Neuroanatomy Flashcards
1
Q
CNS
A
brain
brainstem
spinal cord
- gray matter- consists of unmyelinated neurons and contains capillaries, glial cells, cell bodies, and dendrites
- white matter- consists of myelinated axons and contains nerve fibers without dendrites
2
Q
forebrain
A
prosencephalon
- telencephalon: cerebrum, hippocampus, basal ganglia, amygdala
- diencephalon: thalamus, hypothalamus, subthalamus, epithalamus
3
Q
midbrain
A
mesencephalon
- tectum: superior and inferior colliculi
- tegmentum: cerebral aqueduct, periaqueductal gray, reticular formation, substantia nigra, red nucleus
4
Q
hindbrain
A
rhombencephalon
- metacephalon: cerebellum
- myelencephalon: medulla oblongata
5
Q
PNS
A
cranial nerves and ganglia
spinal nerves and ganglia/plexuses
- spinal nerves have an anterior root carrying motor away from CNS
- spinal nerves have posterior root carrying sensory to CNS
- ganglia are clusters or swellings of cells that give rise to the peripheral and central nerve fibers
6
Q
ANS
A
sympathetic division
- prepares body for emergency response; norepinephrine neurotransmitter; generally a stimulating response
parasympathetic
- conserving and restoring energy; acetylcholine neurotransmitter; generally an inhibitory response
- concerned with innervation for involuntary processes, glands, internal organs, and smooth muscle
- emphasis on homeostasis and response to stress
- impulses often do not reach conscious
7
Q
Somatic nervous system
A
- peripheral and motor nerve fibers
- peripheral nerve fibers send sensory to CNS
- motor send info to skeletal muscle
- somatic motor neurons travel directly to skeletal muscle without intervening synapses
- all nerve fibers are myelinated
- controls voluntary movements and provides ability to sense touch, smell, sight, taste, and sound
8
Q
limbic system
A
corpus callosum olfactory tract mammillary bodies fornix thalamic nuclei amygdala hippocampus parahippocampal gyrus cingulate gyrus hypothalamic nuclei
- involved in the control and expression of mood and emotion, processing and storage of recent memory, olfaction, control of appetite, and emotional responses to food
- lesions to the limbic system can also result in a variety of behaviors including aggression, extreme fearfulness, altered sexual behavior, and changes in motivation
9
Q
Cerebrum
A
- encompasses the major portion of the brain
10
Q
left hemisphere
A
- language
- sequence and perform movements
- understand language
- produce written and spoken language
- analytical
- controlled
- logical
- rational
- mathematical calculations
- express positive emotions such as love and happiness
- process verbally coded info in organized, logical, sequential manner
11
Q
right hemisphere
A
- nonverbal processing
- process info in a holistic manner
- artistic abilities
- general concept comprehension
- hand-eye coordination
- spatial relationships
- kinesthetic awareness
- understand music
- understand nonverbal communication
- math reasoning
- express negative emotions
- body image awareness
12
Q
frontal lobe
A
function
- voluntary movement, intellect, orientation
- Brocas area (left hemisphere: speech, concentration
- personality, temper, judgment, reasoning, behavior, self-awareness, executive function
impairment
- contralateral weakness
- perseveration, inattention
- personality changes, antisocial behavior
- impaired concentration, apathy
- brocas aphasia
- delayed or poor initiation
- emotional lability
13
Q
parietal lobe
A
function
- associated with sensation of touch, kinesthesia, perception of vibration, and temperature
- receives info regarding hearing, vision, motor, sensory, and memory
- provides meaning for objects
- interprets language and words
- spatial and visual perception
impairments
- dominant hemisphere: agraphia, alexia, agnosia
- nondominant hemisphere: dressing apraxia, constructional apraxia, anosognosia
- contralateral sensory deficits
- impaired language comprehension
- impaired taste
14
Q
temporal lobe
A
function
- primary auditory processing and olfaction
- wernickes area: ability to understand and produce meaningful speech, verbal and general memory, assists with understanding language
- the rear of the temporal lobe enables humans to interpret other peoples emotions and reactions
impairment
- learning deficits
- wernickes aphasia
- antisocial, aggressive behaviors
- difficulty with facial recognition
- difficulty with memory, memory loss
- inability to categorize objects
15
Q
occipital lobe
A
function
- main processing center for visual info
- processes visual info regarding colors, light, and shape
- judgement of distance, seeing in three dimensions
impairment
- homonymous hemianopsia
- impaired extraocular muscle movement and visual deficits
- impaired color recognition
- reading and writing impairment
- cortical blindness with bilateral lobe involvement
16
Q
hippocampus
A
- embedded within the lower temporal lobe
- responsible for the process of forming and storing new memories of one’s personal history and other declarative memory
- important in learning language
- sends memories to appropriate areas of the cerebral hemispheres for long-term storage and retrieves memories when needed
17
Q
Basal ganglia
A
- gray matter masses located deep within the white matter of the cerebrum and include the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nuclei
- basal ganglia are collectively responsible for voluntary movement, regulation of autonomic movement, posture, muscle tone, and control of motor responses
- basal ganglia dysfunction has been associated with conditions including parkinsons, huntingtons, tourettes, ADD, OCD, and addiction
18
Q
amygdala
A
- located within the temporal lobes on both sides
- lies adjacent to the hippocampus and just beneath the surface of the front, medial portion of the temporal lobe
- its position results in bulge on surface called the uncus
- main function is emotional and social processing
- is involved with fear and pleasure responses, arousal, processing of memory, and the formation of emotional memories
19
Q
thalamus
A
- a relay or processing station for the majority of info that goes to the cerebral cortex
- coordinates sensory perception and movement with other parts of the brain and spinal cord that also have a role in sensation and movement
- receives info from cerebellum, basal ganglia, and all sensory pathways except for the olfactory tract
- then relays the info to the appropriate association cortex
- damage to thalamus can produce thalamic pain syndrome where there is spontaneous pain on the contralateral side of the body to the thalamic lesion
20
Q
hypothalamus
A
- receives and integrates info from the ANS and assists in regulating hormones
- controls functions such as hunger, thirst, sexual behavior, and sleeping
- regulates body temp, adrenal glands, pituitary gland
- located below the thalamus at the base of diencephalon
- lesions can produce obesity, sexual disinterest, poor temperature control, and diabetes insipidus
21
Q
subthalamus
A
- located between thalamus and hypothalamus
- primarily represented by the subthalamic nucleus
- important for regulating movements produced by skeletal muscles
- associated with basal ganglia and substantia nigra
22
Q
epithalamus
A
- represented by the pineal gland
- secretes melatonin and is involved in circadian rhythms, internal clock, selected regulation of motor pathways, and emotions
- associated with limbic system and basal ganglia
23
Q
midbrain (mesencephalon)
A
- functions as large relay area for information passing from the cerebrum, cerebellum, and spinal cord
- reflex center for visual, auditory, and tactile responses
24
Q
cerebellum
A
- located at the posterior of the brain below the occipital lobes and is separated from the cerebrum by the tentorium
- responsible for fine tuning of movement and assists with maintaining posture and balance by controlling muscle tone and positioning of the extremities in space
- controls the ability to perform rapid alternating movements
- three lobes: anterior, posterior, flocculonodular
- damage to one side will produce ipsilateral impairment to the body
- cerebellar lesions may produce ataxia, nystagmus, tremor, hypermetria, poor coordination, and deficits in postural reflexes, balance, and equilibrium
25
pons
- located below the midbrain and superior to the medulla oblongata
- assists with regulation of respiration rate and is associated with the orientation of the head in relation to visual and auditory stimuli
- cranial nerve V originates from here
26
medulla oblongata
- cone-shaped, connects to the pons superiorly, and to the spinal cord inferiorly
- composed of white matter on the surface, gray matter within the interior
- influences autonomic nervous activity and the regulation of respiration and heart rate
- reflex centers for vomiting, coughing, and sneezing
- damage to motor tracts crossing within produces contralateral impairment
- also responsible for relaying somatic sensory information from internal organs and for the control of arousal and sleep
- cranial nerves IX, X, XI, XII originates from here
27
brainstem information
- located in front of the cerebellum with connection to the spinal cord
- consists of three structures: midbrain, pons, and medulla oblongata
- works as a relay station sending messages between various parts of the body and the cerebral cortex
- primitive functions that are essential for survival: regulation of heart and respiratory rate
- reticular activating system is found within the midbrain, pons, medulla, and a portion of the thalamus
- severe damage to the brainstem will often result in "braindeath"
- majority of cranial nerves originate from here
28
blood supply
consists of two internal carotid arteries and two vertebral arteries (circle of willis)
29
anterior cerebral artery
supplies
- anterior frontal lobe
- medial surface of frontal and parietal lobes
impairments
- contralateral LE motor and sensory involvement
- loss of bowel and bladder control
- loss of behavioral inhibition
- significant mental changes
- neglect
- aphasia
- apraxia and agraphia
- perseveration
- akinetic mutism with significant bilateral involvement
30
middle cerebral artery
supplies
- most of outer cerebrum
- basal ganglia
- posterior and anterior internal capsule
- putamen
- pallidum
- lentiform nucleus
impairment
- most common site of CVA
- wernickes aphasia in dominant hemisphere
- homonymous hemianopsia
- apraxia
- flat affect with right hemisphere damage
- contralateral weakness and sensory loss of face and UE with lesser involvement in the LE
- impaired spatial relations
- anosognosia
- impaired body schema
31
posterior cerebral artery
supplies
- position of midbrain
- subthalamic nucleus
- basal nucleus
- thalamus
- inferior temporal lobe
- occipital and occipitoparietal cortices
impairments
- contralateral pain and temperature sensory loss
- contralateral hemiplegia (central area), mild hemiparesis
- ataxia, athetosis or choreiform movement
- quality of movement is impaired
- anomia
- prosopagnosia with occipital infarct
- hemiballismus
- visual agnosia
- homonymous hemianopsia
- memory impairment
- alexia, dyslexia
- cortical blindness from bilateral involvement
32
vertebral basilar artery
supplies
- lateral aspect of pons and midbrain together with superior surface of cerebellum
- cerebellum: branches from the basilar artery (PICA, AICA, superior cerebellar arteries)
- medulla: PICA, smaller branches from vertebral arteries
- pons: branches from the basilar artery
- midbrain and thalamus: PCA
- occipital cortex: PCA, basilar artery
impairments
- loss of consciousness
- hemiplegia
- tetraplegia
- comatose
- inability to speak
- locked-in syndrome
- vertigo
- nystagmus
- dysphagia
- dysarthria
- syncope
- ataxia
33
meningitis
- fever, headache, vomiting
- complaints of stiff and painful neck, nuchal rigidity
- pain in lumbar area and posterior thigh
- brudzinski's sign (flexion of neck facilitates flexion of the hips and knees)
- kernigs sign (pain with hip flexion combined with knee extension
- sensitivity to light
- lumbar puncture is the gold standard for diagnosis
34
Ventricular system
- designed to protect and nourish the brain
- each ventricle contains choroid plexus that makes CSF
- excess of CSF in brain can cause enlargement causing hydrocephalus
- excess CSF in spinal cord is termed syringomyelia
CSF
- cushions brain and spinal cord from injury and provides mechanical buoyancy and support
- 500-700 mL/day
- provides nutrition to the cns, serves as a conduit for removal of metabolites, is constantly being absorbed and replenished within the brain and the spinal cord
35
blood brain barrier
- consists of meninges, protective glial cells, and capillary beds of the brain
- responsible for exchange of nutrients between the CNS and vascular system
- provides protection for the cns by restricting certain molecules from crossing the barrier while others are able to do so freely
36
spinal cord
- relay for info between peripheral structures and the brain in order to process information
- the vertebral artery forms the anterior spinal artery and two posterior spinal arteries that all surround the spinal cord
- runs from the foramen magnum to the conus medullaris (between L1 and L2)
37
Hydrocephalus
- associated conditions: spina bifida, choroid plexus neoplasm, cerebral palsy, tumor, meningitis, or encephalocele
- enlarged head or bulging fontanelles in infants
- headaches
- changes in vision
- large veins noted on scalp
- behavioral changes
- seizures
- alteration in appetite, vomiting
- sun setting sign or downward deviation of the eyes
- incontinence
38
Peripheral nervous system
- sympathetic nerves originate in the lateral horn of the thoracic spinal cord and the parasympathetic nerves originate from the lateral gray matter of the sacral level of the spinal cord and from the brain itself
39
axon
a projection of a nerve away from the cell body that conducts impulses
40
dendrite
an extension of the cell body that receives signals from the neurons
41
endoneurium
the innermost covering of a peripheral nerve that surrounds each individual axon
42
epineurium
- outermost covering of peripheral nerve that surrounds the entire nerve and provides a buffer for the peripheral nerve
43
motor unit
a single motor neuron and all the muscle fibers that it innervates
44
myelin
proteins and lipids that form to create a sheath around particular nerves; increases conductivity of the nerve impulse
45
nerve conduction velocity
measures the speed of a nerve impulse along the axon of a nerve
46
neurons
nerve cells that receive and send signals to other nerve cells; comprised of a cell body, axon, and dendrite
47
nodes of ranvier
brief gaps in myelination of an axon; serves to facilitate rapid conduction of a nerve impulse via jumping from gap node ot gap node
48
perineurium
the middle layer of covering surrounding the peripheral nerve that envelopes facicles or groups of axons and maintains the blood-nerve barrier
49
saltatory conduciton
an action potential moving along an axon in a jumping fashion from node to node; decreases the use of sodium-potassium pumps and increases the speed of conduction
50
schwann cell
cells that cover the nerve fibers within the peripheral nervous system and form the myelin sheath
51
A fibers
- large
- myelinated
- high conduction rate
- alpha: alpha motor neurons, muscle spindle primary endings, golgi tendon organs, touch
- beta: touch, kinesthesia, muscle spindle secondary endings
- gamma: touch, pressure, gamma motor neurons
- delta: pain, touch, pressure, temperature
sensory:
- muscle spindle (primary afferent): primary for low threshold stretch
- muscle spindle (secondary afferent): receptors that respond to changes in length
- golgi tendon organ: responds to tension/stretch of a tendon
52
B fibers
medium
myelinated
reasonably fast conduction rate
preganglionic fibers of the autonomic system
53
C fibers
small
poorly myelinated or unmyelinated
slowed conduction rate
postganglionic fibers of the sympathetic system
exteroceptors for pain, temperature, and touch
