Brain Flashcards
Telencephalon
Frontal, parietal, temporal and occipital lobes of brain
Diencephalon
Hypothalamus and thalamus
Mesencephalon
Midbrain
Metencephalon
Pons and cerebellum
Myelencephalon
Medulla oblongata
Outer layers of skull
Skin Connective tissue Aponeurosis Loose areolar tissue (emissary veins present here -- venous communication between venous sinuses and veins of scalp) Pericranium/Periosteum
Dura Mater coverings
1) Falx cerebri
- attached anteriorly to crista galli and posteriorly to tentorium cerebelli
- seperates cerebral hemispheres
2) Falx cerebelli
- Separates cerebellum hemispheres
3) Tentorium cerebelli
- Separates cerebrum and cerebellum
4) Diaphragma sellae
- Covers the sella turcica and acts as the roof of pituitary fossa
Arachnoid mater
- Forms Blood brain barrier (BBB)
- Covers gyri only
- Arachnoid granulations – extend into venous sinuses to return CSF back to bloodstream
Pia Mater
-Innermost lining that adheres to sulci and gyri
Venous sinuses
1) Superior sagittal sinus (runs along superior border of falx cerebri)
2) Inferior sagittal sinus (runs along inferior border of falx cerebri)
3) Confluence of sinuses
4) Transverse sinus
5) Sigmoid sinus
6) Internal jugular vein (leaves cranial cavity via foramen magnum)
Ventricular system
- Transportation of CSF throughout cranial cavity
- CSF produced by ependymal cells (+ blood vessels) that lines the choroid plexus
Journey of CSF through ventricular system
1) Left and right Lateral ventricles (in each cerebral hemisphere)
- Frontal (anterior) horn
- Temporal (inferior) horn
- Occipital (posterior) horn
2) Interventricular foramen (of Monro)
3) 3rd ventricle
4) Cerebral aqueduct
5) 4th ventricle
CSF then enters to sub-arachnoid space and returns to bloodstream via arachnoid granulations projecting into venous sinuses
Cranial Nerves origin
Cerebrum (x2):
1) Olfactory nerve
2) Optic nerve
Midbrain (x2):
3) Oculomotor nerve
4) Trochlear nerve
Pons (x4):
5) Trigeminal nerve
6) Abducent nerve
7) Facial nerve
8) Vestibulocochlear nerve
Medulla oblongata (x4):
9) Glossopharyngeal nerve
10) Vagus nerve
11) (Spinal) Accessory nerve
12) Hypoglossal nerve
Olfactory nerve
- Smell (sensory only)
- Exits via cribiform foramina (on cribiform plate)
Optic nerve
- Vision (sensory only)
- Exits via optic canal
Oculomotor nerve
- Most extra-ocular muscles of the eye (motor only)
- Exits via superior orbital fissure
Trochlear nerve
- Superior oblique muscle of eye (motor only)
- Exits via superior orbital fissure
Trigeminal nerve
Facial sensation (sensory):
1) Opthalmic nerve (V1) – forehead, scalp, upper eyelid and nose
2) Maxillary nerve (V2) – lower eyelid, cheeks, nasal mucosa, upper teeth and palate
3) Mandibular nerve (V3) – skin over mandible and lower teeth
Motor innervation:
1) Mandibular nerve (V3) – muscles of mastication
Exits:
1) Opthalmic nerve (V1) – superior orbital fissure
2) Maxillary nerve (V2) – foramen rotundum
3) Mandibular nerve (V3) – foramen ovale
Abducent nerve
- Lateral rectus muscle of eye (motor)
- Exits via superior orbital fissure
Facial nerve
Sensory innervation:
1) Part of external ear
2) Taste for anterior 2/3 of tongue
3) Sensation for hard and soft palate
Motor innervation:
1) Muscles of facial expression
2) Secretomotor to:
- Sublingual gland
- Submandibular gland
- Lacrimal gland
- Mucous gland to mouth and nose
-Exits via internal acoustic meatus
Vestibulocochlear nerve
- Hearing and balance (sensory only)
- Exits via internal acoustic meatus
Glossopharyngeal nerve
Sensory innervation:
1) Taste – posterior 1/3 of tongue
2) Middle ear cavity (+ external ear)
3) Pharyngeal sensation (gag reflex)
Motor innervation:
1) Stylopharyngeus muscle
2) Parotid gland (secretomotor)
-Exits via jugular foramen
Vagus nerve
Sensory innervation:
1) External ear
2) Taste of epiglottic region of tongue
3) Larynx
4) Pharynx
5) Thoracic and abdominal viscera
Motor innervation:
1) Smooth muscles of GIT (until proximal 2/3 of transverse colon)
2) Smooth muscles of larynx and pharynx
3) Most skeletal muscles of larynx and pharynx (except for stylopharyngeus)
-Exits via jugular foramen
(Spinal) Accessory nerve
Motor innervation:
1) Trapezius
2) Sternocleidomastoid
-Exits via jugular foramen
Hypoglossal nerve
Motor innervation:
1) Intrinsic and extrinsic muscles of the tongue (except for palatoglossus – innervated by vagus)
-Exits via hypoglossal canal
