Brain Parts + Functions
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Cerebrum- largest, (Frontal lobe) responsible for conscious mind, memories, emotions, personality, initiates movements. (Parietal lobe) temperature, touch, pain. (Temporal lobe) hearing and smelling. (Occipital lobe) vision.
Corpus Callosum- connects left and right hemispheres, conducts impulses from one side to other
Thalamus- sorting centre, information to appropriate channels to prevent sensory overload
Hypothalamus- above pituitary gland, controls hunger thirst, sleep, body temperature, water balance, homoeostasis, motor and endocrine control.
Cerebellum- rear, lower, butterfly shaped, second largest part, controls muscle coordination, muscle tone, balance, posture.
Medulla Oblongata- brain stem between brain and spinal cord, controls vomiting, coughing, sneezing, swallowing, heart beat, breathing and blood pressure
Corpus Callosum- connects left and right hemispheres, conducts impulses from one side to other
Thalamus- sorting centre, information to appropriate channels to prevent sensory overload
Hypothalamus- above pituitary gland, controls hunger thirst, sleep, body temperature, water balance, homoeostasis, motor and endocrine control.
Cerebellum- rear, lower, butterfly shaped, second largest part, controls muscle coordination, muscle tone, balance, posture.
Medulla Oblongata- brain stem between brain and spinal cord, controls vomiting, coughing, sneezing, swallowing, heart beat, breathing and blood pressure
Nervous System
Fight or Flight Response
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Noradrenalin from sympathetic neurons cause adrenal glands to release adrenalin. Prepare body for fight or flight.
-heart rate up
-increase blood pressure
-passage for air open
-contraction of muscles
-dilation of eyes for maximum visual alertness
-blood to muscles
-decrease blood to digestion
-heart rate up
-increase blood pressure
-passage for air open
-contraction of muscles
-dilation of eyes for maximum visual alertness
-blood to muscles
-decrease blood to digestion
Nerve
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Dendrite- conduct a nerve impulse (message) towards cell body.
Cell Body- contains nucleus and cell organelles to keep cell alive, passes impulse from dendrite to axon.
Axon- conduct nerve impulse away from cell body.
Myelin Sheath- protective coating of Schwann cells and speeds up impulse.
Nodes of Ranvier- interrupted area on Myelin Sheath to speed up impulse.
Synaptic Terminal- end, neurons signal each other, or non-neuron cells such as muscles
Cell Body- contains nucleus and cell organelles to keep cell alive, passes impulse from dendrite to axon.
Axon- conduct nerve impulse away from cell body.
Myelin Sheath- protective coating of Schwann cells and speeds up impulse.
Nodes of Ranvier- interrupted area on Myelin Sheath to speed up impulse.
Synaptic Terminal- end, neurons signal each other, or non-neuron cells such as muscles
Nerve Impulse
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Resting- no signal is being transmitted. sodium potassium pump is active, maintains resting potential.
Action- when stimuli is being transmitted Na+ gates open, known as upswing (depolarization)
Depolarization- (upswing) Na+ rushes in -60mV to +40mV. Interior axoplasm is positive.
Repolarization- (downswing) K+ gates open exit axoplasm.
Recovery Period- active transport where Na/K pump Na+ out and K+ in. Refractory period where action potential cannot occur.
Threshold- all or nothing response, its the amount of stimulation required to create a response.
Action- when stimuli is being transmitted Na+ gates open, known as upswing (depolarization)
Depolarization- (upswing) Na+ rushes in -60mV to +40mV. Interior axoplasm is positive.
Repolarization- (downswing) K+ gates open exit axoplasm.
Recovery Period- active transport where Na/K pump Na+ out and K+ in. Refractory period where action potential cannot occur.
Threshold- all or nothing response, its the amount of stimulation required to create a response.
Neurons + Reflec Arc
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Sensory neurons (to spine) detect stimuli which is replayed to interneuron (CNS) which is then transferred to motor neuron (away from spine), signal ends at effector gland or muscle.
Synapse
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Major Components- voltage calcium gates, Ca+, axon, vesicle (contains neurotransmitters), synaptic clef (space in between), neurotransmitter receptors.
Across Synapse- action potential down axon, voltage gated Ca+ open -> Ca+ in, vesicles containing neurotransmitters secreted out of synapse terminal to synaptic clef, receptors on dendrite (lock and key) with neurotransmitter. Na+ gate open, Na+ in, action potential continues.
Breaking Down- Enzyme monoadmeoxidase breaks down noradrenline to break down neurotransmitter in synaptic clef.
Across Synapse- action potential down axon, voltage gated Ca+ open -> Ca+ in, vesicles containing neurotransmitters secreted out of synapse terminal to synaptic clef, receptors on dendrite (lock and key) with neurotransmitter. Na+ gate open, Na+ in, action potential continues.
Breaking Down- Enzyme monoadmeoxidase breaks down noradrenline to break down neurotransmitter in synaptic clef.