S3Anatomy Flashcards
What are the functions of the skull?
The skull protects the brain and organs of special sense and forms a skeleton for the upper part of the alimentary and respiratory tracts
What makes up the neurocranium?
Ethmoid Sphenoid Frontal Occipital Temporal Parietal
What makes up the viscerocranium?
Vomer Inferior Nasal Concha Zygomatic Maxilla Lacrimal Palatine Mandible Nasal
What are the 3 sutures of the skull?
Frontal
Sagittal
Lamdoidal
What are intersections between sutures called?
Fontanelles
What are the four fontanelles in neonatal skulls?
Anterior
Posterior
Anterolateral (sphenoidal)
Posterolateral
What is the anterior fontanelle called when it is closed?
Bregma
What is the posterior fontanelle called when it is closed?
Lambda
What is the anterolateral fontanelle called when it is closed?
Pterion
What is the posterolateral fontanelle called when it is closed?
Asterion
What is the metopic suture and when does it fuse?
Midline of the frontal bone
fuses around 7 years
What type of joint is the temporomandibular joint?
Synovial, modified hinge joint
What are the superior articulating surfaces of the temporomandibular joint?
Mandibular fossa
Articular tubercle of the temporal bone
What structure forms the inferior articulating surface of the temporomandibular joint?
Head of mandible
what type of cartilage covers the articulating surface of the temporomandibular joint?
Fibrocartilage
What happens when the jaw fully opens?
The head of the mandible slides forward from the mandibular fossa onto the articular tubercle. This movement is termed translation and it occurs in the superior articular cavity. In the inferior articular cavity the head of the mandible rotates around a transverse axis.
What helps prevent posterior dislocation of the mandible?
Lateral temporomandibular ligament
What are the 3 ligaments associated with the temporomandibular joint?
Lateral temporomandibular ligament
Stylomandibular ligament
Sphenomandibular ligament
What are the boundaries of the temporal fossa?
Superior - inferior temporal line
Anterior - frontal process of zygomatic bone
Medial - parietal & temporal bone
Lateral – zygomatic arch
Inferior - infratemporal crest of sphenoid
Posterior – inferior temporal line
What are the boundaries of the infratemporal fossa?
Superior - greater wing of sphenoid
Anterior – maxillary tuberosity
Medial – lateral pterygoid plate
Lateral – ramus & coronoid process of mandible
What are the boundaries of the pterygopalatine fossa?
Superior - inferior surface of body of sphenoid
Anterior - maxillary tuberosity
Medial - vertical plate of palatine bone
Lateral – pterygomaxillary fissure,
Inferior - pterygopalatine canal
Posterior – pterygoid process of sphenoid
What region of the brain is the anterior cranial fossa associated with?
Frontal Lobes
What regions of the brain is the middle cranial fossa associated with?
Pituitary gland and temporal lobes
What regions of the brain is the posterior cranial fossa associated with?
Cerebellum, pons and medulla
What is the arachnoid mater?
Thin, avascular membrane composed of fibroblasts, collagen fibres and some elastic fibres.
It is pushed up against the inner surface of the dura mater by the pressure of the cerebrospinal fluid
lines the dural sac and the dural root sheaths
What is the diaphragmatic sellae?
A sheet of dura mater which attaches to the clinoid process of the sphenoid bone. It covers the pituitary gland and contains an opening through which the infundibulum and hypophysial veins pass
What is the falx cerebelli?
A dural reflection that attaches to the internal occipital crest, it partially separates the cerebellar hemispheres.
What is extradural space?
A pathological space that forms when blood leaks from torn meningeal vessels and pushes the periosteum away from the cranium.
What is the falx cerebri?
An infolding of meningeal dura mater located in the longitudinal fissure. Attaches to the median plane of the calvarium from the frontal crest of frontal bone and crista galli of ethmoid bone anteriorly to the internal occipital protuberance posteriorly.
What is the pia mater?
A very thin, highly vascularized membrane that adheres to the surface of the brain and follows all its contours
directly covers the spinal cord, the roots of the spinal nerves and the spinal blood vessels
What is the subarachnoid space?
Lies between the arachnoid mater and pia mater, it contains cerebrospinal fluid, arteries and veins.
What is the tentorium cerebelli?
Dural reflection which separates the occipital lobes from the cerebellum. It attaches to the clinoid processes of sphenoid bone, petrous temporal bone, internal surface of occipital bone and part of the parietal bone.
What is the the dura mater?
Tough fibrous membrane .
Consists of an outer periosteal layer and an inner meningeal layer.
forms the spinal dural sac
Where does the middle meningeal artery enter the skull?
Enters the middle cranial fossa of the skull via the foramen spinosum
What does the middle meningeal artery bifurcate into?
Frontal and parietal branches
The middle meningeal artery arises in the infratemporal fossa, which vessel does it arise from?
Maxillary artery
Where does the middle meningeal artery lie?
Between meningeal and periosteal dura mater
What is the thinnest part of the skull?
Pterion
What forms the pterion?
Frontal, parietal, sphenoid and temporal bones
The middle meningeal veins accompany the arteries. Where do they drain into?
Pterygoid plexus
What innervates the dura mater?
Branches of the vagus, trigeminal and first three cervical nerves
What causes the sensation of headaches?
Stimulation of the nerves by stretch results in the sensation of headache. Stimulation of nerve endings above the level of the tentorium cerebelli results in headache on the same side of the head. Stimulation of receptors below the tentorium cerebelli leads to pain on the back of the neck and scalp
What is the denticulate ligament?
Fibrous sheet of pia mater which suspends the spinal cord in the dural sac. It extends laterally from the spinal cord and attaches to the inner surface of the dural sac.
What are the dural root sheaths?
Lateral extensions of the spinal dura mater which surround the nerve roots.
What is the lumbar cistern?
An enlargement of the subarachnoid space, caudal to the conus medullaris, extending between L2 to S2 vertebra. It contains CSF and the cauda equina
Where does the spinal cord terminate?
L1
Where does the spinal dura and arachnoid mater terminate?
S2
What plane intersects the spinous process of L4?
Supracristal plane - the highest points of the iliac crest
Describe spina bifida occulta
Failure of vertebral arch fusion alone, a dimple or tuft of hair may overlie the abnormality, clinical abnormalities rare.
Describe Meningomyelocele
Failure of vertebral arch fusion, with herniation of the meninges and elements of the spinal cord. May result in paralysis of the limbs and faecal and urinary incontinence.
Describe Meningocele
Failure of vertebral arch fusion, with herniation of the meninges. May be corrected with surgery with minimal consequences.
What does the ventricular system consist of?
our ventricles (lateral x 2, 3rd and 4th) that are interconnected by channels and are continuous with the central canal of the spinal cord and the subarachnoid space
What are the ventricles lined by?
Ependymal cells
What are the groups of specialised ependymal cells that secrete CSF?
Choroid plexus
What is the route of the CSF?
Lateral ventricles Interventricular foramen Third ventricle Cerebral aqueduct Fourth ventricle Median/ Lateral apertures Subarachnoid space
What returns CSF to the venous system?
Arachnoid villi
What are arachnoid villi?
sections of arachnoid mater which project into the dural venous sinuses
What forms subarachnoid cisterns?
Around the base of the brain, the distance between the arachnoid mater and pia mater is increased in some areas forming subarachnoid cisterns
What do subarachnoid cisterns contain?
Greater amounts of CSF, arachnoid trabeculae and some cranial nerve roots
What is the cerebellomedullary cistern? What is it also known as?
Cisterna Magna
The largest cistern, located between the cerebellum and medulla
receives CSF from the median and lateral apertures
Where is the chiasmatic cistern?
What does it contain?
Lies inferior and anterior to the optic chiasma
Contains the decussation of the optic nerves fibres
Where is the pontocerebellar (pontine) cistern?
Anterior to the pons
Where is the quadrigeminal cistern?
What is it also referred as?
What does it contain?
Cistern of the great vein
Located between posterior part of the corpus callosum and the cerebellum
Contains parts of the great cerebral vein and pineal gland
Where is the interpeduncular (basal) cistern?
Between the cerebral peduncles of the midbrain
Where is the cisterna ambiens?
Lateral aspect of the brain, and is continuous with the quadrigeminal cistern
What are dural venous sinuses?
At the site of attachment of the dural reflections the meningeal and periosteal layers of the dura mater become separated to form epithelial lined spaces
Where do the dural venous sinuses eventually empty?
IJV
Through which foramen does the internal carotid artery enter the skull?
Carotid canal
From which artery does the vertebral artery arise?
Subclavian
What does the internal carotid bifurcate into?
anterior and middle cerebral arteries
What ascends through the foramen transversarum?
Vertebral arteries
The great cerebral vein (of Galen) unites with the inferior sagittal sinus to form which sinus?
Straight sinus
Which sinus does the superior cerebral vein drain into?
Superior sagittal sinus
The inferior and superficial middle cerebral veins drain into which sinuses?
Straight
Transverse
[?]
The superior and inferior cerebellar veins drain into which sinuses?
Transverse
[?]
What makes up the vertebral column?
7 cervical 12 thoracic 5 lumbar 5 sacral 4 coccygeal
Where does the sacrum transfer the body weight to the pelvis?
The sacroiliac joint
What does the lamina connect?
The spinous process and the transverse process
What forms the intervertebral foramen?
the superior notch on The pedicle of one vertebra and the inferior notch on the pedicle of an adjacent vertebra
How is the thoracic section of the vertebral column curved?
Concave anteriorly
What develops first: the lumbar or cervical curvature of the spine?
Cervical
What is a kyphosis?
An exaggerated sagittal curvature in the thoracic region
What is a lordosis?
An exaggerated sagittal curvature in the lumbar region
What might an increased weight of the uterus during pregnancy result in? (regarding spine)
Scoliosis
What movements are possible in the vertebral column?
Flexion, extension, lateral flexion, rotation and circumduction
Which vertebra has triangular vertebral foramen?
Lumbar
Which vertebra has a foramen transversarium on the transverse processes?
Cervical
Which was do the superior articular facets face on cervical vertebra?
Posteriorly and superiorly
Describe the pedicles on lumbar vertebra
Strong
Directed backwards
Which was do the superior articular facets face on thoracic vertebra?
Posteriorly and laterally
Describe the spinous process on cervical vertebra
Small
Bifid
Describe the body on lumbar vertebra
Large
Kidney shaped
Describe the spinous process on thoracic vertebra
Long
Downward pointing
Which was do the superior articular facets face on lumbar vertebra?
Medially
Describe the spinous process on lumbar vertebra
Short
Flat
Quadrangular
Describe the body on thoracic vertebra
Medium sized
Heart shaped
Describe the vertebral foramen on cervical vertebra
Large
Triangular
Where are costal facets present?
Thoracic vertebra
On the body and transverse process
Describe the body on cervical vertebra
Small body
Broad from side to side
Describe the vertebral foramen on thoracic vertebra
Small
circular
Which was do the inferior articular facets face on thoracic vertebra?
Anteriorly and medially
Which was do the inferior articular facets face on lumbar vertebra?
Laterally
Which was do the inferior articular facets face on cervical vertebra?
Anteriorly and inferiorly
Describe C1
The atlas
No body or spinous process
Anterior and posterior arches with two lateral masses
Where do the lateral masses on C1 articulate?
Articulates superiorly with the occipital condyles and inferiorly with the axis
What do C2 possess making it unique?
An odontoid process (dens) projecting superiorly
Why is C7 considered atypical?
Possesses a long, non-bifid spinous process
Foramen transversarium is small and only trasmits the vertebral vein (rather than both vein and artery)
Where are the atlanto-occipital joints found?
Between the occipital condyles and the superior facets of the lateral masses of the atlas
What movements do the atlanto-occipital joints allow?
Flexion, extension and lateral flexion.
What type of synovial joint is the atlanto-occipital joint?
Condyloid
What supports the atlanto-occipital joint?
The anterior and posterior atlanto-occipital membranes. The anterior atlanto-occipital membrane is a continuation of the anterior longitudinal ligament.
The anterior atlanto-occipital membrane connects the anterior arch of the atlas to the anterior margin of which structure?
Anterior inferior margin of the foramen magnum
What does the posterior atlanto-occipital membrane connect?
The posterior arch of the atlas to the posterior margin of the foramen magnum
How many atlanto-axial joints are there?
There are three atlanto-axial joints; two lateral and one medial
Where are the lateral atlanto-axial joints located?
Between the inferior facets of the atlas and the superior facets of the axis
What type of synovial joints are the lateral atlanto-axial joints?
Plane
Where is the medial atlanto-axial joints located?
Between the anterior arch of the atlas and the odontoid process of the axis.
What type of synovial joint is the medial atlanto-occipital joint?
Pivot
What is the job of the apical ligament?
Connects the odontoid process to anterior margin of foramen magnum
What does the Alar ligament connect?
Connects the odontoid process to the medial side of the occipital condyles.
Where is the transverse part of the cruciate ligament attached? What is its role?
Attached to the inner aspect of each lateral mass, holds the odontoid process against the anterior arch of atlas
Where is the vertical part of the cruciate ligament?
Extends between the posterior surface of the body of the axis to the anterior border of the foramen magnum.
What is the membrane tectoria?
An extension of the posterior longitudinal ligament, it attaches to the occipital bone and covers the odontoid process and other ligaments
Where are the zygophophyseal joints located?
Between adjacent vertebral arches
What forms the articular surfaces of zygophophseal joints?
The articular surfaces of adjacent superior and inferior articular facets
What type of joint are zygophophyseal joints?
Synovial plane joints
Where does the intertransverse ligament extend?
Between adjacent transverse processes
Where does the ligamentum favum extend?
Between the lamina of adjacent vertebrae
Where does the supraspinous ligament extend?
Between tips of adjacent spinous processes
What happens to the supraspinous and interspinous ligaments in the neck?
Become thicker to form a strong ligament that extends from C7 to the external occipital protuberance.
What is the name given to the thickening of the supraspinous and interspinous ligaments in the neck?
Ligamentum nuchae
What type of joint is between adjacent vertebral bodies?
Cartilaginous
Which type of cartilage covers the articulating surfaces of the vertebral bodies?
Hyaline
What are intervertebral discs?
The discs are pads of fibrocartilage which bind the bodies together thereby making the vertebral column a semi-rigid structure.
How much of the length of the vertebral column is made up of intervertebral discs?
A quarter
What do intervertebral discs consist of?
The annulus fibrosus and the nucleus pulposus
What is the nucleus pulposis?
Central core of the IV disc
What is the annulus fibrosus made of?
Concentric layers of fibrocartilage
What is the nucleus pulposis composed of?
Semi-liquid gelatinous substance
What is the annulus fibrosus?
The peripheral part of the IV disc
What part of the intervertebral disc is avascular?
Nucleus pulposis
Where does the annulus fibrosus insert?
The epiphyseal rim of the vertebral body
Where does the annulus fibrosus bind?
The anterior and posterior longitudinal ligaments
What is the % of water in the nucleus pulposis at birth? In old age?
~90% at birth
~70% in old age
What is the role of the nucleus pulposus?
It is able to change shape and permit movement between vertebrae
It also facilitates the role of the disc in shock absorption
What is the role of anterior and posterior longitudinal ligaments?
To hold the vertebrae together and allow some movement
What is the anterior longitudinal ligament?
A strong broad ligament that extends from the anterior surface of the sacrum to the occipital bone; it covers the anterolateral aspect of the vertebral bodies and IV discs
Which movement of the vertebral column is limited by the anterior longitudinal ligament?
Extension
Where does the posterior longitudinal ligament run?
Along the posterior border of the vertebral bodies and IV discs
Which movement of the vertebral column is limited by the posterior longitudinal ligament?
Flexion
How many spinal segments are located in the cervical region of the spinal cord?
8
How many spinal segments are located in the thoracic region of the spinal cord?
12
How many spinal segments are located in the lumbar region of the spinal cord?
5
How many spinal segments are located in the sacral region of the spinal cord?
5
How many spinal segments are located in the coccygeal region of the spinal cord?
1
What type of fibres are found in the ventral root?
Motor
What type of fibres are found in the dorsal root?
Sensory
What is located in the dorsal root ganglion?
Cell Bodies {apparently wrong on workbook}
The dorsal and ventral roots unite to form which structure?
Spinal Nerve
What arises from the conus medullaris?
Lumbar (L2 onwards), sacral and coccygeal nerve roots arise from the conus medullaris
Where do the spinal nerves exit the vertebral canal?
Intervertebral foramen
What happens when the spinal nerves enter the vertebral canal?
They divide into dorsal and ventral rami
In the sacral region, where do the rami exit the vertebral column?
The ventral rami exit the vertebral column through the anterior sacral foramina and the dorsal rami exit via the posterior sacral foramina.
Where does the dura mater extend? (spine)
Along the nerve roots and it merges with the connective tissue that surrounds each spinal nerve.
What is the name used for the connective tissue that surrounds the spinal nerve?
Epineurium
Where is the anterior spinal artery? What does it supply?
The anterior median fissure to supply the anterior aspect of the spinal cord.
From which vessel does the anterior spinal artery arise from?
Vertebral artery
Where do the two posterior spinal arteries arise from?
The vertebral or posterior inferior cerebellar arteries.
The spinal blood is supplemented by multiple radicular arteries, what are these branches of?
The ascending cervical, deep cervical, vertebral, posterior intercostal and lumbar arteries.
Through which structure do the radicular vessels enter the vertebral canal?
Intervertebral foramen
What supplies the blood to the vertebrae?
Nutrient and equatorial branches of the vertebral, ascending cervical, posterior intercostal, subcostal, lumbar, iliolumbar and lateral and medial sacral arteries
Where does venous blood from the vertebrae drain?
Internal venous plexus
Where does venous blood from the spinal cord drain to?
Internal vertebral plexus
Describe the venous blood flow from the internal venous plexus
Internal venous plexus
external venous plexus
Regional vessels (vertebral, posterior intercostals, lumbar and lateral sacral veins)
Brachiocephalic veins
Superior vena cava, inferior vena cava or internal iliac veins
Where is the internal venous plexus located?
{?!}
{internet says ocated beneath the bony elements of the vertebral foramina (laminae, spinous processes, pedicles, and vertebral body)}
What nerve roots make up the sacral plexus?
L4-S4
What nerve roots make up the cervical plexus?
C1-C5
What nerve roots make up the brachial plexus?
C5-T1
What nerve roots make up the lumbar plexus?
L1-L4
What does the sciatic nerve bifurcate into?
Tibial and common peroneal
Describe the passage of the sciatic nerve
Greater sciatic foramen Enters buttock under piriformis Lies deep to glut. max. Crosses ischial tuberosity Descends on obturator internus, gemelli and quad. femoris Lies deep to hamstings Crossed by long head of biceps Bifurcates
What nerve roots form the sciatic nerve?
Ventral rami of L4-S3
What supporting cell types can be found in the CNS?
Oligodendrocyte
Microglia
Ependymal
Astrocytes
What supporting cell types can be found in the PNS?
Schwann cells
Satellite cells
What is the role of oligodendrocytes?
Produce the myelin sheath for neurons in the CNS
What is the role of astrocytes?
Provide support to the neurons of the CNS, remove excess neurotransmitter and contribute to the blood brain barrier
What is the role of microglia?
Involved in the immune defence of the CNS.
What is the role of ependymal cells?
Line the ventricles and central canal of the spinal cord.
What is the role of satellite cells?
Supportive cells found in the ganglia of the PNS
What is the role of schwann cells?
Produce the myelin sheath for neurons in the PNS.
What size are nerve cell bodies?
4-150µm
What type of neurons are found at the olfactory mucosa?
Bipolar
What does the dorsal root ganglia contain?
Nerve cell bodies of unipolar neurons
What are located close to nerve cell bodies?
Dendrites
What is the axon hillock?
The region where the plasma membrane generates nerve impulses
What are nissl bodies?
A large granular body found in neurons. These granules are of rough endoplasmic reticulum (RER) with rosettes of free ribosomes, and are the site of protein synthesis
How are proteins synthesised in the nerve cell body transported to the axon terminal?
Anterograde transport
What type of neuron are motor neurons?
Multipolar
What 7 bones contribute to the orbit?
Frontal Sphenoid Ethmoid Maxilla Lacrimal Zygomatic Palatine
What two bones contribute to the superior wall (roof) of the orbit?
Frontal
Sphenoid
What four bones contribute to the medial wall of the orbit?
Ethmoid
Lacrimal
Maxilla
Sphenoid
What three bones contribute to the inferior wall (floor) of the orbit?
Maxilla
Palatine
Zygomatic
What two bones contribute to the lateral wall of the orbit?
Sphenoid
Zygomatic
The superior wall of the orbit separates the orbital cavity from which cranial fossa?
Anterior
The inferior wall of the orbit separates the orbital cavity from which paranasal sinus?
Maxillary
The lateral wall of the orbit separates the orbital cavity from the middle cranial fossa and which other fossa?
Anterior
What is the inferior orbital fissure?
Slit-like opening located posteriorly between the maxilla and the greater wing of sphenoid,
Communicates with the pterygopalatine fossa
What are the anterior and posterior ethmoidal foramina?
Small formaina located on the medial wall of the orbit within the ethmoid bone, communicates with the lateral wall of the nasal cavity
What is the optic canal?
Round opening located at the apex of the orbit, within the lesser wing of sphenoid
What is the lacrimal groove?
A groove located anteriorly on the medial orbital wall
What is the nasolacrimal canal?
The canal leading downwards from the lacrimal groove, through the maxilla and opens into the inferior meatus of the nasal cavity
What is the superior orbital fissure?
A slit like opening located posteriorly between the greater and lesser wing of the sphenoid
What is the supraorbital notch (or foramen)?
A notch (or foramen) located in the superior aspect of the orbital margin
What is the infreorbital groove, canal and foramen?
A groove located in the in the floor of the orbit which extends forwards from the inferior orbital fissure. It becomes covered anteriorly (canal) and passes under the orbital margin to open onto the frontal process of the maxilla (foramen)
What nerve passes through the optic canal?
Optic nerve
What nerve passes through the inferior orbital fissure?
Infraorbital nerve
What nerve passes through the supraorbital notch?
Supraorbital nerve
What is the periorbita?
The periosteum lining the orbit
What is the periorbita continuous with?
The periosteal layer of the dura mater at the superior orbital fissure and optic canal and with the extracranial periosteum at the orbital margin
What does the fascial sheath of the eye facilitate?
Movement
Where does the fascial sheath of the eye extend?
It extends from the optic nerve to the corneoscleral junction. It separates the eyeball from the surrounding periorbital fat.
The medial check ligament is attached to the lacrimal bone. What movement does it limit?
Abduction
The lateral check ligament is attached to the zygomatic bone. What movement does it limit?
Adduction
What are the medial and lateral check ligaments?
triangular expansions of the sheaths of the medial and lateral rectus muscles
What forms the suspensory ligament of the eye?
check ligaments blend with the fascia of the inferior oblique and inferior rectus muscles forming a sling to suspend the eyeball
What does the inferior check ligament do to the inferior eyelid when the gaze is directed downwards?
Retracts the eyelid
Where does the inferior check ligament arise from?
The inferior rectus muscle.
What prevents the eyeball being pulled backwards by the recti muscles?
The check ligaments work with the oblique muscles and the retrobulbar fat to prevent the eyeball being pulled backwards
During disease, dehydration and starvation the eyeballs may be retracted into the orbit. What is the term for this sign?
Enophthalmos
The external surface of the eyelid is covered by thin skin. What is the internal surface covered with?
Palpebral conjunctiva
What is the name for the bands of connective tissue that strengthen the upper and lower eyelids?
Tarsus
What type of secretion is produced by the tarsal glands to prevent the eyelids from sticking together when closed?
Lipid
Which ligament connects the tarsi to the medial aspect of the orbit and provides muscle attachment for the orbicularis oculi muscle?
Medial palpebral ligament
Which nerve innervates levator palpebrae superioris?
Oculomotor
Which nerve innervates levator palpebrae superioris?
Oculomotor
What is the name given to the smooth muscle fibres which are located within the levator palpebrae superioris?
Superior tarsal
Which part of the nervous system innervates the superior tarsal?
Sympathetic
What does the superior tarsal do?
Assist in widening the palpebral fissure, particularly during the fight or flight response
Which part of the fibrous layer provides attachment for the extraocular muscles?
Sclera
What is the function of the cornea?
{refraction?}
The cornea is avascular; which fluid provides its external surface with nutrients and oxygen?
Aqueous body
Which part of the vascular coat is pigmented and supplies the retina with oxygen and nutrients?
{Choroid}
Which component of the vascular coat contains smooth muscle and controls the thickness and focus of the lens?
Ciliary body
The ciliary processes are folds on the internal surface of the ciliary body, what do they secrete?
Aqueous humor
Which part of the retina is the site where the optic nerve enters the eyeball and is insensitive to light?
Optic disc
Which area of the retina is the site of most acute vision?
Fovea
