Flashcards in Topic 5 - Homeostasias And Response Deck (109):
What is a stimulus?
Change in environment
What is negative feedback?
Do the opposite
What is positive feedback?
Do more (i.e womb open)
What is a CNS?
Central nervous system; co-ordinates a response
Where is the CNS?
Brain and spinal chord
What are effectors?
Muscles that respond
What is a synapse?
A gap between neurones that connects them by diffusing chemicals to set off a signal
What is the process of normal responses?
Relay neurone (CNS)
What does a reflex arc do?
It only goes to spinal chord before going to the effector. Is faster.
What is the brain made of?
Billions of interconnected neurones
What is the cerebral cortex and where is it?
Wrinkly: controls consciousness, intellect, memory, lang
Front of brain
What and where is the medulla?
Controls unconscious activity
Front opposite spinal chord lump
What and where is the cerebellum?
Above spinal chord at the bak and is in a special circle
How can we study the brain?
Where it gets damaged and what is affected
Stimulate with electricity
MRI scan when doing things
What does the optic nerve do?
Carry impulses from receptor to brain
What does the lens do?
Focus light on to retina
What happens when there is too much light?
Circular muscles in iris contract, Radial relax
What happens when there is too little light?
Radial muscles in iris contract, circular relax
What happens when focusing on far away objects?
Ciliary muscle contract, lens becomes fat and more refraction happens. Suspensory relax.
What happens when focusing on far away objects?
Suspensory ligaments contract, the lens becomes thin and refracts less, ciliary relax
What is hyperopia?
Unable to focus on near objects
Lens wrong shape/Eyeball too short
Images focus behind retina
Convex to fix
What is myopia?
Unable to focus on distant objects
Lens wrong shape/eyeball too long
Refract too much
Image focus in front of retina
Concave lens to fix
What is long sightedness?
What is short sightedness?
How can you treat vision defects?
Laser eye surgery
Replacement lens surgery
What part of the brain keeps body temp constant?
What is vasoconstriction?
When skin capillaries close
What does working agnostically mean?
Both sides of the negative feedback work together to stay constant
What are hormones
Chemical molecules released directly to blood
What do hormones do?
Control things in organs that need constant adjusting
What is body temp?
Where are hormones produced?
What are the gland you need to know?
Tell me about pituitary gland
Many hormones that regulate body temp
Hormones released act on other glands to make diff hormones
What does the Thyroid do
Regulate metabolism rate, HR and temp
What does the Adrenal gland do
Fight or flight
What does the Pancreas make
Insulin and glucagon
What do Ovaries release
What do Testes control
What are insulin and glucagon?
What can remove glucose from the blood?
Metabolism of cells
What controls the blood glucose level?
What happens when there is too much blood sugar?
Insulin secreted from pancreas to blood
Blood goes to liver
Liver turns excess glucose into glycogen
What happens when there is too little blood sugar?
Glucagon from pancreas into blood
Blood goes to liver
Liver thens glycogen to glucose
What is type one diabetes?
Produce little/no insulin
What is type 2 diabetes?
Resistant to insulin
How can you manage type 1 diabetes?
How can you treat type 2 diabetes?
Where is waste filtered out?
What's the name for filtering out useful products
What gets filtered out of the kidneys?
What is extracted from Urea?
Ammonia turns into urea via kidneys
What is extracted from ions?
Kidney absorbs what it needs and discards the rest
What is lost in sweat?
Unregulated amounts of water, Ions and urea
What is extracted from water?
Kidneys remove excess
What is the conc of water in urine controlled by?
Where is ADH produced?
What monitors water content?
Is the balance of water negative or positive feedback?
What does puberty do?
Releases sex hormones that trigger secondary sexual characteristics
What's a secondary sexual characteristic?
Boobs or stubble
Day one of menstrual cycle
Uterus lining breaks for four days
Day 4-14 of menstrual cycle
Thick layer full of blood vessels builds on lining
Day 14 of menstrual cycle
Day 14-28 of menstrual cycle
What is FSH
Where is FSH produced
What does FSH do?
causes egg to mature in follicle
Stimulates ovaries to make Oestrogen
What does Oestrogen do?
causes uterus to grow
Stimulates release of LH and inhibits FSH
Where is oestrogen made?
What does Progesterone do?
maintains lining is second half of cycle - if it falls the lining does too
Inhibits FSH and LH
What is LH?
Where is LH produced?
What does LH do?
stimulates egg release (day 14)
What happens during dialysis?
blood flows through a partially permeable membrane in dialysis fluid
Same conc as blood
Waste substances diffuse
3 times a week for 3-4 hours
What are methods of dealing with kidney failure?
If you have lots of oestrogen what happens?
inhibits FSH and stops egg from maturing
how does progesterone stop pregnancy?
creates a thick mucus to stop sperm from reaching egg
What two hormones can be used to stop pregnancy?
Progesterone and Oestrogen
what is 'the pill' made from?
progesterone and oestrogen
how effective is 'the pill'
What are the side effects of the pill?
what else can the pill be made from?
what are the advantages of a progesterone only pill?
same effectiveness, less side effects
What is in the patch and how long does it last?
oestrogen and progesterone. Lasts 1 week
What's in an implant and how long does it last?
progesterone. Three years
What's in a pregnancy prevention injection? How long does it last?
progesterone. Lasts two weeks
What types of IUD can you get?
plastic and copper
What does a plastic IUD do?
has progesterone to create a thick mucus
What does a copper IUD do?
What is an IUD?
Intrauterine device: T shaped insert
What are barriers for pregnancy prevention?
condom, diaphragm (cup), spermicide
Completely stop pregnancy?
sterilisation, avoid fertile days, abstinence
What are the problems with giving out hormones to increase fertility?
Too many kids
Where are the adrenal glands?
above the kidneys
What does adrenaline do?
Where is the thyroid gland?
What stimulates the Thyroid gland?
thyroid stimulating hormone (TSH)
Where is Thyroid simulating hormone produced?
What is phototropism?
When something responds to light
What is geotropism?
when something responds to gravity
what is gravitropism?
What do auxins do?
Stimulate growth in tips of shoots and in roots
What happens if there is light on one side of the shoot of a plant?
Auxins move to the dark side and stimulate growth so it bends towards the light
What happens when a root grows sideways?
Gravity pulls the auxins down and they inhibit growth
What are auxins?
hormones that simulate growth in plants
What else can we use auxins for?
Growing cells in tissue culture
Growing from cutting with rooting powder
Killing weeds with broad leaves
What can Gibberellin be used for?
grow larger fruit