Nervous System Part 2 Flashcards
are cavities within the brain filled w/ CSF
(4 in total)
two lateral, and the fourth drains into the central canal of the spinal cord that contains CSF
ventricles
The skeletal system, meninges, CSF and blood brain barrier do what?
protect the brain
are 3 layers of connective tisue that cover and protect the CNS organs and enclose CSF
Meninges
is a leathery double-layer outer meninx
Dura Mater
is a middle loose layer separated from the dura mater by the subdural space
Arachnoid Meninx
area beneath eneath the arachnoid meninx that has blood vessels and is filled with CSF
Subaracnoid Space
separates the arachnoid layer from dura mater
Subdural Space
is a special fluid formed in the walls of the ventricles from blood plasma by permeating through the choroid plexus
helps protect the brains by providing buoyancy to allow it to float
circulates the ventricles and meninges into subarachnoid space
CSF
inner thin connective tissue tightly attached to the brain
pia mater meninx
formed from a network of blood vessels within the ventricles where CSF permeats through
choroid plexus
is a diffusion barrier that prevents most particles from entering CNS tissue, keeping the brain and spinal cord separate from general blood circulation
formed by the relatively impermeable brain capillaries, due to the glial cells astrocytes
maintenance to this is important for providing a stable chemical environment for nervous system and protect neurons from uncontrollable firing
Blood-brain barrier
foremost part of the brain, is the largest part of the brain in humans comprising about 83% of total brain mass
consists of a left and right cerebral hemisphere
responsible for consciousness
governs intelligence, reasoning and higher thinking
controls activities of the lower parts of the brain and can override their functioning (diencephelan, brainstem, limbic system and cerebellum)
initiates voluntary motor control and controls actions of cerebellum by acting on sensory input via thalamus
i.e. using meditation or medical biofeedback to reduce high heart rate
cerebrum
are two left and right large masses of the cerebrum seperated by median longitudinal fissure
cerebral hemispheres
separates left and right cerebral hemispheres from each other
median longitudinal fissure
cerebral cortex is marked by raised riges of tissues called?
gyri
shallow grooves on brain tissue
sulci
deeper grooves that separate large regions of the brain
fissures
separates the cerebrum from the cerebellum
transverse fissure
cerebral hemispheres are connected by a bridge of white nerve fibers
corpus callosum
outer portion of the cerebral hemisphere that is highly convuluted and gray in color
cerebral cortex
controls higher level executive functions, such as reasoning and decision making
controls motor functions and permits voluntary muscle actions
frontal lobe
receives sensory info from receptors in mouth for taste and those located in skin (touch, pressure, pain)
parietal lobe
interprets visual input
occipital lobe
receives sensory info such as hearing and smelling
temporal lobe
receive or send info in each lobe for one type of sensory or motor info
primary areas
act to integrate more than one type of sensory info for purposeful action
located in each of the four lobes which help to integrate higher and more complex levels of consciousness
(intellect, artisitc/creative abilitiy, learning, memory)
i.e. primary motor cortex in part of the frontal lobe
association areas
controls voluntary motor movements for all parts of the body
aka the precentral gyrus or somatomotor cortex
primary motor cortex
found in the frontal lobe that is responsible for speech production
Broca’s area
located in the temporal love that’s responsible for speech comprehension
Wernicke’s area
medulla oblongata, pons and midbrain are part of the?
brainstem
lies between the spinal cord and pons and is anterior to the cerebellum
contains several vital centers for regulating heartbeat, breathing, and vasoconstriction
contains the reflex centers for vomiting, coughing, sneezing, hiccuping, and swallowing
contains tracts that ascend or descend between the spinal cord and brain’s higher centers
medulla oblangata
is constriction of the blood vessels involved in the regulation of blood pressure
vasoconstriciton
contains bundles of axons traveling between the cerebellum and the rest of the CNS
functions with the medulla to regulate the breathing rate and has reflex centers concerned with head movements in response to visual and auditory stimuli
Pons (“pont” = bridge en francais)
acts as a relay station for tracts passing between the cerebrum and spinal cord or cerebellum
also has reflex centers for higher-level reflexes involving visual, auditory, and tactile responses
contain superior and inferior colliculi
midbrain
regions of the midrain that control reflexes for the head and neck in response to sudden visual or auditory stimulus
superior and inferior colliculi
contain the hypothalamus, thalamus and epithalamus
diencephalon
forms the floor of the third ventricle, maintains homeostasis, or the constancy of the internal environment
contains centers for regulating basic body functions, such as hunger, sleep, thirst, body temperature, water balance, and blood pressure
controls the pituitary gland
serves as a link btw nervous and endocrine systems
hypothalamus (think “homeostasis”)
regulates hormones in the body of the endocrine system
pituitary gland
in the roof of the third ventricle
last portion of the brain for sensory input before the cerebrum
serves aas central relay station for sensory impulses traveling upward from other body parts and the rain to cererum
receives all sensory info (Except smell), filters out unimportant sensory info and directs it to right regions of the cerebrum to be interpreted
thalamus
forms the roof of third ventricle
made of pineal gland
epithalamus
“epi” = above
secretes melatonin and located in the epithalamus
pineal gland
hormone responsible for wake-sleep cycle
produced in pineal gland
melatonin
located inferiolry and posterior to brain
convuluted and divided into 2 hemispheres w/ deep fisures
known as the ‘‘mini-brain”
composed of a thin outer cortex of gray matter and inner white matter
serves to coordinate body movements by relaying info to cerebral motor cortex
involved w/ maintaining balance, controlling certain eye movements, maintaining normal muscle tone, and posture
cerebellum
degree at which muscles remain partially contracted when at rest
monitored and mainted by cerebellum constantly to keep bones and joints in place
muscle tone
receive info from the body trunk
influence motor activities of trunk, shoulder and pectoral girdle
anterior and posterior lobes of cerebellum
intermediate part of the cerebellum
coordinates limb movements
vermis
serve to connect the cerebellum to the other parts of the brain
found on the anterior part of the cerebellum
cerebellar peduncles
involves part of unconscious and conscious brain
aka the emotional/feeling brain b/c stimulation of areas cause rage, pain, pleassure or sorrow
affects emotional aspects of our behavior
involved w/ processes of learning and memory (both long and short term)
found beneath cereral cortex and has neural pathways that connect parts of the frontal lobes, temporal lobes, hypothalamus and thalamus
limbic system
located deep to cerebrum which serves to connect different lobes of cerebrum
also called the limbic lobe
cingulate gyrus
acts as a memory center to help retrieve and store memories
why emotionally charged memories are most vivid is due to involvment of limbic system
hippocampus
smal part of the limbic system involved w/ emotions such as rage and anger
amygdala
a bundle of nerve fibers that act as a connection to hippocampus
fornix
contain fibers that project into thalamus and assist w/ memory of smell
mamillary bodies
masses of gray matter deep within each hemisphere of cerebrum
also part of limbic system
responsible for working w/ cerebellum to regulate motor moovments and learning
contain the putamen, caudate nucleus, and Globus pallidus
overall effect is to have an inhibitory effect on cerebral cortex (slow and control precise movements)
basal nuclei (aka basal ganglia)
a disorder of the basal ganglia
Parkinson’s disease
is a symptom of Parkinson’s disease in which an individual has difficulty w/ motor planning and has rigid movements
Apraxia
where the spinal cord terminates at the first lumbar vertebra
conus medullaris
is a collection of nerve roots in which the spinal cord extends from L1
runs to the end at the coccyx
cauda equina
a single layer sheath separated from vertebral columb by the epidural space
spinal dura mater
extension of pia mater that runs from the conus medullaris to the coccyx
acts as the inferior anchor for spinal cord
filum terminale
the removal of fluid for diagnostic testing
located in the cerebrospinal filled subarachnoid space inferior to end of spinal cord
region has less risk of damaging spinal cord from need insertion
spinal tap
two grooves on the surface of the spinal cord
the anterior median fissure and the shallower posterior median sulcus
s an opening that runs the length of the spinal cord and is filled with cerebrospinal fluid
central canal
area within spinal cord composed of myelinated and unmyelinated nerve fibers organized into regions called columns.
white matter
bundle of axons in the CNS
these cross over to the opposite side of the spinal cord in which the left brain side controls the right body and the right brain controls the left body
tract
The white matter fibers of the spinal cord are mostly composed of _____ tracts that proceed up the brain carrying sensory inputs
ascending tracts
these ______ proceed down within the spinal cord carrying motor output w/ a few commissural tracts
descending tracts
carries incoming afferent sensory neurons
dorsal root
contains cell bodies of afferent neurons
dorsal root ganglion
contains axons of motor neurons
ventral root
formed by joining of dorsal and ventral roots on each side of the spinal cord
spinal nerve
a cross bar that connects the ventral anterior horns
gray commissure
contain somatic motor neurons whose axons serve as efferent (motor) pathways to skeletal muscles by ventral roots
anterior (Ventral) horns
serves as one of the afferent (sensory) pathways from receptors via dorsal roots of spinal cord
posterior (dorsal) horns
located at thoracic level of spinal cord of gray matter
contain autonomic sympathetic motor neurons whose axons serve as efferent pathways to visceral organs
exit via the ventral roots of spine along somoatic motor neurons
(2) lateral horns
contains nerves that control skeletal muscles, skin, and joints
includes all nerves that serve the musculoskeletal system and exterior sense organs, including the skin
somatic nervous system
are exterior sense organs, including sense organs embedded in the skin
receive environmental stimuli, and then initiate nerve impulses towards the central nervous system
receptors
bring about a reaction to the stimulus in the peripheral nervous system
these include glands and muscle fibers
effectors
contains nerves that control the smooth muscles of the internal organs and glands
nerves here are called visceral motor when they control smooth muscles or involuntary functions
autonomic system
are either sensory nerves (having long dendrites of sensory neurons only), motor nerves (having long axons of motor neurons only), or mixed nerves (having both long dendrites and long axons)
humans have 12 pairs attached to the brain
control the head, neck and face (Except vagus nerve which controls the internal organs
cranial nerves (CN)
carry information responsible for sight, smell, hearing, or balance
special sensory nerves
s a special sensory nerve responsible for the sense of smell, originates in olfactory epithelium and terminates in the olfactory bulbs
only cranial nerves that are attached to the cerebrum, not the brainstem.
olfactory (CN I)
found in the PNS and consists of thousands of axons together in connective tissue
a nerve
cell bodies of neurons grouped together and make up part of a single nerve
ganglia
C01- C08
cervical (cranial) nerves
two short branches that lie within the vertebral column where each spinal nerve emerges from
root
has axons of sensory afferent neurons that conduct impulses to the cord
dorsal root
contains axons of efferent motor neurons that conduct impulses away from the cord
ventral root
smaller branches that contain nerves serving the dorsal parts of the trunk,
carrying visceral motor, somatic motor and sesnory info to and from skin and back muscles
dorsal ramus
larger branchains that contain nerves serving the ventral parts of the trunk, upper and lower limbs
carrying visceral motor, somatic motor and sensory info to and from body surface, strucutres in the boy wall and limbs
ventral ramus
a network of interconnecting nerves
some ventral rami emrge w/ adjacent ventral rami to form these
nerves emerging here contain fibrers from various spinal nerves carried together to a tarket locaiton
include cervical, brachial, lumbar and sacral plexuses
plexus
region of skin that carries sensory info through a specific pair of spinal nerves to the brain
dermatome
is a combo of ventral rami of spinal nerves C1-C5
cervical plexus
most important nerve of cervical plexus
supplies both sensory and otor fibers to the diaphragm
irritation of this nerve causes hiccups
severing this nerve causes paralysis of the diaphragm
three, four, five keeps the diaphragm alive,” relating to C3-C5 nerve
phrenic nerve
motor loss of function
paralysis
a mechanical respirator that helps one to breath when diaphragm is paralyzed
ventilator
nerves branch off of the upper extremities to form this combo of ventral rami of nerves C5-T1
Roots of C5-T1 form 4 trunks, the superior, middle and inferior
brachial plexus
supplies 3 muscles: the eltoid (shoulder muscle), teres minor (rotator cuff muscle) and triceps brachii (elbow extensor)
also carries sensory info from shoulder joints
axillary nerve
supplies triceps brachii muscle of the arm and 12 muscles in forearm controlling wrist and finger extension
carries sensory info from associated joints and overlying skin
radial nerve
supplies flexor muscles of forearm adn skin of first 3 digits and a half fingers
travels medially on anterior surface of the elbow
median nerve
supplies part of the flexor muscles of forearm, wrist and hand, ring finger and pinky
travels posteriorly behind medial elbow and along ulnar side of forearm
ulnar nerve
arises from the ventral rami of L1-L4
has an anterior and posterior division that branch into nerves to supply the pelvis an lower extremities
lumbar plexus
is the major nerve of the lumbar plexus
supplies the hip flexors and knee extensors as well as sensation to the anterior thigh
femoral nerve
supplies sensory info from skin of anterior, lateral and posterior surfaces of the thigh
lateral femoral cutaneous nerve
receives sensation from the medial side of the leg
saphenous nerve
nerves that arise from ventral rami of L4-S4
sacral plexus
arises from the sacral plexus and makes up the largest nerve in the human body
supplies the inferior trunik and posterior surface of the thigh
has 2 main branches in the lower leg: common fibular and tibial nerve
sciatic nerve
part of the PNS made of motor neurons that control internal organs automatically
sensory neurons from these internal organs allow us to feel pain
cell bodies for these are in the DRG w/ somatic sensory neurons
contain 2 systems: sympathetic and parasympathetic
autonomic nervous system
motor neuron cell body located in the spinal cord or brain
axon synapes w/ a second motor neuron located in the autonomic ganglion outside the spinal cord
preganglionic axon
axon of the ganglionic motor neuron that synapses on an effector organ in PNS
postganglionic axon
also known as the thoracolumbar division b/c it has preganglionic fibers from the thoracic and upper lumbar segments of spinal cord
is our fight or flight response in emergencies,
increases glycose and o2 supply for muscular contraction, active muscles
acceleration of heartbeat, dilation of bronchi, increased breathing rate, inhibits digestion
causes the liver to deliver more glucose for the body’s increased metabolic needs
norepinephrine is the primary neurotransmitter
contains 4 ganglia: sympathetic trunk ganglia, celiac ganglion, superiomesenteric ganglion and inferior mesnteric ganglion
sympathetic system
is the neurotransmitter released in the sympathetic system
the neuron is called adrenergic
norepineprhine (NE)
ganglia located on both sides of the spinal cord that control effector organs in trunk, head, and limbs
contained in the sympathetic nervous system
sympathetic trunk ganglia
largest of the ganglia that innervate the digestive system
contained in the sympathetic nervous system
celiac ganglion
ganglia that innervates the small intestine and parts of the large intestine
contained in the sympathetic nervous system
superiomesnteric ganglion
ganglia that innervates the large intestine, kidneys, bladder, and sex organs.
contained in the sympathetic nervous system
inferior mesenteric ganglion
associated w/ CN 3 (Oculormotor) that targets the intrinsic eye muscles, which change the pupil and lens.
ciliary ganglion
Associated with CN VII (hypoglossal) , the target organs are for tear production, nasal glands, and salivary glands.
Submandibular ganglion & Pterygopalatine ganglion
ssociated with CN IX (spinal accessory) , the target glands are the parotid glands.
Otic ganglion
associated w/ CN X (Vagus) that targets glands in visceral organs and thoracic cavity
Intramural ganglia:
a slight injury of the head that causes mild and transisent symptoms such as diziness or brief loss of consciousness
no permanent neurological damage
concussion
results in signiifcant tissue damage caused by a more serious impact
causes coma for hours or a lifetime
brain contusion
rupture in a blood vessel can cause blood to accumulate in the skull
hemorrhage
when the amount of pressure increases inside the skull
this can occur after a hemorrhage since the BV takes up space
this pressure can force the brain stem down and damage it, which can affect the BP
Intracranial pressure
impaired motor coordination resulting from an injury to cerebellum
Ataxia
occurs when blood ciruclation to the brain is blocked
brain tissue dies due to lack of oxygen and nutrients supplied
severity depends on vessel blocked
CT scans are used to detec them
2 types include a hemorrhagic or ischemic stroke
CVA (cerebrovascular accident) or stroke
an imaging technology called a computer tomography scan that uses x-rays to take visual cross-sections of the brain
can determine if a stroke occured
CT Scan (or CAT scan)
due to blockage by blood clots or fat deposits in a cerebral atery
ischemic stroke
occurs when a very small clot causes a temporary block in blood flow, but then dissolves.
TIA is a transient ischemic attack
occurs due to a “brain bleed” when a blood vessel in the brain ruptures
can cause death if severe
a hemorrhagic stroke
is a phenomenon in which ndamaged neurons in the surrounding area sprout new branches that spread into the area of injury and take over some lost functions
neural plasticity
is a general term for Alheimers and all brain disorders with memory deficits.
dementia
a progressive degenerative disease of the brain, usually seen in the elderly, that ultimately results in mental decline until the brain can no longer control bodily functions
associated w/ strucutural changes in cerebral cortex
plaques form and entangle the dendrites within the brain, preventing neurons from firing which eventually leads to cell death
he progressive loss of brain tissue, particularly in the frontal lobe, causes mood and behavior changes, such as suspicions about family, friends, and caregivers
Alzheimer’s disease
a rare neuromuscular condition that involves progressive destruction of ventral horn motor neurons (motor neuron cell bodies)
causes paralyis in which one loses the ability to speak, swallow and eventually breathe
Amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease
caused by any localized damage to the spinal cord or spinal nerve roots
loss of motor function occurs due to relation w/ skeletal muscles in which nerve inpulses cannot reach them
paralysis or sensory loss
occurs If the spinal cord is completely severed at any level
Total motor and sensory loss is experienced in body regions below the site of the damage
can’t allow signals to be sent up to the brain or receive signals from the brain
complete (total) spinal cord inury
paralysis of the lower limbs due to a spinal cord injury btw T1 and L1
Paraplegia
paralysis of all 4 limbs if spinal cord is injured in cervical region
quadriplegia
Compression of the median nerve in the carpal tunnel
causes decreased sensation in first 3.5 figits
carpal tunnel syndrome
occurs if ulnar nerve is damaged
inability to open 4th and 5th fingers
claw hand/ ulnar claw
due to increased pressure on the sciatic nerve from the surrounding muscles
a condition resulting in pain following the path of the sciatic nerve in the lower pelvis and posterior thigh
sciatica
due to increased pressure on the sciatic nerve from the surrounding muscles
a condition resulting in pain following the path of the sciatic nerve in the lower pelvis and posterior thigh
sciatica
Structures specialized to detect one form of energy to a nerve signal to the brain for processing
made of neurons that respond to stimuli in the environment
sensory receptors
Receptors that respond to temperature
thermoreceptors
Receptors that are sensitive to light
photoreceptors
receptors that respond to chemicals (Taste or smell)
Receptors that respond to chemicals (taste or smell)
receptors that sense pain
nocioreceptors
is created by a network of blood vessels within the ventricles that produces CSF
choroid plexus
What does the median longitudinal fissure do?
It separates the left and right cerebral hemispheres from one another.
what separates the cerebrum from the cerebellum?
the transverse fissure
receives sensory info from the upper lip and upper gums
maxillary branch of the trigeminal nerve
