Flashcards in Sievert: Cranial Primordia, skull, face, and scalp Deck (84):
Ectodermal thickenings that form structures for some of our special senses
List three important placodes
The nasal placode is induced by the adjacent (blank) of the forebrain
The nasal placode forms the primary (blank) - the cells of smell grow into the olfactory bulb through the (blank) bone
olfactory epithelium; ethmoid bone
An outpocketing of the forebrain induces a thickening of the surface ectoderm which will form the (blank) placode or vesicle
The otic placode forms what two things? So basically, what does the otic placode form up?
membranous labyrinth and sensory neurons of cranial nerve VIII; the inner ear!
The inner ear develops fairly slowly. Why is this important to consider?
may be susceptible to environmental defects
What does the middle ear cavity form from?
the adjacent 1st pharyngeal pouch lined by endoderm
Masses of mesorderm that form skeletal muscles
(blank) somites form muscles that move the eye, but not muscles of the iris or the lens. (blank) somites form muscles of the tongue.
Masses of mesenchyme tissue that flank the developing gut
When do pharyngeal arches appear around the developing gut?
Each pharyngeal arch consists of a core of mesenchyme surrounded by (blank) on the outside and (blank) on the inside.
What exists in the core of pharyngeal arches to contribute to skeletal components of the face?
neural crest cells
List the pharyngeal arch derivatives
bone or cartilage
skin from the overlying ectoderm
lining of the gut from the lining endoderm
Each pharyngeal arch forms (blank) or (blank)
The maxillary process forms what three things?
part of the temporal bone
The madibular process forms what three things?
The second arch, or the hyoid arch, forms what things?
lesser horn of hyoid bone
What does the third arch form?
the rest of the hyoid bone
What do the 4th and 6th arches fuse to form?
the laryngeal cartilages
What muscles are derived from the first pharyngeal arch?
muscles of mastication
What muscles are derived from the second pharyngeal arch?
muscles of facial expression
What muscle is derived from the third pharyngeal arch?
What muscles are derived from the 4th and 6th pharyngeal arches?
muscles of the pharynx, larynx, and palate
What innervates the endoderm lining each pharyngeal arch?
the nerve of that arch
What does the first pharyngeal pouch form?
What does the second pharyngeal pouch form?
What does the third pharyngeal pouch form?
inferior parathyroid glands
What does the fourth pharyngeal pouch form?
superior parathyroid glands
What does the fifth pharyngeal pouch form?
C cells of the thyroid gland
What are the three cranial nerves to placodes?
1, 2, 8
What are the four cranial nerves to somites?
3, 4, 6, 12
What are the four cranial nerves to branchial arches?
5, 7, 9, 10
Which cranial nerve is associated with the olfactory placode?
cranial nerve 1 - olfactory
Which cranial nerve is associated with the optic vesicle?
cranial nerve 2 - optic
Which cranial nerves are associated with preotic somites (3)?
cranial nerve 3 - oculomotor
cranial nerve 4 - trochlear
cranial nerve 6 - abducens
Which cranial nerve is associated with branchial arch 1?
cranial nerve 5 - trigeminal
Which cranial nerve is associated with branchial arch 2?
cranial nerve 7 - facial
Which cranial nerve is associated with the otic placode?
cranial nerve 8 - vestibulocochlear
Which cranial nerve is associated with branchial arch 3?
cranial nerve 9 - glossopharyngeal
Which cranial nerve is associated with branchial arch 4?
cranial nerve 10 - vagus
Which cranial nerve is associated with branchial arch 6?
cranial nerve 10 - vagus
Which cranial nerve is associated with postotic somites?
cranial nerve 12 - hypoglossal
What four things may spinal nerves contain?
general sensory (GSA)
Potential cranial nerve components. Give an example of each:
1. Special somatosensory
2. General somatosensory
3. General viscerosensory
4. Special viscerosensory
1. vision and balance/hearing
4. taste buds/nasal placode
6. muscles from somites
7. muscles from branchial arches
Cell bodies of nuclei are organized. All motor neurons of cranial nerves are in the (blank). All sensory neurons of cranial nerves 3-12 are in ganglia except which?
brainstem; except for the proprioceptive fibers for the face
What is the order of columns within the alar plate (from lateral to medial)?
general and special viscerosensory
What is the order of columns within the basal plate (from lateral to medial)?
Which cranial nerves have somatomotor components?
3, 4, 6, 12
Which cranial nerves have visceromotor components?
3, 7, 9, 10
Which cranial nerves have branchiomotor components?
5, 7, 9, 10
Which cranial nerves have special sensory components?
1, 2, 7, 8, 9, 10
Which cranial nerves have general sensory components?
5, 7, 9, 10
Which cranial nerves have visceral sensory components?
Which cranial nerves include taste?
7, 9, 10
Which cranial nerve has neurons that are not in the brainstem, but may have somato and branchio components?
cranial nerve 11
What are the three components of the sensory innervation of the face and scalp?
dorsal rami of cervical spinal nerves (greater occipital nerve)
branches from cervical plexus (ventral rami)
What are the three divisions of the trigeminal nerve?
ophthalmic division (V1)
maxillary division (V2)
mandibular division (V3)
What are the three foramina and what branches do they transmit?
1. supraorbital foramen for supraorbital nerve from V1
2. infraorbital foramen for infraorbital nerve from V2
3. mental foramen for mental nerve from V3
What is a distinguishing feature of the medulla?
What are two distinguishing features of the pons?
1. pyramids are sunken into the pontine gray
2. there is a mass of cells whose axons form the middle cerebellar peduncle
In the midbrain, the corticospinal, corticobulbar, and corticopontine fibers are collected into a bundle known as the (blank), which gives the midbrain an easily recognizable look.
Where do cranial nerves 5, 6, 7, 8 exit the brainstem?
Where do 9, 10, 11, 12 exit the brainstem?
Where do 3 and 4 exit the brainstem?
Where do cranial nerves 1 and 2 emerge from?
cerebrum or forebrain
In general, motor nuclei are present (blank), and sensory nuclei are present (blank).
The muscles of facial expression are derived from which pharyngeal arch? Where do this muscles insert? What do they produce? What other function do they have?
2; insert into the skin; produce facial expressions; protective function
What are the terminal branches of cranial nerve 7?
**ten zebras bought my car
The terminal branches of cranial nerve 7 pass through what structure?
The terminal branches of the 7th cranial nerve exit via the (blank) foramen, and are mostly (blank)
stylomastoid foramen; motor
The facial motor nucleus is in the (blank) column and sends its axons on a circuitous route over the (blank) nucleus to exit with the facial nerve from the caudal pons.
The motor fibers from the facial motor nucleus leave the nucleus and arch over the top of the (blank) nucleus before exiting on the facial nerve. The facial nerve has an interesting route through the skull. Why is this important?
abducens; the facial nerve can be damaged at many places and the symptoms vary depending on the place
As the facial nerve leaves the stylomastoid foramen, what component is affected if it is damaged?
What is this: the muscles of facial expression are paralyzed, so all of the muscles on that side of the face are involved.
What are the superficial arterial branches of the head?
external carotid artery
internal carotid artery (**via ophthalmic artery)
What are the external carotid artery branches?
What are the internal carotid artery branches?
**numerous anastomoses between branches
List the layers of the scalp from superficial to deep
The first 3 layers of the scalp are usually considered the (blank). Which layer has numerous arteries anastomosing? Why is this significant? Which layer is considered the danger space? Why?
scalp proper; CT layer; significance for bleeding; loose CT layer; can lead to spread of infection
frontal, parietal, occipital;
sagittal, coronal, lambdoid;
Premature suture closure
occurs in 1/2500 births
found in >100 genetic syndromes