Lab 2: The back Flashcards
epidermis
- one of the cutaneous layer
- four layers in itself (except on the palms of foot and hands)
1. superficial stratum
2. stratum germinativum
cutaneous part
- two layers:
- epidermis
- dermis
hypodermis
- below the dermis
- aka superficial fascia
- contains abundant adipose tissue
- permits movement of the skin
- thermal regulation
superficial stratum
- comprises the outer two (or three) layers of dead or dying cells
- outermost: stratum corneum
- deep to stratum corneum is the stratum granulosum
- **in the case of the palms between the stratum coreum and stratum granulosum is the stratum lucidum
stratum germinativum
- comprises the deepest two layers of the epidermis
- where cell division and growth takes place
- stratum spinosum
- stratum basale
- melanocytes are here- produce dark pigment
dermis
- makes up the bulk of the thickness of skin
- contains the papillary layer and reticular layer
- contains nerves, lymphatic vessels, blood vessels, hair follicles, sweat (sudoriferous) glands, and sebaceous (oil) glands
- continuous
- dermal papilae -> receptors
papillary layer
-connects dermis to epidermis
sweat (sudoriferous) glands
- two types:
- eccrine glands- sweat in response to heat, watery, everywhere, released directly to skin
- apocrine glands- sweat in response to stress (odor)
apocrine glands
- sweat in response to stress (odor)
- sudoriferous gland
- mammary glands- specialized to secrete milk
- within the canal of the outer ear produce watery component of cerumen (wax)
- connected to hair follicle -> released from area of hair follicle
sebaceous oil glands
- connected to hair follicles
- secrete an oily substance -> sebum
- lubricates
- waterproofs skin
Meissners corpuscles
- nerve endings responsible for touch reception
- in the papillae
- in papillary layer
- specialized mechanoreceptor
nerve plexuses
- surround the bulbs of hair follicles
- receptive to touch
pacinian corpsules
-responsible for pressure reception
free nerve endings
- within the dermis
- responsible for pain sensation
- respond to temperature
- general sensory receptors
arrector pilli
- smooth muscle attached to the epithelial root sheath and base of the epidermis
- when it contracts- pulls the follicle and hair to errect position
- goose bump
- forces sebum from the sebaceous gland
body
- present in every vertebrae except the first cervical (C1=the atlas)
- weight bearing
pedicles
- there are two
- project posterior from the body
- connection between transverse process and body
lamina
- each pedicle becomes a flattened area -> lamina
- connects the transverse process and spinous process
neural arch
-lamina and pedicles makeup the neural arch
vertebral foramen
- neural arch and posterior surface of the body form the borders around the vertebral foramen
- series of vertebral foramen is called the vertebral canal
transverse process
- projects laterally from the pedicle
- pierced by the foramen transversarium in C1-C7
spinous process
-projects posteriorly form the midline junction of the laminae
superior/inferior articular processes
- projects upward and downward from the neural arch
- these form synovial joints between adjacent vertebrae
intervertebral disc
- between adjacent vertebral bodies
- forms cartilaginous joints between bodies
- imparts a degree of mobility
- gelatinous core (nucleus pulposus) surrounded by concentric layers of dense fibrous connective tissue (annulus fibrosus)
intervertebral foramen
- the gap between the pedicles of adjacent vertebrae
- the gap is bordered anteriorly by the vertebral bodies and intervertebral disc
- the gap is due to pedicles not being as deep as the vertebral body
spinal nerve
-each intervertebral foramen transmits a spinal nerve
atlas
- uppermost cervical vertebrae (C1)
- supports the skull
- lacks a body and spinous process
- movement of the atlas on the axis allow person to shake ‘no’
- movement of skull on atlas allows to nod
cervical vertebrae
-C1-C7
superior articular facet
- elongated and concave to accommodate the occipital condyles of the skull
- use this joint when nodding head up and down
foramen transversarium
- transmits the vertebral artery and vertebral vein
- in C7 it does not transmit the vertebral artery only the vertebral vein
Axis
- C2
- atlas rotates about it when turning the head
- has dens (odontoid process)
- spinous process is long and commonly bifid at the tip
dens
- odontoid process
- projects superiorly to articulate with the back of the anterior arch of the atlas
- transverse ligament of atlas holds dens in place
C3-C7
- presence of foramen transversarium
- presence of bifid spinous process
- body tends to be mediolaterally concave superiorly and convex inferiorly -> body has lateral superior lips and an anterior inferior lip
costal facet
- distinguish thoracic vertebrae
- present for the articulation of the ribs
- located at the tips of the transverse processes (except T11 and T12) which articulate with the tubercle on the neck of the ribs
- the ones located on the posterosuperior and posteroinferior corners of the lateral surface of the body (except T10-12) articulate with the head of the ribs
- most ribs have three facets and articulate with the thoracic vertebrae (synovial joint) -> permit easy breathing
thoracic vertebrae
- 12
- distinguished by costal facets
- long, inferiorly projecting spinous process
- superior articular facets tend to face posteriorly
- vertebral body tends to be heart shaped
lumbar vertebrae
- L1-L5 (5)
- distinguished by absence of foramen transversarium in the transverse process
- costal facets on the body and/or transverse processes
- spinous process is stocky and horizontal
- superior anterior facets tend to face medially
- vertebral body is large
sacral vertebrae
- S1-S5 (5)
- fused into a single element by about age 23-24 (first two about 32)
- although fused you can identify all five
- bodies are marked by a raised transverse line
- intervertebral foramina are represented by four anterior and four posterior sacral foramina
- spinal nerves exit from sacral canal
ala
- aka lateral mass
- represents a fusion of the transverse processes
auricular surface
-sacrum articulates laterally with the iliac portion of the os coxae (hip bone) at the sacroiliac joint by a large auricular surface
coccygeal vertebrae
- Co1-Co4 (4)
- part of the coccyx
- lack any component of the neural arch
- simply rudimentary bodies
- Co1 has stubby transverse processes and vestigial superior articular processes (coccygeal cornua)
coccyx
- two pieces
- the first vertebrae (Co1) and the fused inferior segments (Co2-Co4)
curvature of vertebral column
-sigmoid profile with 2 anteriorly concave curves and 2 posteriorly concave curves
kyphotic curvature
-anterior concavity
lordotic curvature
-posterior concavity
cervical lordosis
- posterior concavity
- develops when a child begins to raise its head and the intervertebral discs in the neck thicken anteriorly
thoracic kyphosis
-thoracic portion of the column retains its original curve because the bodies are higher posteriorly
lumbar lordosis
- lumbar vertebral bodies and intervertebral discs thicken anteriorly
- as child begins to walk
sacral kyphosis
- original curve of the sacral and coccygeal vertebrae
- bc the sacrum is fixed to the os coxae
manipulating the curve of the vertebral column
- extension of spine eliminate the thoracic kyphosis
- flexion eliminates the cervical and lumbar lordoses
- postural stability is maintained by 5 intervertebral ligaments
supraspinous ligaments
- connects the tips of the spinous process
- in the neck it forms the powerful ligamentum nuchae- attached the external occipital protuberance of the skull
interspinous ligaments
-run between the inferior and superior edges of adjacent spinous processes
ligamentum flavum
-runs between the inferior margin of one lamina and the superior edge of the next lower lamina
posterior longitudinal ligament
- runs form the skull to the sacrum
- it attaches to the posterior surface of each vertebral body and each intervertebral disc
anterior longitudinal ligament
-attaches to the anterior and lateral aspects of the vertebral bodies and intervertebral discs
ligaments of the vertebral column
- supraspinous ligaments
- interspinous ligaments
- ligamentum flavum
- posterior longitudinal ligament
- anterior longitudinal ligament
- prevents excessive movement in a particular direction (extension)
central nervous system
- spinal cord
- brain
peripheral nerves
- cranial nerves
- spinal nerves
spinal cord
- runs through the vertebral canal
- continuous medulla oblongata of the brain stem
- conveys sensory information from most of the body to the brain
- motor impulses to the muscles of most of the body
- runs to the level of the intervertebral discs between L1-L2 where it tapers to an end known as the conus medullaris
meninges
- surrounds spinal cord
- 3 protective membranes
- dura mater
- pia mater
- arachnoid mater
dura mater
- outer most layer
- meninges
- tough and fibrous
- membrane
- surrounds the spinal cord
arachnoid mater
- middle layer meninges
- delicate and cobweblike
- surrounds spinal cord
- membrane
pia mater
- innermost layer
- intimately attached to the cord
- meninges
- membrane
- surrounds spinal cord
- membrane
epidural space
- between the dura mater and vertebral periosteum
- contains fat and a plexus of veins
subarachnoid space
- between the layers of arachnoid and pia mater
- contains the CSF
length of spinal cord
- spinal cords ends at the level L1-L2
- dura mater and arachnoid sheath extends to S2
filum terminale
- pia mater extends from the end of the conus medullaris as a thing band called the filum terminale
- attached to the coccyx
cauda equina
- bundle of descending fibers
- fibers include lower lumber, sacral, and coccygeal spinal nerve
- runs through the vertebral canal (caudal to the conus medullaris) to form nerves that will eventually exit through lumbar intervertebral foramina or sacral foramina
gray matter
-neuronal cell bodies and unmyelinated axons occupy a region of H-shaped grey matter in the center of the cord
white matter
- surrounds the gray matter
- myelinated axons
spinal nerves
- 31 pairs that emerge from the spinal cord
- named according to region
- 8 cervical nerves
- 12 thoracic nerves
- 5 lumbar nerves
- 5 sacral nerves
- 1 coccygeal nerves
cervical nerves
- first nerve exits between the skull and the atlas
- last nerve of the neck exits between the seventh cervical vertebrae and the first rib-bearing (thoracic) vertebrae
- C1-C7 comes out above the vertebrae
- C8 comes out below C7
- after this everything comes out below
- 8
thoracic nerves
-12
lumbar nerves
5
sacral nerves
5
coccygeal nerves
1
motor neuron cell bodies
- located in the located in the ventral horn of gray matter of the spinal cord
- send out axons through ventral rootlets
ventral root
- motor neurons send out axons through ventral rootlets -> form a ventral root
- motor fibers of ventral root are joined by sensory fibers to form a short, true spinal nerve
dorsal ramus
- each spinal nerve divides into dorsal ramus
- provides innervation to the intrinsic muscles of the back (epaxial muscles)
ventral ramus
-provides innervation to all other skeletal muscles (hypaxial muscles)
dorsal horn
-sensory neurons synapse here
dorsal root
- sensory axons from the spinal nerve diverge toward the dorsal horn of the spinal cord through the dorsal root
- portion of the dorsal root is the dorsal root ganglion
dorsal root ganglion
swollen by the cell bodies of the sensory neurons
cervical plexus
-nerves C1-C4
brachial plexus
C5-T1
lumbar plexus
T12-L4
sacral plexus
L5-S3
Lumbosacral plexus
-lumbar and sacral plexuses are joined by small branches from L4 to L5 known as the lumbosacral
muscles of the back
- two groups:
- superficial (hypaxial) muscles innervated by the ventral rami of spinal nerve
- intrinsic (epaxial) muscles innervated by the dorsal rami of spinal nerve
trapezius
- attached to occipital bone of the skull, the ligamentum nuchae, and the spines of the thoracic vertebrae
- inserts onto the spine and acromion process of the scapula and clavicle
- action- fixes, elevates, and rotates the scapula
- extends the head
- innervated by the accessory (XI) cranial nerve
- superficial muscle of back
latissimus dorsi
- attaches to the spines of vertebrae from T7, sacrum, iliac crest and two ribs
- inserts into the intertubercular sulcus of the humerus
- action- extends, adducts, and medially rotates the arm
- innervated by the thoracodorsal nerve (C6-C8)
- superficial muscle of back
levator scapulae
- attaches to the transverse process of C1-C4
- inserts onto the medial border of the scapula above the root of the spine
- action- fixes and elevates the scapula, flexes the neck laterally
- innervated by the dorsal scapular nerve (C5)
- superficial muscle of back
rhomboideus
- comprises two muscles:
- R. minor- attaches to the spine of T1
- R. major- attaches to the spine of T2-T5
- both insert onto the medial border of the scapula
- action- fix, retract, and rotate scapula
- innervated by the dorsal scapular nerve (C5)
- superficial muscle of back
quadratus lumborum
- attaches to the iliolumbar ligament and iliac crest
- inserts onto the transverse process of L1-L4 and the lowermost rib
- action- laterally flexes the spine
- forms part of the posterior abdominal wall
- innervated by spinal nerves
- superficial muscle of back
splenius
comprises two groups of muscle fibers that attach to the spines of T1-T6 and the lower part of the ligamentum nuchae
- two groups of fibers
- S. Cervicis- inserts to transverse processes of C1-C4
- S. Capitis- inserts on mastoid process and superior nuchal line of the skull
- action- laterally flexes, rotates the head and neck and extends the head and neck
- innervated by middle and lower cervical nerves
- superficial intrinsic muscles
stratum basale
- skin cells are born here
- proliferate
- they then move up
- by the time they are at stratum corneum it is dead
thick skin
- have extra layer
- stratum lucidum
- only in palms in feet and hands
plexus
nerves come together and forms a apck
root hair plexus
- surround the bulb of a hair follicle
- anytime a hair follicle moves it sends a signal to the brain that it is moving
- touch receptor
facet
-flat surface where bones articulate
telling cervical vertebrae apart
- has transverse foramen (transmit vertebral artery and vein)
- bifid spinous process
telling apart C1
- atlas
- lacks a body and spinous process
- huge foramen
- large facets
telling apart C2
-dens (odontoid process)
C1-C2 joint
shaking no
Skull-C1
nodding head yes
vertebral prominence
C7
-longer spinous process
tubercle
- articulates with transverse process
- costal facet
telling apart thoracic vertebrae
- costal facet on the transverse process
- giraffe
- long spinous process that projects inferiorly
- has three spots where it articulates with ribs (superior articular process, inferior articular process, transverses costal facet)
rib articulation
-always in between two vertebrae touching both
transverse costal facet
-thoracic vertebrae articulate with the rib at the tubercle here
telling apart lumbar vertebrae
- no transverse foramen (not cervical)
- no costal facets (not thoracic)
- chunky
- large body
- spinous process is stocky
intervertebral foramen
spaces between vertebrae
-spinal nerves go through here
anulus fibrosus
- cartilaginous ring in the intervertebral disc
- dense fibrous connective tissue
- on the inside of the ring there is the nucleus pulposus- gelatinous core
intervertebral discs
- cartilaginous joints (synchondrosis)
- shock absorber
- can herniate and compress nervous tissue
- two parts:
- anulus fibrosus
- nucleus pulposus
herniated disc
- tears through fibrocartilaginous disc
- nucleus pulposus goops out
- puts pressure on spinal nerves -> pain
spinal cord ends at
-L1-2
conus medullaris
- where the spinal cord ends
- L1-2
filum terminale
anchors end of spinal cord to bone
organization of spinal cord
- nerve roots coming from anterior and posterior side
- dorsal ramus -> spinal nerve -> dorsal root -> dorsal horn (synapse here) -> ventral horn -> ventral root -> gray ramus -> white ramus -> ventral ramus
- dorsal = sensory
- ventral= motor
test*
motor cell bodies are located in the ventral horn
-neuron itself
dorsal root ganglion
-cluster of sensory cell bodies
epaxial muscle**
innervated by dorsal ramus
- located in a tiny strip up and down your vertebral column
- intrinsic back muscles
hypaxial muscles**
- superficial
- innervated by ventral ramus
- superficial back muscles
ramus
-contains both sensory and motor information
trapezius
- innervated by ventral ramus
- hypaxial muscle
- elevates shoulder blades
deltoid
- shoulder muscle
- hypaxial
- innervated by ventral ramus
latissimus dorsi
- innervated by ventral ramus
- hypaxial
rhomboid major and minor
- innervated by ventral ramus
- hypaxial
levator scapulae
- innervated by ventral ramus
- hypaxial
S. Cervicis
- a group of splenius fibers
- runs to the transverse processes of C1-C4
S. Capitis
-runs to the lateral aspect of the mastoid process and lateral part of the superior nuchal line of the skull
erector spinae
- comprises 3 vertical columns of overlapping muscle fascicles that mount up the vertebral column and ribs from a common tendinous origin to the sacrum, the posterior part of the iliac crest of the pelvis, and the spines of the lowermost lumbar vertebrae
- common tedinious- origin on sacrum pelvis and lower lumbar spines
- individual columns are descriptively recognized by the regions that they transverse
- innervated by spinal nerves
- superficial intrinsic muscles
- iliocostalis
- longissimus
- spinalisse
iliocostalis
- form the lateral column
- attaches to lower and upper six ribs
- insertion- transverse processes of the lower cervical vertebrae
- action- extends and laterally flexes the spine
- superficial intrinsic muscles
longissimus
- from the intermediate column
- inserted: to the lower portion of transverse processes of the thoracic vertebrae
- inserted: upper portion between the transverse processes of the cervical vertebrae and mastoid process of the skull
- action- lower portions: (longissimus thoracis and longissimus cervicis) extend and laterally flex the spine
- action- upper part: (longissimus capitis, a narrow, straplike muscle) extends and rotates the head
- superficial intrinsic muscles
spinalis
- forms the medial column
- attachment: spines of lumbar vertebrae
- insertion: upper thoracic vertebrae between L2 and T2
- fibers may run to cervical vertebrae sometimes
- action: extends the vertebral column
- superficial intrinsic muscles
semispinalis
- most superficial of the deep intrinsic muscles
- two components innervated by spinal nerves that emerge at levels crossed by the muscle fibers
- semispinalis
- semispinalis capitis
semispinalis
- forms the lower portion
- attachment: runs between T12 and C2 from the transverse processes to the spines of superior vertebrae
- each fiber bundle spans from 4 to 6 vertebrae
- divided into two parts: S. thoracic and S. Cervicis
- action: rotates and extends the vertebral column of the trunk
semispinalis capitis
- forms the upper portion
- attachment: fibers run from the transverse processes of T1-T6
- inserted: onto the medial part of the occipital bone between the superior and inferior nuchal lines
- action: powerful rotator and extensor of the head and neck
multifidus
- most powerful of the deep intrinsic muscles
- runs from the vertebral arches from S4-C2
- each fiber bundle spans from 2 to 4 vertebrae
- movement: laterally flexes, rotates, and extends the vertebral column
- innervated by spinal nerves that emerge at levels crossed by the muscle fibers
- deep intrinsic muscles
small segmental muscles
- 4 groups of rather trivial deep back muscles that bridge the gaps between successive vertebrae
- muscles are used principally in postural “steadying” because they have little leverage
- 4 are rotatores, intertransversarii, interspinales, and levatores costarum
- deep intrinsic muscles
suboccipital muscles
- 4 muscles that either connect the axis to the atlas or connect one of these vertebrae to the occipital bone of the skull
- these muscles are mainly postural
- intervertebral muscle is obliquus capitis inferior
- 3 that attach to the skull are obliquus capitis superior, rectus capitis posterior major, and rectus capitis posterior minor
- deep intrinsic muscles
intrinsic back muscles: deep group
- semispinalis
- multifidus
