Anatomy Exam 2 Flashcards

o Cardiac
 Striated muscle (regular array of actin and myosin in the sarcomeres)
 Each muscle has a single, centered nucleus
 Cells are connected by intercalated discs

o Skeletal
 Hundreds of randomly located nuclei per cell (cells fuse together in development)
 Striated

o Smooth
 Single nuclei
 Not striated

muscle covered with epimysium
made up of fascicles (bundle of cells) covered in perimysium
made up of muscle fibers (cells) covered in endomysium
myofibrils (made of molecular motors) make up each muscle fiber and sarcomeres are contained in each myofibril

blood vessels line in between the connective tissue coverings in between the fascicles
sarcolemma is the cell membrane of muscles with invaginations (t tubules) that go into the cells
sarcoplasmic reticulum stores calcium

epimysium- covers whole muscle (allows muscles to contract with respect to each other without friction between them)

perimysium- covers the fascicles

endomysium- covers each muscle fiber

tendons- formed by the fusion of these 3 connective tissues

too much calcium is released and not stored in the sarcoplasmic reticulum so muscle keeps contracting and generating heat

• Actin filaments (thin filaments) are held at the Z line
• Myosin (molecular motor) makes up the thick filament and is located on the A band
o I band only has thin filaments
o A band- mostly thick filaments with some areas where thick and thin filaments overlap
o Z line are thick vertical lines
o H zone/band- only thick filaments
o M line- holds thick filaments together

o The entire sarcomere decreases in width
o A band is the same width
o Z lines are closer together
o I band decreases in width
o Whole sarcomere decreases in width

skeletal muscle
1- Z line
2- H zone
3- I band
4- M line
5- A band

skeletal muscle
1. Z line
2. M line
3. H zone
4. I bands
5. A band
6. Sarcomere

Actin (thin) filaments are made of G proteins with binding sites for myosin that are covered up with tropomyosin when the muscle is relaxed

sarcolemma receives an electrical impulse that releases acetylcholine which causes a change in membrane potential that travels to the t tubules that connects directly to the sarcoplasmic reticulum

sarcoplasmic reticulum then releases calcium

calcium causes a conformation change which causes tropomyosin to be released and the binding site to be uncovered

myosin binding sites are uncovered

ATP oxidation (ADP + Pi -> ATP)causes myosin to flip up in the activated position so actin can bind and begin the power stroke (pulls thin filaments in towards the center)

ATP hydrolysis (ATP-> ADP + Pi) causes ACh to be removed

sarcoplasmic reticulum recaptures calcium

myosin binding site on the actin filament are covered by tropomyosin

contraction ends

no more ATP is left 8-12 hours after death to replace the ADP on the myosin head, so there is no relaxation in muscle tissues

1. triad (2 terminal cisternae and a t tubule in between)
2. sarcolemma (plasma membrane)
3. myofibril (bundled thick and thin filaments, contains a chain of sarcomeres)
4. t tubule (transmit the action potential deep inside the fiber to the terminal cisternae)
5. terminal cisternae (widened sarcoplasmic reticulum that receive t tubule signals)
6. sarcoplasmic reticulum (endoplasmic reticulum that stores calcium)
7. sarcomere (smallest structural and contractile unit of a muscle myofibril)
8. thin filament (mostly actin)
9. Thick filament (mostly myosin)

10. actin (thin proteins)
11. tropomyosin (covers the myosin binding site until calcium releases it)
12. troponin
13. myosin crossbridges (heads project towards actin, myosin cross bridges attach to actin and pull the thin filaments past the thick filaments)
14. myosin tails

muscles of facial expression
facial nerve
2. orbicularis oculi
3. zygomaticus
4. orbicularis oris
5. platysma

facial nerve
to test, have the patient:
orbicularis oculi- shut their eyes tightly
zygomaticus- smile
orbicularis oris- purse their lips
buccinators- whistle (buccinator presses cheek inward)
platysma- depresses mandible (pouting)

2. Orbicularis Oculi (facial expression, facial nerve)
3. Zygomaticus (facial expression, facial nerve)
4. Buccinator (facial expression, facial nerve)
5. Orbicularis oris (facial expression, facial nerve)
6. Masseter (mastication, trigeminal nerve (mandibular))
7. Platysma (facial expression, facial nerve)

muscles of facial expression
infrahyoid (strap) muscles (raise and lower hyoid)
abdominal muscles
splenius and semispinalis capitis (deep neck muscles that hold your head up)
erector spinae (longitudinal deep back muscles responsible for posture)

pectoral girdle- holds the upper extremity to the trunk
upper extremity- mostly in charge of controlling the hand
pelvic girdle- holds the lower extremity to the trunk
lower extremity

upper extremity
flexors are anterior
extensors are posterior

lower extremity
extensors are anterior
flexors are posterior

1. Temporalis (trigeminal nerve, muscles of mastication)
2. Buccinator (facial nerve, facial expression)
3. Orbicularis oris (facial nerve, facial expression)

1. Sternocleidomastoid (Neck muscles)
2. Splenius Capitis (Neck Muscles)
3. Trapezius (Scapula movers and stabilizers)
4. Levator Scapulae (scapula movers and stabilizers)
5. Platysma (facial expression)

1. Infrahyoid muscles (neck muscles)
2. Suprahyoid Muscles (neck muscles)
3. sternocleidomastoid (neck muscles)

trigeminal nerve (mandibular)

Temporalis- elevates and retracts mandible
Masseter- elevates and retracts mandible

innervated by the cervical plexus

sternocleidomastoid (flexes head (looking down), rotates "no")
infrahyoids (depresses the hyoid bone during speaking and swallowing)
suprahyoids (elevates the hyoid bone during speaking and swallowing)
splenius capitis (holds your head up, helps to turn your neck)

1. Platysma (facial expression)
2. Pectoralis Major (movers of the shoulder joint)
3. Latissimus Dorsi (movers of the shoulder joint)
4. Serratus Anterior (Scapula movers and stabilizers)
5. External oblique (abdominal wall)
6. sternocleidomastoid (neck muscles)
7. Trapezius (scapula movers and stabilizers)
8. Internal intercostals (respiratory muscles)
9. External intercostals (respiratory muscles)
10. Internal Oblique (abdominal wall)
11. Transverse abdominus (abdominal wall)
12. Rectus Abdominis (abdominal wall)

innervated by the lumbar plexus
• External oblique- most superficial side, runs down your sides (down and medially)
• Internal oblique- run up and medially under the external oblique and deeper
• Transverse abdominus-comes across (run transversely)
• rectus (straight) abdominalis- 6 pack muscles

anterior: innervated by the brachial plexus
serratus anterior- abducts scapula and rotates it upward (throwing a punch), holds the scapula to the trunk, wings scapula back if it is injured

posterior
trapezius- shoulder shrugging, test by having a patient shrug their shoulders against resistance (accessory nerve)
levator scapulae- elevates scapula and rotates it downward (dorsal rami)
rhomboids- elevates and adducts scapula and rotates it downward, stabilizes scapula (dorsal rami)

all are innervated by the brachial plexus

Posterior and anterior
deltoid- powerful abductor (raises shoulder and arm away from the body, anterior medically rotates arm, posterior laterally rotated the arm)

Anterior
Pectoralis Major- flexor (moves the humerus towards the trunk), stretchs from the chest to the humerus

posterior
Teres Major- extends, adducts, and medially rotates the arm
latissimus dorsi- pulling the arm down if it is above your head (swimming)

lateral

coracobrachialis- flex and medially rotate the arm

1. sternocleidomastoid (neck muscles)
2. Trapezius (scapula movers and stabilizers)
3. Deltoid (movers of the shoulder joint)
4. Infraspinatus (movers of the shoulder joint, rotator cuff)
5. Teres Major (movers of the shoulder joint)
6. Latissimus Dorsi (movers of the shoulder joint)
7. External Oblique (abdominal wall)
8. Splenius Capitis (neck muscles)
9. Levator Scapulae (scapula movers and stabilizers)
10. Rhomboids (scapula movers and stabilizers)
11. Supraspinatus (movers of the shoulder joint, rotator cuff)
12. Teres Minor (movers of the shoulder joint, rotator cuff)

erector spinae- group of longitudinal deep back muscles, responsible for posture, helps to turn the neck

innervated by the dorsal rami

1. Subscapularis (movers of the shoulder joint, rotator cuff)
2. Teres Major (movers of the shoulder joint)
3. Coracobrachialis (movers of the shoulder joint)
4. Biceps Brachii (movers of the elbow joint)
5. Supraspinatus (movers of the shoulder joint, rotator cuff)
6. Infraspinatus (movers of the shoulder joint, rotator cuff)
7. Teres Minor (movers of the shoulder joint, rotator cuff)
8. Triceps Brachii (movers of the elbow joint)

SITS

innervated by brachial plexus and branches

supraspinatus- posterior, assists the deltoid in abducting the arm
infraspinatus- posterior, laterally rotates and adducts the arm
teres minor- posterior, laterally extends, adducts, and rotates the arm
subscapularis- anterior, medially rotates the arm

little branches that have motor and sensory rami (mixed spinal nerves)

only go to the deep back muscles and skin on the back

innervates the erector spinae and splenius capitis

when people break their humerus they can damage thier radial nerve (part of the brachial plexus)

cannot extend their arms/wrist, everything is flexed

triceps brachii- major extensor of the upper extremity

biceps brachii- flexes the arm

brachialis- most powerful flexor of the forearm

brachioradialis- weak flexor of the elbow

1- subscapularis (movers of the shoulder joint, rotator cuff)
2- teres major (movers of the shoulder joint)
3- biceps brachii (movers of the elbow)
4- brachialis (movers of the elbow)

1- pronator teres (movers of the wrist and fingers)
2- flexor carpi radialis (movers of the wrist and fingers)
3- brachioradialis (movers of the elbow)
4- palmaris longus (movers of the wrist and fingers)
5- flexor carpi ulnaris (movers of the wrist and fingers)

All flexors or abductors

1. biceps brachii (flexes arm)
2. brachialis (flexes forearm)
3. pronator teres (pronates and weakly flexes forearm)
4. brachioradialis (flexes forearm)
5. flexor carpi radialis (flexes wrist)
6. palmaris longus (weakly flexes wrist)
7. flexor carpi ulnaris (flexes and adducts hand)
8. flexor digitorum (flexes the digits-IMPORTANT)
9. flexor pollicis longus (flexes distal phalanx of thumb)
10. Abductor Pollicis brevis (abducts the thumb)

1- extensor carpi radialis (extend and adduct hand)
2- extensor carpi ulnaris (extends and adducts hand)
3- extensor digitorum (extends hand and phalanges)
4- flexor carpi ulnaris (flexes and adducts hand)

space in the wrist containing flexor digitorum tendons and median nerve

carpal tunnel syndrome- overuse of the hand causes the tendons to become inflamed which compresses the median nerve

Adductor Longus
pectineus
iliopsoas- major hip flexor
tensor fascia lata- flexes and abduct the thigh
gluteus maximus
gluteus medius
piriformis
sartorius- flexes leg and flexes, abducts and laterally rotates the thigh (allows us to cross our legs)
gracilis

changes in the hand depending on where the brachial plexus was injured

claw hand

Crutches push on the brachial plexus and can cause numbness in the hands when the brachial plexus is compressed (affects all nerves of the upper extremity)

innervated by the brachial plexus
lumbricals- little worms, flex the metacarpal joint
abductor pollicis- abducts the thumb
flexor retinaculum- carpal tunnel is underneath
interossei- muscle group in hand

gluteus maximus- powerful extensor of the hip joint
gluteus medius- abducts and medially rotates the thigh

test gluteal region strength by having someone sit in a chair and and stand up without using their hands or by walking up stairs

1- iliopsoas
2- tensor fasciae latae
3- sartorius
4- rectus femoris (Quadriceps)
5- iliotibial tract (tendon, abducts the thigh)
6- vastus lateralis (Quadriceps)
7- vastus intermedius (Quadriceps)
8- vastus medialis (Quadriceps)
9- pectineus
10- adductor longus
11- gracilis

medial adductors in the groin region are innervated by the obturator nerve

adductor longus (anterior, medial adductor)
pectineus (anterior, adducts and flexes thigh)
iliopsoas (anterior, major hip flexor)
tensor fascia lata (lateral, adductor of the thigh)
gluteus maximus (posterior, powerful extensor of the hip, laterally rotates the thigh)
gluteus medius (posterior, adducts and medially rotates the thigh)
piriformis (deep posterior, laterally rotates and extends the thigh, sciatic nerve is underneath it)
sartorius (anterior, allows us to cross our legs, innervated by the femoral nerve)
gracilis (anterior, adducts and medially rotates thigh, flexes leg)

hip adductors get injured in a groin pull

largest nerve in the body
branches into the tibial nerve (posterior) and the fibular nerve (anterior)

sciatic nerve and its branches innervates mostly the whole lower extremity (except parts of the thigh)

piriformis syndrome- an overactive piriformis (sciatic nerve sits underneath the piriformis)caused a compressed sciatic nerve which causes major lower extremity problems

Quadriceps (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius)- knee extensor, innervated by the fibular nerve

hamstrings (bicep femoris, semimembranosus)- flexes knee (more important) and extends the hip

1- inguinal ligament
2- gracilis
3- adductor longus

1- gluteus medius
2- gluteus maximus
3- gracilis
4- iliotibial tract (tendon, abducts the thigh)
5- semimembranosus
6- biceps femoris (hamstring)

gastrocnemius- posterior, plantar flexes the foot and flexes the leg
soleus- posterior, plantar flexes the foot
fibularis (peroneus) longus- lateral anterior, plantar flexes and everts the foot
fibularis brevis
tibialis anterior- lateral anterior, dorsiflexes and inverts the foot (innervated by the fibular nerve)
tibialis posterior- inverts the ankle
flexor digitorum longus- posterior, flexes the toes
flexor hallucis longus- posterior, flexes the big toe
extensor digitorum- lateral anterior, dorsiflexes the foot and extends the toes (innervated by the fibular nerve)
extensor hallucis longus

anterior leg muscles dorsiflex (extend) the ankle
tibialis anterior and posterior (together) invert the ankle
deeper posterior leg muscles cause plantar flexion of toes
lateral leg muscles are everters

1= tibialis anterior
2= extensor digitorum
3- fibularis (peroneus) longus
4= fibularis (peroneus) brevis
5= gastrocnemius
6= soleus
7= flexor digitorum longus

1- gastrocnemius
2- soleus
3- fibularis (peroneus) longus
4- flexor hallucis longus
5- calcaneal (Achilles) tendon

1- tibialis posterior
2- flexor digitorum longus
3- flexor hallucis longus

injury to the fibular nerve causes the foot to stay plantarflexed (lack of dorsiflexion, toes point down)

fibular nerve is the most commonly injured nerve in the body

CNS- brain and spinal cord, develops from neural tube
integrates sensory (afferent) and motor (efferent) information

PNS- formed from neural crest cells that migrated from the neural tube
 Somatic (innervated skeletal muscle), autonomic (innervates smooth muscle, cardiac muscle, and glands), and sensory ganglia brings information into the nervous system
connected to receptors and effectors

PNS
develop from neural crests
myelinate peripheral axons (form protective covering for all axons)

disease that affect peripheral myelin usually go away

cells that myelinate axons of the CNS
diseases of the CNS myelin are usually contiguous (ex. multiple sclerosis goes on and off but is usually progressive)

motor neuron
3- dendrites
4- axon
5- axon hillock
6- cell body
7- nucleus

1. axon terminal
2. schwann cell
3. node of ranvier
4. axon collateral
5. axon
6. dendrites
7. cell body
8. axon hillock
9. trigger zone
10. myelin sheath of schwann cell

sensory neurons (afferent)- conduct signals from receptor to CNS when environmental changes are detected, unipolar neuron

interneuron (association)- confined to CNS, multipolar neurons

motor neuron (efferent)- conduct signals from the CNS (spinal cord) to effectors such as muscles and glands, multipolar neurons

1- unipolar (sensory (afferent) neuron)
2- multipolar (interneuron)
3- bipolar (motor (efferent) neuron)

dorsal root ganglia, unipolar cells

1= process
2= satellite cells
3= nucleus
4= neuron cell body

cerebral cortex, multipolar neurons

5- neuron cell body
6- nucleus
7- process

1- neurolemma
2- myelin sheath
3- node of ranvier
4- axon

Spinal nerves (below the neck)- sensory and motor

Autonomic Nervous System (ANS, innervates things that are automatic, spinal or cranial nerves, ex. salivation)- sympathetic and parasympathetic

Cranial nerves (generally innervate the things in the head, ex. salivation)- come off the brain but innervate structures outside of the CNS

(“horse’s tail”)= nerve roots at the lower part of the spinal cord (lumbar and sacrum)

At birth the spinal cod has equal length as the vertebra (spinal cord and spinal nerve labels match their places in the vertebral column)

As an adult the spinal cord ends at the L1/L2 vertebrae since the spinal cord grows much slower then the vertebral column. Vertebrae pulls nerve roots down with it during development so the nerve roots still exit at their appropriate vertebrae

best place for a Lumbar puncture/spinal tap

Best place to get cerebral spinal fluid (CSF) is between L4 or L5 in the cauda equina because you can get CSF without puncturing the spinal cord since there is lots of CSF and only small nerve roots (like sticking a fork into cooking spaghetti)

1. posterior root
2. lateral white column
3. central canal
4. posterior median sulcus
5. posterior white column
6. posterior gray horn
7. posterior root ganglion
8. anterior root
9. anterior gray horn
10. anterior white column
11. Gray commissure
12. Anterior median fissure

cross section of spinal cord

1- pia mater- delicate covering where small blood vessels are located
2- dura mater- tough, plastic like outer covering
3- epidural space- space in between the dura mater and vertebral bone where epidural anesthesia is injected for pelvis and lower extremity surgeries
4- subarachnoid space- where cerebral spinal fluid is located
5- arachnoid matter- spider web-like covering

cross section of spinal cord

1- spinal nerve
2- posterior root ganglion
3- posterior root
4- posterior median sulcus
5- central canal
6- anterior root
7- anterior median fissure
8- white matter
9- gray matter

5- sympathetic ganglion
6- spinal nerve
7- intervertebral foramen
8- anterior ramus
9- posterior ramus
10- rami communicantes

1- sacral plexus
2- lumbar plexus
3- brachial plexus
4- cervical plexus
5- cervical nerve
6- thoracic nerve
7- lumbar nerve
8- sacral nerve
9- coccygeal nerve

1- axillary nerve
2- musculocutaneous nerve
3- median nerve
4- ulnar nerve
5- radial nerve
6- phrenic nerve

1- obturator nerve
2- pudendal
3- femoral nerve
4- sciatic
5- tibial
6- common fibular

1- cerebrum
2- cerebellum
3- diencephalon
4- brain stem

1- olfactory bulb
2- olfactory tract
3- pituitary gland
4- optic tract
5- mammillary body
6- cerebellar peduncles
7- olive
8- pyramids
9- spinal nerve C1
10- spinal cord
11- cerebrum
12- cerebral peduncle of midbrain
13- pons
14- medulla oblongata
15- cerebellum

blood vessels that run between the dura mater and the skull

 if one breaks they bleed between the dura and the skull- epidural hematoma (creating a space that shouldn't be there, arterial bleed so it compresses the brain pretty rapidly)

 Middle meningeal artery- between the dura and the temporal bone
• Artery that breaks if someone gets hit in the temporal part of the head

normally occurring and blood drains from bridging veins from the brain and the subarachnoid space into these sinuses that eventually form the jugular vein

 If a brain shrinks (can happen with aging and dementia) then the bridging veins stretch and if someone hits their head, then the veins will rupture and cause a subdural hematoma

• Subdural hematoma- slow bleed, person becomes confused, major problems later, serious but difficult to diagnose
• Bleeds into the subdural space

o Arteiries in brain also travel through the subarachnoid space
 Artery break- subarachnoid hematoma
• Weakness in walls of arteries of high blood pressure

consists of the midbrain (processes visual and auditory data), pons (relays sensory information to cerebellum and thalamus) and medulla (relays sensory information to thalamus)

origin of all cranial nerves (except I and II)

many nervous pathways travel through the brainstem

31 levels of the spinal cord (each level gives off mixed spinal nerves (motor and sensory))

8 cervical spinal cord levels (7 cervical vertebrae)
12 thoracic spinal cord levels (1 for each rib)
5 lumbar levels
5 sacral levels
1-2 coccygeal levels (usually considered to have 1)

White matter (axons) are on the outside of the spinal cord carrying sensory info up to the brains and motor info down to the limbs

Gray matter-cell bodies (sensory info enters at the dorsal root via the dorsal horn (dorsal root ganglia are sensory cell bodies), ventral part of gray matter contains motor neuron cell bodies that exit the spinal cord at the ventral root)

Dorsal root ganglia- sensory cell bodies
Dorsal root- bringing info into the spinal cord (sensory neurons, unipolar)
Ventral root- axons of motor neurons, goes directly to muscles

Mixed spinal nerves- signals to and from the goal location (everywhere neck down), travel in the same nerve in opposite directions like a highway, made by dorsal and ventral roots joining, split into dorsal and ventral rami

Dorsal rami-only innervates deep back muscles, erector spinae muscles, skin of midline of the back

Ventral rami- much larger than dorsal, innervates everything else that isn’t covered by dorsal rami (neck and below), can go off on their own or form plexi (how upper and lower extremities are innervated)

all from the brachial plexus

musculocutaneous- flexors of arm (biceps and brachialis)

median- most flexors of the wrist, lateral phalanges, most thumb muscles. passes through the carpal tunnel

ulnar- some flexor of the wrist, all flexors of medial phalanges (funny bone, medial side of humerus)

radial- all extensors of the upper extremity

axillary- deltoid and part of the rotator cuff

o dermatome- sensory information from a single dorsal root
If you injure a dorsal root you get a dermatome pattern of sensory losses

shingles-the virus lives in a dorsal root and becomes activated and comes out of a dorsal root to cause painful symptoms along a dermatome (single stripe pattern on skin)

all are made from ventral rami

cervical plexus: C1-C5, innervates strap muscles
brachial plexus: C5-T1, innervates the entire upper extremity, has 5 branch nerves
T2-T12 we don't form plexi, just intercostal nerves
Lumbar plexus: L1-L5, innervates abdominal muscles
Sacral Plexus: S1-S4
Lumbosacral plexus- gives rise to sciatic nerve which innervates the entire lower extremity

five rise to the following nerves

femoral nerve- innervates quadriceps

obturator nerve- innervates adductors

sciatic nerve- L4 to S3 (largest nerve in the body)
innervates hamstrings
gives rise to: tibial nerve (innervates all flexors), and fibular nerve (innervates all extensors)

sacral nerve damage- bladder and bowel problems due to parasympathetic innervations

all glands and smooth muscle innervations and cardiac muscle
parasympathetic and sympathetic nervous systems

both parasymp and symp divisions have 2 motor neurons between the spinal cord and the effectors (the first motor neuron (preganglionic) synapses with the second motor neuron (postganglionic) in the ANS ganglia

Sympathetic- go everywhere (innervated sweat glands in skin that are located everywhere), preganglionic sympathetics located in 14 thoracolumbar (T1-L2 in CNS), in chain that extends the entire length of the trunk, Every spinal nerve from C1 to coccygeal must have sympathetic innervations

Parasympathetic- in head in places that drip [pupil of eye, lacrimal gland (tears), salivary gland], vagus nerve (heart, lungs), sacral nerve (bowel and bladder)
go to oculomotor nerve (constrict pupils) and facial nerve (glands(

motor fibers for muscle
postganglionic sympathetic fibers to innervate sweat glands in skin
sensory fibers for sensation

brainstem (formed by 6,7,8)

6- midbrain
7- pons
8- medulla oblongata
9-spinal cord

cerebellum

1- cerebellar hemispheres
2- vermis
3- folia
4- superior colliculus
5- inferior colliculus
6- arbor vitae (white matter)
7- cerebellar cortex (gray matter)
8- pons
9- medulla oblongata

1- pineal gland
2- thalamus
3- hypothalamus
4- diencephalon
5- cerebrum
6- cerebellum
7- spinal cord
8- midbrain
9- pons
10-medulla oblongata
11- brainstem

diencephalon

5- mammillary body
6- pineal gland
7- thalamus
8- intermediate mass of thalamus
9- hypothalamus
10- infundibulum
11- pituitary gland
12- optic chiasm

cerebrum

1- internal capsule
2- cerebral cortex
3- white matter
4- corpus callosum
5- fornix
6- basal nuclei

1- central sulcus (shallow groove separating the frontal lobe and parietal lobe)
2- postcentral gyrus (elevation located just posterior to the central sulcus)
3- parietal lobe
4- occipital lobe
5- transverse fissure (deep groove separating the cerebrum from the cerebellum in the posterior/ inferior part of the brain)
6- precentral gyrus (elevation located just anterior to the central sulcus)
7- frontal lobe
8- insula (inner lobe deep to the lateral cerebral fissure)
9- temporal lobe (cut)

1- Broca's speech area
2- primary gustatory area
3- primary motor area
4- central sulcus
5- primary somatosensory area
6- primary visual area
7. Wernicke's area
8. primary auditory area

1- subarachnoid space
2- arachnoid villus
3- falx cerebri
4- white matter
5- superior sagittal sinus
6- parietal bone
7- dura mater
8- arachnoid mater
9- pia mater
10- cerebral cortex

8- lateral ventricles
9- interventricular foramen
10- 3rd ventricle
11- cerebral aqueduct
12- 4th ventricle
13- central canal of the spinal cord

14-superior sagittal sinus
15- arachnoid villus
16- subarachnoid space
17- lateral ventricle
18- choroid plexus
19- 3rd ventricle
20- cerebral aqueduct
21- 4th ventricle
22- central canal

groove that separates the frontal and parietal lobes

part of the motor areas to the cerebral cortex

located in the precentral gyrus of each frontal lobe

controls impulses to muscles

• A lot of cortex controls the face, fingers
• Medially controls toes and lower extremities
• Lateral cerebral cortex stroke- effects of facial expression, speech (left side), movements of hands and fingers
o Problems with motor control on the opposite side

 Premotor (or motor association) cortex- programs of motor movement are made

part of the motor areas to the cerebral cortex

located anterior to the primary motor cortex

initiates impulses that result in speech

• Lateral cerebral cortex stroke- effects of facial expression, speech (left side), movements of hands and fingers

part of the sensory areas to the cerebral cortex

determines where on the body the sensory stimulation occurred

mostly devoted to hands and face

part of the sensory areas to the cerebral cortex

in the temporal lobe

interprets auditory stimuli from auditory receptors

part of the sensory areas to the cerebral cortex

receives impulses from taste receptors

judgement and decision making

in occipital lobe

part of the sensory areas to the cerebral cortex

receive information from the retina and interprets the visual stimulu

located on in the temporal lobe

part of the sensory areas to the cerebral cortex

receives impulses from olfactory receptors

part of the association areas to the cerebral cortex

recognize spoken words, translates words into thoughts, and possibly helps us sound out strange or new words

part of the association areas to the cerebral cortex

adjacent to their corresponding sensory cortex

integrate sensory information from the sensory cortex with past experiences

crossing pathways from one side of the brain to the other

o Corpus callosum (connects 2 cerebral hemispheres)- major commissure
 Almost everything in the right cortex contributes info to the left cortex via crossing fibers
o Optic chiasm is another example

o Projects from higher to lower
o Like for your cerebral cortex (motor cortex) to tell your muscles what to do you need fibers that go from the cortex to the spinal cord (motor neurons for muscles are in the spinal cord, for these neurons to fire they need a signal from the cortex)
o Projection pathways- north to south or south to north

connect parts of our brain on the same side

ex. seeing and interpreting what your hand is writing

huntington's disease

the patient cannot suppress unwanted movements

• Basal ganglia (deeper nuclei, gray matter)- suppresses unwanted movement

2 hemispheres with the vermis connecting them

regulates posture and balance, smooths and coordinates skilled skeletal muscle movements

2 main regions: thalamus, hypothalamus, and epithalamus

thalamus- gets all sensory infor except olfaction (olfaction needs to be faster for survival)
suppresses unwanted sensory infor- allows for focus, selects what sensory info is important and sends it to the cerebral cortex

hypothalamus- control many bodily functions and homeostasis
contains the optic chiasm- where the optic nerve crosses

epithalamus- contains some glands

head trauma (brain swelling, broken artery) causes the brain to squish to the only space available which compresses the oculomotor nerve

uncus is a piece of the temporal lobe that herniates if the brain swells which pushes on the oculomotor nerve
o Pupils cannot compress and stay dilated and are not responsive to light

tumor of Schwann cells (peripheral nervous system cells), compresses nerve VIII (vestibulocochlear and facial VII), and can affect the cerebellopontine angle (angle between the cerebellum (important for coordination) and the pons)
• Nerve damage causes uncoordinated gate, droopy face, hearing loss, ringing in the ears can only all happen together at the cerebellopontine angle

CSF leaks out of the choroid plexus blood vessels
ependymal cells with cilia push the CSF in one direction into the lateral ventricle

the CSF then moves into the 3rd ventricle then into the 4th ventricle via cerebral aqueducts

the CSF then goes into the subarachnoid space surrounding the brain and spinal cord (CSF follows the central canal of the spinal cord then goes back into the subarachnoid space)

CSF it then returned to the blood through arachnoid villi located at the superior sagittal sinus

I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal (Ophthalmic, Maxillary, Mandibular)
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal

Oh, Oh, Oh To Touch And Feel Very Good Velvet, AH

1. olfactory
2. optic
3. Oculomotor
4. Trochlear
5. Trigeminal (Ophthalmic, Maxillary, Mandibular)
6. Abducens
7. Facial
8. Vestibulocochlear
9. Glossopharyngeal
10. Vagus
11. Accessory
12. Hypoglossal

• Usually if you have a problem with one olfactory nerve then the other one will take over

You may regenerate olfactory neurons (but not any others)
Olfactory nerves are tiny branches that are attached to receptors, axons go through the cribriform plate then form into the olfactory nerve
What we often call the olfactory nerve is actually the olfactory tract (CNS)

Test by having a patient smell something through one nostril at a time

purely sensory

goes straight to the cerebrum for processing (only sensory nerve that doesn't go through the thalamus)

Optic nerve starts in the retina ((retinal ganglion cells give rise to the optic nerve [myeleinated by an oligodendrocyte which speeds up conduction in the CNS]). Optic nerve is very fast conducting nerve

Actually a CNS tract

Right visual field process on the left side of the brain, visa versa

Tested using visual fields, doctors move fingers from lateral to medial parts of visual fields

CNS disease affecting myelination and oligodendrocytes

deteriorates CNS myelin and is first noticed in the optic nerve since conduction is usually so fast

when the optic nerve crossed over in the brain above the pituitary gland (commissure). Optic nerve comes from the lateral part of your visual field.

Pituitary gland tumors causes “tunnel vision” which limits your vision into the center of your visual field due to damage to the optic chiasm, damages the crossing fibers

Always tested together, more extra-ocular muscles

Oculomotor- innervates the levator palpebrae (oculomotor lesion would cause trouble elevating the eyelid) and 4 extra ocular muscles and pupil (parasympathetic, constrict)
Oculomotor Damage- causes droopy eyelid (ptosis) and a dilated pupil

Trochlear lesion- Can’t look down and in (trouble reading)
Abducens- abducts the eye, cannot abduct both eyes are the same time (one abducts and the other stays neutral)

test these by observing eyelids (ptosis is abnormal), moving eye in different directions, and making sure pupil constricts

main sensory nerve to the head, motor to muscles of mastication (gives you sensation on your face)

• Ophthalmic nerve (afferent, corneal blink reflex with facial nerve)- innervates forehead and cornea
o Test afferent by putting a whisp of cotton on their eye to get them to blink or tap forhead
o Afferent=ophthalmic, efferent=facial -> V-VII reflex

• Maxillary nerve- innervates the upper teeth, cheek, around the nose (purely sensory)

• Mandibular division- lower teeth, chin, motor component
o Trigeminal motor component- muscles of mastication (chewing, temporalis, masseter)
test by tapping chin

motor to muscles of facial expression, taste, anterior 2/3 of tongue, ANS to lacrimal submandibular and (sublingual)salivary glands

Innervates muscles of facial expression- test it by having the patient make faces or by testing the corneal blink reflex

Carries taste, autonomic to the lacrimal gland and 2 of the salivary glands

corneal blink refllex (V-VII)
shutting the eye is a muscle (nerve VII) for facial expression (open with III-oculomotor), puff of air causes patient to blink which tests facial nerve

purely sensory

Tumor on VII cranial nerve- dizziness, ringing in ears, hearing loss
Acoustic Schwannomas

sensory to pharynx (back or throat, or motor to 1 small pharynx muscle)
taste, posterior 1/3 of tongue
visceral sensory

Test using the gag reflex (IX-X reflex)- sticks a tongue depressor on the tongue to push it down and see the back of the throat and make you gag
Afferant- IX (vagus), constricts pharynx
Efferent- causes gag (X)

Motor:larynx and pharynx
ANS: visceral organs
Sensory:visceral organs
Taste

Vagabond: wanders out of the head to innervate the pharynx and larynx (swallowing and speaking)
Parasympathetic to all the organs down to the the small intestine
Tested using the gag reflex (IX-X reflex)

Accessory (XI)- innervates sternocleidomastoid (test by having the look from side to side) and trapezius (check by putting hands on pts shoulder and having them shrug against resistance)

Hypoglossal (XII)- innervates the muscles on the tongue, test by sticking the tongue out and having the patient move it from side to side, damage on one side has the tongue pointed towards the side of the lesion

1. interneuron
2. sensory neuron (afferent)
3. sensory receptor
4. preganglionic motor neuron
5. autonomic ganglion
6. postganglionic motor neuron
7. visceral effector

1. superior oblique
2. superior rectus
3. lateral rectus
4. medial rectus
5. inferior oblique
6. inferior rectus

1. scleral venous sinus
2. ciliary muscle
3. ciliary process
4. ciliary body
5. choroid
6. sclera
7. retina
8. cornea
9. pupil
10. iris
11. suspensory ligaments
12. ora serrata

retina

1. macula lutea
2. central fovea
3. blood vessel
4. optic disc

6. cornea
7. pupil
8. iris
9. ciliary body
10. lens
11. choroid
12. sclera
13. retina
14. optic disc
15. optic nerve

retina

1. lobule
2. auricle
3. helix
4. external ear
5. malleus
6. incus
7. stapes attached to oval window
8. middle ear
9. internal ear
10. auditory tube
11. tympanic membrane
12. external auditory canal

1. anterior semicircular canal
2. posterior semicircular canal
3. lateral semicircular canal
4. ampulla of semicircular canal and duct
5. utricle
6. saccule
8. membranous semicircular duct
9. vestibule
10. round window
11. cochlea
12. cochlear duct

fibrous (cornea=clear layer, sclera= opaque layer)

choroid (highly vascular, gives rise to iris and ciliary body)

retinal layer (inner, sensory (photo) receptors)

connective tissue layer that lines the eyelid, makes a bend and reflects over the sclera, does not go over the cornea (or you wouldn’t be able to see)
 Contact lenses can get stuck behind the ledge

o Light goes through the cornea, through the anterior chamber of the eye through fluid, through the pupil, through the lens where its focused, through the vitreous (eye jelly) then to the retina

o Aqueous humor- circulating fluid, produced by cells in Ciliary body, circulated then is reabsorbed in the canal of schlemm
 If the canal of schlemm is blocked then pressure builds in the eye and causes glaucoma

o Middle ear has ossicles (tiny bones) that vibrate with sound waves and that vibration is transduced to pressure waves which is then transduced to an electrical signal in the cochlea
o Hair cells run against the tectorial membrane to transmit sound
o 2 tiny muscles (tensor tipany, )that are in the ear that contract with very large sounds to dampen the sound and damaging the cochlea

• innervated by the cranial nerves III (oculomotor), IV (trochlear), VI (abducens)
• ocular motor nerve- droopy eye lid, opens the eye (lavatory palpebrae)
• lateral rectus- abducens nerve, that abducts, lets the eye move laterally

axon terminals on a neuromuscular junction

arrows point to motor end plates

cochlea

ganglion

neuron
arrow pointing to nissl substance

peripheral nerve in cross section
arrow is pointing to perneurium

spinal cord

1. dorsal horn (gray matter)
2. white matter
3. Ventral horn (gray matter)

lumbodorsal (thoracolumbar) fascia (tendon)

central tendon of the diaphragm

1. flexor retinaculum of the wrist (tendon)
2. median (nerve)