Nervous system Flashcards
On a basic level, the nervous system functions as the body’s:
internal information relay system
Nervous system is composed of:
*networks of interconnected neurons [cells of NS] that function to transfer info to and from the periphery into the central NS [Brain & spinal cord]
Nervous system functions [specific]
*detection and processing of sensory info [pain, temperature, touch, oxygen, blood pressure,ph]
*decision making, memory, emotion
*control and coordination of muscles & glands; motor
*integrative- coordinating response after interpreting sensory info
Structurally, the nervous system is divided into:
- Central NS [brain, spinal cord]
- Peripheral NS [tissue outside the CNS]
Neural tissue consist of which 2 cell types?
Neurons
Neuroglia
Neurons VS Neuroglia
Know the structure of a neuron
What are the 3 types of synapses?
Nerve impulse:
action potential of a nerve
the action potential is due to :
exchange of ions across the membrane
The ability to conduct the impulse is known as:
excitability
stimulus:
anything that causes an action potential to occur
the stimulus has to overcome the ____________ of that particular neuron
threshold level
What are the 3 neuron structures?
Bipolar [rare]
Psuedo / Unipolar
Multipolar
Which neuron structure is most common in the Central NS?
Multipolar
What are the 3 functional classifications of neurons?
The neuroglial cells of the peripheral NS are the:
functions?
Schwann cells
*wrap around axons
*perform myelination in PNS neurons
*repair process after injury
what are the 4 types of neuroglial cells of the Central NS?
Nervous tissue is divided into:
Gray matter [cell bodies, soma, dendrites, messages being received at dendrite, processed at soma]
White matter [just axons of cells, transmitting info]
Oligodendrocytes are responsible for:
*making myelin insulation around axons in the CNS
*can insulate multiple neurons or group neurons together by function
*only found in white matter [wrap axons]
Microglial cells in white and gray matter play a role in:
repair & defense
*resident phagocytic cells of the CNS
Ependymal cells form a lining of:
Function?
hollow cavities in the brain and spinal cord
[ciliated, epithelial-like cells; together with capillaries, they produce cerebrospinal fluid traveling in central canal that the brain and spinal cord float in]
Explain the formation of myelin sheath in PNS
Shwann cells in the peripheral NS will wrap their cell membrane around axon of a neuron
[helps impulses travel more quickly]
Astrocytes
*Star-shaped cells
*physically support and nourish neurons (communicate with blood)
*anchor neurons and blood vessels, maintain the extracellular environment around neurons, assist in the formation of the blood-brain barrier
What are the 5 brain divisions?
Telencephalon - cerebrum [blue] - higher fx
Diencephalon - thalamus, hypothalamus [orange]
Mesencephalon - (midbrain) [purple]
Metencephalon - [green] - pons, cerebellum
Myelencephalon - medulla oblongata
The spinal cord is a continuation of the :
brain stem [& directly- medulla oblongata]
Meninges :
are three layers of membranes that cover and protect your brain and spinal cord
What are the meninges in order?
innermost : pia mater
[subarachnoid space]
middle: arachnoid mater
outermost: dura mater [tough mother]
Identify A-D
A- superior sagittal sinus
B- falx cerebri
C- tentorium cerebelli
D- falx cerebelli
the only sulcus that travels all the way down the side of the brain from superior aspect all the way to inferior aspect is the :
central sulcus
identify A
central sulcus
identify A
longtitudinal fissure
Identify A-D
A- frontal lobe
B- parietal lobe
C- occipital lobe
D- temporal lobe
Frontal lobe functions
*executive function, thinking
*planning, organizing, problem-solving
*emotion, behavioral control, personality
*movement; producing speech
Parietal lobe functions
*sensory cortex: sensations
*perception
*making sense of the world
*arithmetic, spelling
*understanding speech
Temporal lobe functions
*memory
*language
*understanding
*primary auditory location
Occipital lobe functions
*vision, information abought sight
The primary sensory cortex is part of the parietal lobe, part of the cerebral hemispheres. The cerebral hemispheres are also known as the:
telencephalon
What is A and its function?
Olfactory bulbs - first cranial nerve - transmits odors to cortex
Mesencephalon/midbrain functions:
*motor control
*sleep-wake cycle
*temperature regulation
identify A-C
A- medulla oblongata
B- cerebellum
C- spinal cord
The blood supply to the brain is called
cerebral arterial circle
[joining of several arteries at anterior brain]
[used to be called circle of Willis]
functionally, the nervous system is divided into:
Somatic NS- conscious perception and voluntary responses
Autonomic NS- unconscious stimuli perception & responses
the peripheral NS is divided into what 2 divisions?
Afferent (sensory) division: receive info from sensory structures and sends to CNS
Efferent (motor) division: nerve cells carry info from CNS
2 parts of the autonomic NS:
Sympathetic NS- fight, flight, freeze, prepare for stressful situation
Parasympathetic NS- rest, digest, calm down body
Insula (insular lobe)
~brain lobe not visible at surface of brain
~wide range of fx: processing visceral, auditory, gustatory sensation, cognition, emotional awareness
______________ produces cerebrospinal fluid (CSF)
ependymal cells
Peripheral NS
Cranial and spinal nerves
*cells responsible for relay of sensory and motor info to and from CNS and peripheral organs
The _________ is the single most complex organ in the body
brain
[contains 98% of all neuronal cells]
Cerebrum functions
largest portion of brain
~processes conscious info, intellectual fx, speech, memory
What are the functions of the thalamus?
*Relay center for sensory & motor info
*role in emotions, memory, learning
Mesencephalon/ midbrain functions
additional relay center for visual and auditory info, coordinating reflexive motor control
Cerebellum functions
coordinates smoothing ongoing body movements & integrating body for orientation, balance, and muscle tone
Pons functions
relay center for sensory info to the cerebellum and thalamus
~visceral motor responses like respiration, swallowing, salivation, tears
~houses corticospinal tracts carrying conscious motor control to the trunk and extremities
Medulla oblongata functions
relay center for sensory info and additional site of autonomic control of cardiovascular, respiratory, and digestive function
Dura mater
[tough mother]
outermost layer covering the brain and spinal cord
~2 thick CT layers
-Outer periosteal (endosteal) layer lines the inside of skull
-Inner meningeal layer faces the meninges
Falx cerebri
long sagittal (vertical) extension that divides the cerebral space into 2 major regions, stabilizing them.
~attached anteriorly to crista galli and runs down longitudinal cerebral fissure between the 2 hemispheres
Tentorium cerebelli
horizontal fold of dura extending between cerebral hemispheres and cerebellum in the deep space of the horizontal cerebral fissure
~functions to hold weight of the large cerebral hemispheres off the cerebellum and brain stem
Falx cerebelli
small sagittal fold between right and left cerebellar hemispheres
Dural sinuses function to:
collect venous blood and CSF from the brain and drain it into the jugular veins
Arachnoid mater
[spider mother]
-deep to dura mater
*forms a smooth covering over brain and spinal cord
*Between the dura and arachnoid layers = subdural space
*under arachnoid = subarachnoid space - filled with CSF and maintained with arachnoid trabeculae. fluid cushions brain and nourishes tissue.
identify the pink
basilar artery
identify the pink
basilar artery
Pia mater
[delicate mother]
*directly on surface of brain; functions to adhere blood vessels supplying brain [looks similar to arachnoid matter]
identify the pink
internal carotid arteries
the human brain cortex is heavily folded into ridges called:
gyri
Gyri leave depressions called:
sulci
Gyri (gyrus)
ridges of cortical tissue
*allows expansion of processing areas of brain to be folded into cranial space
*outward folds of gray matter [areas where neurons are communicating]
Identify A-C
A- precentral gyrus
B- central sulcus
C- postcentral gyrus
What are the differences between gray and white matter?
why does white matter appear white?
myelin sheat surrounding the axons
gray matter on the surface of the brain is called:
neural cortex
Collection of gray matter neuron cell bodies in the interior of the CNS is called:
nuclei
_________ are bundles of white matter CNS axons that share an origin and destination.
several of these are called:
tracts; columns
Bundles of white matter axons in the PNS are called:
nerves
collections of gray matter neuron cell bodies in the PNS are called:
Ganglia
Clusters of neuron cell bodies in the peripheral nervous system are called:
ganglia
Cauda equina
“horses tail”
*long inferiorly extending dorsal and ventral roots
filum terminale
*last strand [slender thread of CT] of pia mater that provides longitudinal support to spinal cord
cross-sectioning of the spinal cord at any level results in _______________________ in regions inferior to the cut
total motor and sensory loss
Paraplegia results from:
any transection of spinal cord between T1 and L1
Quadriplegia results from:
transection in cervical region
the projections of gray matter toward outer surface of spinal cord are called:
horns [posterior, lateral, and anterior gray horns]
cell bodies of neurons in gray matter of spinal cord are organized into:
sensory nuclei [posteror] - receiving, relaying info from peripheral receptors
motor nuclei [anterior] - issuing commands to peripheral effectors
white matter of the spinal cords are organized into:
columns that contain tracts
[posterior, lateral, anterior white column]
Nerve:
enclosed, cable-like bundle of axons in the PNS
*transmits electrical impulses
*provides a common pathway for nerve impulses
what is the basic unit of the PNS?
nerve
What wraps individual axons?
endoneurium
Axons wrapped together in a bundle are referred to as:
what wraps this?
fascicle; perineurium
Fascicles of axons together are called:
What wraps this?
nerve; epineurium
spinal nerves emerge from the spinal cord in 2 different places:
dorsal side
[dorsal roots are afferent; form ganglia] - sensory
ventral side
[ventral roots are efferent; no ganglia] - motor
These join to form spinal nerve
Afferent VS Efferent
Afferent- arrives [afferent neurons are neurons whose axons travel towards. bring info into a central point]
Efferent- exits [cell sends axon/ carries info away from a central point]
SAME — Sensory- afferent ; Motor-efferent
DAVE — dorsal afferent ; ventral efferent
Pnemonic :
SAME
DAVE
SAME —
Sensory- afferent ;
Motor-efferent
DAVE —
dorsal afferent ;
ventral efferent
the autonomic NS uses _____ neurons
Why?
two-[preganglionic & postganglionic neuron]
[somatic NS uses 1 neuron]
*allows for increased communication & control; neuronal convegence or divergence
increased blood flow to skeletal muscles, dilation of pupils, and accelerating heart rate are effects of:
sympathetic autonomic nervous system
CSF is produced in the :
lateral ventricles
CSF produced in the lateral ventricles then travels through:
the interventricular forament > 3d ventricle in diancephalon > cerebral aquaduct in midbrain > 4th ventricle > drains into central canal through medulla oblangata > spinal cord
The third ventricle is located in what brain region?
diencephalon
what are the 3 important functions of CSF cerebrospinal fluid?
*keeps brain buoyant [acts as cushion / shock absorber]
*acts as a vehicle for nutrient delivery and waste removal
*compensates for changes in blood volume in brain
identify A-D
A- corpus callosum
B- Thalamus or 3d ventricle
C- choroid plexus of 3d ventricle
D- 4th ventricle
Identify E, F, G, H
E- arbor vitae [tree of life] of the cerebellum
F- hypothalamus
G- Pons
H- superior and inferior colliculi
The spinal cord is about how long?
18 inches [adults]
The outer portions of spinal cord are all:
The inferior parts are:
white matter [columns]
gray matter [horns]
Cranial nerve 1/ I
Olfactory nerve
*look like Antanae
*large paired nerves
*ONLY sensory info to brain [sense of smell]
Cranial nerve 2/ II
Optic nerve
*large paired nerves that cross over at optic chiasm
*Carry ONLY Visual sensory info from eye
Cranial nerve 3/ III
Oculomotor nerve
*ONLY motor nerves
*innervates muscles that move eye
Cranial nerve 4/ IV
trochlear nerve
*motor
*small nerves carrying a little info [superior oblique muscle]
Cranial nerve 5/ V
trigeminal nerve
*large paired nerves carrying BOTH sensory and motor info
Cranial nerve 6/ VI
Abducent nerve
*motor nerve; controls muscle that moves eye
Cranial nerve 7/ VII
facial nerve
*small paired nerve carrying BOTH sensory and motor info
Cranial nerve 8/ VIII
Vestibulocochlear
*Only sensory info from ear
Cranial nerve 9/ IX
Glossopharyngeal nerve
*small paired nerves
*BOTH sensory and motor info
Cranial nerve 10/ X
Vagus nerve
*Big; carries BOTH sensory & motor info
*represents big portion of parasympathetic autonomic NS
Cranial nerve 11/ XI
spinal accessory nerve
*Motor nerve
Cranial nerve 12/ XII
hypoglossal nerve
*motor nerve
Pneuominics for cranial nerves in order + functions
Nerves in order:
Oh once one takes the anatomy final, very good vacations are happening
Functions: sensory/motor/both:
Some say marry money, but my brother says big brains matter more
motor nervous system transmits:
motor information to effectors
effector:
skeletal muscle fiber
_____________ make myelin sheath in CNS.
oligodendrocytes
___________ cells respond to CNS infection
microglial
Multipolar neurons are:
neurons with multiple dendrites
what do interneurons do?
sensory to motor neuron communication
chemical synapse uses a:
neurotransmitter
dendrite is
neuron part that usually receives incoming impulses
dura mater fold between cerebral hemispheres is called:
falx cerebri
which lobe contains the motor speech area?
frontal
first portion of the brainstem is the
midbrain
autonomic center for heart rate and respiration is the
medulla oblongata
cranial nerve X is the
vagus nerve
which lobe is responsible for language comprehension?
temporal lobe
relay center for sensory information is the
thalamus
rapid, involuntary motor reaction is:
reflex
conus medullaris
narrow tapering end cone of spinal cord
cervical enlargement
enlarged diameter of spinal cord for upper extremities
dorsal root
where sensory neurons enter the spinal cord
ventral root
where motor neurons exit the spinal cord
lateral horn contains:
cell bodies of autonomic motor neurons
what is the hormone secreted by the adrenal medulla?
norepinephrine
connective tissue enclosing a nerve is called:
epineurium
parasympathetic division is what kind of divison
craniosacral
sympathetic division is associated with what response?
fight or flight
paravertebral ganglion chain is _________ to spinal cord
lateral
neurotransmitter for all preganglionic axons is:
acetylcholine
gray ramus contains:
sympathetic postganglionic axons only
corpus callosum:
dense white fiber tract/ large bundle of 200 million+ myelinated nerve fibers that connect the two brain hemispheres, permitting communication between the right and left sides of the brain.
Hypothalamus functions
*monitors visceral organ activities
*regulates temperature, pituitary gland control [regulating hormone release]
*emotions, basic body drives
mamillary bodies
small, round inferior projections that function in recollective memory
Pons functions
relays information between higher brain regions; coordinates breathing rhythms
the ___________ physically and functionally connects the brain to the spinal cord
medulla oblongata
arbor vitae
“tree of life”
*distinct white fiber branches indicates areas where info is carried in and out of the cerebellum
pineal body (gland)
[structure, functions]
*small, pea-shaped structure
*regulates circadian cycle [sleep/wake]
*secretes the hormone melatonin
Majority of cerebrospinal fluid CSF is formed through an intricate filtration system which occurs through networks of capillaries called :
choroid plexus
the lateral ventricles are separated from each other by a thin membrane called:
septum pellucidum
the 4th ventricle is connected to the 3d ventricle by a small canal called the:
cerebral (mesencephalic) aqueduct
identify the highlighted area
cauda equina
identify A
conus medullaris
identify blue area
optic chiasm
identify blue area
optic tract
identify blue area
olfactory tract
[bulbs above]
identify blue area
optic nerve (CN II)
identify blue area
Oculomotor nerve (CN III)
identify tiny blue area
Trochlear (CN IV)
identify the blue
pons
identify the blue
Mammillary body
identify the blue
Infundibulum of pituitary gland
identify the blue
Abducent (CN VI)
identify the blue
Trigeminal (CN V)
identify the blue
Vestibulocochlear (CN VIII)
identify the blue
Vagus (CN X)
identify the blue
Hypoglossal (CN XII)
identify small blue area
Spinal Accessory (CN XI)
identify blue area
Glossopharyngeal (CN IX)
identify blue area
Facial (CN VII)
the main receptive structure of the neuron is
dendrites
the brain cortex region not visible on the external surface of the cerebrum is
insula
which nervous system division increases blood flow to GI tract, called rest and digest, associated with vagus nerve, and relaxes the body?
parasympathetic autonomic nervous system
the spinal nerve root that contains only motor neurons is
ventral root
the deep fold of dura mater that lies in the transverse fissure is the
tentorium cerebelli
Sensory neurons can also be described as:
afferent neurons.
In general, nerve impulses travel most quickly along:
myelinated neurons
Stimulation of the occipital cortex (i.e. the surgeon stimulates the cortex with an electrical stimulus) will cause the patient to perceive sensations of:
light and color
[vision, sight]
Neurons that transmit nerve impulses away from the central nervous system are described as:
efferent
The ________________ is the toughest and thickest of the meninges.
dura mater
Bundles of axons (forming white matter) that are located in the central nervous system are called:
tracts
identify D
falx cerebelli
C
B
Identify all parts
A- precentral gyrus
B- central sulcus
C- postcentral gyrus
D- parietal lobe
E- occipital lobe
AB- temporal lobe
AC- cerebellum
AD- medulla oblongata
AE- pons
BD- lateral sulcus
BE- frontal lobe
V [trigeminal]
Identify the red and blue
blue- dorsal side
red- ventral side
identify the blue
fourth ventricle of brain
identify the blue
mesenphalic/Cerebral aqueduct
identify the blue
third ventricle
identify the blue
lateral ventricle
identify the green
Insula lobe of brain
[located deep within the lateral sulcus separating the temporal lobe from the parietal and frontal lobes]
identify the red line
lateral fissure
what is it pointing to?
transverse fissure
identify the blue
thalamus
what is it circling?
hypothalamus
what is it pointing to?
pituitary gland
identify colored area
midbrain
what is it pointing to?
cerebral peduncles
Identify A, B, C, D
A- anterior cerebral artery
B- anterior communicating artery
C- middle cerebral artery
D- posterior communicating artery
Identify E, F, G, H
E- posterior cerebral artery
F- basilar artery
G- vertebral artery
H- internal carotid artery
