Nervous System Flashcards
Organization of Nervous System
- Central Nervous System
1a. Brain
2a. Spinal Cord - Peripheral Nervous System
2a. AFFERENT (to CNS)
2b. EFFERENT (fr CNS)
Process of Nervous System
a. special sensory receptors, visceral receptors, somatic sensory receptos»_space; PNS AFFERENT DIV.»_space; CNS for info processing»_space; PNS EFFERENT DIV»_space;
a. SOMATIC»_space;> skeletal muscles
b. AUTONOMIC»_space; sympathetic or parasympathetic»_space; smooth and cardiac muscles, glands, adipose
2 Tyes of Cells in the Nervous System
Neuroglia
Neurons
SOMA
neuron cell body
PERIKARYON
region around nucleus in neuron
DENDRITES
branching sensory processes on SOMA
In CNS, dendrites are highly branched
SYMPATHETIC NERVES
aka fight or flight
- THORACIC 1 - LUMBAR 2 regions of spinal cord
Short pre-synaptic nerve, long post synaptic
-up heart rate, up respiration rate, control amount of blood reaching target structures, up sweat, pupils dilate, slow digestive process
PARASYMPATHETIC NERVES
aka rest, digest, + read
- BRAINSTEM + SACRAL
regin of spinal cord “craniosacral branches” - up digestion, slow down heart rate, slow down rate of respiration, pupil constriction
- CN III, VII, IX, X + Pelvic Splanchnic Nerves for inferior left abdominal area.
Symphatetic Chain
connects the ganglion vertically
carries PRE-SYNAPTIC sympatehtic fibers to superior and interior paravertebral ganglia
SPLANCHNIC NERVE
contains fibers that do not synapse in chain
1 pre-ganglionic cell body in CNS
2 axon exit out thru spinal nerve and then travel to sympathetic chain
3 nerve fiber descent infeo-medially towards the pre-aortic ganglia
4 post-ganglionic body received and sends to organs
PARASYMPATHETIC NERVOUS SYSTEM
has a motor and sensor function
PARASYMPATHETIC MOTOR
LONG pre synaptic nerve + SHORT synaptic nerve
because synapses between pre and post synaptic nerves takes place either next to or w target organs
ENTERIC NERVOUS SYSTEM
autonimic nervous sys
important for parastalsis
embedded in hollow muscular organs of digestive tract (esophagus to rectum)
has 5x as many neurons then spinal cord
ENTERIC PLEXUSES
1 MYENTERIC (AUERBACH) PLEXUS - within circular layer muscles
2 SUBMUCOSAL (MEISSNER) PLEXUS - deep to mucous linings of organs
Conus Medullaris
Conal end of spinal cord at L1/L2
Cauda Equina
“horse tail”
Inferior to the conus medullaris (end of the spinal cord) are a bunch of axon nerves that continue from L2-Coccyx
Cervical Enlargement +
Lumbosacral Enlargement
parts of the spinal cord with more neural cell bodies.
cervical for upper extremity
lumosacral for lower extremities
Brachial Plexus + Sacral Plexus
Brachial P is main large plexus of Cervical Enlargement
Sacral Plexus is main large plexus of Lumbosacral Enlargement
Meninges of Spinal Cord
Dura Mater
Arachnoid Mater
Pia Mater
Dura Mater of Spinal
outermost covering of spinal cord
forms dural sac which contains the spinal cord within vertebral canal
White Matter
axons/tracts
sends info
Grey Matter
neural cell bodies
processing power
Anterior - motor
Posterior - sensory
SAME
DAVE
Sensory Afferent|Motor Efferent
Dorsal Afferent|Ventral Efferent
Spinal Nerves
mixed nerve formed by unioin of anterior and posterior nerve roots. as it continutes a short length distally, it branches out into anterior and posterior rami
contains both motor + sensory fibers fr spinal cord
Ventral Primary Rami
innervates almost everything else in body especially the extremities
includes plexuses: cervical, brachial, thoracic, and lumbosacral plexuses
Dorsal Primary Rami
innervates a small amount of structures in body: deep back muscles, skin overlying them
Denticulate Ligaments
What makes up the Pia Mater and is found between each vental and dorsal rootlets
Arachnoid Mater
soft transluscent weblike membrane pushed up against Dura Mater (which is superficial) fr pressure of CSF
Pia Mater
delicate layer Spinal Cord Tissue.
Surrounded by SUBARACHNOID SPACE which is surrounded by Arachnoid Mater
Denticulate Ligaments
teeth like extensions of pia mater that holds spinal cord in place laterally onto Dura Mater
Epidural
outside of dura mater but inside of vertebral column
Subarachnoid Space
space bw pia mater and arachnoid mater which is filled w CEREBRAL SPINAL FLUID (CSF)
Cerebral Spina Fluid
CSF
found in subarachnoid space and central canal.
usually retrieved from a spinal tap in L4/L5 or at the filum terminale of sacrum, and cauda esquina
dermatome
an area of skin that is innervated by a single spinal nerve
what part of the brain does the spinal cord attach to superiorly
Medulla
Real.Truckers.Drink.Cold.Beer
Roots: each individual nerve
Trunks: C5 + C6 form Superior Trunk, C7 makes Middle Trunk, C8 + T1 form Inferior Trunk
Divisions: each trunk splits into Posterior Division and Anterior Division
Cords: 3 Posterior Trunks combine into one Posterior Cord, 2 most superior Anterior Divisions will form Lateral Cord, last, inferior Anterior Division will form Median Cord. 3 Cords are surrounding axillary artery
Terminal Branches: Musculocutaneous Nerve (fr Lateral Cord), Median Nerve (fr Lateral and Medial Cord), Ulnar Nerve (fr Medial Cord), Axillary Nerve (fr Posterior Cord), Radial Nerve (fr Posterior Cord)
Brachial Plexus
vertebral: C5, C6, C7, T1
VENTRAL ANTERIOR nerves: C5 C6, C7, C8 T1
Musculocutaneous Nerve
innervates Anterior Arm:
1 coracobrachialis
2 biceps brachii
3 brachialis
dermatome:
lateral cutaneous region (lateral forearm)
from C5, C6, C7
Radial Nerve
innervates Posterior Arm:
1 deltoid
2 teres minor
3 triceps brachii
innervates Anterior Forearm:
4 brachioradialis
5 supinator
dermatome
dorsal aspect of hand and digits (except the tips) from thumb to half of ring finger
Median Nerve
innervates Anterior Forearm:
1 pronator teres
2 flexor digitorum profundus
3 flexor digitorum superficialis
innervates Hand:
4 thenar muscles (thumb)
5 2 lateral lumbricals
6 carpal tunnel to reach 9 tendons
dermatome:
anterior 3.5 digits + palm from thumb to half of ring finger.
posterior 3.5 digits’ tips only!
Ulnar Nerve
innervates Anterior Forearm:
1 flexor carpi ulnaris
2 (only medial part of) flexor digitorum profundus
innervates Hand:
3 2 medial lumbricals
4 intrinsic muscles (15 small muscles)
dermatome:
posterior and anterior aspects of 1.5 digits + palm from middle of ring finger to pinky finger
Nerves of Arms
musculocutaneous nerve (anterior) radial nerve (posterior)
Nerves of Forearm
median nerve (anterior) ulnar nerve (anterior) radial nerve (posterior)
Nerves of hands
median nerve (thenar muscle + lumbricals) ulnar nerve (lumbrical + intrinsic muscles)
Medial Cutaneous Nerve
dermatome
medial forearm and arm from brachial plexus or axilla
Lumbar Plexus
L1-L4
Sacral Plexus
L4-S3
Lower Limb NErves
Lumbosacral Trunk (L4+L5) Femoral Nerve (L2+L4) Obturator Nerve (L2+L4) Sciatic Nerve (L4-S3)
Posterior Gluteal Muscle Nerves
Femoral Nerve
Inferior Gluteal Nerve
Superior Gluteal Nerve
Femoral Nerve
posterior limb:
Psoas Major
Iliacus muscle
L2-L4
Inferior Gluteal Nerve
**inferior, more superficial branching from anterior primary rami
posterior limb:
1 gluteus maximus
Superior Gluteal Nerve
posterior limb:
1 gluteus medius + minimus
2 tensor of fascia lata
Anterior Primary Rami
from L4-S2 into pelvic region and exits via Greater Sciatic Foramen.
Splits into Inferior and Superior Gluteal Nerves (named in location to Piriformis muscle)
Thigh Region Nerves
Femoral Nerve (Anterior Thigh) Obturator Nerve (Medial Adductor Thigh) Sciatic Nerve, Tibial Nerve, Common Fibular Nerve (Posterior Thigh)
Femoral Nerve
Anterior Hip Flexion/Knee Extensor Thigh:
1 Quadriceps Femoris Muscle
2 Rectus Femoris
3 Sartorius
L2, L3, L4; travels via Inguinal Canal, lateral to Femoral Artery
Obturator Nerve
Medial Thigh + Adductors: 1 Adductor Gracilis 2 Adductor Brevis 3 Adductor Longus 4 Adductor Magnus 5 Obturator Externus
branch of Lumbar Plexus from L2, L3, L4
*travels along lateral aspect of pelvic to pass thru Obterator Canal which is within Obturator Foramen (pubis + ischial)
Sciatic Nerve
splits into Tibial Nerve + Common Fibular Nerve
Posterior Hip Extendor/Knee Flexor Thigh:
1 biceps femoris short + long head
2 Semitendinosus
3 Semimembranosus
Lumbosacral Plexus L4, L5, S1, S2, S3.
*exits hip via greater sciatic foramen, enters glutes, and travels posteriorly
Tibial Nerve
Posterior Leg for plantarflexion of ankle: 1 Flexor hallucis longus 2 Flexor digitorum longus 3 Tibialis Posterior 4 Popliteus 5 Gastrocnemius
Distally splits into Medial Plantar N. + Lateral PLantar N. at posterior Dorsum of foot
Common Fibular Nerve
Originates from L4-S2 which form the Sciatic Nerve. Sciatic N
then splits into Common Fibular N. + Tibial N.
Distally splits into Deep Fibular N. + Superficial Fibular N.
Deep Fibular Nerve
Anterior Leg for Dorsiflexion of Ankle: 1 large Tibialis Anterior 2 Extensor digitorum longus 3 Extensor hallucis longus 4 Fibularis Tertius
Dorsum of Foot to extend toes:
5 Extensor digitorum brevis
6 first 2 dorsal interossei muscles
Dermatome:
small wedge of dorsum: medial side of 2nd toe and lateral side of great toe (where flip flip tongs go)
**branch of Common Fibular Nerve
Superficial Fibular Nerve
Lateral Leg Inverion and plantarflexion of foot:
1 Fibularis longus
2 Fibularis brevis
Dorsum of Foot:
mostly sensory so check dermatome
Dermatome
lateral-anterior leg; most of dorsumof foot
**branch of Common Fibular Nerve
Medial Plantar Nerve
Plantar surface of foot: 1 Adductor hallucis 2 Flexor digitorum brevis 3 Flexor hallucis brevis 4 1st lumbrical
dermatome
medial plantar
*from Tibial Nerve
Lateral Plantar Nerve
Plantar surface of foot: 1 Abductor digiti minimi 2 Quadratus plantae 3 Flexor digiti minimi 4 Brevis 5 2-5 lumbricals 6 plantar + dorsal interossei muscles
dermatome
lateral plantar
*from Tibial Nerve
Cluneal Nerves
dermatome
glutes
Posterior Cutaneous N. of Thigh
dermatome
posterior thigh
Anterior Cutaneous N. of Thigh
dermatome
front thigh
Lateral Cutaneous N. of Thigh
dermatome
lateral thigh
Sural N.
dermatome
posterior leg
Nerves of Abdomen
nerves will begin much higher and will travel anteriorly-inferiorly down to target areas
Nerves of Foregut
PARASYMPATHETIC N. from brainstem via VAGUS NERVE:
travels thru Vagus N., passes thru Coeliac Ganglion (no synapse), continues along Coeliac trunk (branches laterally), reaches target organs via synapse.
SYMPATHETIC N. travels via THORACIC SPLANCHNIC N.:
chain of nerves emerge at Coeliac Ganglion where they synapse. Post synaptic axons continue to along the blood supply to their target organs.
Foregut
refers to superior portion of GI tract from mouth to duodenum.
esophagus, stomach, liver, pancreas, spleen, gallbladder, duodenum
innervated by ENTERIC NERVOUS SYSTEM to control secretion and peristalsis
Vagus Nerve
10th cranial nerve (CN X); longest course of any cranial nerve fr brainstem to Celiac Plexus (collection of cell bodies), and to the Celiac Trunk to target organs
Nerves of Midgut
Parasymp. N. course down Vagus N., pass by Celiac Ganglia, continue inferiorly to Superior Mesenteric Artery to target organs
Symp N. arise fr central part of Spinal Cord thru Symp. Chain Ganglias via Thoracic Splanchnic N. to target organs
Midgut
distal part of duodenum, jejunum, ileum, cecum, ascending colon, 2/3 of transverse colon
innervated by Enteric Nervous Sys. controls secretion + peristalsis
Nerves of Hindgut
Parasymp. N. fr S2-S4 via Pelvic Splanchnic N. and course directly to target organs. does not follow blood vessels like others.
Symp. N. Lumber Splanchnic N. fr. L1-L2 course into Inferior Mesenteric Ganglion where branches continue along vessels of Inferior Mesenteric Trunk to target organs
Hindgut
distal Transverse Colon, Descending Colon, Sigmoid Colon, Rectum + Anus
Innervation of Kidneys
Parasymp. N. fr. brainstem via Vagus nerve, passes thru celiac ganglia (no synapse), reaches Aorticorenal Ganglia (no synapse) and reach kidneys
Symp. N. fr L1 via Thoracic + Lumbar Splanchnic N., pass thru Aorticorenal Ganglia to synapse and send post-synaptic axons along to kidneys
Lobes of Cerebrum
Frontal Lobe
Temporal Lobe
Parietal Lobe
Occipital Lobe
Central Sulcus
separates Frontal Lobe fr Parietal Lobe
Longitudinal Fissure
separates the cerebrum into right + left hemispheres
physically divided by FALX CEREBRI a dural unfolding that extends down the fissure
Corpus Callosum
large white matter fiber tract that attached the four lobes
responsible to the left-right pathways in the brain
Frontal Lobe
(motor, memory, emotion, prob solve, speech)
posterior is PRECENTRAL GYRUS that contains Primary Motor Cortex (important for control of mvmt)
Parietal Lobe
(sensory cortex, interpreting mvmt, body orientation)
anterior is the POSTCENTRAL GYRUS that contains Primary Somatosensory Cortex associated w interpreting mvmt
Occipital Lobe
(vision, optic nerves terminate here)
Temporal Lobe
(perception recognition of auditory stimuli, speech patterns, memory)
Superior Temporal Gyrus is Primary Auditory Cortex for receiving + processing sound
Lateral Sulcus
separates Temporal Lobe fr Parietal Lobe
Transverse Fissure
horizontal gap that separates cerebrum from cerebelum
TENTORIUM CEREBELLI meningeal fibersto physically divide these structures
Parietal-occipital Sulcus
separates Parietal Lobe + Occipital Lobe
Cerebellum
“little brain”
coordinates voluntary mvmt, refining mvmt, maintaining balance/posture
located inferior to Transverse Fissure. Densely layered surface called FOLIUM made of tiny infoldings
VERMIS divides the cerebellum into left + right hemispheres
3 Penducles of Cerebellum
Superior - communicates w cerebral cortex
Middle - largest; communicates w PONS
Inferior - communicates w other brain centers
Brainstem
made of Midbrain, Pons, Medulla Oblongata, 10/12 Cranial Nerves
Below conscious awareness
Anterior portion is descending motor signals via Corticospinal Tract
Posterior portion is ascending sensory information via Spinothalamic Tract
Medulla Oblongata
most inferior aspect of brainstem; continuous w spinal cord @ foramen magnum
along w CN XI, IX, XII: carries PARASYMPATHETIC FIBERS for homeostatic functions.
PONS
b/w midbrain and medulla; anterior to cerebellum + 4th ventricle
major communication pathway for cerebrum, cerebellum, + spinal cord. Has CN V-VIII
Midbrain
most superior portion of brainstem
consists of Cerebral Peduncles which allows for communication in/out of cerebellum hemispheres
has Corpora quadrigemini (responsible for reflex actions)
Medullary Olive + pyramid
Olive is more superior lateral. contains olivary nuclie to help learn complex motor mvmt
3 Types of White Matter Tracts
1 Association - communication from one region to another of same cerebral hemisphere
2 Commissural - communicates from one cerebral hemisphere to another for coordination of complex mvmt or behavior
3 Projection - communication be higher + lower brain area and spinal cord centers for motor/sensory info
Ventricular System
ventricle= hollow cavity
1,2 Lateral Ventricles (makes CSF and transfers via Interventricular Foramen) 3rd Ventricle (CSF is received and sent via Cerebral aqueduct) 4th Ventricle (received CSF and transported out of ventricular system thru subarachnoid space and central canal to spinal cord
fluid filled cavities that has Choroid Plexus in all ventricles to make CSF
Lateral Ventricles
internally lined w Choroid Plexus (specialised secretory epithelium responsible for production of CSF)
largest of 4 ventricles
Cranial Meninges
surround + protect the brain
Front part of skull, Crista Gallo, holds the anterior lateral Falx Cerebri
Dura Mater (makes up Falx Cerebri, Tentorium Cerebelli, Disgpragma sellae, and sunises), Arachnoid Mater, Pia Mater
Middle Meningeal Artery
delivers arterial supply
branch of maxillary artery that enters via Foramen Spinosum
Dura Mater Brain Sinus
sagittal, tranverse, sigmoid
responsible for draining venous blood out of the brain
