Exam 1 anatomy

Peripheral nervous system

Cranial nerves

Spinal nerves

\#of cranial nerves

12

Right and left for each

\#spinal nerves

31 pairs

Right and left for each

Spinal nerve root

Within the vertebral canal

Ventral root

Motor

Efferent

Dorsal root

Sensory

Afferent

Activation happens somewhere in the body

Rami

Mixed spinal nerve

Outside vertebral canal

Sensory and motor

Ventral rami

Anterior and lateral trunk limbs

Dorsal rami

Joints of column skin and muscles of paraspinal region

Root

An organization of fibers by function

Motor or sensory

Located within the vertebral canal

Ramus

An organization of fibers by target location

\-paraspinal region vs rest of body wall and limbs

First division of a spinal nerve after it exits the intervertebral foramen

Spinal nerves

Branches directly off of the spinal cord

Plexus

A network of nerves

Brachial plexus

Network of 6 spinal nerves

C5-T1

Branches

Often named for the region where it exists or its target

Cutaneous nerve

A sensory nerve that supplies the skin

Motor nerve

A branch that innervates skeletal muscle producing movement

Pure efferent nerve

Motor impulse from CNS to muscles (

Most peripheral nerves are

Sensroimotor nerves

have terminal cutaneous and motor branches

Fascicles

Bundles of nerve fibers

Connective tissue surrounds the fiber bundles

Nerve fibers

Axons and dendrites that are processes of neurons

\-specifically the process of the cell body of a neuron

\-propagate an action potential

Myelin

Insulating material helps to propagate the action potential

Nodes of ranvier

Classification of fibers in PNS by target

Somatic or body wall

\-skin skeletal muscles and joints

Autonomic or visceral

\-organs glands smooth muscle

Classification of fibers in PNS by function

Afferent or sensory

\-propagates action potentials to the CNS from the periphery

Efferent or motor

\-propagate action potentials from the CNS to the periphery

Somatic- sensory

Touch pain temperature from body wall and limbs

Innervate discrete areas of skin

Conscious sensation

Autonomic -sensory

Pain from organs

Sensitive to pressure (distension) or lack of blood supply not too discrete

Not a great level of specificity

Somatic -motor

Motor impulses to skeletal muscle

Innervates specific muscles

Voluntary movement

Autonomic- motor

Motor impulses to smooth muscle

Autonomic nervous system

2 neuron system

One neuron in the spinal cord or brain

—preganglionic (presynaptic) neuron and associated fiber

One neuron in the peripheral ganglion

—postganglionic (postsynaptic) neuron & associated fiber

Ganglion

Cluster of neurons

\-no peripheral ganglion associated with the somatic nervous system

Sympathetic nervous system (ANS)

Fight or flight

Preganglionic neuron - in thoracic and upper lumbar spinal cord (T1-L2)

—-short preganglionic fiber

Postganglionic neuron - in sympathetic chain ganglion

—-long postganglionic fiber

Parasympathetic nervous system (ANS)

Homeostatic response

Preganglionic neuron - in brain or sacral spinal cord (CN 10)

—-long preganglionic fiber

Postganglionic neuron - in peripheral ganglia near the target organ

—-short postganglionic fiber

Example of sympathetic motor

Contraction of smooth muscle in arterioles

Parasympathetic motor

Contraction of smooth muscle in small intestine

Sympathetic sensory

Pain from ischemia of the myocardium

Parasympathetic sensory

Distension of the bladder

Nerve lesion

Lose function distal to the injury along the distribution of the affected nerve

\-location is diagnostic of signs and symptoms

NL loss of somatic sensory function

Numbness and tingling

NL loss of somatic motor function

Weakness and paralysis

Dominance by non-affected muscles

NL loss of autonomic function

Disruption in gland or smooth muscle function

Nerve injuries - lesions

Lacerations compression avulsions

Spinal nerve lesion - affects muscles and areas of skin defined as a myotome or dermatome

Myotome

Muscles Innervated by a spinal nerve

Dermatome

Area of skin Innervated by a spinal nerve

Spinal cord

Continuous with brain

Lies in vertebral canal

Enlargements

\-cervical

\-lumbosacral

Ends at L2

\-medullary cone

Cauda equina

Gray matter

Internal area containing cell bodies of spinal neurons

Dorsal horn - sensory

Ventral horn - motor

Horns are continuous with spinal roots

How many cervical vertebrae

7

How many thoracic

12

How many lumbar

5

How many sacral

5 but fused

How many coccygeal

4

Primary curvature

Thoracic and sacral

Concave anterior Aly

Secondary curvature

Cervical and lumbar

Convex anteriorly

Vertebral foremen

Space in middle for spinal cord

Transverse foremen

For the vertebral artery

Anterior longitudinal ligament t

C1 to sacrum

Ties vertebral column together

Posterior longitudinal ligament

Broadens out over intervertebral discs

Not as strong

Atlanta occipital joint

C1 and skull

Synovial

Nodding

Atlantoaxial joint

C1 and C2

“No” movement

Transverse ligament of atlas

Side to side

Keeps odontoid process in place

No contractile proteins

Alar ligaments

Limit rotation and movement

Cruciate ligament

Broad CT membrane

\-tectoral membrane

Arterial supply

Bring oxygen to tissue organs

Off of aorta

Every segment gives off branches which enters intervertebral foremen

Flexion of vertebral column

Greatest in cervical region

Extension of VC

Greatest in lumbar region

Lateral flexion (bending) of VC

Greatest in lumber and cervical regions

Rotation of VC

Greatest in thoracic region

Extrinsic back muscles

Superficial - limb movement

Intermediate - respiratory movement

Intrinsic muscles of the back

Act on vertebral column

3 layers

\-superficial

\-intermediate

\-deep

Superficial extrinsic muscles

Trapezius

Latissimus Dorsi

Levator scapulae

Rhomboids

Intermediate layer extrinsic muscles

Serratus posterior

\-superior and inferior

Accessory muscles of respiration

Superficial intrinsic back muscle

Splenius muscles

\-capitus

\-cervicis

Intermediate intrinsic back muscles

Erector spinae

\-illiocostalis

\-longissimus

\-spinalis

White matter

External area

Ascending and descending fiber tracts between spinal cord segments

Spinal cord

Brain

Main arterial supply of spinal cord

Vertebral artery

Aorta

Cervical region arterial supply

Anterior spinal artery

Paired posterior spinal arteries

Thoracic region arterial supply

Anterior and posterior segmental medullary arteries

Cervical plexus

Lesser occipital

Greater auricular

Transverse cervical

Supraclavicular

Lateral cervical triangle muscles

Splenius Capitus

Levator scapulae

Posterior scalene

Middle scalene

Anterior scalene

Veins of the neck

Anterior jugular vein

Subclavian vein

Brachiocephalic vein

Internal jugular vein

Axillary vein

Formed by union of brachial veins

Receives the cephalon vein

Empties into and continuous with eh subclavian vein

First part of the axillary artery

Superior thoracic artery

Second part of axillary artery

Thoracoacromial artery

\-deltoid pectoral acromial clavicular br.

Third part of axillary artery

Subscapular artery

Anterior and posterior numeral circumflex artery

Rami of brachial plexus

Ventral rami of C5 C6 C7 C8 T1

Trunk of brachial plexus

Superior

\-C5 C6

Middle

\-C7

Inferior

\-C8 T1

Divisions of brachial plexus

Anterior

Posterior

Cords

Lateral

Medial

Posterior

Blood circulation

Hydrostatic pressure in capillaries force fluids into the extra cellular space

Fluid with waste products is usually reabsorbed by osmotic pressure l

Lymphatic system function

Remove excess fluid

Absorption and transport of dietary fat

Immune response

Synovial joints

Articulate capsule

Articulate cartilage

Joint cavity

Synovial fluid

Plane hinge saddle condyloid ball and socket and pivot

Fibrous joints

Sutures syndesmosis Interserrous membrane gomphosis

Cartilaginous joints

Lined by hyaline or fibrocartilage

Symphyses intervertebral discs a

Axillary lymph nodes

Pectoral

Subscapular

humeral

Central

Apical

Extrinsic shoulder

Superficial posterior thoracoappendicular muscles

\-trapezius

\-latissimus dorsi

Deep posterior thoracoappendicular muscle

\-Levator scapulae

\-rhomboids

Intrinsic shoulder

Scapulohumeral muscles

\-deltoid teres major

\-rotator cuff

—-teres minor , supraspinatus , infraspinatus , subscapularis

Proximal row of carpus

Scaphoid

Lunate

Triquetrum

Pisiform

Distal row of carpus

Trapezium

Trapezoid

Capitate

Hamate

Lateral hand (anatomical snuffbox)

Potential site of tenosynovitis

Metacarpophalangeal joint

Condyloid type synovial joint

-flex/ext And add/add

Strengthened by medial and lateral collateral ligaments

-taut in flexion But relaxed in extension

Dense cord like band

Thinner fan like part - attach to palmar ligaments , deep transverse metacarpal ligaments

Interphalangeal joint

Hinge type synovial joint

-proximal IP joint

-distal IP joint

-permit flexion and extension

Strengthened by medial and lateral collateral ligaments

Claw hand

Weakness of interposed and 3rd and 4th lumbricals

-Innervated by ulnar nerve or medial cord or lower trunk brachial plexus

Signs

-hyperextension of proximal phalanges at MCP

-flexed position of IP joint

- more prominent medial hand

—-lumbricals 1 and 2 Innervated by medial nerve