coordination and control test Flashcards
describe a reflex arc
receptor detects…
electrical impulse moves along sensory neurone to relay neurone
neurotransmitters diffuse across synapse
motor neurone to effector, which carries out response (muscle contraction)
what is the central nervous system
consists of the brain and spinal cord (movement and reflexes)
name 3 diff neurones and their purposes
Sensory neurones - carry impulses to central nervous system
Relay neurones - decreases response time between sensory and motor
Motor neurones - carry neurones away from central nervous system, to the effector
what is an effector
usually a muscle, carries out a response
advantages of reflexes
fast, no brain involvement- involuntary, causes less damage/ harm
how does the eye adjust to looking at distant object
Suspensory ligaments contract
Ciliary muscles relax
Lens becomes long and thin (less concave shape)
Less refraction of light
how does the eye adjust to looking at a close object
Suspensory ligaments relax
Ciliary muscles contract
Lens becomes thicker with a more concave shape
More refraction of light
how does the eye adjust to bright light
Circular muscles contract
Radial muscles relax
Iris becomes wider
Pupil constricts, letting less light in
how does the eye adjust to dim/ no light
Radial muscles contract
Circular muscles relax
Iris becomes narrower
Pupil dilates to let more light in
what happens if blood glucose is too high
Pancreas produces the hormone insulin.
Insulin stimulates cells to take glucose in from the bloodstream (particularly from the liver and muscles cells)
In liver and muscle cells excess glucose is converted into glycogen for storage.
what happens if blood glucose is too low
Pancreas produces the hormone glucagon.
Stimulates liver and muscle cells to convert stored glycogen into glucose to be released into the bloodstream, increases the blood glucose levels.
how does the body respond when it is cold
Piloerection - Hair stands on end. Warm air becomes trapped underneath the hairs, creating a convection current that acts as a warm insulating layer.
Vasoconstriction - Arterioles supplying the capillaries near the surface of the skin constrict (get narrower). Less blood flows near the surface of the skin so less heat is lost by radiation.
Less sweat released so less heat lost by evaporation.
how does the body respond when it is hot
Pilorelaxation - Hairs lie flat and so an insulating layer of air isn’t formed. More heat is lost.
Vasodilation - Arterioles supplying the capillaries near the surface of the skin dilate. More blood flows near the surface of the skin, so more heat is lost by radiation.
More sweat is released - When sweat evaporates, heat energy is taken away from the skin as the evaporation of water requires energy.
organ definition
group of different tissues working together to do a specific job
advantages to these 4 things (release of adrenaline)
-pupil dilating
-increase heart rate
-narrows small arteries
-converts glycogen into glucose
- increased visual sensitivity
-more blood to muscles, more oxygen/ glucose to cells
-blood flow to muscles
-more respiration- fight or flight
