Term
What are the two classes of neurotransmitters? |
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Definition
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Term
What do excitatory neurotransmitters do? |
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Definition
-cause Na influx, AP travels through postsynaptic membrane |
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Term
What do inhibitory neurotransmitters do? |
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Definition
-hyperpolarize postsynaptic membrane -membrane potential is decreased, Cl- moves in K+ moves out -inside of cell becomes more negative |
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Term
Is acetyl choline excitatory or inhibitory? |
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Definition
excitatory between somatic motor neurons & muscles inhibitory between neurons & heart |
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Term
Give an example of inhibitory neurotransmitters |
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Definition
GABA glycine acetyl choline |
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Term
Give an example of excitatory neurotransmitters |
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Definition
acetyl choline epinephrine norepinephrine dopamine |
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Term
What happens if a neurotransmitter remains in synapse? |
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Definition
Continuous stimulation of post synaptic receptor (generation of AP's) |
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Term
How is Ach released from the postsynaptic membrane? |
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Definition
Achase breaks down Ach, components are reabsorbed by synaptic knob & re-synthesized into Ach |
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Term
How is norepinephrine released from the postynaptic membrane? |
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Definition
released by the receptor, picked up by the synaptic knob, broken down |
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Term
What regulates the autonomic nervous system? |
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Definition
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Term
Where does the sympathetic nervous system originate from? |
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Definition
thoracic & abdominal regions of spinal cord |
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Term
Where does the parasympathetic nervous system originated from? |
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Definition
the brain & pelvic regions of spinal cord |
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Term
Which classes of vertebrae is the ANS involved with? |
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Definition
thoracic, lumbar & sacral |
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Term
What is the preganglionic neuron? |
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Definition
1st neuron of efferent nerves in SYM & PARA -carries impulse to ganglia |
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Term
What is the postganglionic neuron? |
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Definition
2nd neuron of efferent nerves in SYM & PARA -carries impulse from ganglia to target organ |
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Term
Where is the cell body of the 1st neuron found? |
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Definition
in the brain or spinal cord |
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Term
What does the preganglionic neuron synapse with? |
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Definition
-the sympathetic chain or -passes through chain & synapses with a ganglion outside the chain |
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Term
Describe the length of post- & pre-ganglionic neurons in the SYM & PARA NS |
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Definition
SYM: short pre long post
PARA: long pre short post |
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Term
What system deals with emergency situations? |
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Definition
sympathetic nervous system |
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Term
What are some changes that occur in the body when the sympathetic nervous system is active? |
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Definition
bronchodilation (increase gas exchange) increased heart rate (increase O2 delivery) dilate arterioles (increase O2 delivery) dilate pupils (light & peripheral vision) reduce blood flow to GIT, skin, kidneys (not necessary in emerg.) decreased GIT activity (not needed in emerg.) |
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Term
What is the key neurotransmitter in the sympathetic nervous system |
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Definition
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Term
What neurons release norepinephrine? |
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Definition
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Term
What neurons release Ach? |
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Definition
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Term
Where are alpha adrenergic receptors found? What is their function? |
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Definition
blood vessels -vasoconstriction of skin, GIT & kidneys |
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Term
What is the function of B1 andrenergic receptors? |
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Definition
increase heart rate & force of contraction |
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Term
What is the function of B2 andrenergic receptors? |
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Definition
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Term
What is the function of the parasympathetic nervous system? |
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Definition
-decrease excitatory effect of fight/flight -allow body to replenish stores -return body to homeostasis |
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Term
True or False
PARA has little effect on blood vessels? |
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Definition
True
Except blood vessels in the GIT |
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Term
What neurotransmitter is released by PARA? |
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Definition
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Term
What are reflexes? What are the two types? |
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Definition
rapid automatic responses to protect the body -somatic & autoomic |
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Term
What do somatic reflexes do? |
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Definition
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Term
What do automatic reflexes do? |
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Definition
regulate smooth muscle, cardiac muscle, endocrine glands |
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Term
What is the origin of a reflex? Describe the process briefly |
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Definition
a sensory receptor -receptor is stimulated to threshold, AP travels along sensory neuron, terminates in grey matter of SC or brain |
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Term
What happens after an AP has reached the CNS grey matter? |
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Definition
-information is integrated with impulses from other neurons -integrated response is sent from SC or brain by the motor neuron to the target tissue |
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Term
Describe the stretch reflex |
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Definition
-muscle spindle stretches, impulse send via afferent neuron to SC -sensory neuron synapses with motor neuron at SC -stimulation of efferent motor neuron causes contraction |
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Term
Describe the stretch reflex caused by tapping on the patellar tendon |
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Definition
-quad muscle is stretched, reflex arc is stimulated, quadricep contracts, lower leg extends (kicks) -afferent neuron also sends impulse that causes a 2nd reflex arc so the opposing muscles relax -cerebellum is simultaneously informed of what is going on |
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Term
What are the 4 different sections of the brain? |
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Definition
cerebrum cerebellum diencephalon brain stem |
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Term
What region of the brain is responsible for the highest order functions & behaviours? |
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Definition
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Term
What are the functions of the cerebrum? |
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Definition
-receiving & processing sensory info -initiate conscious nerve impulses -integration of neuron activity for conscious activity -reason & planning |
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Term
Describe the structure of the cerebrum |
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Definition
-gyri, fissures & sulci on the brain surface -longitudinal fissure separating L & R hemispheres -hemispheres further divided into lobes -outer layer is cerebral cortex |
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Term
What are gyri, fissures & sulci? What is the function of gyri & sulci? |
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Definition
Gyri: folds Fissures: deep grooves Sulci: Shallow grooves
-G&S increase surface area to allow large bundles of nerve cell bodies to connect with bundles of axons |
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Term
An impulse in the left hemisphere will cause muscle movements on the ____ side of the body |
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Definition
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Term
Describe the cerebral cortex |
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Definition
-outer 6 layers of neurons -made of grey matter -mainly nerve cell bodies which receive info from all around the body via the CNS |
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Term
Describe the region below the cerebral cortex |
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Definition
-white matter dominated by axons -nerve fibers linking different regions f the cortex & connect it to other parts of the brain & SC |
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Term
What is the basal ganglion? |
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Definition
-pools of neurons controlling semivoluntary movements e.g. walking & running -initiation & maintenance of normal motor activity |
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Term
Describe the position of the cerebellum relative to the cerebrum |
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Definition
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Term
What is the function of the cerebellum? |
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Definition
-coordinates motor activity -compares the intent of the body w/ actual position -fine tunes movements |
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Term
What is the diencephalon, and what are its 3 major structures? |
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Definition
-NS passageway btwn cerebrum & primitive brain stem
Thalamus, Hypothalamus, Pituitary Gland |
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Term
What is the function of the thalamus |
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Definition
relay station, transferring sensory info from all over body to the cerebrum |
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Term
What is the function of the hypothalamus |
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Definition
interface between NS & endocrine system integrates functions of ANS -stimulate release of hormones to respond to temperature, hunger, thirst, rage, anger, stress, blood pressure, reproductive system etc |
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Term
Does the hypothalamus have PARA or SYM components? |
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Definition
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Term
What is the function of the pituitary gland? |
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Definition
master gland of the endocrine system regulates hormone production & secretion |
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Term
What is the most primitive part of the brain? |
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Definition
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Term
Waht is the function of the brain stem |
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Definition
-connects rest of brain to spinal cord -maintains basic support functions of body heart rate, contractions, respiration, vasoconstriction, swallowing, vomiting, coughing, sneezing |
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Term
What are the components of the brain stem? |
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Definition
Medulla Oblongata Pons Midbrain |
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Term
What is the tissue surrounding the brain & spinal cord? |
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Definition
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Term
What is the function of the meniges |
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Definition
Cover & protect CNS, provide nutrients & oxygen to the superficial layers off brain & SC |
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Term
Describe the 3 layers of the meniges |
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Definition
Dura mater: outer ayer, tough, fibrous Arachoid: delicate & spider web like Pia mater: inner thin, lies directly on brain & SC |
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Term
What is the function of cerebrospinal fluid |
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Definition
-protects CNS from the surfaces of skull & vertebral column -minimize displacement of brain -maintain external environment for brain cells -route for removing metabolites from brain |
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Term
What is cerebrospinal fluid derived from? |
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Definition
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Term
What is the structure & function of the blood-brain barrier |
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Definition
-separates brain capillaries from nervous tissue -not porous, prevents ions, drugs etc from reaching brain |
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Term
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Definition
specialized glial cells which selectively transport materials into the brain |
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Term
When does the brain stem become the spinal cord? |
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Definition
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Term
What is the function of the spinal cord? |
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Definition
-conduct sensory info & motor instructions -process/modify impulses between brain & peripheral nerves |
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Term
What 2 systems are involved with coordination & control of tissue & organs? |
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Definition
Nervous System Endocrine System |
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Term
What is the difference between endocrine exocrine glands? |
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Definition
Endocrine: ductless Exocrine: secrete through a duct |
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Term
True or False
All cells have receptors for all types of hormone, some are just not switched on |
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Definition
False
not all cells have receptors to specific hormones |
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Term
Describe the negative feedback system of thyroid hormone |
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Definition
-T3 & T3 levels in blood decrease to certain level -pituitary detects low evels -TSH is produced to stimulate thyroid gland -T3 & T4 levels rise -antuitary detects this, stops production of TSH |
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Term
What are the two methods of hormone secretion? |
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Definition
negative feedback direct stimulation from NS |
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Term
Describe hormone secretion by direct stimulation from NS |
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Definition
-nerve impulses stimualate endocrine gland to release hormone e.g. adrenal medulla stimulated to release catecholamines for fight/flight response |
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Term
Describe the position of the pituitary relative to the hypothalamus |
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Definition
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Term
Does the hypothalamus have neurons or glands secreting hormones? |
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Definition
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Term
What is another term for the pituitary? |
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Definition
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Term
What is the composition & function of the anterior pituitary |
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Definition
-glandular tissue -produces 7 hormones -stimulated by hypothalamus & direct feedback |
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Term
What is the composition & function of the posterior pituitary |
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Definition
-nervous tissue -stores & releases 2 hormones produced by hypothalamus (ADH & oxytocin) |
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Term
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Definition
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