anatomy Test 3 Flashcards
(49 cards)
what are the three types of neurons?
-sensory
-interneuron
-motor
what is the function of a sensory neuron?
-takes impulses from sensory receptors to CNS
what is the function of an interneuron?
-take impulses between various parts of the CNS as part of integration
-form complex pathways in the brain where process that account for thinking, language, and memory occur
what is the function of a motor neuron?
-take nerve impulses from CNS to muscles or glands
-innervate structures cause them to contract or secrete
what are the parts of the neuron?
-cell body
-dendrites
-axon
-myelin sheath
-nodes of ranvier
how is action potential/nerve impulses generated?
-action potential uses charge difference (inside negative outside positive) and gated open channels
-axon conducts nerve impulse, Na+ gates open, Na+ rushes into cell, inside becomes positive, Na+ gates close, K+ gates open, inside becomes negative again
-process continues down entire axon
how is a signal carried across the synaptic cleft?
-the presynaptic cells release neurotransmitters
-able to cross cleft
-bind to receptors on the postsynaptic cell
-response is either excitation or inhibition
what are the structures of the brain?
-cerebrum
-cerebral cortex
-diencephalon: hypothalamus, thalamus, pineal gland
-cerebellum
-brainstem: midbrain, pons, medulla oblongata
-limbic system: hippocampus, amygdala
what is the function of the cerebrum?
-communicates with the other parts of the brain
-coordinates the activities of the other parts of the brain
what is the function of the cerebral cortex?
-covers the cerebrum (gray matter)
-interprets and initiates sensation, voluntary movement, and higher thought processes
what is the function of the hypothalamus in the diencephalon?
-integrating center
-helps maintain homeostasis
-regulates sleep, hunger, thirst, body temp, water balance
-controls pituitary gland
what is the function of the thalamus in the diencephalon?
-recieving end for all sensory input but smell
-integrates info and sends it to appropriate places in cerebrum
-involved in arousal of cerebrum
-participates in motor function, memory, and emotion
what is the function of the pineal gland in the diencephalon?
-secretes hormone melatonin
what is the function of the cerebellum?
-recieves from eyes, ears, joints, skeletal muscles
-recieves motor output from cerebral cortex about where the parts should be
-integrates info about to maintain posture and balance
-ensured coordinated, smooth, voluntary movements
what is the function of the brain stem?
-connects the rest of the brain to the spinal cord
-contains tracts that ascend or descend btwn spinal cord and higher brain centers
what is the function of the midbrain in the brain stem?
-contains important visual and auditory reflex centers
what is the function of the medulla oblongata in the brain stem?
-contains reflex centers for regulating heartbeat, breathing, and vasoconstriction
-also for vomiting, coughing, sneezing, hiccuping, and swallowing
what is the function of the pons in the brain stem?
-links the medulla with the midbrain
-vital in controlling breathing
what happens during a reflex action?
-stimulus occurs
-impulse sent to axon
-travels to dorsal root ganglion
-sensory axon has a cell body of sensory neuron and then the impulse travels to the interneuron of the gray matter of the spinal cord
-impulse travels through the motor axon of the motor neuron and ends at the effector (muscle)
somatic nervous system
-nerves take sensory info from external sensory receptors to the CNS
-takes motor commands away from the CNS to skeletal muscles
-voluntary control and reflexes
autonomic nervous system
-automatically and involuntarily regulates the activity of glands, cardiac muscle, and smooth muscle
parasympathetic nervous system
-“rest and digest” “housekeeper”
-promotes all internal responses associated with a relaxed state
-includes a few cranial nerves and axons arising from the last portion of the spinal cord
-uses acetylcholine
sympathetic nervous system
-“fight or flight”
-arises from portions of the spinal cord
-uses norepinephrine
antidiuretic hormone (function and releasing gland)
-released by posterior pituitary/hypothalamus
-causes water uptake by kidneys
