Block 1 Learning Objectives Flashcards
central nervous system
consists of brain and spinal cord
gray matter
collection of neural cell bodies
white matter
axons with glial sheath (myelin)
CNS gray matter and white matter
gray matter- cortex and nucleus
white matter- pathway (tract, vesicle)
peripheral nervous system
neurons outside the CNS, 12 pairs of cranial nerves and 31 pairs of spinal nerves
PNS gray matter and white matter
gray matter- ganglion
white matter- nerve
afferent
approaches CNS, sensory, voluntary, pseudo unipolar neuron
efferent
exits CNS, motor, involuntary, multipolar neuron
somatic tissues
skin, bone, joints, dura, skeletal muscle
visceral tissues
glands, smooth muscle, cardiac muscle
somatic afferent
somatic pain, well localized. sensory. touch, vibration, temp
somatic efferent
volitional movement, motor
visceral afferent
visceral pain, poorly localized, sensory, dissension of organs, unconscious sensations associated with homeostasis
visceral efferent
autonomic NS, motor, modulate glandular secretions and contraction of smooth and cardiac muscle
visceral efferent (ANS) divisions
sympathetic- thoracolumbar NS, fight or flight
parasympathetic- craniosacral NS, rest and digest
enteric- modulated by ANS but functions independently
gray matter- ventral horn
somatic efferent cell bodies
gray matter- lateral horn
visceral efferent cell bodies
gray matter- dorsal horn
central processes of afferent neurons synapse
roots and rootlets
rootlets from one spinal cord segment merge to form a root
dorsal root from dorsal horn
ventral root from ventral horn
spinal nerve
made of one dorsal root and one ventral root that merge to form one spinal nerve
a single pair of spinal nerves represents a single spinal cord segment
rami
spinal nerve branches to form dorsal and ventral rami
dorsal rami supplies
synovial joints of vertebral column, intrinsic back muscles and overlying skin
ventral rami supplies
anterior and lateral regions of trunk and limbs
dorsal root nerve type
afferent only
ventral root nerve type
efferent
plexus
branching network of intersecting nerves
what forms a plexus
ventral rami
types of plexuses
cervical C1-C4
brachial C5-T1
lumbar L1-L4
lumbosacral L4-S4
dermatome
region of skin innervated by somatic afferent fibers of a single spinal nerve
all spinal nerves (except 1) transmit sensory Information from the skin
*where it came from
myotome
muscle mass innervated by somatic efferent fibers of a single nerve, most muscles are innervated by more than one spinal nerve
cutaneous nerves
peripheral nerves to skin
cutaneous territory of a peripheral nerve is region of skin supplied by that nerve
*how it got there
enlargements of the spinal cord
cervical C4-T1– upper limb innervation
lumbar L1-S2– lower limb innervation
conus medullaris
tapered caudal tip
S2-coccygeal spinal cord segments
located at L1/L2 vertebral level
cauda equina
looks like a horse tail
spinal nerve roots from lumbosacral enlargement and conus medullaris
filum terminale
not a nerve
anchors inferior end of spinal cord (tip of conus medularis) to the coccyx
filum terminale internum- from pia
filum terminale externum- from dura
pia mater
delicate, innermost layer
adherent to brain, spinal cord, and nerve roots
denticulate ligaments
formed from pia mater
lateral extension of pia mater, tooth like
attaches pia to arachnoid and dura
provides support for spinal cord
arachnoid mater
delicate, middle layer, looks like spider webs
encloses the subarachnoid space- filled with CSF
arachnoid trabecular connect arachnoid and pia
dura mater
tough, outermost layer
forms dural root sleeve which blend with epineurium
subdural space- potential space btw dura and arachnoid
lumbar cistern
enlargement of subarachnoid space
extends from conus medullaris to end of dura mater and subarachnoid space
contains CSF, cauda equina, and filum terminale internum
location of lumbar punctures- subarachnoid for CSF and epidural space for anesthetic
functions of bone
support, protection, movement of body, storage of minerals and lipids, blood cell production
hyaline cartilage
provides stiff but flexible support
reduces friction between bony surfaces
articular surfaces of joints
elastic cartilage
provides support but tolerates distortion
epiglottis and ear
fibrous cartilage
resists compression
limits relative movement
intervertebral disc
fibrous joint
amount of movement depends on fiber length
sutures of skull and between ulna and radius
*made of fibrous connective tissue
primary cartilaginous joint
permits growth of long bones and allows slight bending
*made of hyaline cartilage
secondary cartilaginous joint
strong, slightly mobile and located at midline of body *contains fibrocartilage and hyaline cartilage
synovial joint
most common, nearly all joints of the limbs, allow significant mobility, synovial fluid lubricates and nourishes
*contains synovial membrane, articular cartilage, and joint capsule
skeletal muscle
voluntary
movement of body, maintenance of posture, communication, respiration, maintenance of body heat
smooth muscle
involuntary
constriction of hallow organs and vessels
arrestor pili- raise hair
cardiac muscle
involuntary contraction of heart
reflexive contraction
autonomic, not voluntarily controlled
tonic contraction
slight contraction assisting stability of joints and maintaining posture
phasic contraction- isometric
muscle length remains the same
phasic contraction- isotonic
muscle length changes to produce movement
concentric- muscle shortens
eccentric- progressive relaxation/lengthening of contracted muscle
prime mover/agonist
main muscle responsible for movement
synergist
complements action of prime mover
antagonist
opposes action of prime mover to produce smooth movement
fixator
fixes position of proximal limb while distal limb moves
subcutaneous tissue/superficial fascia
deep to skin
loose ct- contains fat, cutaneous nerves, and vessels
deep fascia
surrounds all muscles, divides compartments, invests individual muscles and neurovascular bundles
cutaneous nerves
mixed afferent and efferent
preganglionic cell bodies
found in the lateral horn of gray matter
sympathetic preganglionic cell bodies
T1-L2
parasympathetic preganglionic cell bodies
S2-S4
no preganglionic cell bodies
above T1, between L2 and S2, and below S4
sympathetic postganglionic cell bodies
found in para or pre vertebral ganglion
sympathetic chain- series of connected ganglia, on either side of vertebral column(para) or above aorta (pre)
pathway of sympathetic nerve- skin
originate at T1-L2
synapse at paravertebral ganglion
dermatomes C2-S5
peripheral NS- preganglionic axons synapse on ganglia of sympathetic chain either same level, above T1, and below L2
postganglionic axons travel in gray rami in spinal nerve, dorsal or ventral rami in cutaneous branches to visceral branches
pathway of sympathetic nerve- head, neck, thoracic viscera
originate at T1-T4
synapse at paravertebral ganglion
head and neck viscera- preganglionic axons ascend chain and synapse on cervical ganglia
postganglionic axons follow blood vessels
thoracic viscera-
preganglionic axons synapse on ganglia of the same level or ascend
postganglionic axons travel in splanchnic nerves through cardiac and pulmonary plexuses
pathway of sympathetic nerve- abdominal viscera
originate at T5-L2
synapse at pre vertebral ganglia
peripheral NS-
preganglionic- axons pass through chain without synapsing, exit chain in splanchnic nerves, descend to abdomen, synapse at pre vertebral ganglia
postganglionic- axons follow blood vessels to targets
foregut-celiac trunk, midgut- superior mesenteric artery, hindgut- interior mesenteric artery
pathway of sympathetic nerve- pelvic viscera
originate at T12-L2
synapse on ganglia in hypogastric plexus
peripheral NS-
preganglionic- axons pass through without synapsing, exit chain in splanchnic nerve, synapse on hypogastric plexus
postganglionic- axons in plexus follow blood vessels or directly innervate organs
axial vs apendicular skeleton
apendicular- contains upper and lower limbs, shoulder girdle, and pelvic girdle
axial- contains skull, vertebral column, and rib cage
viscerocranium
facial skeleton made up of lacrimal, nasal, zygomatic, maxilla, mandible, palatine, vomer, nasal conchae, ethmoid
neurocranium
brain case made up of frontal, parietal, occipital, sphenoid, temporal, and ethmoid
normal curvatures of the back
lordosis- cervical and lumbar curve, secondary curvature
kyphosis- thoracic curve, primary curvature
hyperlordosis
exaggerated lumbar curvature
likely to happen during pregnancy
hyperkyphosis
exaggerated thoracic curvature
likely to happen with old age
scoliosis
lateral exaggerations of curvatures
can be cervical, thoracic, or lumbar (one area)
can be thoracolumbar- same direction or combined- opposite direction (combination of areas)
functions of vertebrae
protection of spinal cord- vertebral arch and body
movement- transverse and spinous process and articular processes
support of body weight- body
cervical vertebrae characteristics
bifid spinous process
transverse foramen
atlas– A/P tubercle, A/P arch, no body, facet for dens
axis– dens
cervical vertebrae characteristics
bifid spinous process
transverse foramen
atlas– A/P tubercle, A/P arch, no body, facet for dens
axis– dens
thoracic vertebrae
costal facets- attach to ribs
looks like a giraffe
lumbar vertebrae
looks like a moose
large body
intervertebral disc function
help support body weight and absorb shock
intervertebral disc
discs have resilient deformity- can compress and change shape
changes in intervertebral disc
composition of disc changes- loss of water from nucleus pulpous and lamellae thicken
IV disk can herniate and compress spinal nerve root- affects nerve roots of higher #
bony lesions can compress spinal cord and roots
intervertebral joints
secondary cartilaginous joint
made of 2 vertebral bodies an IV disc
small movements in all directions
zygapophysial/facet joing
synovial joint
made of 2 facets of vertebrae at different levels
direction depends on orientation of process
orientation of articular facets- cervical
oblique orientation
good flexion/extension
good roation
orientation of articular facets- thoracic
coronal
limited flexion/extension
good rotation
orientation of articular facets- lumbar
sagittal orientation
good flexion/extension
limited/absent rotation
Atlanta-occipital joints
between occipital bone and atlas
craniocervical flexion/extension
lateral flexion/bending
rotation of head
first layer of trunk muscles
innermost intercostal
transversus abdominis
second layer of trunk muscles
internal intercostal
internal oblique
third layer of trunk muscles
external intercostal
external oblique
intercostal muscles
accessory breathing muscles
anterior flexion muscles
rectus abdominis
psoas major
innervation- ventral rami
posterior extension muscles
erector spinae
multifidus
semispinalis
thoracis
gluteus maximus
innervation- dorsal rami
ipsilateral contraction
Splenius
iliocostalis and longissimus
internal oblique
contralateral contraction
sternocleidomastoid
transversospinalis
external oblique
intrinsic muscle
origin and insertion are spinal
semispinalis capitis
Splenius capitis
splenius cervicis
spinalis, iliocoestalis, and longissimus
innervated by dorsal rami
external muscle
only one insertion is axial
trapezius
rhomboid
latissimus
innervated by ventral rami
external muscle
only one insertion is spinal
trapezius
rhomboid
latissimus
innervated by ventral rami
functions of neck
protection of CNS
deglutination, respiration, pronation
conduit for respiratory and alimentary structures
support and movement of head to orient special senses
location of endocrine structures
defines spaces that may limit the spread of infection and tumors
functions of fascia
compartmentalizes viscera and muscles
provides a lubricated surface allowing for unimpeded movement
provides a route for the passage of neuromuscular structures
superficial cervical fascia (SCF)
fatty loose CT under dermis of head, face, and neck
contains- muscles of facial expression (platysma), cutaneous sensory nerves of cervical plexus (postganglionic symp fibers), superficial veins (external jugular, anterior jugular, and communicating), and superficial cervical lymph nodes
deep cervical fascia
investing fascia- superficial layer
pretrachial fascia- middle layer
pre vertebral fascia- deep layer
investing fascia, superficial layer (SLDCF)
surrounds entire neck
invests trapezius and SCM
pretrachial fascia, middle layer (MLDCF)
muscular layer- invests infrahyoid muscles
visceral layer- invests thyroid gland, larynx, trachea, pharynx, and esophagus
prevertebral fascia, deep layer (DLDCF)
surrounds vertebral column and associated muscles
carotid sheath
surrounds common and internal carotid arteries, internal jugular vein, vagus nerve, sympathetic chain poster medial
retropharyngeal space
danger space
extends inferiorly to posterior mediastinum
extends down to diaphragm
in between esophagus and vertebrae and carotid
Sternoceiomastoid
invested by SLDCF
head/neck- bilateral extension and contralateral rotation with ipsilateral bending
thorax- elevation of sternum and ribs
trapezius
invested by SLDCF
head/neck- bilateral extension and lateral bending
scapula- retraction, elevation, depression, and rotation
Splenius and levatator scapulae
invested by DLDCF
head/neck- bilateral extension, lateral bending, and rotation
rectus capitis, longus capitis/coli, and scalenes
invested by DLDCF
head/neck- bilateral flexion, lateral bending
thorax- elevation of ribs
pretrachial fascia (MLDCF)
muscular layer that invests hyoid muscles
hyoid bone and stylohyoid ligament
stylohyoid ligament allows hyoid bone to swing anteriorly and posteriorly, causes elevation and depression of larynx
supra hyoid muscles
elevate the hyoid, closing the airway during swallowing, supplied by cranial nerves
infra hyoid muscles
depresses the hyoid, opening the airway, supplied by cervical ventral rami
visceral layer of MLDCF
endocrine- thyroid, alimentary-pharynx, respiratory- trachea and cricoid
dermatomes of head
ventral rami- C2-C4 ear and neck region
dorsal rami- C2-C4 back of head/neck
cervical plexus sensory fibers
transverse cervical C2-C3
lesser occupital C2
great auricular C2-C3
supraclavicular C3-C4
cervical plexus motor fibers
nerve to geniohyoid C1
nerve to thyrohoid C1
ansa cervicalis superior C1 inferior C2-C3
phrenic nerve C3-C5
anterior scalene divides subclavian into three regions
aorta, brachiocephalic trunk, common carotid
where does the subclavian artery provide blood to
structures in upper limb, thoracic, and neck
common carotid
bifurcates into internal and external carotid C3-C4
internal carotid has no branches in neck
body- chemosensory receptor
sinus- baroreceptor
external carotid provides most blood
external carotid provides blood to
superior thyroid artery
ascending pharyngeal a
lingual a
facial a
occipital a
posterior auricular a
maxillary a superficial temporal a
some anatomists like freaking out poor medical students
veins that don’t share a pathway with an artery
retromandibular
common facial
internal jugular
external jugular
superficial lymph nodes
pericervical collar- horizontal ring
superficial cervical nodes- vertical collection associated with the external jugular vein
deep lymph nodes
vertical collection associated with internal jugular vein
jugulodigastic and juguloomohyoid nodes- part of a larger collection of deep cervical nodes, more palpable
lymph drainage
lymph from head and neck- superficial nodes- deep nodes- venous circulation at venous angle
lymph from head and neck- deep nodes- venous circulation at venous angle
lymph nodes from scalp and face
pericervical collar nodes- deep cervical nodes
lymph nodes from anterior nasal and oral cavities
submandibular and submental nodes- deep cervical nodes
lymph nodes from posterior nasal and oral cavities, pharyngeal and palatine tonsils
deep cervical nodes
lymphatic drainage
lateral regions drain ipsilaterally
central regions drain bilaterally
submandibular triangle
lymph nodes
mylohyoid
salivary glands
facial artery and vein
hypoglossal CN XII
carotid triangle
carotid sheath- internal jugular vein, vagus nerve, common carotid artery
ansa cervicalis
sympathetic chain
deep cervical lymph nodes
SERIOUS DAMAGE
muscular triangle
thyroid cartilage
thyroid gland
cricothyroid muscle
cricoid cartilage
infrahyoid strap muscles- throhyoid, sternohyoid, sternothyroid, omohyoid
submental triangle
submental lymph nodes
mylohyoid
pectoral girdle bones and joints
clavicle, scapula, acromioclavicular joint, glenohumoral joint
elbow joint
proximal radioulnar joint
forearm bones
radius- lateral
ulna- medial
wrist joint
radoiocarpal joint and distal radioulnar joint
hand bones and joints
carpu, metacarpus, and phalanges
mid carpal joint
carpometacarpal joint
metacarpophalangeal joint
interphalangeal joint
nerves in anterior compartment of arm
musculocutaneous and axillary
nerves in anterior compartment of forearm
median nerve
nerves in palmar compartment
ulnar nerve
nerves in posterior compartment of arm and forearm
radial nerve
brachcial plexus testing lateral arm
C5
elbow flexion
biceps reflex
brachial plexus testing thumb
C6
wrist extension
brachioradialis reflex
brachial plexus testing middle finger
C7
elbow extension
tricep reflex
brachial plexus testing little finger
C8
finger flexion
brachial plexus testing medial elbow
T1
finger adduction
weakness- elbow flexion
sensory deficit- lateral forearm
musculocutaneous nerve
weakness- finger adduction
sensory deficit- medial hand and little finger (P/D)
ulnar nerve
weakness- thumb abduction
sensory deficit- lateral hand, thumb, and first two fingers (P)
median nerve
weakness- elbow extension
sensory deficit- palmar surface of hand and lateral two fingers
C7
weakness- finger adduction
sensory deficit- medial elbow and forearm
T1
weakness- wrist extension
sensory deficit- distal lateral forearm, hand, and thumb
C8
weakness- decreased grip strength
sensory defecit- lateral palm and fingers
median nerve
weakness- diminished biceps and weak shoulder abduction
sensory defecit- lateral arm
C5
weakness- difficulty holding paper between fingers
sensory deficit- medial hand and 1.5 fingers (P/D)
ulnar nerve
weakness- thumb adduction
sensory defecit- medial hand and 1.5 fingers (P/D)
ulnar nerve
neuropathy
nerve that is damaged
