A&P Exam 5 - Final Flashcards
what is multimodel association areas
communicate with many regions of the brain to process incoming niformation
anterior association area aka
prefrontal cortex
where is the anterior association area
at anterior tip of the frontal lobe
in front of motor areas
what is the anterior association area for
holds your personality
it is also involved with intellect and complex learning ability
what is the anterior association area closely linked to
the limbic system
what happens when there is damage to the anterior association area
causes personality issues
loss of intelligence
affects self control
posterior association area where is it
portions of the temporal parietal and occipital lobes
what is the posterior association area for
recognizing things like faces and it localizes us in space
what else does the posterior association area do
integrates multiple types of sensory stimuli to produce a single idea
limbic association area
part of the limbic system
what is the limbic association area for
allows conscious stimuli to have an emotional effect
so as we understand a situation we get appropriate emotional responses
hippocampus
part o the limbic association area establishes memories of momentous events
cerebral white matter
used for communication between different regions of the brain
what is cerebral white matter composed of
myelinated axons
commisural tracts
connects grey matter between the two hemispheres
what is the largest commisural tract
corpus collosum
association tract
connect grey matter within the same hemisphere
projection tract
connect grey matter between cerebral hemispheres and lower areas of the brain like the brain stem, cerebellum, and diencephalon
basal nuclei
found within cerebral white matter
structures of the basal nuclei
caudate nucleus, the putamen, and the glabus pallidus
what is basal nuclei important for
controlling body movement
filter out excessive or abnormal movement
plays a role in attention in cognition
diencephalon
composed of three paired areas of gray matter that enclose the third ventricle
three regions go the diencephalon
thalamus
hypothalamus
epithalamus
thalamus
forms the middle region of the diencephalon
longest region of the diencephalon (about 80%)
what does the thalamus do
acts as a relay to the cerebral hemispheres
it sorts, edits, and packages info. for higher brain areas
how are related stimuli packaged in the thalamus
together
where does all sensory info pass through
the thalamus on its way to cerebral processing areas
hypothalamus
forms the anterior part of diencephalon
what does the hypothalamus do
acts as a main visceral control center of the body
visceral
organs in a body cavity
hypothalamus functionality
very multifunctional
sets body temp. regulates pituitary gland, regulates thirst and food intake
epithalamus
posterior portion of the diencephalon
what does the epithalamus do
contains the pineal gland
- secretes melatonin
melatonin
regulates sleep/wake cycle
brain stem
connects the brain to the spinal cord
midbrain
superior portion of the brainstem
midbrain structure
has 2 cerebral peduncles that contain pyramidal corticospinal motor tracts
contains substantia nigra
nigra
dark to the naked eye
contains melanin
melanin
precursor to dopamine
parkinsons disease
due to degeneration of the substantial nigra
dopamine
prevents basal nuclei from becoming overactive
helps to limit abnormal and excessive motor natters
dopamine in parkinsons
release decreases and basal nuclei become overactive causing abnormal motor patterns
pons
middle portion of the brain stem
what does pons contain
mostly a conduction tract
medula oblongata
inferior portion of the brain
what does the medulla oblongata contain
many autonomic center which controls organ function blood pressure and heart rate regulation, cardio center
what does the medulla oblongata allow for
contralateral control
cerebellum
lies at the posterior of the brain
what does the cerebellum do
provides precise timing and patterns for muscle movements
compares planned movements w/ actual movements and makes adjustments
allows for smooth agile movements
what does the cerebellum work with
motor areas in cerebral hemispheres and provides feedback to the primary cortex
how are the neurons in the cerebellum arranged
in a homunculus
neurons that control a body part are located together
show ipsilateral control of the body
cerebellar structure
surface is finely folded
vermis
thin strip tissue that connects the left and right hemispheres in the cerebellum
cerebellar peduncles
3 paired tracts in the cerebellum
motor tracts that connect to the brain stem
cerebellar lobes
posterior anterior and flocolanodular lobes
limbic system
emotional portion of the brain
what is the limbic system composed of
multiple structures that circle above brain stem (form a halo)
formnix
a tract that links limbic structures together
amygdaloid body
assesses danger
recognizes angry and fearful facial expressions
what does the amygdaloid body do
elicits a fear response or aggressive response
cingulate gyrus
help express emotions through body gestures
when do coagulate gyrus activate
when we are frustrated
rhinocephalon
composed of several nuclei linked to the smell legion in brain
what does the rhinencephalon do
links particular odors to strong emotional responses
- both good and bad
hypothalamus location
at the center of the limbic system
what does hypothalamus do in the limbo system
links emotional reactions to body responses
- hearth rate increase
- breathing rate increasing
- sweating
heart rate increase
can lead to a psychosomatic illness (so emotional you get sick)
reticular formation composed
multiple structures that pass through the brainstem
reticular formation neurons
synapse onto brain area
Reticular activating system
synapses onto cerebral cortex
what does RAS do
stimulates brain to keep you alert and awake
what stimulates the RAS
Sensory information such as light and sound
protection of the brain
by the bones of the cranium, the meninges and cerebrospinal fluid
meninges
three connective tissue membranes wrap and protect the brain
dura mater
outermost layer
most durable layer
composed of fibrous connective tissue
arachnoid mater
intermediate layer
thin and elastic
produces arachnoid villi
arachnoid villi
absorbs old CSF
Pia mater
innermost layer
tightly wraps the brain
delicate and richly vascularized
cerebrospinal fluid
fluid in the CNS acts as a liquid cushion that protects the delicate soft brain
choroid plexuses
sites of CSF formation
where is the choroid plexuses
in the ventricles
how does the choroid plexuses work
select compounds are pumped from blood into the brain
what is CSF a product of
blood plasma
how are compounds pumped in the choroid plexuses
by ependymal cells
how often is the entire volume of CSF replaced
about 3 times a day
every 8 hours
how much CSF is there in the brain
about 150 mL
blood-brain barrier
prevents CSF and blood from mixing
what is the blood-brain barrier composed of
continuous capillaries
the walls are not very leaky
what does the blood-brain barrier protect
the brain from microorganisms and fluctuations in blood chemistry
how does the blood-brain barrier work
it is only effective against polar compounds
nonpolar compounds pass through
the spinal cord
connects the brain to the body
spinal dura mater
single layered
epidural space
it’s a space between the dura mater and the bone
what can the epidural space be used for
to inject medication and sample CSF
conus medullaris
inferior round end of the spinal cord
where does the conus medullaris end at
at the L1
can go below this point to sample CSF also
filum terminale
fibrous extensions of the pia mater
where does the filum terminale anchor at
on coccyx
what does the filum terminale do
prevent spinal cord from moving excessively during body movement
cauda equina
a mass of spinal nerve roots that extend from the conus medullaris (horses tail)
spinal nerves
each segment of the spinal cord produces a nerve pair (31 pairs)
nerves for limbs
enlarged in these areas
cervical enlargement
for upper limbs (nerves)
lumbar enlargement
for lower limbs (nerves)
cross sectional anatomy
spinal cord is composed of interior gray matter with white matter on the exterior
almost divided in to two halves
ventral median fissure
front of spinal cord
dorsal median fissure
back of spinal cord
gray matter in the spinal cord
is arranged as horns
dorsal
ventral
lateral
what do horns contain
multipolar neuron cell bodies
cray commusure
a thin strap that connects the left and right halves of the spinal cord
what does each horn produce
a root (a bundle of axons)
ventral roots
produced by ventral horn
contains motor axons
dorsal roots
produced by the dorsal root
contains sensory axons
spinal nerves
ventral and dorsal roots merged to form a spinal root
white matter in the spinal cord
arranged in columns called funiculi
ascending pathways in white matter
carry sensory information to the brain
descending pathways in white matter
carry motor stimuli to muscles
motor pathways in white matter
crossover for contralateral regulation
paired with a pathway on each side
left and right
the peripheral nervous system
is a link between the central nervous system and the outside world
nerves
a bundle of axons wrapped in connective tissue
nerve structure
contains several layers of connective tissue
connective tissue and myelin
a fascicle
a bundle of axons
endoneurium
surrounds an individual neuron
perineurium
surrounds a bundle of neurons (a fascicle)
epinerium
surrounds a whole nerve
afferent nerves
sensory in function
efferent nerves
motor in function
mixed nerves
can carry motor and sensory axons
autonomic nerves
subconscious
somatic nerve
voluntary
spinal nerves
arise from the spinal cord
what are all spinal nerves
mixed nerves
cervical nerves C1 to C8
8 pairs
thoracis nerves (T1 to T12)
12 pairs
lumbar nerves (L1 to L5)
5 pairs
Secral nerves S1 to S5
5 pairs
Loccygeal nerves
i pair
rami
spinal nerves are very short
less than an inch long
split to form two rami
dorsal ramus
short
extends posteriorly
mixed
serves all body tissues behind the spinal cord
ventral ramus
longer -majority of body is in front of spinal cord
extends anteriorly
mixed
serves all body tissues in front of spinal cord
nerve plexuses
a region where multiple rami meet and intersect
which rami do not enter the plexuses
t1 - t12
they travel alone as intercostal nerves
cervical plexus
located at the back of the neck
what are the cervical plexus formed by
c1 - c5
what do cervical plexus produce
cutaneous nerves for skin sensation and motor nerves in segmental branches
brachial plexus
located near the meeting of the shoulder and the neck
what are the brachial plexus formed by
ventral rami c5-t1
how is the brachial plexus damaged
by pulling at the arm with force or by forcing shoulder downward it causes loss of sensation and muscle weakness
what nerves do the brachial plexus serve
only the upper limb and it is the most complicated plexus
named nerves of the brachial plexus
axillary ulnar radial median musculocutaneous dorsal scapulator long thoracic subscapular pectoral
nerve forming process
rami combine to form trunks
trunks split to form divisions
divisions recombine to form cords
cords split to form named nerves
lumbar plexus
lies anterior to the pelvis
what are lumbar plexus formed by
rami l1 - l4
what nerves do the lumbar plexus serve
the lower limb
named nerves of lumbar plexus
femoral, obturator, lateral femoral cutaneous, illiohpogastric, illioinguinal, genitofemoral
sacral plexus
lies posterior to the pelvis
what is the sacral plexus formed by
l4 - s4
what does the sacral plexus serve
the lower limb
namedn elves of the sacral plexus
sciatic, tibial, common fibular, superior gluteal, inferior gluteal, pudental, posterior femoral cutaneous
sensory receptors
specialized afferent neurons
classification of receptors by stimulus
naming based on the type of stimulus that activates the cell
mechanoreceptors
responsive to physical forces like touch, pressure, vibration, stretch
thermoreceptors
responsive to temperature changes
cold receptors
are superficial
heat receptors
are deep
photoreceptors
responsive to light energy
where are photoreceptors found
only in the eye
chemoreceptors
sensitive to chemical changes
nociceptors
responsive to damaging stimuli that cause pain
classification of receptors by location
naming based on the origin of the stimulus
exteroceptors
sensitive to external stimuli located near the surface of the body
interoceptors
sensitive to internal stimuli
usually a subconscious perception of internal conditions
propriceptors
a type of internal receptors found in skeletal muscles, tendons, ligaments, and joint capsule
what do propriceptors do
collect info on body movement and limb position
produce feedback to brain on body movements
send info to brain to related position and limb movement
classification of receptors by structural complexity
naming based on their components
nonencapsulated nerve endings
aka nerve endings
mostly free dendrites in group C neurons
nonencapsulated nerve endings characteristics
abundant in epithelial tissue
dendrites have knob-like swellings
mostly responsive to pain and temperature
itch receptor
a very small free nerve ending
what are itch receptors stimulated by
pro-inflammatory chemicals such as histamine
encapsulated nerve endings
neurons with a connective tissue capsule around dendrites
almost all are mechanoreceptors
meissner’s corpuscles
touch receptors that are sensitive to ligament pressure and discriminative touch
particularly in hairless skin
aka tactile corpuscles
muscle spindles
a propriceptor inside skeletal muscle
located deep to a skeletal muscle
detects muscle stretch
