AUT Head and Neck Anatomy DR Week 6-8 Flashcards
What are the bones in the calvarium?
Frontal Bone
Parietal Bones
Occipital Bones
What other osteological features does the calvarium have?
Coronal Suture
Sagittal Suture
Lambdoid Suture
What is the name for the point at which the Coronal and Sagittal suture meet anteriorly called?
What else lies here in infancy?
Bregma
Anterior Fontanelle
What is the name for the point at which the Sagittal and Lambdoid sutures meet posteriorly?
What else lies here in infancy?
Lambda
Posterior Fontanelle
What are the osteological features of the frontal bone?
Superciliary Arches
Supraorbital Margin
Glabella
What are the osteological features of the Zygomatic Bone?
Temporal process of zygomatic bone
What are the osteological features of the Temporal Bone?
Zygomatic process of temporal bone Superior and Inferior Temporal Lines External Acoustic Meatus Mastoid Process Styloid Process Squamous Suture
What are the osteological features of the maxilla?
Hard palate
Infraorbital Foramina
What exits the infraorbital foramina?
The Infraorbital Nerve, a branch of the Maxillary division of the Trigeminal Nerve (Vb).
What are the osteological features of the occipital bone?
Occipital condyles
External occipital protuberance
Superior nuchal line
Where the the region known as the pterion?
What runs directly behind it?
This is where the parietal, frontal, temporal, and sphenoid bones meet (lateral aspect of the skull).
The middle meningeal artery runs behind the pterion.
What bones make up the orbit?
Frontal, Greater wing of the sphenoid bone, ethmoid bone, lacrimal bone, zygomatic bone, maxilla (NOTE: palatine bone also contributes to the formation of the orbit - between maxilla and ethmoid).
What openings are within the orbit?
Optic Canal
Superior Orbital Fissure
Inferior Orbital Fissure
What is the Nasion?
The intersection between the frontal bone and the two nasal bones. Just inferior to the glabella. Depressed area between the eyes.
What is the Inion?
Most prominent part of the external occipital protuberance
What runs through the supraorbital notch?
The supraorbital nerve from the ophthalmic division of the Trigeminal Nerv (Va)
Where are the superciliary arches?
Part of the frontal bone. It forms the separation between the forehead portion itself (the squama frontalis) and the roof of the eye sockets (the pars orbitalis). Normally, in humans, the ridges arch over each eye = mechanical protection.
What are the layers of the Scalp?
S - Skin C - Connective Tissue A - Aponeruosis (of Occipitofrontalis) L - Loose Areolar Connective Tissue P - Pericranium (periosteum)
Then BONE, Dura, Arachnoid and Pia.
From which blood vessel does the middle meningeal artery arise?
Maxillary artery from the External Carotid Artery. (Maxillary artery is a terminal branch of the Ext.Carotid.
Discuss the middle meningeal artery course.
Branches off the Maxillary Artery in the Infratemporal Fossa, runs through Foramen Spinosum into the Middle Cranial Fossa and supplies the Dura Mater and the Calvarium.
Where does the middle meningeal artery enter the base of the skull?
Through the Foramen Spinosum
What are the branches of the middle meningeal artery?
Anterior, Posterior, (Superior Tympanic Artery)
What are the three meningeal layers?
Dura Mater
Arachnoid Mater
Pia Mater
Which layer of the meninges is avascular?
Arachnoid Mater
What are the features of the Dura Mater? (Dural infoldings)
Falx Cerebri
Tentorium Cerebelli
Falx Cerebelli
Diaphragma Sellae
What are the layers of the Dura Mater?
Superficial Layer - Endocranium
Deep Layer - Meningeal Layer
Where is the Falx Cerebri?
Separates the two cerebral hemispheres of the brain, located in the longitudinal cerebral fissure between the hemispheres.
Where is the Tentorium Cerebelli?
Exists between and separates the cerebellum and brainstem from the occipital lobes of the cerebrum
Where is the Falx Cerebelli?
A vertical dural infolding that lies inferior to the cerebellar tentorium in the posterior part of the posterior cranial fossa. It partially separates the cerebellar hemispheres.
Where is the Diaphragma Sellae?
Lies over the Hypophyseal Fossa.
The sellar diaphragm is the smallest dural infolding and is a circular sheet of dura that is suspended between the clinoid processes, forming a partial roof over the hypophysial fossa. The sellar diaphgram covers the pituitary gland in this fossa and has an aperture for passage of the infundibulum (pituitary stalk) and hypophysial veins.
The crista galli is in which cranial fossa?
Anterior cranial fossa
What is the crista galli?
A thick, median ridge of bone posterior to the foramen caecum which projects superiorly from the ethmoid bone
What is the cribriform plate?
On each side of crista galli in ethmoid bone. Has many tiny forminae that transmit the olfactory nerves from the olfactory areas of the nasal cavities to the olfactory bulbs of the brain, which lie on this plate.
What are the dural venous sinuses?
Endothelium-lined spaces between the periosteal and meningeal layers of the dura. Form where the dura septa attach along the free edge of the fall cerebra and in relation to formations of the cranial floor.
Where is the superior sagittal sinus?
Where does it run from and to?
In the upper border of the convex falx cerebri.
From then crista galli to near the internal occipital protuberance
What is the confluence of sinuses?
A meeting place of the Sup. Sagittal, Straight, Occipital, and Transverse Sinuses.
Where is the inferior sagittal sinus?
Lower concave free border of the falx cerebri.
What is the straight sinus?
Formed by the union of the inferior sagittal sinus with the great cerebral vein. Runs Infero-posteriorly along the line of attachment of the falx cerebri to the tentorium cerebelli where is joins the confluences of sinuses.
Where are the transverse sinuses?
Pass laterally from the confluence of sinuses, forming a groove in the occipital bones and parietal bones. Course along the posterolateral attached margins of the tantrum cerebella and then become the sigmoid sinuses as they approach the posterior aspect of the petrous temporal bones.
Where does blood drain from the confluence of sinuses?
Into the transverse sinuses.
Where are the sigmoid sinuses?
In the posterior cranial fossa. Follow an S-shaped course. Each sigmoid sinus turns anteriorly then continues inferiorly as the IJV
Discuss the pattern of venous drainage within the dural venous sinuses
Superior Sagittal Sinus - Confluence of Sinuses - RIGHT Transverse Sinus
Inferior Sagittal Sinus - Straight Sinus - Confluence of Sinuses - LEFT Transverse Sinuses
R and L Transverse sinuses - R and L Sigmoid Sinuses - becomes Internal Jugular Vein at the Jugular Foramen
What are the three regions of the Brain?
Forebrain, Midbrain, Hindbrain
What makes up the Forebrain?
Cerebral Hemispheres, Thalamus and Hypothalamus
What makes up the Hindbrain?
Pons, Medulla Oblongata and Cerebellum.
What makes up the Brainstem?
Midbrain, Pons, Medulla Oblongata.
What is the diencephalon?
It is composed of the epithalamus, dorsal thalamus, and hypothalamus and forms the central core of the brain.
What are the lobes of the brain?
Frontal Lobes Parietal Lobes (Motor and Sensory Function) Temporal Lobes (Smell, Hearing and Emotion) Occipital Lobes (Vision)
What does the longitudinal fissure separate?
The two cerebral hemispheres
Where is the central sulcus
Between the frontal and parietal lobes
Where is the lateral sulcus?
Separates the temporal and parietal lobes
Where is the pre-central gyrus?
What occupies this part of the brain?
Anterior to the central sulcus
Primary Motor Cortex
Where is the post-central gyrus?
What occupies this part of the brain?
Posterior to the central sulcus
Primary Sensory Cortex
Describe the structure and location of the arachnoid and pia mater.
The avascular arachnoid, although closely applied to the meningeal layer of the dura, is not attached to the dura; it is held against the inner surface of the dura by the pressure of the CSF.
The pia adheres to the surface of the brain and follows all its contours.
What is the cerebrum?
Includes the cerebral hemispheres and basal ganglia
What is the corpus callosum?
Connects the R and L cerebral hemispheres
Where is the thalamus?
Forms wall of 3rd Ventricle and floor of lateral ventricles
Where is the Hypothalamus?
Anterior and inferior to the thalamus.
Where is the midbrain?
lies at the junction of the middle and posterior cranial fossae. CN III and IV are associated with the midbrain.
Which Cranial Nerves are associated with the midbrain?
CNIII and CN IV
Where is the Pons?
Which cranial fossa is it in?
Which Cranial Nerves are associated with the Pons?
Between midbrain rostrally and medulla oblongata caudally.
edulla oblongata caudally
It lies in the anterior part of the posterior cranial fossa.
CNV (Trigeminal)
Which cranial nerves are associated with the Medulla Oblongata?
CNIX, CNX, CNXII
Which nerves are associated with the ponto-medullary junction?
CNVI, CNVII, CNVIII.
Where does each cranial nerve arise from?m
CNI - Nose CNII - Eye CNIII - Midbrain CNIV - Midbrain CNV - Lateral Aspect of the Pons CNVI - Ponto-medullary junction CNVII - Ponto-medullary junction CNVIII - Ponto-medullary junction CNIX - Medulla Oblongata CNX- Medulla Oblongata CNXI - Spinal Root up through Foramen Magnum, Joins Cranial root and exits at Jugular Foramen CNXII - Medulla Oblongata.
Where is the calcarine sulcus?
Most inferior sulcus, can only be seen on sagittal section
What separates Parietal and Occipital Lobes?
Parieto-occipital Sulcus
Where is the arbor vitae
Cerebellum - ‘tree-like appearance’ when cut.
What makes up the Basal Ganglia?
Caudate Nucleus, Lentiform Nucleus, Internal Capsule
What makes up the Lentiform Nucleus?
Globus Pallidus (inner, whiter) and Putamen (outer, darker).
What are the branches of the External Carotid Artery?
Superior Thyroid Artery Lingual Artery Facial Artery Maxillary Artery Superficial Temporal Artery Posterior Auricular Artery Occipital Artery Ascending Pharyngeal Artery
Where does the middle meningeal artery enter the base of the skull?
Foramen Spinosum
What are the features of the Spinal Cord?
Medulla Oblongata Conus Medullaris Cauda Equina Spinal Nerves Dura Mater
Describe the location and formation of the spinal nerves
Spinal nerves initially arise from the spinal cord as rootlets, these converge to form two nerve roots:
- An anterior (ventral) nerve root - MOTOR (efferent) fibers passing from nerve cell bodies in the anterior horn of spinal cord gray matter to peripheral effector organs
- A posterior (dorsal) nerve root - SENSORY (afferent) fibers from cell bodies in the spinal sensory or posterior (dorsal) root ganglion that extend peripherally to sensory endings and centrally to the posterior horn of spinal cord gray matter.
The two nerve roots unite, within or just proximal to the intervertebral foramen, to form a mixed SN, immediately divides into two rami: a posterior (dorsal) ramus and an anterior (ventral) ramus.
What is a dermatome?
The unilateral area of skin innervated by the sensory fibers of a single spinal nerve
What closes the eye?
Obicularis Oris Muscle
What opens the eye?
Levator Palpaebrae Superioris
Where does the nasolacrimal sac open into?
Inferior Nasal Meatus
What action does the Superior Oblique Muscle have?
Move the eyeball DOWN and OUT
What action does the Inferior Oblique Muscle have?
Move the eyeball UP and OUT
What are the parts of the Caudate Nucleus?
Head
Body
Tail
What lies at the end of the tail of the Caudate Nucleus?
Amygdaloid Nucleus
Describe the path of the Internal Carotid Artery as it enters the skull.
Enters the Carotid Canal in the petrous part of the temporal bone, traverses Foramen Lacerum and enters the cavernous sinus in the middle cranial fossa.
