Head & Neck Superficial Anatomy-Sievert Flashcards
(168 cards)
1
Q
What are the 3 main structures of the developing head & neck?
A
placodes
somites
branchial arches
2
Q
What is another name for branchial arches? What are the 2 subtypes?
A
aka pharyngeal arches
clefts (come from the outside)
pouches (come from the inside)
3
Q
What are placodes? What are the 3?
A
they are thickenings of the ectoderm that form structures for some of our special senses. Otic placode (ear) Lens Placode (eye) Olfactory Placode (nose)
4
Q
What separates the bilateral placodes?
A
the neural tube.
5
Q
Describe the location of the somitomeres (baby somites) in relation to the placodes.
A
There are 3 somitomeres above the otic placode. Called preotic somites. There are 3 somitomeres that are below the otic placode (postotic somites).
6
Q
What do the preotic somites contribute to? What do the postotic somites contribute to?
A
preotic: extraocular muscles
postotic: tongue muscles
7
Q
What does the olfactory placode form?
A
the primary olfactory epithelium (found in the superior nasal cavity). these are the cells of smell.
8
Q
Where is the olfactory placode located?
A
near the forebrain the telencephalon part.
9
Q
As the telencephalon develops you get something that induces the formation & thickening of the olfactory placode. What’s the deal with all of this?
A
the telencephalon develops & forms the olfactory bulb. This induces the olfactory placode to thicken
10
Q
The cells of smell (primary neurosensory cells) of the olfactory placode meet up with the olfactory tract in the olfactory bulb. What must they penetrate to do this?
A
they have to get thru little holes in the cribriform plate of the ethmoid bone to get to the olfactory bulb.
11
Q
Describe briefly how the lens placode forms.
A
an out pocketing of the forebrain (the diencephalon part) induces the surface ectoderm to thicken & form the lens placode.
12
Q
How is the lens placode different from the otic & olfactory placodes?
A
it has nothing to do with neurons or receptors.
All that it is is something that thickens, invaginates, & breaks off to form the lens.
13
Q
What does the lens placode help form?
A
the remaining surface ectoderm forms the cornea.
14
Q
What are the 3 parts of the ear?
A
external
middle
inner
15
Q
What does the otic placode form?
A
the inner ear
the membranous labyrinth
sensory neurons of cranial nerve 8
ganglion cells of cranial nerve 8
16
Q
What are ganglion cells of cranial nerves?
A
they are very much like a DRG but they are located outside of the CNS
- *don’t have a synapse
- *have pseudo unipolar cells with a peripheral & central process
17
Q
What should moms know about the ear’s development?
A
it is very slow to develop & therefore very susceptible to environmental defects
furthermore, it is difficult to tell when there are defects in an ear–have to specific tests w/ a baby.
18
Q
What induces the otic placode?
A
the CNS induces the otic placode
it then invaginates creating the sensory neurons & inner ear.
19
Q
What makes the external part of the ear?
A
the external auditory canal is formed by a cleft. an invagination of surface ectoderm
20
Q
What makes the middle ear?
A
the middle ear is formed by 1st branchial pouch
an out pocketing of the endoderm of the pharynx
21
Q
What’s cool about the tympanic membrane?
A
3 embryonic derivates live together!
22
Q
T/F In the tympanic membrane you will find ectoderm, endoderm, and a little mesenchyme.
A
True.
23
Q
What are somites?
A
masses of mesoderm that form skeletal muscles
24
Q
T/F Preotic somites take care of the pupillary dilator & constrictor muscles.
A
False. Only extraocular muscles
muscles that move the eyeball & open eyelid NOT pupil or ciliary body stuff.
25
What nerves do we associate with somites?
GSE. General Somatic Efferents. So extraocular muscles (came from somites) are innervated by GSE fibers. Somatomotor.
26
What are GVE?
These are General Visceral Efferents. These are the fibers that innervate muscles that are smooth muscle, cardiac muscle etc. Visceromotor.
27
Branchiomotor nerve fibers innervate what?
muscles that came from branchial arches. This includes skeletal muscles, striated muscle. ??
28
What muscles come from postotic somites?
tongue muscles
29
Which cranial nerves are associated w/ the preotic somites?
3, 4, 6
30
Which cranial nerve is associated w/ the postotic somites?
Cranial Nerve 12-->hypoglossal nerve.
31
What are pharyngeal/branchial arches?
masses of mesenchymal tissue that flank the developing gut tube.
32
What does each pharyngeal arch have associated w/ it?
artery
nerve
block of tissue-->muscles
33
What direction do the pharyngeal arches develop in?
cranial-->caudal direction
34
Developmentally, when do the pharyngeal/branchial arches show up?
4th-5th week.
35
What does a pharyngeal arch look like in cross section?
it has a nerve, artery, & a part that becomes cartilage or bone
also has mesenchymal tissue & some neural crest cells
***outside lining is ectoderm. When this invaginates =cleft.
***inside lining is endoderm. When this invaginates=pouch.
36
What are the different derivates of the pharyngeal arches?
muscle
bone or cartilage
skin (from ectoderm)
gut lining (endoderm)
37
Describe the first pharyngeal arch. What does it give rise to?
So this arch has 2 parts. The maxillary arch & the mandibular arch.
Maxillary arch-->Upper jaw
Mandibular arch-->Lower jaw & small inner ear bones (malleus & incus) & part of temporal bone
**zygomatic bone formed by something in the 1st pharyngeal arch.
38
What is the 2nd pharyngeal arch called? What does it give rise to?
hyoid arch
| **gives rise to part of the styloid process & the stapes & part of the hyoid bone
39
What does the 3rd pharyngeal arch give rise to?
the rest of the hyoid bone?
40
What does the 4th pharyngeal arch give rise to?
the cartilage of the larynx
41
What arch (aside from the 4th) helps contribute to the cartilage of the larynx? What's the deal here?
the 6th arch contributes to the cartilage of the larynx, specifically the cricoid cartilage. The 4th specifically takes care of the thyroid cartilage.
These 2 arches fuse.
42
Which muscles arise from the 1st pharyngeal arch?
the muscles of mastication
43
Which muscles arise from the 2nd pharyngeal arch?
muscles of facial expression
44
Which muscles arise from the 3rd pharyngeal arch?
1 muscle. The stylopharyngeus muscle. Goes from the styloid process to the pharynx.
45
Which muscles arise from the 4th pharyngeal arch?
muscles of the pharynx, larynx, & palate.
46
Where do the pharyngeal arches get their sensory innervation?
the endodermal lining of the pharyngeal arches is innervated (cutaneous innervation) by the nerve of that arch.
47
What's the deal with cutaneous innervation & the 1st pharyngeal arch?
so...the 1st pharyngeal arch forms the anterior 2/3 of the tongue. It overgrows the 2nd pharyngeal arch. This area of the tongue for some reason is more associated w/ ectoderm. Therefore, the cutaneous anterior 2/3 of the tongue (1st arch) is innervated by the 5th cranial nerve.
48
What's the deal with cutaneous innervation to the 2nd pharyngeal arch?
remember, overgrown by the 1st arch! Poor guy.
49
What's the deal with cutaneous innervation & the 3rd pharyngeal arch?
this covers the posterior 1/3 of the tongue. Behind the sulcus terminalis & the foramen cecum.
this area is more associated w/ endoderm.
This is innervated by the 9th cranial nerve. Cutaneous innervation, that is.
50
What's the deal with cutaneous innervation & the 4th pharyngeal arch?
this forms the epiglottis
| cutaneous innervation by cranial nerve 10
51
What are the important pharyngeal clefts & what do they give rise to?
really one 1 important cleft.
| 1st pharyngeal cleft gives rise to external auditory meatus
52
What happens to the other pharyngeal clefts?
they close off & can make cervical sinuses or cysts
53
How many important pharyngeal pouches are there?
4
54
What happens to the 1st pharyngeal pouch?
the 1st pouch merges w/ the 1st cleft & makes the auditory tube/eustachian tube. The pouch also makes the middle ear.
55
What happens to the 2nd pharyngeal pouch?
it forms the palatine tonsil
56
What happens to the 3rd pharyngeal pouch?
inferior parathyroid gland
| thymus
57
Why is the inferior parathyroid gland formed by a higher pouch than the superior parathyroid gland?
b/c the thymus migrates downward. Eventually, the inferior parathyroid gland is in fact inferior.
58
What happens to the 4th pharyngeal pouch?
it forms the superior parathyroid gland & the ultimobranchial body (C cells of thyroid gland)
59
The olfactory placode is associate w/ which cranial nerve? What is the nature of this nerve?
Cranial Nerve 1-->Olfactory Nerve
| sensory nerve
60
Lens placode. Associated w/ which cranial nerve? What is the nature of this nerve?
Cranial Nerve 2-->Optic Nerve
sensory nerve
**really talking about responding to an out pocketing of neural tube here
61
Preotic Somites. Associated w/ which cranial nerve? What is the nature of this nerve? Which embryonic derivative? Which muscles do they innervate?
```
Cranial Nerve 3-->Oculomotor Nerve
Cranial Nerve 4-->Trochlear Nerve
Cranial Nerve 6-->Abducens Nerve
Somatomotor (think somites!)
Mesoderm
Extraocular Muscles
```
62
1st pharyngeal arch. Associated w/ which cranial nerve? What is the nature of this nerve?
Cranial Nerve 5-->Trigeminal Nerve
| Both motor & sensory.
63
2nd pharyngeal arch. Associated w/ which cranial nerve? What is the nature of this nerve?
Cranial Nerve 7-->Facial Nerve
| motor & sensory??
64
3rd pharyngeal arch. Associated w/ which cranial nerve?
Cranial Nerve 9-->Glossopharyngeal Nerve
65
4th pharyngeal arch. Associated w/ which cranial nerve?
Cranial Nerve 10-->Vagus Nerve
66
Postotic Somites. Associated w/ which cranial nerve?
All Cranial Nerve 12-->Hypoglossal Nerve
| **does the muscles of the tongue
67
What's the deal with Cranial Nerve 11?
Spinal Accessory Nerve. Innervates the trapezius. Controversy in terms of which primordial structure it came from.
68
What are the cranial Nerves to the placodes?
Cranial Nerve 1: Olfactory Nerve
Cranial Nerve 2: Optic Nerve
Cranial Nerve 8: Vestibulocochlear
69
What are the cranial nerves to the somites?
Cranial Nerve 3: Oculomotor
Cranial Nerve 4: Trochlear
Cranial Nerve 6: Abducens
Cranial Nerve 12: Hypoglossal
70
What are the cranial nerves to the branchial arches?
Cranial Nerve 5: Trigeminal
Cranial Nerve 7: Facial
Cranial Nerve 9: Glossopharyngeal
Cranial Nerve 10: Vagus
71
Which of the cranial nerves are branchial motor?
5, 7, 9, 10
72
Which of the cranial nerves are sensory only?
1, 2, 8
73
Which of the cranial nerves are somatomotor?
3, 4, 6, 12
74
The alar plate gives rise to what?
sensory cell bodies & columns.
| Including: GSA, GVA
75
The basal plate gives rise to what?
motor cell bodies & columns.
| Including: GSE & GVE
76
GVA likes to communicate w/ what?
GVE
77
Where are the GVE located? Where are the GSE located?
GVE: lateral horn
GSE: ventral horn
78
T/F Spinal columns are incomplete.
True.
79
T/F Every cranial nerve is unique in terms of its components.
True.
80
What are the potential afferent components of a cranial nerve?
SSA: special somatosensory (vision and balance/hearing)
GSA: general somatosensory (skin etc.)
GVA: general viscerosensory (like vagus) (gut, etc.)
SVA: special viscerosensory (taste buds and nasal placode)
81
What are the potential efferent components of a cranial nerve?
GVE: visceromotor (autonomic)
GSE: somatomotor (muscles from somites)
SVE: branchiomotor (muscles from branchial arches)
82
the sulcus limitans separates what 2 structures?
the alar & basal plate.
| **in the middle of these 2 plates you find the developing neural tube
83
What do you find ventral to the sulcus limitans?
3 motor groups
Visceromotor
Branchiomotor
Somatomotor
84
What do you find dorsal to the sulcus limitans?
3 sensory groups
Viscerosensory (General & Special)
General Somatosensory
Special Somatosensory
85
There is something that you find leading into the 3 cell columns that are dorsal to the sulcus limitans. What do you find?
Ganglia (collection of cell bodies outside the CNS)
86
What is associated w/ the 4th ventricle?
the medulla & pons
87
The branchiomotor cell column is sandwiched b/w which other 2 cell columns?
Visceromotor
| Somatomotor
88
5, 6, 7, 8, who do we appreciate?
PONS PONS!!
89
All motor neurons of cranial nerves are found where?
in the brainstem
90
All sensory neurons (1st order) of cranial nerves 3-12 are found where?
in ganglia
| EXCEPT: proprioreceptive fibers for the face. Remember, also NOT Cranial nerves 1 &2
91
Cranial Nerve 1-Olfactory Nerve. What is its fcn & associated "nature"?
fcn smell--special sense
92
Cranial Nerve 2-Optic nerve. What is its fcn & associated "nature"?
fcn-vision--special sense
93
Cranial Nerve 3-Oculomotor nerve. What is its fcn & associated "nature"?
fcn-moves eye & eyelid--somatomotor
| fcn-moves lens & pupil-visceromotor
94
Cranial Nerve 4-Trochlear Nerve. What is its fcn & associated "nature"?
fcn-moves eye--somatomotor
95
Cranial Nerve 5-Trigeminal Nerve. What is its fcn & associated "nature"?
fcn-sense from face, eyes, & anterior tongue--general sense
| fcn-muscles of mastication--branchiomotor
96
Cranial Nerve 6-Abducens Nerve. What is its fcn & associated "nature"?
fcn-moves eye--somatomotor
97
Cranial Nerve 7-Facial Nerve. What is its fcn & associated "nature"?
fcn-facial expression-branchiomotor
fcn-taste from anterior tongue-special sense
fcn-secretory to glands-visceromotor
fcn-sensory from ear-general sense
98
Cranial Nerve 8-Vestibulocochlear Nerve. What is its fcn & associated "nature"?
fcn-balance & hearing-special sense
99
Cranial Nerve 9-Glossopharyngeal Nerve. What is its fcn & associated "nature"?
fcn-taste from posterior tongue-special sense
fcn-stylopharyngeus muscle-branchiomotor
fcn-carotid bodies--viscerosensory
fcn-Sense from ear, pharynx, posterior tongue, upper esophagus--General sense
fcn-parotid secretion--visceromotor
100
Cranial Nerve 10--Vagus Nerve. What is its fcn & associated "nature"?
fcn-Heart, Gut etc--visceromotor
fcn-Sense from heart, gut, etc.--viscerosensory
fcn-Taste from epiglottis--special sense
fcn-Sense from ear, larynx, pharynx and upper esophagus--general sense
fcn-Motor to larynx, pharynx and palate--branchiomotor
101
What's the deal w/ Cranial Nerve 11?
Spinal Accessory Nerve. Probably branchiomotor, but not certain. Controversy. All you have to know is cell body not in brainstem & innervates the trapezius muscle.
102
Cranial Nerve 12-Hypoglossal Nerve. What is its fcn & associated "nature"?
fcn-Motor to muscles of tongue--somatomotor
103
Which cranial nerves have somatomotor components?
3,4,6,and 12
104
Which cranial nerves have visceromotor components?
3,7,9 and 10
105
Which cranial nerves have branchiomotor components?
5,7,9,10
106
Which cranial nerves have special sensory components?
1,2,7,8,9,and 10
107
Which cranial nerves have general sensory components?
5,7,9 and 10
108
Which cranial nerves have visceral sensory components?
9 and 10
109
Which cranial nerves have taste components?
7,9 and 10
110
T/F You never have a cranial nerve that has both somatomotor & branchiomotor components.
True. Somites v. Arches.
111
T/F Cranial nerves 1, 2, 8 have 4 different components, including special sense.
False. 1 component. Special sense. No overlap. Although other cranial nerves will also have special sense associated w/ taste mainly.
112
Describe the cutaneous sensory innervation to the head/neck.
Most of the face-->Trigeminal Nerve.
Forehead/Eyes-->Tip of Nose-->V1
Nostrils & upper lip & side of face-->V2
Lower jaw & side of head, little bit of external ear-->V3
Neck & most of external ear--->Cervical Plexus
Back of head & neck-->C2 Greater Occipital Nerve
113
What are the 3 divisions of the Trigeminal Nerve?
V1: Opthalmic Division
V2: Maxillary Division
V3: Mandibular Division
114
Which component of C2 innervates the cutaneous region of the back of the head & neck?
the dorsal ramus of C2.
115
Describe how the cervical plexus contributes to cutaneous innervation of the neck.
Ventral rami off of the cervical plexus innervate the neck & part of external ear.
This includes:
Lesser occipital nerve
Great auricular nerve
Transverse cervical nerve
Supraclavicular nerves
116
What is the terminal branch of the opthalmic division & where does it exit the skull?
V1's terminal branch is the suprorbital nerve which comes out of the supraorbital foramen.
117
What is the terminal branch of the maxillary division & where does it exit the skull?
Infraorbital nerve which comes out of the infraorbital foramen
118
What is the terminal branch of the mandibular division & where does it exit the skull?
mental nerve which exits the mental foramen
119
The opthalmic, maxillary, & mandibular divisions of the trigeminal nerve all insert into which column?
GSA. General Sensory Afferent. They all have sensory components. The mandibular also has a motor components for the muscles of mastication. WhBut for the opthalmic, for example, it only has GSA & therefore only has sensory.
120
T/F Sympathetics & parasympathetics don't actually go into the brainstem. They just hop on & off nerves for a ride to their targets.
True.
121
Which ganglion is associated w/ Cranial Nerve 5? Where does it reside?
trigeminal ganglion
| resides in the cavernous sinus
122
Which bony structure do the following divisions leave the skull from?
V1
V2
V3
V1: superior orbital fissure
V2: foramen rotundum
V3: foramen ovale
123
Which part of the brainstem does the 5th cranial nerve come out of?
the pons
124
Which structure goes thru the midbrain & opens up into the 4th ventricle?
the cerebral aqueduct
125
T/F At the 4th ventricle the columns get compressed & stack on top of one another.
False. At the 4th ventricle, the columns kind of flare out. This is b/c of the shape of the ventricle.
126
Which is more superior to the pons: the midbrain or medulla?
The midbrain is superior.
| The medulla is inferior.
127
How do most of the cranial nerves exit the brainstem?
ventromedially
128
What is the one exception to the cranial nerves exiting from the ventral aspect of the brainstem?
Cranial Nerve 4-->Trochlear Nerve.
129
Which cranial nerves are found in the medulla?
9, 10, 12
130
If you are looking from down above at a 4th ventricle...which column is most medial? Which is most lateral?
Most medial: somatomotor column
| Most lateral: special somatosensory column
131
What's the deal w/ Weigert stains?
myelinate axons (white matter) appears black. The lighter areas are the nuclei or the grey matter.
132
If you're looking at a Weigert stain of the medulla...what structure will you see at the bottom?
2 pyramids
133
If you see GSE column in the medulla...which nerve will come off of there?
hypoglossal nerve (Cranial Nerve 12).
134
What is special about the branchiomotor nuclei that are found in the medulla?
they are dragged out laterally.
| They are still ventral to the sulcus limitans.
135
What do the pyramids of the medulla do? What are they composed of?
They carry info from the motor cortex to the lower motor neurons.
They are composed of upper motor neurons.
136
What's the deal w/ lower motor neurons?
they are stupid
they are found pretty much everywhere--in the brainstem & spinal cord.
these are neurons whose axons go directly to muscle
137
So...lower motor neurons are stupid & can't make decisions on their own. Therefore, they can only respond via 2 routes. What are they?
Route 1: incoming afferent info
| Route 2: descending signals from above
138
Where do you find upper motor neurons?
mainly in the cortex
| also a few in the brainstem that are involved w/ postural reflexes/muscles.
139
What helps you to recognize the pons?
the pyramids are sunken into a mass of cells called the pontine grey. Also, the axons of these cells extend out to form the middle cerebellar peduncle.
can also see the 4th ventricle at the top.
140
How can you recognize the midbrain?
you no longer see the 4th ventricle
now you see the cerebral aqueduct
2 mickey mouse ears called the cerebral peduncle
141
What makes up the cerebral peduncle of the midbrain?
this is a big collection of descending fibers
| specifically the: corticospinal, corticobulbar and corticopontine fibers
142
T/F There is a large cell column of sensory stuff for the trigeminal nerve that we will learn about one day. For now, we need to know that sensory info comes back to the chief sensory nuclei in the pons.
True.
143
What are the muscles of facial expression derived from? What is their nerve?
The 2nd pharyngeal arch. Facial Nerve, Cranial Nerve 7.
144
Facial expression muscles insert into what? What is their fcn?
into the skin! How strange!
| fcn is protection (like closing eyelid) & facial expression
145
What is the function of the buccinator?
to move food around in your mouth
146
What are facial expression muscles responsible for in terms of old people?
wrinkle lines
147
What are the terminal branches of the facial nerve? How can you remember this?
```
Ten Zebras Bought My Car
T: Temporal
Z: zygomatic
B: buccal
M: mandibular
C: cervical
```
148
Parts of the facial nerve pass thru which gland?
the parotid gland
149
The facial motor nucleus is in the ______ column and sends its axons on a circuitous route over the _____ nucleus to exit with the facial nerve from the ______.
branchiomotor
abducens
caudal pons
150
The TZBMC terminal branches of the facial nerve are only one section. This is the section that exits the _________. This is the _______ section.
branchiomotor section that exits the stylomastoid foramen.
151
SVE=?
Branchiomotor
152
What happens in Bell's Palsy?
all of the muscles on the affected side of the face are paralyzed. This happens w/ issues w/ the facial nerve. Such as a lower motor neuron lesion.
153
What are the superficial arterial branches that supply the head?
external carotid artery
| internal carotid artery via opthalmic artery
154
What are the external carotid branches?
Superficial temporal
| Facial / Angular
155
What are the internal carotid branches?
Supraorbital
| Supratrochlear
156
T/F There are numerous anastomoses b/w the external carotid & internal carotid branches on the head.
True
157
What are the 5 layers of the scalp?
S: skin
C: connective tissue (arterial anastomoses)
A: aponeuroses (b/w frontalis & occipitalis muscles)
L: loose CT (easy to spread an infection via veins into cranium)
P: periosteum
158
Which layers of the scalp make up the scalp proper?
The first 3 layers. Skin, CT, Aponeuroses.
159
What are the 3 thin & pliable bones of the baby cranium?
frontal
parietal
occipital
160
What are the 3 sutures that you will find in a baby cranium?
sagittal
coronal
lambdoid
161
What are the 4 fontanels that you will find in a baby cranium?
anterior
posterior
sphenoid
mastoid
162
What is Craniosynostosis & how often does it happen?
this is caused by premature closure of sutures in a baby skull.
this happens in 1/25K births
found in >100 genetic syndromes.
163
Scaphocephaly is caused by premature closure of which suture?
the sagittal suture
164
Brachycephaly
| Or Oxycephaly caused by premature closure of which sutures?
coronal or lambdoid sutures
165
What does calvaria mean?
skull cap
166
What is bregma v. lambda?
Bregma: intersection point b/w the coronal suture & the sagittal sutures
Lambda: intersection point b/w the occipital sutures & the sagittal sutures
167
The foramen on the superior aspect of the calvaria is for what vessel?
the emissary vein
168
What are some impressions to look out for on the interior of the calvaria?
Grooves for middle meningeal vessels
Groove for superior sagittal sinus
Foveolae granulares (for archanoid granulations)
