Neuroanatomy 1 Flashcards
- How many bones make up the cranium?
- What are their names?
- Which ones are paired?
- 8 bones:
- frontal
- parietal (paired)
- temporal (paired)
- occipital
- sphenoid
- ethmoid
- What are the two major areas of the cranium?
- What do they make up?
- cranial vault (calvarium): superior/lateral/posterior wall of the skull
- cranial floor: bottom of the skull
What are the 3 fossae that make up the cranial floor?
- anterior cranial fossae
- middle cranial fossae
- posterior cranial fossae
- What sutures (fibrous joints) make up the cranium?
- Where are they found between?
- Which joint is the only non-sutured joint of the skull?
- coronal suture (frontal bone/parietal bone)
- squamous suture (parietal bone/temporal bone)
- sagittal suture (parietal bone/parietal bone)
- lambdoid suture (parietal bone/occipital bone/temporal bone)
- only non-sutured: TMJ
- What are the 4 parts/regions of the temporal bone?
- What structures are found on the temporal bone?
- squamous, tympanic, mastoid, petrous
structures: - zygomatic process
- external acoustic meatus
- styloid process
- internal acoustic meatus
What structures are found on the occipital bone?
- foramen magnum (entry/exit of spinal cord)
- occipital condyles (atlas-C1)
What is the only bony articulation of the head with the rest of the body?
occipital condyles
- Which cranial bone is bat-shaped and is the keystone of the cranium as it articulates with all other cranial bones?
- What are the important structures found on this bone?
- sphenoid
- sella turcica (hypophyseal fossa - surrounds pituitary gland)
What does the sella turcica surround?
the pituitary gland
- What does the ethmoid form?
- What important structures are found on this bone?
- roof of nasal cavity, upper nasal septum, part of the medial orbit walls
structures: - crista galli
- cribriform plates
What is a vertical projection that provides a point of attachment for the dura, helping to secure the brain within the skull?
crista galli
What is found lateral to the crista galli and allows olfactory fibers to pass to the brain from the nasal mucosa?
cribriform plates
What structure in the cranium serves as an attachment site for multiple muscles?
styloid process
- What is housed in the anterior cranial fossa?
- What is housed in the middle cranial fossa?
- What is housed in the posterior cranial fossa?
- frontal lobe
- temporal lobe
- cerebellum
- What foramina/apertures are found within the anterior cranial fossa?
- What is found in these foramina?
- foramen cecum: nasal emissary vein (1% of population; in danger of injury during surgery)
- cribriform foramina in cribriform plate: axons of olfactory cells in olfactory epithelium that form olfactory nerves (CN I)
- What foramina/apertures are found within the middle cranial fossa?
- What is found in these foramina?
- optic canals: optic n (CN II) and ophthalmic aa
- superior orbital fissure: ophthalmic vv, CN III, IV, VI, and ophthalmic n (CN V1), sympathetic fibers
- foramen rotundum: maxillary n (CN V2)
- foramen ovale: mandibular n (CN V3)
- foramen spinosum: middle meningeal a and v, meningeal branch of CN V3
- foramen lacerum: connective tissue
- carotid canal: internal carotid a, internal carotid plexus
- internal acoustic meatus: facial n (CN VII) and vestibulocochlear n ( CN VIII)
What runs over the foramen lacerum?
carotid canal
- What foramina/apertures are found within the posterior cranial fossa?
- What if found in these foramina?
- foramen magnum: medulla/meninges (spinal cord), vertebral aa, CN XI, anterior/posterior spinal aa, dural vv
- jugular foramen: CN IX, X, XI; internal jugular vein
- hypoglossal canal: hypoglossal n (CN XII)
- What are fontanelles called in lay terms?
- Why are they important clinically?
- How long before the anterior fontanelle closes?
- soft spots
- providers can tell if a baby is dehydrated of it is sunken in, or if they have increased cranial pressure if it is bulging out; also, can provide a spot for IV access in infants
- 12 months (should be completely closed by 2 years)
- How many bones make up the facial bones?
- How many are paired?
- What are the bones?
- 14 bones
- 12 paired
bones: - mandible
- maxilla
- lacrimal
- palatine
- zygomatic
- nasal
- vomer
- inferior nasal conchae
- Which two facial bones are not paired?
- What is the smallest facial bone?
- vomer and mandible
- lacrimal
What bones form the nasal cavity (7)?
- nasal
- maxilla
- palatine
- vomer
- ethmoid
- sphenoid
- inferior nasal concha (independent bone)
What bones form the orbit (7)?
- frontal
- sphenoid
- ethmoid
- lacrimal
- maxilla
- palatine
- zygomatic
What bones make up the cheek bone?
- zygomatic bone
- temporal bone (zygomatic process)
The zygomatic bone (commonly called “_____”), articulates with the (…), forming the zygomatic arch
- “cheekbone”
- zygomatic process of the temporal bone
Which wall of the orbit is the weakest?
the medial wall
Because of the thinness of the (1) and (2) walls of the orbit, a blow to the eye may fracture the orbital walls while the margin remains intact
- medial
- inferior
Indirect traumatic injury that displaces the orbital walls is called a (…)
“blowout” fracture
Fractures of the (…) wall may involve the ethmoidal and sphenoidal sinuses, whereas fractures in the (…) wall may involve the maxillary sinus and may entrap the inferior rectus muscle, limiting upward gaze
- medial wall
- inferior wall
Although the (…) wall is stronger than the medial and inferior walls, it is thin enough to be translucent and may be readily penetrated. Thus, a sharp object may pass through it into the (…) of the brain.
- superior
- frontal lobe
A tumor in the middle cranial fossa may enter the orbital cavity through the (…)
superior orbital fissure
What are the borders of the scalp covering calvaria? (anterior, posterior, lateral)
- anterior: supraorbital margin
- posterior: external occipital protuberance, superior nuchal line
- lateral: zygomatic arch
- The scalp is composed of how many layers?
- What are these layers?
5 layers:
- skin
- connective tissue
- aponeurosis
- loose connective/areolar tissue
- pericranium
Which layers of the scalp are connected and move as a unit (when wrinkling the forehead)?
the first three layers (skin, connective tissue, aponeurosis)
What is contained in the skin layer of the scalp?
- sweat glands
- sebaceous glands
- hair follicles
What are the features/what is contained in the connective tissue layer of the scalp?
- richly vascularized
- supplied with cutaneous nn
- blood vessel walls have fibrous attachments that prevent closure when lacerated
What are the features/what is contained in the aponeurosis (epicranial aponeurosis) layer of the scalp?
- strong tendinous sheet that covers the calvaria
- serves as intermediate tendon of frontal and occipital belly of the occipitofrontalis muscle
What are the features/what is contained in the loose connective tissue layer of the scalp?
- sponge-like layer
- has potential spaces that may distend with fluid due to injury or infection
- allows for free movement of the first 3 layers
What are the features/what is contained in the pericranium layer of the scalp?
- dense connective tissue
- forms external periosteum of calvaria
- firmly attached but can be stripped from calvaria of living people, except at cranial sutures
The (…) layer is the danger area of the scalp because pus or blood spreads easily in it. Infection in this layer can also pass into the cranial cavity through (…), which pass through the calvaria and reach intracranial structures such as the meninges.
- loose connective tissue
- emissary veins
Infection can spread from the scalp into the cranial cavity via the (…)
emissary veins
What connects the dural venous sinuses with veins outside the cranium?
emissary veins
How can you close gaping wounds on the scalp?
- stiches
- hair apposition
- staples
What are two scalp hematomas that occur as a result of vaginal birth trauma and where are they located between?
- cephalohematoma: between periosteum and bone
- caput succedaneum: between skin and aponeurosis (temporary, interferes with venous flow)
Which scalp hematoma resulting from vaginal birth trauma is temporary and interferes with venous flow?
caput succedaneum
- Which hematoma results from a blow to the head causing bleeding in the subgaleal space?
- What symptoms can this cause?
- Where is this hematoma found between?
- subgaleal hematoma
- black eyes due to blood slowly pooling in eyelids b/c frontalis has no bony attachment
- between apponeurosis and periosteum
- What are the coverings of the brain that lie immediately internal to the cranium?
- What is the function of these?
- meninges
- protect and enclose the brain in a fluid-filled cavity, the subarachnoid space
What forms the supporting framework for arteries, veins, and venous sinuses?
- meninges
What are the 3 membranous connective tissue layers of the cranial meninges and what are their features?
- dura mater: tough, thick, external fibrous layer
- arachnoid mater: thin intermediate layer
- pia mater: delicate internal layer (attached directly to brain)
- Which layer is the dura mater?
- Which layer is the arachnoid mater?
- Which layer is the pia mater?
- 1
- 3
- 2
- What are the different layers of the dura mater?
- What are these layers attached to? What are their features?
- outer periosteal layer: attached to inner aspect of the cranium
- inner meningeal layer: in close contact with the underlying arachnoid mater; continuous with the spinal dura mater at the level of the foramen magnum
The meningeal dura mater separate to form thick connective tissue folds or layers that separate the various brain regions and lobes, what are they?
- falx cerebri
- falx cerebelli
- tentorium cerebelli
- diaphragma sellae