Anatomy Flashcards
Identify the muscles of the face
And identify their nerve supply
Orbicularis occuli
Orbicularis oris
Buccinator
Nerve supply: Facial nerve
What is the origin of the facial artery?
And identify its branches
Origin: external carotid artery in the neck
Branches:
-Temporal branches
-Zygomatic branches
-Buccal branches
-marginal mandibular branches
-cervical branches
What are the parts of the Orbicularis occuli muscle?
It is a circular muscle around the orbital opening
Parts:
-Orbital
-Palpebral
-Lacrimal
What is the action of the Orbicularis oris muscle?
Circular muscle surrounding mouth opening
Action:
-Compresses the lips together (kissing)
- Very important during articulation
What is the action of the buccinator muscle?
Action:
-it empties the vestibule of the mouth by compressing the cheeks against the teeth
What are the divisions of the external ear?
Auricle
External acoustic (auditory) Meatus
Tympanic membrane (ear drum)
Where is the the tympanic membrane located within the external ear ?
And what is the ossicle attached to the tympanic membrane?
- The tympanic membrane lies at the medial end of the external auditory meatus
- The handle (manubrium) of the malleus, the first bone of the ossicular chain of middle ear is attached to the tympanic membrane
Describe the structure of the middle ear
- Air reaches it from the nasopharynx via the auditory (eustachian) tube and spreads into the mastoid air cells
- It contains the auditory ossicles and the muscles (tensor tympani and stapedius) that attach them to the middle ear muscles
- the tympanic segment of the facial nerve runs along it’s walls
What are the muscles of the middle ear?
And mention their nerve supply and action
There are 2 muscles in the middle ear:
- Tensor tympani (attached to the malleus)
- Stapedius (attached to the stapes)
Nerve supply:
-Branches of trigeminal (tensor tympani)
-Branches of facial (stapedius)
Action:
To prevent excessive vibration of the tympanic membrane and the stapes respectively
Describe the structure of the eyeball
-it is formed of 3 coats; outer fibrous, middle vascular and inner nervous
- a biconvex lens is responsible for reflection of light on the retina
- the optic nerve emerges from the eyeball
Identify the extraoccular muscles and mention their nerve supply
Recti muscles:
-superior rectus
-inferior rectus
-Medial rectus
-Lateral rectus
Oblique muscles:
- Superior oblique
- Inferior oblique
Eyelid muscle:
Levator palpebrae superioris
Cranial nerve innervation:
-lateral rectus = abducens nerve 6th
-superior oblique = trochlear nerve 4th
- rest are all = occulomotor nerve 3rd
What is the tendinous ring?
It surrounds the optic canal and a part of the superior orbital fissure
It gives rise to the 4 rectus muscles
These muscles are inserted into the sclera
What are the actions of the rectus muscles?
Superior rectus = elevation and adduction
Inferior rectus = depression and adduction
Medial rectus = adduction
Lateral rectus = abduction
What is the origin, insertion and action of the oblique muscles?
- Superior oblique muscle:
Origin = roof of the orbit
Insertion = the tendon curves posteriorly at the trochlea to the upper lateral posterior quadrant
Action = depression and abduction - Inferior oblique muscle:
Origin = floor of the orbit
Insertion = lower lateral posterior quadrant
Action = elevation and abduction
What are the borders of the cerebellum?
It is the posterior part of the hindbrain
It lies in the posterior cranial fossa
It is separated from the pons and the medulla oblongata anteriorly by the fourth ventricle
It is covered superiorly by the tentorium cerebelli that separates it from the cerebrum
Identify the parts of the cerebellum
Cortex:
- deeply convoluted
- composed of numerous small gyri called folia
White matter:
Within which the deep nuclei of the cerebellum are embedded
2 cerebellar hemispheres
Vermis:
- midline structure connecting the 2 hemispheres
- the superior surface of the vermis is the superior vermis and its inferior surface is the inferior vermis
Identify the fissures/structures on each surface of the cerebellum
Superior surface:
Primary fissure ( a V-shaped fissure that cuts the superior vermis at the junction between the anterior lobe and posterior lobe)
Inferior surface:
-Secondary fissure
-Posterolateral fissure
-cerebellar tonsils
Identify the lobes of the cerebellum a
And identify their functions and connections
Anterior lobe (spinocerebellum):
Regulation of muscle tone (spinal cord)
Posterior lobe (cerebrocerebellum):
Coordination of movement (cerebral cortex)
Flocculonodular lobe (vestibulocerebellum):
Maintenance of equilibrium (vestibular nuclei)
Identify the deep cerebellar nuclei of the cerebellum
Laterally = dentate nucleus (associated with the posterior lobe)
Medially = fastigial nucleus (associated with the flocculonodular lobe)
In between = interposed nuclei (globose and emboliform nuclei) (associated with the anterior lobe)
What is the arterial supply of the cerebellum?
Superior cerebellar artery (SCA):
Arises from basilar artery
Anterior inferior cerebellar artery (AICA): Arises from basilar artery
Posterior inferior cerebellar artery (PICA): Arises from vertebral artery
Identify the parts of the lateral ventricle and mention the duct that connects it to the third ventricle
C-shaped cavity inside each cerebral hemisphere
Parts:
Body and anterior, posterior and inferior horns
Connected to the third ventricle via the foremen of monro
Identify the boundaries of the body of the lateral ventricle
Roof:
Body of corpus callosum
Floor:
Thalamus and body of caudate
Medially:
Septum pellucidum
Identify the boundaries of the anterior horn of the lateral ventricle
Related to parts of corpus callosum
Laterally: head of caudate
Medially: septum pellucidum
Identify the boundaries of the posterior horn of the lateral ventricle
Related to the tapetum of the corpus callosum
Identify the boundaries of the inferior horn of the lateral ventricle
Roof:
Thalamus, tail of caudate and amygdaloid body
Mention the connection between the thalamus and the lateral ventricle
The body : lies above the thalamus
Anterior horn: lies in front of the thalamus
Posterior horn: lies behind the thalamus
Inferior horn: lies below the thalamus
Where does the third ventricle lie and what structure traverses it?
It lies between the 2 thalami and is connected to the lateral and fourth ventricles
It is traversed by the Interthalamic connection or adhesion
Identify the boundaries of the third ventricle
Roof and anterior wall: ependymal membrane
Posterior wall: pineal body attached to the ependymal membrane
Laterally: thalamus, hypothalamus and hypothalamic sulcus
Floor: optic chiasma, pituitary, infundibulum and mamillary bodies
Where does the fourth ventricle lie and what structures form its roof?
It lies between the cerebellum and the brain stem
Roof: formed by the cerebellum and the 6 cerebellar peduncles
Identify the structures in the floor of the fourth ventricle
The floor has 2 parts:
Upper pontine part:
-medial eminence
-facial colliculus
-superior fovea
-superior vestibular area
Lower medullary part:
-inverted v-shaped inferior fovea
-inferior vestibular triangle
-hypoglossal triangle
-vagal triangle
What are the openings of the fourth ventricle?
Cerebral aqueduct
Lateral openings
Median openings
Central canal
