Chapter 17 - The Nervous System Flashcards
what are the two parts of the CNS?
the brain and the spinal cord
what are the three parts of the brain?
forebrain, midbrain and hindbrain
what are the two systems in the PNS?
autonomic nervous system and somatic nervous system
what are the two parts of the autonomic nervous system?
sympathetic and parasympathetic
which way do sensory neurons send messages?
towards the CNS
which way do motor neurons send messages?
away from the CNS
def: receive input from sensory neurons and other neurons in the CNS
interneurons
def: contains the nucleus and other organelles
cell body
def: extensions leading toward the cell body that receive signals from other neurons and send them to the cell body
dendrites
def: conducts nerve impulses away from the cell body toward other neurons or effectors
axon
where is the myelin sheath in the PNS formed?
by Schwann cells
what are the gaps between axons called?
nodes of Ranvier
does nerve regeneration occur in the CNS?
no
what does the myelin sheath in the PNS do when an axon is severed?
serves as a passageway for new fibre growth
def: cells that transmit nerve impulses between parts of the nervous system
neurons
def: support and nourish neurons, maintain homeostasis, form myelin that surrounds neurons, and aid in signal transmission
neuroglia
what kind of axons does grey matter in the CNS contain?
short, nonmyelinated axons
are axons in white matter in the CNS myelinated?
yes
what is the charge at resting potential?
-70 mV
what is the charge rising up to for depolarization?
35 mV
what does the charge fall to during repolarization and hyperpolarization?
-90 mV
resting potential shows that the inside of the axon is ______ compared to the outside
negative
def: rapid change in polarity across the axonal membrane as the nerve impulse occurs
action potential
does the strength of an action potential every change?
no, it simply fires more often
where is myelin found in the PNS?
in sensory and motor neurons
myelinated axons cause _____ nerve conduction
saltatory
where are non-myelinated axons found in the CNS?
in the brain and spinal cord
def: protective membranes that cover the brain and spinal cord
meninges
what fills the spaces between the meninges?
cerebrospinal fluid
def: contains the cerebrospinal fluid
central canal
def: centrally located, shaped like the letter H
grey matter in the spinal cord
def: contains sensory fibres entering grey matter
dorsal root
def: contains motor fibres exiting grey matter
ventral root
def: surrounds grey matter
white matter
what are the 4 major parts of the brain?
cerebrum
diencephalon
cerebellum
brain stem
what are the grooves in the brain called?
sulci
what are the 4 different parts of the cerebrum?
frontal lobe
parietal lobe
temporal lobe
occipital lobe
what is the frontal lobe responsible for?
- voluntary movement
- motor functions
- reasoning and planning
- Broca’s area
what is the Broca’s area responsible for?
speech musculature (lips, tongue, larynx)
what is the parietal lobe responsible for?
- somatic sensing
- taste
- processes and analyzes sensory information from skin and muscles
what is the temporal lobe responsible for?
- hearing
- audio association
- Wernicke’s area
what does Wernicke’s area do?
help us understand written and spoken words
what is the occipital lobe responsible for?
- associating new visual information with previous information
- vision
what does the hypothalamus do?
- maintain homeostasis
- regulate hunger, sleep, thirst, body temperature, and water
what does the thalamus do?
- receive all sensory input except smell
- integrates sense transmissions
- higher mental functions (memory, emotions)
what does the pineal gland do?
secretes melatonin for sleep
what is in the diencephalon?
- hypothalamus
- thalamus
- pineal gland
what is in the cerebrum?
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
- central white matter
- basal nuclei
what is in the cerebellum?
white matter and a thin layer of gray matter
what is the cerebellum responsible for?
maintaining balance and posture
smooth coordinated movements
what are the parts of the brain stem?
- midbrain
- pons
- medulla oblongata
- reticular activating system
what does the midbrain do?
contains reflex centres for visual, auditory and tactile resposnses
what does the pons do?
functions with medulla oblongata to regulate breathing rate
what does the medulla oblongata do?
regulates heartbeat, breathing and blood pressure
reflex centres for vomiting, coughing, sneezing, hiccupping and swallowing
