what do C1-C6 do that C7 does not?
-vetebral artery does NOT go through the transverse foramen of C7
-as ascends C6-C1 turns inward on C1 but doesnt go through C7
facial expression is derived from what?
derived from 2nd branchial arch and innervated by cranial nerve VII
at what level do bronchi divide?
sternal angle
what are the contents of the carotid sheath?
1. common carotid arter (internal carotid artery at more superiorlevels)
2.internal jugular vein
3. vagus nerve
what are the suprahyoid muscles? what are the infrahyoid muscles?
suprahyoid muscles:
-anterior belly of digatic
-posterior belly of digastic
-mylohyoid m
-stylohoid m
-geniohyoid
infrahhyoid muscles
-sternohyoid m
-omohyoid m
-sternothyroid m
-thyrohyoid m
is the deep investing fascia located superficially or deep?
BOTH --> muscles completely wrapped in fascial represents roof of posterior triangle
what are the deep muscles of the neck that represent the FLOOR of the posterior triangle?
1. scalenus anterior
2. scalenus medius
3. scalenus posterior
4. levator scapulae
5. splenius
what is the only muscle in the floor of the neck innervated by dorsal primary rami? what are the other muscles of the floor of the neck innervated by?
splenius m and ventral primary rami
what veins drain into the brachiocephalic vein?
1 superficial temporal v --> retromandibular v --> external jugular v --> brachioceophalic and subclavian vv
2 maxillary --> retromandibular v --> external jugular v --> brachiocephalic and subclavian v
3 retromandibular v --> external jugular v --> brach
define the boundaries of the root of the neck
laterally = first rib
anteriorly = manubrium of the sternum
posteriorly = cervical vertebrae
what can happenw hen a person is stabbed in the neck?
big chance of piercing the lung, lung collapses because no gas exchange. lung projects over the superior borderof the 1st rib. if knife wound is deep enough will penetrate pleural cavity
where is the brachial plexus located in relation to scalenus muscles?
between anterior and middle scalene muscles. muscle attaches to the first rib and anteriorly forces subclavian vein and posterior has subclavian artery. scalenus anterior m subdivides muscle into anterior/proximal, middle and lateral
what is berry aneurism?
walls of basilar artery become incompetent --> blow up like a balloon --> rupture --> bleed to death
retropharyngeal space is between ______ and ________
preveterbral fascia and alar fascia
what is the overall trend in development of bones?
going from multiple bones to fewer bones because of fusion.
which bones in he skull have sinuses? what is the danger of having air sinuses?
pneumatic bone (air filled bones)
paranasal- connected to specific regions of nasal cavity- frontal bone - frontal sinus- sphenoid bone - in middle- ethmoid bone - top end of cavity- maxilla - right under maxilla; biggest air sinus
-temporal bone is the f
what is the only paired bone?
temporal bone ; all others are unpaired/singular
once ossification is complete, how do you determine which type of ossification took place with each structure?
once process is complete, cannot tell which type of ossification took place
explain the development of the human skull from the primitive cranial skeleton.
the pharyngeal arches of humans are modified from the gill apparatus (brachial arches) of primitive vertebrates. the skeletal elements of the gill bars formed the foundation for the human jaw and neck skeleton. the expanding brain in the line of fish lead
what surrounds the body of the sphenoid and houses the pituitary gland? what are its contents?
cavernous sinus
contents CN III, IV, VI, V1, V2
what happens with aneurism and injury to internal carotid artery
lose movements of the eyeball; anesthesia of eyeball V1, anesthesia of mastication
what is cushings syndrome?
tumor of pituitary gland. caused by overactivity of adrenal cortex
what is the only bone in basicranium that forms by only endochondral ossification?
ethmoid bone
what type of problems may arise with the cribiform plate?
lose sense of smell -> anosia
bleed
rhinorrhea -> colorless liquid coming down from nasal cavity because tore meninges
which cranial fossa houses CN 3 ,4,5 and 6?
middle cranial fossa
which cranial fossa houses CN 1 and 2?
anterior cranial fossa
what passes through the optic canal?
CN II and opthalmic a, NO VEINS
what happens if you compress CN II?
blurred vision or even blindness
37 year old woman with severe head ach stiff neck and fever is admitted to the hospital with a likely diagnosis of meningitis. infection may spread from the nasal cavity to the meninges along the olfactory nerves. olfactory fivers pass fromt he olfactory
cribiform plate --will have spread of infection because through holes CN 1 passes through
if cut bone at location of foramen rotundum and injure the nerve that passes through it, what happens?
anesthesia of all maxillary teeth and palate (injury of CN V2)
what happens with injury to CN V3?
MOTOR AND SENSORY
-paralysis of masticatory muscles -> no chewing
-anesthesia of chin and temporal area
-anesthesia of mandibular teeth
-anesthesia of tongue
what is the function of parietal foramina?
connect vasculature of scalp with vasculature of interior of cranium
identify those areas of the skull that develop as capsules that hold organs of special sensation
olfactory capsule
optic capsule
otic capsule
describe where fontanelles are found and thier developmental fate
-in new born see parietal temporal occipital separate by open sutures and wide gaps
-must allow for growth of the skull after birth
-if fused at birth no further possibility of further brain growth
-this happens to provide a lot of flexibility of the skul
what happens if the neural tube does not close or fails to close completely?
the CNS is basically hollow so if it doesnt close over, the skin doesnt close over and the vertebral arches dont form all hte way to the part of the brain --> the higher parts of the brain does NOT form
what happens if one or more sutures of the skull close prematurely?
if saggital suture closes prematurely but brain keeps growing, get expansion --> scaphocephaly "wedged in
primitively do muscles of the 2nd branchial arch extend to the facial region?
no, most do not have superficial muscles attached to face which change facial expressions
the superficial facial muscles are primitively derived from what 3 muscles sheaths?
most superficial was the sphincter colli superficialis, which has been lost in humans. next is the platysma which forms a longitudinal sheet on the side of the neck and also gives rise to the auricularis posterior, occipitalis and depressor labii inferior
what is the danger area of the face?
upper lip, side of nose
-4th layer of scalp where tearing of emissary area can occur
-infections here can spread to orbit and cranial cavity
-has deep connections to the pterygoid plexus and to the cavernouse sinus, which is inside the cranial cavity. the
what are the layers of the scalp?
S-kin
C-onnective tissue
A-poneurosis
L-loose areolar tissue
P-ericranium
what are the branches of the facial nerve?
Temporal
Zygomatic
Buccal
Mandibular
Cervical
what three major foramina transmit sensory branches of the trigeminal nerve to areas of the face where major groups of tactile vibrissae were located in more primitive mammals?
supraorbital foramen, infraorbital foramen, mental foramen
T/F the buccinators muscle does NOT close the jaw
true
what is ptosis
palsy of CN III = closed eyelid
1st sign of CN III injury is complete ptossi
what is bell's palsy?
compression of the facial nerve, partial of complete paralysis on one side, when face is relaxed cannot close eyelids because orbicularis oculi paralyzed, whole face drops to 1 side.
name the 2 areas of major differences in the arterial and venous connections?
there is a connection in the veins that is not present in the arteries. also posteriorly the retromandibular vein which goes dwon tothe facial vein and then drains into the external/internal jugular vein.
if you have a cut of a scalp that goes longitudinally versus transverse, which will produce more bleeding?
transverse cute because muscles will pull the edges of the incision apart, the connective tissue will keep the lumina of vessels open, and exacerbated because muscles will make the wound gape more than if longitudinal cut.
what is the precursor to the mandible?
Meckels Cartilage
would ossification take place in meckels cartilage
no, takes place in the membrane SURROUNDING the bone --> membranous ossification, ossification in membrane not cartilage
most of the mandible forms in membrane that invests and surrounds meckels cartilage EXCEPT where?
endochondral centers, where mandibular condyle forms is a joining that forms by endochonral ossification the rest is by membranous ossification
what happens to Meckels cartilage as the bone develops?
gets reabsorbed and disappears, early vertebrates do not have teeth, higher vertebrates have teeth because reabsorbed into canal into which nerves and blood vessels can migrate --> stimulate development of teeth
there are ____cleftes, ___ pouches and ___arches before proliferation of the second arch
4, 5, 5
1- branchial grooves or clefts lined by ectoderm - ectodermal origin
2branchial arches formed by mesoderm
3 branchial pouches lined by endoderm --> endodermal origin
4 branchial membranes comprised of fused ectodermand endoderm
arches begin to develop during the 4th as rounded ridges or bars one ach side of the future head and neck. six pairs of arches appear by the end of the 5th week. they develop in rostral to caudal sequence. the arches are separated from eachother externall
branchial clefts, branchial pouches and stomodeum
each arch is composed of a core of ____covered externally by ____________ and ined internally by_________
mesoderm,ectoderm, endoder,
what develops in the floor of the pharynx
tongue
stylopharyngeus muscle is derived from what arch? innervation?
3rd arch
CN IX - glossopharyngeal nerve
what develops in the floor of the pharynx?
tongue
what is inside of each arch? what is on the exterior lateral to each arch?
nerve, artery, cartilage
thin layer of endoderm
what does the endoderm form?
endothelial lining of the gut
rostral most portion of gut tube (pharynx)
what cleft do you have between 2nd and 3rd arch? 3rd and 4th arch? 4th and 6th?
2 ,3, 4
what is the only cleft that develops into a normal structure? what structure does it develop into? what happens to the other clefts?
1st cleft: external auditory meatus
#1 dorsal part penetrates the underlying mesoderm in the direction of the 1st pharyngeal pouch and gives rise to the external auditory meatus
#2 active proliferaton of this one (2nd arch) causes it to grow caudal overla
the distal and medain tongue buds are derived from which arch?
1st branchial arch
the hypopharyngeal eminece is derived from which arch?
3rd branchial arch
the mucosal lining of the tongue is involved with what 3 cranial nerves?
5,9,10
anterior 2/3 of the tongue = CN 5
posteriror 1/3 of the tongue = CN 9,10
describe innervation to the tongue
taste sensation from chorda tympani (CN VII)--> grows into undersurface of anterior 2/3 of tongue, contacts in several places and induces taste buds of anterior 2/3 of tongue to taste
-posterior 1/2 of tongue--taste bud---also CN IX
-motor innervation --h
what is significant about the foramen cecum?
where thyroid gland develops initially in endodermal tissue -->migrates down tot he thyroglossalduct -->stops for short time tin front of hyoid bone then goes down to upper tracheal rings where it resides
the pharyngeal pouches are derived from what germ layer?
endoderm
the 1st cleft comes from
external auditory meatus
where does the thyroid gland reside in a newborn?
superior and anterior
what does the thymus gland do?
form T-cells
why do we call the parathyroid of 3rd pouch inferior and the one below it superior?
parathyroid of 4th pouch detaches before the the 3rd one
-3rd one has secondary detachment --> 4th becomes superior and 3rd becomes inferior
all glands are derived from what germ layer? nerves? blood vessels?
endoderm, ectoderm, mesoderm
how does the cervial sinus form?
2nd cleft: active proliferation of this one (2nd arch) causes it to grow caudally, overlapping with the 3rd, 4th ridge. this buries the 2nd. 3rd and 4th clefts - these clefts form a cavity lined with ectodermal epithelium - cervical sinus
in the 6th week the nasal placodes undergo what important transformation?
form pit in center --> each one has 2 swellings (medial and lateral swellings)
early in development there was no palate between oral and nasal cavities. how did it form and what changed?
innovation in warm blooded animals; some very active dinosaurs could do this --> develop hard palate -->allow us to breath and eat
-palatine shelves start to grow downward, lengthen and then rotate up to form hard secondary palate
-secondary palate forms
what happens if the cleft extends between primary and secondary palate?
unilateral cleft lip and primary palate
85% of bones in the brain (neurocranial bony complex) are derived from ___ the rest come from ____
neural crest; paraxial mesoderm
our skull appears to be unitunitary/singular with the exception of the___
mandible ( can be separated out)
the following are derived form teh neural crest EXCEPT?
-occipital/ arise around foramen magnum and laryneals