Module 2: Brain Flashcards
What are the 2 main divisions of CNS
brain and spinal cord
What are the parts of the brain
cerebrum, brainstem, diencephalon, cerebellum
What protects the parts of the brain
skull of skeletal system, meninges, CSF and blood brain barrier
What is a ventricle
cavity filled with CSF
What are 4 main ventricles
2 lateral, 3rd and 4th drain into central canal of spinal cord
What are meninges
3 layers of connective tissue cover and protect CNS organs and enclose CSF
what are 3 layers of meninges
dura mater: leathery double layered outer
arachnoid meninx: loose layer separated form dura mater by subdural space
pia mater: thin connective tissue tightly attached to brain
What is CSF
cerebral spinal fluid formed in walls of ventricles from blood plasma permeating choroid plxus
what is coroid plexus
formed from network of blood vessels within ventricles
CSF circulating through ventricles into reneges fusion brain and spinal cord, bathe brain in in CSF
What is blood brain barrier
diffusion barrier prevents most particles from entering CNS
formed by impermeable capillaries due to astrocytes
What is location and function of cerebrum
foremost part of the brain
largest part of the brain: 83% of total brain mass
2 large masses divided into L and R hemisphere
Median longitudinal fissure separates L and R
L hemisphere controls R
R hemisphere controls L
What is cerebral cortex
marked by ridge of tissue called gyri separated by grooves( sulci)
What are fissures
deep grooves separate large region
What is transverse fissure
separate cerebrum from cerebellum
What is corpus callosum
bridge of nerve fiber that connects cerebral hemisphere
How many lobes are each hemisphere divided into
4: frontal, parietal, occipital, temporal
What is function of frontal lobe
increased level executive function- reason and decision making, controls motor function and permits control over voluntary actions
What is parietal lobe
receives sensory info from receptors in mouth for taste and skin-> touch, pressure and pain
What is occipital lobe
interpret visual input
What is temporal lobe
sensory for hearing and smell
What are the different area of cerebral cortex
primary, association, primary motor, primary sensory, association area
What is significant for primary area of cerebral cortex
lobes receive info for 1 type of sensory information
What is significant for association area of cerebral cortex
integrate more than 1 type of sensory info for purposeful action: all 4 lobes contain this
intellect, artistic ability, learning and memory
What is significant for primary motor cortex
also called precentral gyrus/ somatomotor cortex- controls voluntary movement for all parts of the body- part of frontal lobe
What is significant for primary sensory cortex
also called post central gyrus/somatosensory cortex- is place in parietal lobe where sensory info is received
What is Broca’s Area
located frontal lobe responsible for speech
What is Wernicke Area
located temporal lobe: responsible for speech comporehension
What is structure and function cerebrum
responsible for consciousness
governs intelligence, reasoning and higher thinking
controls activities of all lower parts of the brain: meditation to control HR as an example
initiate voluntary motor activities and control action of cerebellum by acting on sensory input via thalamus
What are the parts of the brainstem
medulla oblongata
pons
midbrain
What is structure and function of medulla oblongata
lies between spinal cord and pons and is anterior to cerebellum
contain center for regulating heart beat, breath and vasoctonstriction
contains reflex center for vomit, cough, sneeze, hiccup, swallow
has tracts that ascend/descend between spinal cord and higher brain center
What is vasoconstriction
constriction of blood vessels involved in regulation of BP
What is structure and function of Pons
contains bundles of axon traveling between cerebellum and rest of CNS
functions with medulla to regulate breathing rate and has reflex center concerned with head movement in response to visual and auditory stimuli
What is structure and function of Midbrain
acts as relay station for tracts tasing between cerebrum and spinal cord or cerebellum
reflex center for higher level- visual, auditory tactile response
Where are superior and inferior colliculi located and function
posterior portion of midbrain
control reflexes for head and neck in response to sudden visual and auditory stimulus
What is structure and function of Diencephalon
houses hypothalamus, thalamus and epithalamus
What is hypothalamus structure and function
forms floor of 3rd ventricle, maintain homeostasis of environment
regulate body function: hunger, sleep, thirst, body temp, water, balance BP
Controls pituitary gland
serves as link between nervous and endocrine system
What is structure and function of Pituitary Gland
regulate hormone in endocrine system
What is thalamus
roof of 3rd ventricle: last part of brain for sensory input before cerebrum
serves as relay station for sensory impulse traveling up from other parts of body and and brain to cerebellum
receives all sensory impulse-> filters out whats not important-> directs to appropriate region of cerebrum for interpretation
What is structure and function of epithalamus
roof of 3rd ventricle: mostly composed of pineal gland
what is pineal gland
secretes melatonin
what is melatonin
hormone controls sleep/wake cycle
What is the structure of cerebellum
located interiorly and posteriorly to brain
2 hemisphere with deep fissure divided into 3 lobes
called mini brain
grey and white matter
What is function of cerebellum
coordinate body movement by relay info to cerebral motor cortex
helps maintain balance, control eye movements, maintain muscle tone and posture
What is muscle tone
degree in which muscle remain partial contracted while at rest
What is function of anterior and posterior lobes of cerebellum
receive info from body, trunk and influence motor activity trunk, shoulder and pectoral girdle
What is function of intermediate lobe of cerebellum
also called vermis
coordinate limb movement
What are the cerebellar peduncles
connect cerebellum to other part of the brain
located with flocculonodular lobes on anterior portion of cerebellum
What is the limbic system
controls portions of unconscious and conscious brain
lies beneath cerebral cortex and has neural pathway connect portion of frontal lobe, temporal lobe, thalamus and hypothalamus
what is the cingulate gryus
limbic lobe
lies deep to cerebrum
connects different lobes of cerebrum
what does hippocampus do
involved in retrieval and storage of memories
What does amygdala do
small portion of limbic system that is involved in emotions such as rage and anger
What is the fornix
bundle of nerve fibers serve as connection to hippocampus
What are maxillary bodies
fibers project into thalamus and assist with memory of smell
What is the limbic system referred to as
feeling brain, affects emotional aspect of behavior outcome, how people evaluate reward and consequenes
How is short term memory defined
example: ability to recall 7 digit# long enough to dial i
What is an example of long term memory
recall events from the day
Where are memories stored
throughout cerebral hemisphere
hippocampus acts as memory center: storage and retrieval
explains how emotionally charged events result in vivid dreams because of limbic system involvement in hippocampus
What are basal ganglia structure and function
masses of grey matter that lie deep in each hemisphere of cerebrum
responsible for working with cerebellum to regulate motor planning and movement
effect is to have inhibitory effect on cerebral cortex-> slow and control precise movements
Name the parts of basil ganglia
putamen
caudate nucleus
globus pallidus( medial and lateral)
Name a disease of basal ganglia
parkinson’s
Define apraxia
difficulty with motor planning symptoms of parkonsin
rigid movement and can’t execute motor plan
How long is the spinal cord and what is it protected by
is 17in in length and protected by vertebral column
What ends at conus medullaris
spinal cord: originate brainstem and terminate 1rst lumbar
What is caudal equina
extension of spinal cord as nerve roos beyond L1 and run to end of coccyx
How many meninges does spinal cord have
3
What is the spinal dura mater
single layer sheath separated from veterbral column by cushioned fat filled epidural space
what is epidural space
space between middle arachnoid and inner pia mater meninges filled with CSF
What is extension of pia mater called
filum terminate
runs from conus medullar is to coccyx
provides inferior anchor for spinal cord
Where is a spinal tap performed
CSF filled subarachnoid space inferior to spinal cord at L1
What is a spinal tap
remove fluid for testing
How many grooves on surface of spinal cord
2: anterior median fissure and posterior median sulcus
What is the central canal of the spinal cord
opening runs length of spinal cord and filled with CSF
How many pairs of cranial nerves and how to classify
12 pairs
classified as sensory, motor or mixed
What do cranial nerves control
head, neck face except vagus
vagus: inner organs
What are special sensory nerves
carry info responsible for sight, smell, hearing or balance
What are the 12 cranial nerves
olfactory, optic, oculormotor, trochlear, trigeminal, abducen, facial, vestibular cochlear, glossopharayngeal, vagus, accessory, hypoglossal,
Define olfactory nerve
CN1 sensory nerve- control sense of smell originate in olfactory epithelium terminate in olfactory bulb only nerves attached to cerebrum not brainstem
Define optic nerve
CN2
sensory nerve- sense sight
originate in retina of each eye and cross at optic chiasm to synapse in thalamus
neurons connect to send info to visual cortex of occipital lobe
Define oculomotor nerve
CN3
motor nerve: control eye movement in both somatic motor and visceral motor
somatic: control superior and inferior and medial rectus
Visceral: control dilation of pupil
What is dilation and contraction in the eye
dilation: open pupil: allow light in
contraction: close- not allow light in
Define Trochlear nerve
CN4
motor nerve: eye movement
innervates superior oblique muslce
Define Trigeminal nerve
CN5
mixed nerve: chewing and sensation of face, nose, mouth has 3 branches
What are 3 branches of trigeminal nerve
- ophthalmic: sensory: receive info from skin to eyebrow and upper part of nose
2.) maxillary: sensory: receive info from lower eyelid and upper lip, upper gum and part of pharynx
3.) mandibular: mixed: receive info from lower gum, teeth and lips; sense from tongue, heat, cold, pressure- no taste
motor of mandibular= mastication control
Define abducen nerve
CN 6
motor: control eye movement: innervate lateral rectus muscle
contraction of this muscle makes eye move outward( abduct eye)
Define facial nerve
CN7
mixed: controls facial expression, sensation of tongue and taste on anterior portion of tongue
visceral motor function: control tear gland( lacrimal) and nasal mucuous glands
Define vestibulocochlear nerve
CN8
special sensory nerve responsible for hearing and balance
travel through hole in temporal bone-> to internal acoustic meatus
vestibular branch: balance and equilibrium
cochlear branch: sense of hearing
Define Glossopharayngeal nerve
CN9: mixed
motor: swallowing muscles
sensory: taste on posterior portion of tongue
visceral motor neuron: control paratoid salivary gland
Define Vagus nerve
CN10: mixed
spread widely in abdomen
aid in digestion, regulate HR, sensation of digestive tract
Define accessory nerve
CN11: spinal accessory: motor
control muscles involved in rotation of head and movement of upper shoulders
Define Hypoglossal nerve
CN12: motor: controls voluntary tongue movements
How many pairs of spinal nerves
where do they originate
cervical: 8 Thoracic: 12 Lumbar: 5 Sacral: 5 Coccygeal: 1 originate in spinal cord and branch out to rest of the body
What are the 2 branches of spinal nerve called after emerging from vertebral column
dorsal ramus
ventral ramus
Deine dorsal ramus
smaller of 2 branches
dorsal portion of trunk carrying visceral motor, somatic motor, sensory info to and from skin and muscles of back
Define ventral ramus
larger of 2 branches
ventral part of trunk and helps upper and lower trunk
carry visceral motor, somatic motor, sensory info to and from body surface, structure in body wall and limbs
What is a plexus and how is it formed
network of interconnecting nerves
nerves emerging contain fibers from various spinal nerves
connect with each other
What are the major plexuses in the body
cervical, brachial, lumbar and sacral
How does a spinal nerve carry information systematically
sensory info is received by spinal nerve distributed through body
signal passes through dorsal root into spinal cord then to brain for processing
motor command initials in CNS-> command signal sent down spinal cord to appropriate level
leaves out ventral root and signal carried via nerve to destination to muscle fiber to enable voluntary muscle contraction
What are dermatomes
region of skin that carries sensory info through specific pairs of spinal nerves to spinal cord and up to brain
Where are the different dermatomes
Cervical: C1-C5
Thoracic: T1-T12
Lumbar: L1-L5
Sacral: S1-S5
what is structure and function of cervical plexus
ventral rami spinal nerves C1-C5
contains phrenic nerve
What is the phrenic nerve
most important nerve
motor and sensory fiber to diaphragm, irritation= hiccup
if severed= paralysis
what is saying for phrenic nerve
3,4,5 keeps diaphragm alive
C1-C5
What is structure and function of brachial plexus
ventral rami nerves C5-T1
roots combine to form 3 trunk: superior, inferior, middle
trunks: anterior/posterior division
division then branch into 3 cord: lateral, posterior and middle
What nerves do the cords terminate in of the brachial plexus
musculocutandous axillary median radial ulnar other nerve that supply upper extremity: long thoracic, supra scapular, pectoral, thoracodorsal
What is structure and function of axillary nerve
supplies deltoid, teres minor, long head tricep
carries sensory infö from shoulder joint
What is function of radial nerve
supplies triceps, 12 muscles in forearm- controlling wrist and finger extension
carries sensory info from associated joint and skin
follows posterior surface of humerus and wrap around anterior surface close to elbow joint- then follow radius in to forearm
what is function of ulnar nerve
supply part of flexor muscles forearm, wrist and hand as well as half ring and pinky finger
travels posteriorly behind medial side of the elbow then travels along ulnar side of forearm
What is function of median nerve
supplies flexor muscles of forearm and skin of first 3.5 fingers
what is function of musculotaneous nerve
flexor muscle of arm including bicep, brachial, travels radial side of forearm
What is structure and function of Lumbar plexus
ventral rami L1-L4
anterior and posterior division: pelvis and lower extremity
contains femoral, lateral femoral cutaneous and saphenous nerves
What is function of femoral nerve
supplies hip flexor and knee extensor, sensation to skin of anterior thigh
what is function of lateral femoral cutaneous nerve
supply sensory info from skin of anterior lateraled and posterior surface of thigh
what is function of saphenous nerve
receive sensation of medial surface of the leg
What is structure and function of Sacral Plexus
ventral rami L4-S4
contains sciatic nerve- largest nerve in the body
What is function of sciatic nerve
supplies inferior trunk and posterior surface of thigh
2 branches in lower leg
common fibular: travels laterally
Tibial: posterior surface of tibia
What is a preganglionic axon in autonomic system
motor neuron cell body located in spinal cord
axon synapse with 2nd motor neuron in autonomic ganglia outside spinal cord
what is postganglinoic axon in autonomic system
after synapse in autonomic ganglion axon of ganglionic motor neuron synapse on effector organ in PNS
What are 2 divisions of autonomic system
parasympathetic and sympathetic
What is structure and function of sympathetic nervous system
often called thoracolumbar division
contain preganglinoing fiber in lateral grey matter
governs fight/flight by accelarte HR, dilate bronchi, increased breathing rate results in increase O2, decreased digestion
what is the primary neurotransmitter for sympathetic nervous system
Norepinephrine( NE)
if released then the neuron is called adrenergic
What are the 4 different ganglia in sympathetic nervous system
sympathetic trunk ganglia- located both sides of spinal cord-> contain ganglia for control of organisms in trunk, heads and limb
Celiac ganglion: largest- innervate digestive tract
Superiormesenteric ganglion: innervate small and lg intestine
inferior mesenteric gangion: innervate lg interstine, kidney, bladder and sex organs
What is structure and function of parasympathetic nervous system
primarily craniosacral: promote internal responses in relaxed state
promote digestion through stimulation smooth muscle of GI, secretion of digestive gland
Slow HR
What is primary neurotransmitter for parasympathetic system
acetylcholine( ACh)
if released neuron is cholinergic
What is ciliary gangion
associated with CN3: intrinsic eye muscle, changes pupil and lense
what is function of pterygopalatine gangling and submandibular gangion
associated with CN7
target organ for tear production, nasal glands and salivate glands
What is function of optic ganglion
CN9: target paratid gland
What is function of intramural ganglion
CN10: target visceral organ in thoracic cavity
What is a concussion
brain recoil and hit opposite side of skull: symptoms usually mild and transient
What is a brain contusion
significant tissue damage which usually causes unconsciousness( coma) ranging from hours to a lifetime
What is a hemorrhage
rupture in blood vessel, causes blood to accumulate inside skull
What is intracranial pressure
amount of pressure available inside skull
arises after hemorrhages because extra blood volume take up additional space and compress brain tissue
what happens if pressure isn’t released in skull
forces brain stem down through foramen magnum which causes damage to brain stem and affects control of BP, HR and finally respiration
What are 2 major symptoms of brain disorders
apraxia and ataxia
Define apraxia and ataxia
apraxia: impaired motor planning- results in rigid movement and difficult execution movement
ataxia: impaired motor coordination- result from injury to cerebellum
What is a CVA
cerebrovascular accident: stroke
occurs when blood circulation to a brain area is blocked
tissue in that area dies due to lack of O2 and nutrients
severity depends on which vessel is blocked
larger the artery the more damage there will be
Whats a CT
image to look visual cross-section of the brain
what are 2 types of strokes
ischemic: due to blockage: clot or fat deposit in cerebral artery
Hemorrhagic: occur due to brain bleed- severe often = death, if survives deal with paralysis, cognitive deficits, speech problem, emotional difficulty and pain
what is a TIA
transient ischemic attack: occurs when very small clot causes temporary block in blood flow but dissolves
what is neural plasticity
undamaged neuron is surrounded area sprout new branches that spread into injured area take over lost function
What is alzheimer’s disease
form of dementia
progressive degenerative disease of the brain- results in mental decline until brain no long control body function
plaques form and tangle together with brain to prevent nerve firing
What are symptoms of alzheimer
early: difficulty remembering newly learned info
middle: more issues with basic memory and behavior changes
final: problems with speech, walking and swallowing
What is ALS
amyotrophic lateral sclerosis: lou gehrig disease
rare neuromuscular condition that involves progressive destruction of ventral horn motor neuron
as progresses cause paralysis
define paralysis
loss of motor function: sensory los causes by local damged to spinal cord or spinal nerve roots
define paraplegia
lower limb paralysis spinal cord injury T1-L1
define quadriplegia
paralysis of all 4 limbs-> may occur if spinal cord is injury in cervical spine
What is carpal tunnel
compression of median nerve causing decreased sensation in first 3 digit and 1/2 of 4th digit
What is claw hand
damage to ulnar nerve
inability to open 4th, 5th finger at metacarpal joint
What is sciatica
increased pressure on sciatic nerve from surrounding muscles result in pain in lower pelvis and posterior thigh
