Chapter 11: The Nervous System Flashcards
cerebellum
- inferior to occipital lobes
- dorsal to pons & medulla
- two hemispheres separated by flax cerebelli
- vermis connects hemispheres
- cerebellar cortex (gray matter)
- arbor vitae (white matter)
- cerebellar peduncles
- dentate nucleus (largest)
- integrates sensory info concerning position of body parts
- coordinates skeletal muscle activity
- maintains posture
cerebellar cortex
gray matter in cerebellum
arbor vitae
white matter in cerebellum
vermis
connects cerebellum hemispheres
fall cerebelli
separates hemispheres of cerebellum
brain waves
recordings of fluctuating electrical charges in brain; EEG, via electrodes on scalp that detect electrical changes in extracellular fluid of brain
4 types of brain waves
- alpha
- beta
- theta
- delta
alpha
awake, resting, eyes closed
beta
active mental activity, under tension
theta
mostly in children
delta
mainly during sleep
apnea
no breathing, airway constricts
spinal cord
- slender column of nervous tissue
- begins at foramen magnum & terminates at the L1 - L2 space
- consists of 31 segments; each gives rise to a pair of spinal nerves
spinal cord portions (5)
- cervical enlargement
- lumbar enlargement
- conus medullaris
- filum terminale
- cauda equina
conus medullaris
tapered end of spinal cord, between L1 & L2`
filum terminale
extension of Pia mater, extends down from conus medullaris
cauda equina
horse tail; bundle of spinal nerves L2-L5, S1-S5, Co1-Co4, extends from conus medullaris
meninges
membranes that protect brain and spinal cord; dura mater, arachnid, pia mater
white matter is referred to as..
funiculi
gray matter is referred to as..
horns
where is an epidural injection given during childbirth?
L2-L3
functions of spinal cord
- center for spinal reflexes
- conduit (pathway) for impulses to & from the brain
reflex
automatic, subconscious response to stimuli in/outside the body
reflex arc
neural pathway consisting of a sensory receptor, 2 or more neurons, and an effector; simple & most common
simple reflex arc
contain only sensory & motor neurons
most common reflex arc
sensory neuron, interneuron, motor neuron
sensory
into posterior
motor
out of anterior
stretch reflex
- monosynaptic
- consists of sensory and motor neuron; synapse in spinal cord
- ex. knee jerk reflex
- helps maintain upright posture
withdrawal reflex
- occurs when person touches or steps on something painful
- prevents of limits tissue damage by removing limb from painful stimulus
- polysynaptic
- reciprocal innervation
polysynaptic
contains sensory neuron, interneuron, and motor neuron
reciprocal innervation
flexors contract, extensors inhibited
crossed extensor reflex
- during withdrawal reflex, flexors on affected side contract, and extensors are inhibited (ipsilateral)
- at some time, extensors on opposite sides contract, flexors inhibited
- also shifts body weight, so person remains upright
ascending tracts
conduct sensory impulses to brain
descending tracts
conduct motor impulses from brain via motor neurons reaching muscles and glands
what are tracts composed of?
axons