Head and Neck Week 3 - dry room Flashcards
what is the flooor of the skulldivided into?
three fossae
what is present in each fossa?
many foramina (or holes) through which nerves and blood vessels enter/leave the calvarium
there is also grooves and depression which indicate the position, in life, of blood vessels and other structures
which bone forms the posterior boundary of the anterior cranial fossa?
sphenoid bone
what are 2 main features found in the anterior cranial fossa?
cribriform plate of the ethmoid bone
crista gali in the midline (falx cerebri attaches to this)
which bone forms the anterior boundary of the middle cranial fossa?
sphenoid bone
which bones forms the floor of the middle cranial fossa?
body and greater wing of sphenoid and the temporal bone (squamous and petroud part)
which bones forms the posterior boundary of the middle cranial fossa?
temporal and sphenoid bone
what 4 bones come together to form the pterion? (H-shaped suture)
forntal
aprietal
temporal
sphenoid
which bone forms the anterior and which the posterior border of the posterior cranial fossa?
anterior - sphenoid and temporal
posterior - occipital
the larger foramina in the skull are for nerves and blood vessels to leve/enter the cranial avity but what structures pass through the small foramina in the skull?
emissary veins
in the anterior cranial fossa, what passes through the foramina of the cribriform plate?
olfactory nerve (CNI)
in the middle cranial fossa, what passes through the optic foramen?
optic nerve
opthalmic artery
in the middle cranial fossa, what passes through the superior orbital fissure?
CN III, IV, VI
V1
opthalmic veins
in the middle cranial fossa, what passes through the foramen rotundum?
maxillary nerve (CN V2)
in the middle cranial fossa, what passes through the foramen ovale?
Mandibular nerve (CN V3)
in the middle cranial fossa, what passes through the foramen spinosum?
middle meningeal artery and vein
meningeal branch of mandibular nerve
in the middle cranial fossa, what passes through the foramen lacerum?
artery of pterygoid canal, nerve of pterygoid canal and some venoud drainage
in the middle cranial fossa, what passes through the carotid canal?
ICA
in the posteior cranial fossa, what passes through the inernal acoustic foramen?
facial nerve (CNVII)
vestibulocochlear nerve (CNVIII)
in the posteior cranial fossa, what passes through the jugular foramen?
glossopharyngel nerve (CN IX)
vagus nerve (CN X)
accessory nerve (CN XI)
in the posteior cranial fossa, what passes through the hypoglossal foramen?
hypoglossal nerve (CNXII)
in the posteior cranial fossa, what passes through the foramen magnum?
spinal cord, vertebral arteries, anterior and posterior spinal arteries, accessory nerve
study this image
a
olfactory nerve (CNI)
b
optic nerve (CNII)
c
oculomotor nerve (CNII)
trochlear nerve (CNIV)
opthalmic nerve (CNV1)
abducens nerve (CNVI)
d
maxillary nevre (CNV2)
e
madinbular nevre (CNV3)
f
facial nerve (CNVII)
vestibulocochlear nerve (CNVII)
g
glossopharyngeal nerve (CNIX)
vagus nerve (CNX)
accessory nevre (CNXI)
h
hypoglossal nerve (CNXII)
whata re grooves in the skull formed by?
arteries or intra-cranial venous sinuses
where are the intra-cranial venous blood sinuses found?
between the inner and outer layers of dura - the inner layer is the dura proper and the outer layer the periosteum on the inside face of the skull bone
what is the groove just lateral to the foramen spinosum formed by?
middle meningeal artery
the middle meningeal arteyr is commonly damaged in blows to the head as the artery is thin and a branch of this artery crosses the pterion on its inner surface
reuslts in a bleed collecting between the periosteum of the skull and the dura mater (an extradural haemorrhage)
such haemorrhages are classically biconvex, lens-shaped
what anatomical factor prevents the collected blood from spreading over a wider area, restricting it to a lens-shaped area?
durs mater is firmly attached to the grooves of the skull
what grooves run laterally on both sides starting from the internal occipital proturbance in the posterior cranial fossa?
they are for the intracranial venous sinus clled the transverse sinus
if you trace the transverse sinus laterally, what do they continue as
they continue as the S-shaped groove for the sigmoid sinus
into which formaen does the sigmoid sinus lead?
jugular formamen
which major vein in the neck emerges into the neck form the jugular foramen?
internal jugular vein
what is the sella turcica?
a depp depression in the midline in the middle cranial fossa which houses the pituitary gland
found in the body of the sphenoid bone
what can be found either side of the sella turcica
anterior and posterior clinoid processes
what attaches to the clinoid processes?
fold of the dura mater called the tentorium cerebelli
what groove is found either side of the sella turcica?
groove for the cavernous sinus
which foramen lies immediatley anterior to the groove for the cavernous sinus?
optic foramen or the superior orbital fissure
on the interal surface of the skull cap, what is the groove in the midline made by?
superior sagittal sinus
what bones make up the base of the skull
maxillary bone
palatinr bone
vomer
temporal bone
occipital bone
where are the pterygoid plates and hamulus on the base of the skull?
and what bone are they a part of?
sphenoid
what muscle attaches to the medial pterygoid plate?
superior pharyngeal constrictor muscle
tensor veli palatini msucle
what attaches to the lateral pterygoid plate?
lateral and medial pterygoid msucles
a neonatal skull is not fully ossified, making it less rigid and more flexible
what are the advantages of having a comparatively flexible skull?
during child birth it allows for easier passage of child
during infancy it allows the brain to grow
in the event of accidents such as falls it stops fractures but can bruise the brain
what type of ossification occurs in:
flat bones of the vault of the skull?
irregular bones of the base of the skull?
membranous ossification
endochondral ossification
how do foetal, child and adult skulls differ in the following respects?
fontanelles
dentition
tympanic membrane
styloid and mastoid processes of temporal bone
fontanelles - gaps in skull in children, fused in adults
dentition - less teeth in children
tympanic membrane - smaller, thinner, more superficial in children
styloid and mastoid processes of temporal bone - not formed, 1 year post-natal
what age do the anterior and the posterior fontanelles fuse?
anterior - 18-24 months
posterior - 1-2 months
what type of epithelium lines the dorsal surface of the tongue?
keratinised stratified squamous epithelium
what type of msucle fibres underlies the epithelium of the tongue?
skeletal msucle fibres
what secretions could a salivary gland release?
predominantly serous
predominantly mucous
mixed
different is reflected in histology in the presence and amount of serous or mucous acini (secretory components)
what colour do acini stain?
serous acini secrete proteins, which means they stain strongly
mucous acini secrete the glycoprotein mucous which stains poorly
what is the function of a myoepithelial cells
they are contractile
help expell secretions form the lumen of secretory units
what do each of the following secrete:
parotid
sublingual
submandibular
parotid - predominantly serous
sublingual - predominantly mucoud
submandibular - mixed
what type of salivary gland is shown?
Parotid gland - serous glands
what type of salivary gland is shown?
Sublingual gland - majority of the glands are mucous secreting
what type of salivary gland is shown?
Submandibular gland - mixed serous and mucous glands
