Exam 2 Flashcards
Contents of the superficial posterior compartment of the leg
Gastrocnemius (medial and lateral)
Plantaris
Soleus
Tendo calcaneus
Contents of the deep posterior compartment of the leg
Popliteus
Flexor digitorum longus
Tibialis posterior
Contents of the anterior compartment of the leg
Tibialis anterior
Deep fibular nerve and anterior tibial vessels
Extensor hallicus longus
extensor digitorum longus
Contents of the lateral compartment of the leg
Superficial fibular nerve
Fibularis brevis
Fibularis longus
Gastrocnemius
Crosses both knee and ankle joint
two heads form inferior boundaries of the popliteal fossa
Popliteus
lies in the floor of the popliteal fossa
flexes and rotates the knee
Flexor digitorum longus
tendon passes posterior to medial malleoulus and to tendon of tibialis posterior
plantarflexes foot at the ankle joint
Crural Fascia
Continuous with fascia latae: attachment to anterior and medial borders of tibia. Continuous with periosteum
Fascia forms retinacula in foot: superior retinaculum, inferior retinaculum, flexor retinaculum, superior/inferior peroneal retinaculum
Superior (extensor) retinaculum
proximal to malleoli
binds tendons in anterior crural compartment: tibialis anterior, extensor hallucis longus, extensor digitorum longus, peroneus tertius
Covers: deep peroneal (fibular) nerve and anterior tibial artery
Inferior (extensor) retinaculum
“y” - shaped
Flexor retinaculum
binds tendons of the deep posterior compartment: flexor hallucis longus, flexor digitorum longus, and tibialis posterior
Covers: tibial nerve and posterior tibial artery
Superior/inferior peroneal retinacula
binds tendons of lateral crural compartment: peroneus longus and brevis
Cutaneous nerves of the superficial posterior compartment of the leg
Lateral sural cutaneous nerve: from common peroneal (fibular) nerve
Medial sural cutaneous: from tibial nerve
Sural nerve runs with lesser saphenous vein
Flexor hallicus longus
Tendon occupies groove on posterior surface of talus
Continuous with groove on plantar surface of sustentaculum tali
Tendon passes posterior to medial malleolus
Tendon passes between 2 sesamoid bones
Push off muscle for walking, jumping, running
Tibialis posterior
functions in plantar flexion and foot inversion
helps maintain medial longitudinal arch
Nerve supply to the deep posterior compartment of the leg
tibialis nerve
Blood supply to the deep posterior compartment of the leg
posterior tibial artery
Tibialis anterior
Lateral to crest of tibia
Foot dorsiflexion and inversion
L4-L5
Paralysis results in foot drop
Extensor digitorum longus
four tendons of insertion
each tendon inserts on an extensor expansion similar to arrangement in the hand
toe extension at MTP and also dorsiflexion
Peroneus (fibularis) tertius
Part of extensor digitorum longus
foot dorsiflexion and eversion
sometimes missing
Function of the anterior compartment of the leg
toe extension
ankle dorsiflexion
Innervation of the anterior compartment of the leg
Deep peroneal (fibular) nerve: L4-5 to tibialis anterior L5-S1 for remaining muscles Runs deep to extensor digitorum longus accompanies anterior tibial artery between extensor hallicus longus and tibialis anterior muscles.
Blood supply to the anterior compartment of the leg
Anterior tibial artery:
smaller terminal branch of the popliteal artery
begins at inferior border of popliteus muscle
becomes dorsalis pedis artery at ankle joint
Peroneus (fibularis) longus
more superficial muscle of the lateral compartment
easily palpated
its tendon uses lateral malleolus as a pully
tendon crosses sole of foot and inserts on first metatarsus and cuniform
helps maintain transverse and longitudinal arches of the foot
Peroneus (fibularis) brevis
Deep to peroneus longus
inserts on lateral tuberosity
functions in plantar flexion and foot eversion
Nerve supply to the lateral compartment of the leg
Superfical peroneal (fibular) nerve:
deep to peroneus longus
inserts on lateral tuberosity
Spinal cord levels: L5, S1-S2
Blood supply to lateral compartment of the leg
No major arteries
Muscular branches arise from the peroneal artery
Hindfoot
talus and calcaneus
Midfoot
Navicular, cuboid and cuneiforms
Forefoot
Metatarsals and phalanges
Talotibial (talocrural) joint
aka ankle joint
synovial hinge joint
Movements: dorsiflexion, plantar flexion
Ankle ligaments
Medial collateral (deltoid) - components: tibionavicular, tibiocalcaneal, anterior tibiotalar, posterior tibiotalar Lateral collateral (weakest) - components: anterior talofibular, posterior talofibular, and calcaeofibular
Talocalcaneal (subtalar) joint
very stable, uniaxial
three surfaces:
Posterior - concave facet on talus with convex facet on calcaneus
Anterior - convex facets on body and neck of talus, concave facets on calcaneus
Tarsal tunnel - nonsynovial, ligament = talocalcaneal ligament
Movements: inversion - adduction, supination, plantarflexion. Eversion.
Talocalcaneonavicular joint
Composite joint: talocalcaneal joint + talonavicular joint
Movements: inversion and eversion
Ligament: calcaneonavicular ligament. Helps maintain medial longitudinal arch
Transverse tarsal joint
Composite joint: talonavicular + calcaneocuboid
Function: links hindfoot and forefoot, adds to inversion/eversion range, keeps distal foot inverted with lateral surface in contact with ground while hind foot is everted
Primary support ligament for medial longitudinal arch
plantar calcaneonavicular
Primary support ligament for lateral longitudinal arch
long plantar
Support ligaments for plantar arches
plantar aponeurosis
plantar calcaneocuboid (short plantar)
marginal abductors
Blood supply to the dorsum of the foot
Anterior tibial artery via dorsalis pedis artery
Arcuate artery
Deep plantar artery
Muscles of the dorsum of the foot
Extensor digitorum brevis
Extensor hallucis brevis
Dorsal interossei: abductors (2nd toe is reference)
Nerve supply to dorsum of the foot
Superficial peroneal nerve - cutaneous
Deep peroneal nerve - lateral branch is motor to extensor hallucis brevis and extensor digitoum brevis. Medial branch is cutaneous
Sural nerve - gives off lateral dorsal cutaneous nerve
Tendons of the peroneus longus and brevis pass through which retinacula?
Superior and inferior peroneal
Blood supply to the sole of the foot
Posterior tibial artery
Perforating arteries
Nerve supply to the sole of the foot
Cutaneous: tibial nerve (medial calcaneal, medial plantar and lateral plantar), saphenous nerve and sural nerve
Motor: tibial nerve via lateral and medial plantar nerves
Muscle layers in sole of foot
Superficial: skin, plantar aponeurosis
1st muscle layer: abductor hallucis, flexor digitorum brevis, abductor digiti minimi
Tendons in 1st layer: flexor digitorum longus tendon, flexor hallucis longus tendon
2nd muscle layer: quadratus plantae, lumbricals
3rd muscle layer: flexor hallucis longus tendon, adductor hallucis and flexor digiti minimi brevis
4th muscle layer: peroneus longus tendon, tibialis posterior tendon, interossei (3 PADs, 4 DABs)
Ethmoid bone
Only bone that is entirely preformed in cartilage
Components: cribiform plate, crista galli, perpendicular plate, lbyrinth, ethmoid air cells
Sphenoid bone
Formed from cartilage and dermal elements
Components: pterygoid plates, body
Greater wings of the sphenoid bone
Lower flaps: contribute to floor of middle cranial fossa. Foraminae - foramen rotundum (V2), foramen ovale (V3) and foramen spinosum (middle meningeal vessels)
Upper flaps: foraminae - optic canal, anterior clonoid porcess
Temporal bones
Petrous part: surrounds ear apparatus, forms auditory tube, forms carotid canal
Mastoid process: mass of air-filed outpocketings (air cells) from petrous part
Styloud process: fuses to petrous portion in front of mastoid, attachment site for muscles and ligaments
Squamous part: thin dermal bone forming lateral wall of braincase above auditory meatus
Tympanic part: forms ring of dermal bone around eardrum, becomes external auditory meatus
Occipital bone
Squamous part: forms lower back of the head
Basilar part: formed from anterior vertebral elements, forms from 4 separate bones to fuse around the spinal cord to form the foramen magnum
Frontal bone
paired in fetus, fused in adult
has supraorbital foramina (notches)
Maxillary bones
alveolar process
infraorbital foramina
Membrane bones
frontal bone
maxillary bone
zygomatic bone
nasal bone
Mandible
Consists of:
Ramus - area for muscle attachment, lingula, condylar process, mandibular notch and coronoid process
Angle
Body - mental protuberance, mental foramen
Anterior cranial fossae
Mostly formed by frontal bone
located superior to orbits
features: crista galli, cribiform plate and olfactory formina
contains: frontal lobes of cerebrum
Middle cranial fossae
Formed mostly by body and greater wings of sphenoid
features: attachment for diaphragma sellae, dorsum sellae, posterior clinoid processes, chiasmatic sulcus, optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum and foramen lacerum
contains: temporal lobes of cerebrum
Posterior cranial fossa
Formed mostly by occipital bone
Features: clivus, foramen magnum, jugular foramen, hypoglossal canal, condylar canal, mastoid canal, roofed by tentoium cerebelli, tentorium incisure
Contains: cerebellum, pons, medulla
Bony articulations of occipital bone
occipital condyles
Bony articulations of atlas
posterior tubercle, posterior arch, anterior arch, transverse process with foramina, lateral masses (articulation with occipital condyles and axis)
Bony articulations of axis
Dens (odontoid process), spinous process, transverse processes with foramina
Ligaments of vertebral column
Anterior longitudinal ligament, posterior longitudinal ligament, ligamentum flavum, ligamentum nuchae (supraspinous + interspinous ligaments)
Muscles of suboccipital muscles
Obliquus capitis superior: weak extensor of neck
Obliquus capitis inferior: strong rotator of atlas
Rectus capitis posterior major: extension of vertebral column
Rectus capitis posterior minor: extension of vertebral column
Floor of suboccipital triangle
posterior atlanto-occipital membrane
Roof of suboccipital triangle
semispinalis capitis muscle
Contents of suboccipital triangle
suboccipital nerve: dorsal ramus of C1, no sensory funtion and no dorsal root, motor to muscles of suboccipital triangle
Greater occipital nerve: dorsal ramus of C2, sensory to back of skull
Third occipital nerve: dorsal ramus of C3
Vertebral artery
Platysma
Origin: Sub Q of infraclavicular and supraclavicular regions
Insertion: Base of mandible, skin of cheek, lower lip, angle of mouth, orbicularis oris
Action: depresses mandible; tenses skin of inferior face and neck
Occipitofrontalis
Origin: anteriorly from epicranial aponeurosis, posteriorly from superior nuchal line
Insertion: Epicranial aponuerosis posteriorly and skin and sub Q of eyebrows and forehead anteriorly
Action: elevates eyebrows, protracts scalp
Orbicularis occuli
Origin: orbital margin, palpebral ligament, lacrimal bone
Insertion: sin around margin of orbit; tarsal plates
Action: closes eyelids
Procerus
Origin: facial aponeurosis; lateral nasal cartilages
Insertion: skin between eyebrows
Action: depresses medial sides of eyebrows and wrinkles skin over dorsum of nose
Nasalis
Origin: frontal proesses of maxillae
Insertion: alar cartilage
Action: depresses alae laterally and dilates anterior nasal aperture
Orbicularis oris
Origin: medial maxilla and mandible; deep surface of skin around mouth
Insertion: mucosa of lips
Action: Closes of oral fissure; compresses and protrudes lips
Levator labii superioris
O: infraorbital margin
I: skin of upper lip
A: part of dilators of mouth
Zygomaticus minor
O: anterior part of zygomatic bone
I: skin of upper lip
A: part of dilators of mouth
Zygomaticus major
O: lateral part of zygomatic bone
I: angle of mouth
A: elevates labial commissures (corner of mouth)
Risorius
O: parotid fascia and buccal skin
I: angle of mouth
A: depresses labial commissures (corner of mouth)
Depressor anguli oris
O: anterolateral base of mandible
I: angle of mouth
A: depresses labial commissures
Depressos labii inferioris
O: platysma and anterolateral body of mandible
I: skin of lower lip
A: mouth dilator; depresses and everts lower lip
Facial Artery
Branch of external carotid artery
Winds around lower border of mandible and becomes superficial
Passes lateral to angle of mouth
Branches: superior and inferior labial arteries, lateral nasal artery and angular artery
Superficial temporal artery
Terminal ranch of external carotid artery
Emerges between TMJ and auricle
Enters temporal fossa
Divides into frontal and parietal branches
Transverse facial artery
Arises from superficial temporal temporal artery
Crosses face superficial to masseter muscle
Anastomoses with facial artery
Branches supply: parotid gland, masseter muscle and skin of face
Which cranial nerve provides sensory innervation to the face?
Trigeminal nerve (CN V)
What are the 3 branches of the trigeminal nerve?
opthalmic, maxillary and mandibular
Besides the trigeminal nerve, what other sensory nerves innervate the head?
Greater occipital, lesser occipital and great auricular
Which foramina does the opthalmic branch exit?
superior orbital fissure
Which foramina does the maxillary branch exit?
foramen rotundum
Which foramina does the mandibular branch exit?
foramen ovale
Which cranial nerve provides motor innervation to the face?
Cranial nerve VII (facial nerve)
Which foramina does cranial nerve VII exit through?
stylomastoid foramen
Layers of the Scalp
Skin Connective tissue Aponeurosis - frontalis and occipitalis Loose areolar tissue Pericranium
Vascular supply to the head
Branches of the external carotid: occipital, posterior auricular and superficial temporal
Branches of the internal carotid: supratrochlear and supraorbital
Vascular supply to the brain
Two internal carotid arteries and two vertebral arteries.
The four arteries form the circle of willis on the inferior surface of the brain.
Components: posterior cerebral arteries, internal carotids/middle cerebral arteries, anterior cerebral arteries, anterior communicating artery, and posterior communicating arteries
Meninges and spaces (superficial to deep)
Epidural space (absent around brain) Dura mater Subdural space Arachnoid membrane Arachnoid villi Pia mater
Dural sinuses
endothelial-lined spaces between the periosteal and meningeal layers of the dura
Falx cerebri
midline fold of the dura mater extending between the two cerebral hemispheres
Tentorium cerebelli
Dural fold located between cerebellum and occipital lobes of cerebral hemispheres
falx cerebelli
dural fold between two cerebellar hemispheres
Diaphragma sellae
dural fold over hypophyseal fossa
superior sagittal sinus
lies along superior margin of falx cerebri
begins at crista galli and ends at occipital prottuberance
inferior sagittal sinus
lies along inferior margin of falx cerebri and ends in straight sinus
Straight sinus
lies at intersection of falx cerebri and tentorium cerebrelli
fformed at intersection of inferior sagittal sinus and great cerebral vein
joins confluence of sinuses
Confluence of sinuses
common confluence of superior sagittal, transverse and straight sinuses
Transverse Sinus
begins at confluence, extends along edges of tentorium cerebelli
right receives blood from superior sagittal sinus
left (dominant) receives blood from straight sinus
Sigmoid
continuations on wither side of straight sinus
s - shaped
end at jugular foramina
become internal jugular veins
CSF flow
Choroid plexuses -> ventricles -> through apertures -> into subarachnoid space -> through arachnoid villi -> into dural venous sinuses -> into internal jugular veins
Arterial supply to the upper part of the spinal cord
anterior spinal artery from union of vertebral arteries
sulcal branches from anterior spinal artery into anterior median fissure
posterior spinal arteries branch from vertebral arteries or from posteroinferior cerebellar arteries
Sensory innervation to outer ear
great auricular nerve, auroculotemporal nerve, lesser occipital nerve
Auditory ossicles
Malleus - attached to TM
Incus
Stapes - attached to oval window
Stapedius muscle
inserts onto neck of stapes
contracts reflexively in response to loud sounds
innervated by CN VII
Tensor tympani muscle
inserts on malleus
contracts reflexively in response to loud sounds
innervated by CN V-3
Contents of inner ear
bony labyrinth
membranous labyrinth, cochlea, vestibule
Semicircular canals
sense rotational acceleration
Utricle and saccule
senses linear acceleration and pull of gravity
Roof of orbit
orbital plate of frontal bone
lesser wings of sphenoid
Features: fossa for lacrimal gland
Floor of orbit
orbital plate of maxilla
zygomatic
orbital process of palatine
Features: infraorbital groove and canal, infraorbital artery
Medial wall of orbit
lacrimal
frontal
ethmoid
features: fossa for lacrimal sac, opening for nasolacrimal canal
lateral wall of orbit
zygomatic
greater wing of sphenoid
frontal
Sympathetic supply of lacrimal apparatus
from T1
to superior cervical ganglion
to lacrimal gland
Parasympathetic supply of lacrimal apparatus
from lacrimal nucleus via CN VII
to sphenopalatine ganglion
to lacrimal gland curtesy of CN V
Superior orbital fissure
Cranial nerves: III, IV, V-1, VI
superior ophthalmic vein
Optic canal
Cranial nerve II
ophthalmic artery
Anterior and posterior ethmoidal foramina
exit for anterior and posterior ethmoidal nerves
Inferior orbital fissure
Cranial nerve V-2
Extrinsic muscles of the eye
Inferior oblique (CN III): abducts, elevates, laterally rotates eye ball Superior rectus (CN III): elevates, adducts and medially rotates Medial rectus (CN III): adducts Inferior rectus (CN III): depresses, adducts, laterally rotates Superior oblique (CN IV): abducts, depresses, medially rotates Lateral rectus (CN VI): abducts Levator palpebrae superioris (CN III): raises upper eye lid
Sensory innervation to orbit
Optic nerve Ophthalmic nerve (V-1)
Parotid duct
opposite upper second molar
Oropharynx
from soft palate above to upper border of epiglottis below
Lies at level of second and third cervical vertebrae
Contains: palatine tonsils, tonsilar branch of facial artery, glossopharyngeal nerve
Muscles of oropharynx
Palatopharngeus muscle: elevates pharynx during swallowing, vagus nerve
Palatoglossus muscle: depresses palate, vagus nerve
Tensor veli palatini: tenses soft palate
Levator veli palatini: elevates soft palate
Sensory innervation to mucous membranes
anterior ethmoidal nerves
nasopalantine nerves
Motor innervation to mucous membranes (parasympathetic)
To pterygopalatine ganglion via CN VII
To mucous glands via maxillary nerve
Motor innervation to mucous membranes (sympathetic)
to blood vessels from superior cervical ganglion via maxillary nerve
Maxillary sinus
Largest
Opens to: middle meatus via semilunar hiatus
Nerve supply: superior alvealar nerve and infraorbital nerves
Frontal sinuses
Paired
Opens to: middle meatus via frontonasal duct
Nerve supply: supratrochlear nerves and supraorbital nerves
Ethmoidal sinus
group of ethmoidal air cells
open to middle of superior meatus
Sphenoidal sinus
paired
opens to nasal cavity via sphenoethmoidal recess
Nerve supply: maxillary nerves and ethmoidal nerves
