goes straight to the spinal cord - this is much quicker.
What are glands?
Secrete chemicals.
What are the different parts of the brain?
Cerebral cortex, cerebellum and medulla oblongata.
What does the cerebral cortex do?
memory, speech and problem solving.
What does the Cerebellum do?
motor skills: movement, balance and coordination.
What does the Medulla Oblongata do?
unconscious actions: heart and breathing rate, signals to adrenal glands to release adrenaline.
How can you see the activity in the brain?
MRI scans.
what happens when we see an object from far away?
Ciliary muscles relax, Suspensory ligaments tighten and the lens is thin.
What happens when we see something up close?
Ciliary muscles contract, suspensory ligaments slacken and there is a thick lens.
What does the pupil do?
Pupil can change shape depending on the amount of light.
What is Myopia?
Short-sightedness
What is Hyperopia?
Long-sightedness.
What is thermoregulation?
Body controlling its internal temperature.
What happens when we are too hot?
Sweat glands produce water which evaporates, taking away heat. Blood vessels dilate: vasodilation.
What happens when we are too cold?
Hairs stand on end to trap air (layer of insulation), shivering - muscles produce more heat, blood vessels contract - vasoconstriction.
What is the Endocrine system?
A system of glands that secrete hormones to send signals to effectors, transported via blood.
What is the Pituitary gland?
‘master’ gland. It sends signals to other glands.
What is the Thyroid gland?
Controls growth, metabolism and more.
What does the Pancreas do?
Secretes insulin (and glucagon) to control blood sugar.
What does the Adrenal gland do?
Release adrenaline.
What do the ovaries do?
release eggs and secrete hormones.
What do the testes do/
produce sperm.
What happens when there are high blood glucose levels?
- pancreas secretes insulin.
- causes glucose to move from bloodstream into cells to be used for respiration.
- excess glucose converted into glycogen as energy store.
What happens if there is low blood glucose levels?
- pancreas secretes glucagon.
- causes liver and muscles to convert glycogen back into glucose.
What is type 1 diabetes?
- pancreas cannot produce enough insulin.
- insulin injections needed.
What is type 2 diabetes?
- cells do not absorb glucose as they should.
- obesity increases risk.
What hormone causes the storage carbohydrate to break down back into glucose?
Glucagon
What carbohydrate can be stored?
Glycogen
Other than injecting insulin, what is another way a diabetic person could help control their concentration of glucose in the blood?
Limit intake of simple carbohydrates.
What is the function of testosterone?
Regulate sex drive, produce sperm and red blood cells.
What is FSH?
Produced in pituitary gland, causes egg to mature in the ovaries, stimulates ovaries to release oestrogen
What is Oestrogen?
Produced in ovaries, causes uterus lining to grow, stimulates release of LH.
What is LH?
Produced in pituitary gland, stimulates release of an egg at day 14.
What is Progesterone?
Produced in ovaries, maintains lining of uterus, inhibits release of LH and FSH
What is the system for classifying humans?
Species, genus, family, order, class, phylum, kingdom
Who created classification?
Carl Linnaeus
What is involved in the Carbon cycle?
Death and decomposition, CO2 in atmosphere, photosynthesis, fossil fuels, combustion, cellular respiration.
