Gross Anatomy Exam 1

• 1. enables the body to react to changes in its external and internal environments via collection of information and eliciting the appropriate response (homeostasis)
• 2.Transduce (convert) energy into signals usable by the central nervous system- perception
• 3.Transfer information rapidly over long distances- sensory and motor functions
• 4.Store ( and process) information- learning & memory
• 5. Release neurotransmitters (or signals) that act on the nervous system- emotions

a network of specialized cells including neurons and neuroglia

Nerve cells that are structural and functional units of the nervous system; electrically excitable cells that transmit and process information; neurons are core components of the brain, spinal cord, and peripheral nerves

• Dendrites
• cell body
• axon
• axon terminal

cellualr extensions that recive impulses and conducts them to the neuron cell body (or soma)

soma

central part of the neuron that consists of the nucleus of the cell; where protein synthesis occurs

nerve fiber responsible for carrying nerve impulses away from the cell body to another cell (neuron or end organ)

contains synapses, or specialized structures where neurotransmitters are released to communicate with another cell

• 1. Sensory (Afferent)
• 2. Motor (Efferent)

composed of one dendrite (peripgeral process), one axon (central process), and a cell body;

most sensory (or afferent) neurons are pesudounipolar neurons which mean they carry information (touch, pain, and temperature) to the central nervous system

"To carry towards or bring to"

have multiple (two or more) dendrites and a single axon; most common type of neuron in the nervous system

-they carry information away from the CNS

"to carry away or bring out"

multipolar motor neurons

cells that support, insulate, and nourish the neurons

• -5 times more abundant than neurons
• -non-neuronal
• -non excitable cells that form a major component of nervous tissue

neuroglia (glial cells or glia)

they minimize metabolic expensie while maintaing rapid nerve conduction, many neurons are insulated with sheaths  of myelin or layers of lipid/protein substances around their axons

• 1. glial cells
• 2. oligodendrocytes
• 3.Schwann Cells

glial cells that produce myelin in CNS

glial cells that produce myelin in perioheral nervous system PNS

• -made of spinal cord and brain
• -integrates and coordinate incoming & outgoing neural signals 
• -carry out higher mental functions (thinking and learning)

• -nucleus
• -tract
• -white mater
• -gray matter

collections of cell bodies in the central nervous system

• bunde of nerve fibers (axons) connecting nuecli
• (also called fiber bundles, columns,pathways)

where axons form nundles within the CNS

where cell bodies (nuclei) congregate together in the CNS

gray matter

-they reside within the anterior gray horns of the spinal cord

- they convey motor (efferent) information to the body

composed of nerves and ganglia

• 1. bundles of nerve fibers (axons) outside the central nervous system
• 2. the connective tissue (endoneurium, perinuerium, and epineurium) to bind the nerve fibers
• 3.the blood vessels ( vasa nervorum) that supply the nerves

how they exit the bony encasement of CNS

via openings (foramina) in cranium (skull)

• -12 pairs of cranial nerves
• -identified by bame, Roman numeral, or both
• -all (but one) of the cranial nerves arise from brain (exception: accessory)
• -cranial nerves can be purely sensory, purely motor, or mixed

• -identified by a latter (region) and a number (first cervical nerve=c1)
• -arise from the spinal cord
• -31 pairs= 8 cervical, 12 thoraic, 5 lumbar, 5 sacral, 1 coccygeal

exit from the vertebral column (spine)

multipolar neurons innervate muscle cells (which contact and shorten) or glands (which secrete)

pseudounipolar neruons detect changes in the internal and external environment and infrom the CNS of the changes

-cell bodies of sensory nerusons are located in the spinal ganglia in spinal nerves or sensory ganglia of cranial nerves

• 1. Somatic (or parietal)
• 2. Visceral (or splanchnic)

• 1. somatic motor
• 2. visceral motor
• 3. general sensory
• 4. visceral sensory

• innervate skeletal muscle (voluntary)
• -one neuron from CNS to viscera
• -somatic= related to body wall

• innervate smooth (involutary) muscle, cardiac muscle, and glands
• -2 neurons (presynaptic and post synaptic) conduct impulses from the CNS to viscera
• -visceral motor neurons are the autonomic nervous system
• -visceral= related to the body organs 

transmit sensations ( fine touch, pain, temperature, proprioception, etc) from the body to the CNS

transmit visceral sensations, both conscious (pain) and unsconscious (reflexive) 

collection of nerve cell bodies outside the CNS (or within the PNS) 

-classified as motor or sensory ganglia

a collection of cell bodies of sensory (afferent) neurons, which forms a visisble swelling in the course of a peripheral nerve 

• 1. spinal ganglia=ganglia of the spinal cord
• 2. cranial nerve ganglia= ganglia associated with cranial nerves

ganglia associated with motor (or efferent) nerves of the autonomic nervous system (ANS)

-the sympahteic division of the ANS includes ganglia of the sympathetic trunk and prevertbral ganglia

lie anterior to the vertebral column

terminal ganglia

-SNS Somatic Nervous System and ANS Autonomic Nervous System

• voluntary nervous system
• -general sensory fibers carry pain from the skin and joints and somatic motor fibers supply skeletal muscle

-SNS is under your conscious control

SNS

• involuntary/viscera; nervous system
• -visceral motor that innervate smooth & cardiac muscle, glands, and the internal organs in the body cavities

-is purely motor or efferent system****

serves to form axis of the body and provide a proctective bony covering of the spinal cord.

upper limb or vertebral column

spine

coccyx bone

the spinal cord and spinal nerves

• -supports the weight of the body superior to the pelvis
• -prvides a pivot for the head
• -provides rigid and felxible axis for body
• -has roles in posture and locomotion
• -formed by 5 reguons of vertebrae named by the corresponding body reguons where they are located: cervical, thoracic, lumbat, sacral, and coccygeal

33

7 cervical

12 thoracic

5 lumbar

5 sacral segments (fused)

4 coccygeal semgents (fused)

total= 33

weight bearing portion of vertebra

consists of a pair of pedicles and a pair of laminae that surroind the vertrebral foramen where the spinal cord passes through 

one on posterior portion and site for muscle attachments

one on each side and sites for muscle attachments

have smooth facets where adjacent vertebrae form joints'

**between the vertebral notches of adjacent vertrbrae form INTERVERTEBRAL FORAMINA and this is where SPINAL NERVES emerge and divide into POSTERIOR and ANTERIOR rami

extrinisic muscles and intrinisc muscles

1. Superficial Shoulder Muscles= conect the back to the upper limbs

• 2. Accessory Respiratory Muscles= connect to ribs
• **Innervated by ventral primary rami of spinal nerves: (Except, the trapezius m. is innervated by Cranial Nerve XI).

also called "ture" or "deep" back muscles. 

**attached on and primary movers of vertrbral column

Innervated by dorsal (posterior) primary rami of spinal nerves.

• -trapezius
• -latissimus dorsi
• -levator scapulae
• -rhomboid major and rhomboid minor

• bounded by lateral border of trapezius middle
• -superior border of latissimus dosi m and medial border of scapula
• -mo muscles overlie intercostal space 6 here****
• -good location for stethoscope placement for listening to lung sounds

• 1. ascending= depress scapula
• 2. middle- retract scapula
• 3. descending= elevate scapula

**innervation by accessory nerve 

• -adducts and medially roates humerus
• -innervation by ventral ramus (thoracodorsal nerve)

• -elevates scapula
• -innervation by verntral ramus (dorsal scapular nerve)

• -retract scapula
• -innervation by ventral ramus 

they connect to ribs and primarily propioceptive

• serratus posterior superior
• serratus posterios inferior
• **both innervated by th ventral ramus (intercostal nerve)

the vertrbral column

• -splenius
• -erector spinae muscles
• -iliocastalis
• -longissimus
• -spinalis

Splenius

• -thick muscles
• -looks like a bandage, lateral back of neck
• -splenion is latin for bandage
• -when both sides act together, they extend the head & neck
• -when one side acts a;pme,they laterally flex and rotate the head toward the side of the contracting muscle
• -innervated by ventral (dorsal) ramus

• -Iliocastalis
• -Longissimus
• -Spinalis

• -chief extensor of vertebral column
• -innervation by dorsal (posterior) ramus

• -iliocostalis= lateral
• -longissimus=intermediate
• -spinalis= medial

Transversospinalis Group

• -attach to transvere and spinous processes and located between adjacent vertebrae to stabilize vertebral column.
• -innervatd by the posterior rami

-

Semispinalis!!!!


-Semispinalis, multifidus, rotatores

• -located on about half the vertebral column deep to the splenius m
• -greater occipital nerve (cutaneous branch of dorsal ramus C2) penetrates this muscle to provide sensory innervation to the back of the head

smooth articular surface on vertrbrae.

anither name for "anterior"

Another name for "posterior"

first braches from the spinal nerves

rami** is the singular form

Vertebrae is plural

an opening or hole that structure transverse through

• 1. axial skeleton
• 2. appendicular skeleton

formed by articulated bones

• -cranium
• -vertebral column
• -ribs
• -sternum
• -sacrum

• -limbs
• -scapula
• -clavicle
• -pelvis

spine

• -extends from the skull to the tip of the coccyx
• -forms the main part of the axial skeleton
• -fucntions include: maintaing posture, support body weight and protection of spindal cord and spinal nerves
• -consists of 33 bones (vertebrae), intervertebral (IV) discs connected by joints and ligaments that form the "Axis" of the axial skeleton

• -maintaing posture
• -support body wieght
• -protection of spinal cords and spinal nerves

• 1. cervical
• 2.thoracic
• 3.lumbar
• 4.sacrum
• 5.coccyx

• 7 bones (C1-C7)
• -cervical vertebrae are small vertebral bodies and have a transverse foramen ( for vertebral artery)

• Atypical C1 (Atlas)
• -has no body or spinous process instead it has a posterior and anterior arch with tubercles and foramen for the dens

-Dens-projects uo through foramen for the dens (c1) allowing head to rotate

it is the VERTEBRAL PROMINENS, which is evident when the neck is flexed and you can see a palpable landmark

• -12 bones (T1-T12)
• -slightly larger
• -heart shaped vertebral bodies than cervical region
• -facets for articulation with the ribs
• -long spinous process that overlaps the vertebra below for additional protection of the spinal cord

• -L1-L5
• -5 bones
• -large, kidney shaped bodies
• -triangular vertebral canal
• -large and slender transverse processes
• -short & sturdy spinours processes

• -5 fused bones
• -immovable
• -S1-S5
• -provides strength & stability to pelvis

• -4 fused bones (sometimes less)
• -immovable
• -development of these vertebrae form a break line bone that articulates with the sacrum
• -provides for muscle attachment and support of certain structures

33

fetus= is "C" shaped or cuved due to the embryo folding, fetal position

adult= four cuvatures

• - maintain balance
• -. increase strength for weight bearing
• -without curvatures the body weight on vertebral column would be 10 times greater

• primary=
• -concave anteriorly
• -develop during fetal life & persist
• -thoracic & sacral curvutures

• secondary=
• -concave posteriorly
• -develop later in life
• -cervical= develop during infancy, attain head control in space, head erect
• -lumbar= develop during infancy, sitting, erect when standing & walking

• 1.kyphosis
• 2.lordosis
• 3.scoliosis

• -exaggerated thoracic curvuture
• -called "humpback" or "hunchback"
• -result of erosion of the anterior part of one or more vertebra osteoporosis

• -exaggerated lumbar or cervical curvuture
• -called "hollowback" or "swayback"
• -caused by weakened trunk musculature

• -abnormal lateral curvature
• -called crooked or curved back
• -caused by asymmetrical weakness of the intrinisc back muscles, failute of vertebra to develop

to resist displacement of vertebral bodies while allowing movement on one another and acts a as a shock absorber

• -connect articulating surface of adjacent body vertebrae
• -second component of vertebral column
• -designerd for weight bearing and strength
• -thickest in lumbar region > thoracic > cervical

• 1. anulus fibrosus
• 2. nucelus pulposus

• -outer fibrous ring
• -consisting of concentric lamellae of fibrocartilage forming the outer region of the IV discs
• -insert into the epiphysal rims of the vertebral bodies
• -posterior portion is thin and predisposed to rupture of the ring

• -inner portion
• -central core of the IV disk
• -composed of gelatinous matrix embedded in collagen
• -water content is 85%
• -water content decreases with age therefore you get shorter as you age

• 1. anterior longitudinal ligament
• 2. posterior longitudinal ligament
• 3. ligamentum flavum

• -covers the anterolateral aspects of the vertebral bodies & IV discs
• -limits extension

• -limits flexion
• -naroower ligament that runs within the spinal canal along the posterior aspects of the vertebral bodies

• -joins together the lamina of adjacent vertebral arches
• -resist seperation of vertebral lamina

• -part of the CNS
• -contuniatuon of the medulla oblongata of the brain
• -accessed via a laminectomy (cutting through the laminae of vertebral arch) 
• -in adults extends to L1 or L2

• -tapering inferior end of spinal cord
• -cone ends at L2
• -thus, spinal cord occurpies superior 2/3 or vertebral canal

• 1. cervical enlargement
• 2.lumbosacral enlargement

• -widening of the spinal cord from c4- t1
• -due to innervation of the upper limb via the brachial plexus

• -widening of the spinal cord from T11-L1
• -due to innervation of the lower limb via the lumbosacral plexus

• -called "horse's tail"
• -loose collection of spinal nerve arising from the lumbosacral enlargement and conus medullaris
• -entends from inferior end of spinal cord

• -arises from tip of the conus medullaris and inserts in the coccyx bone
• -anchors the inferior end of the spinal cord and spinal meninges
• -contunuation of the pia mater

Pia, arachnoid, & Dura mater

• -protects the spinal cord
• -serve as supporting framework for vessels
• -encloses the subarachnoid space, where blood vessels and cerebrospinal fluid CSF reside

collagen and elastic fibers

• -outermost layer
• -known as the "tough mother"
• -ends at S2 level
• -forms a long dural sac
• -covers dorsal and ventral roots

• -middle layer
• -thin delicate an avascular
• -spider web like

• -innermost later
• -delicate, highly vasuclar layer of connective tissue
• -directly adheres to spinal cord and brain
• -inferior to conus medullaris, the pia contunes as the filum terminale

a network of CT connecting arachnoid to pia mater

• -epidural space
• -subdural space
• -subarachnoid space

• -between the vertebral canal and dura mater
• -contains fat and loose connective tissue
• -internal vertebral venous plexuses are located

• -NOT A REAL SPACE
• -between the dura and subarachnoid mater
• -can become a REal spae, due to pathological conditions (ex: bleeding into this layer)

• -between the arachnoid and pia mater
• -contains CSF (cerebrospinal fluid)= clear colorless fluid which bathes the brain tissue to help protect it
• -contains blood vessels

• -formed by the dura
• -long tubular shealth within the vertebral canal
• -the spinal cord is suspended in the dural sac
• -superiorly adheres to foramen magnum of cranium
• -inferiorly anchored by filum terminale of coccyx

denticulate ligaments

20-22

dilations in the subarachnoid space

from L2 (where the spinal cord ends) to S2 (dural sac ends)

according to location

it is a great place to sample CSF or administer drugs

the brain CSF

three artieries can supply only the superior part of the spinal cord, so additional artieries are needed and are branches of the vertebral a.

1- artery located in the midline that supplies the anterior of the spinal cord

2 laterally placed arteries which supply the posteror of the spinal cord

derived from spinal branches of nearby arteries and supply additional regions of the spinal cord

-most of these arteries do not supply the spinal cord, some do supply superficial (peripheral) parts of spinal cord, mostly supply roots of spinal nerves

follow the anterior roots of the spinal nerves

follow the posterior roots of the spinal nerves