Year 13 Mrs Winters Key Terms Flashcards
Actin
Thin filaments in proteins which bind with myosin in muscle contraction
Actinomyosin bridge
Formation when myosin head binds to actin
Action potential
When an axon membrane is depolarised and stretch mediated sodium ion channels open diffusing sodium ions across the membrane
All or nothing principle
Threshold intensity generates an action potential. Action potential always the same size. Strong stimuli creates more frequent action potentials.
Antagonistic
Opposed
Atrioventricular node
Mass of conducting cells in atrioventricular junction of heart
Responsible for passing waves of electical activity onto bundle of his during heart beat
Bundle of his
Group of muscle fibres responsible for conduction the waves of electrical activity between ventricles and bottom of heart
Chemoreceptors
Monitor carbon dioxide in blood located in aorta and carotid arteries. Allow body to know if heart rate needs to increase or decrease.
Cholinergic synapse.
A junction between two neurones which uses acetylcholine as it’s neurotransmitter
Cones
Receptors which give colour vision. They absorb high light intensity, bright light. They have low sensitivity so if not enough light they will not work. They give high acuity
Acuity
Resolution
Depolarisation
Process which must happen to produce an action potential. Where the axon charge is more positive on inside than outside
Fast muscle fibres
Used for short bursts of activity. Quick to fatigue. Fast contraction causing more force. Fewer blood vessels and mitochondria. Low conc of myoglobin. High conc of glycolysis enzymes and atp hydrolyse
Generator potential
A local change in resting potential from a stimulus which may result in an action potential occurring
Moron neurone
Transfers electrical impulse from relay neurone to effector
Myelinated neurone.
Axons which have myelin on around membrane. Allowing for Saltatory conduction- jumping from node of ranveir
Myofibril
Tightly packed proteins bundled together in muscle
Myosin
A quaternary protein that has a coiled structure of two proteins intertwined on tail and then a head with a short and long chain
Myoglobin
Stores oxygen in muscle
Neuromuscular junction
Junction between a motor neurone and an effector muscle
Non myelinated neorun
Neurone with no myelin around it’s membrane preventing impulse from jumping between each node of ranvier. Causes impulse speed to be much slower
Pacinian corpuscle
A mechanoreceptor which responds to pressure causing a distortion in membrane of naked axon causing sodium ions to diffuse through stretch mediated sodium ion channels. Creating an action potential
Phosphcreatin
Molecule used to phosphrilate ADP to ATP in muscle contraction
Purkyne tissue
Carries wave of electrical activity from bundle of his to muscular walls in ventricles causing them to contract allowing heat beat
Receptor
Chemical structures which respond to stimulus
Refractory period
Time delay between the conduction of one action potential and the next. Ensures no overlapping of impulses and that no impulse can travel backwards.
Rods
Receptors which give black and white vision. Work in low light intensities. Have high sensitivity meaning don’t need much energy to form and image. Results in low acuity