internal skull and cns

what intervertebral discs will the spinal cord end?

between L1 and L2

Is this higher or lower in infants?

lower

dorsal horn

sensory

ventral horn

motor

white matter

axons that convey afferent signals to the higher order centers and efferent signals to effector neurons

Dorsal

GSA, GVA

Ventral

GVE, GSE

how is the spinal cord protected?

by layers of meninges

what are the 3 layers of meninges?

Dura mater (outermost), arachnoid mater, pia mater (directly attached to CNS)

What are the functions of the meninges?

• Protect CNS

• Protect blood vessels

• Contain CSF

What does the neurocranium contain?

• Cranial vault

• Cranial base

What does the viscerocranium contain?

Facial Skeleton

Which suture do the 4 bones come together to fuse?

Pterion

Why is the pterion a weak point?

bc there is an artery that can tear if damaged (middle meningeal artery)

zygomatic

cheek bone

maxilla

upper jaw

mandible

lower jaw

What is the anterior cranial fossa composed of?

composed of sphenoid and ethmoid

what is the middle cranial fossa composed of?

sphenoid and parietal

what can you find in the posterior cranial fossa?

brainstem and cranial nerves

what does the foramen magnum connect?

medulla and spinal cord

What does the carotid canal contain?

Internal carotid artery

what comes off common carotid ?

Internal carotid artery

What does the jugular foramen contain?

Internal Jugular Vein CN IX (Glossopharyngeal) CN X (Vagus) CN XI (Spinal Accessory)

What does the glossopharyngeal nerve supply?

sensory carotid sinus, pharnyx

where does the vagus nerve go up to?

left colic flexture

Which layer lies immediately superficial to the brain?

pia mater

what does the middle meningeal artery supply?

supplies the M. dura mater

What is dural venous sinus?

Channels formed between layers of dura.

Function:

Drain venous blood from the brain

Arteries bring blood ____

Dural sinuses help blood get ___

IN
OUT

where does the dural venous sinuses drain venous blood?

Posteriorly in confluence of sinus

what is the pathway from superior sagittal sinus to internal jugular vein?

Superior Sagittal Sinus
↓
Confluence of Sinuses
↓
Transverse Sinus
↓
Sigmoid Sinus
↓
Internal Jugular Vein

what does the falx cerebri do?

separate into right and left hemispheres

what does the tentorium cerebelli do?

separates cerebellum from occipital lobe

CSF is produced by the:

Choroid plexus

What are ventricles

spaces inside the brain filled with CSF and where its generated

Drainage of CSF back into Venous Drainage

CSF produced by: Choroid Plexus

Step 2 Flows through: Ventricles

Step 3 Flows through: Subarachnoid Space

Step 4 Reabsorbed through: Arachnoid Granulations

Into:Venous Sinuses

What two major systems get blood to brain?

internal carotid arteries and vertebral arteries

what do the internal carotid arteries supply?

Supply most of the:

• Cerebrum

• Anterior brain

what branches off the internal carotid artery?

ophthalmic a.

middle cerebral a.

anterior cerebral a.

• anterior communicating a.

what do the vertebral arteries supply?

• Brainstem

• Cerebellum

• Posterior brain

what branches of vertebral artery?

basilar artery

posterior cerebral artery

posterior communicating artery

superior cerebellar artery

Which arteries unite to form the basilar artery?

Right and left vertebral arteries

what is circle of wilis?

A backup circulation system

If one artery is blocked, blood can sometimes reroute.

what does the basilar artery feed?

posterior cerebrals.

Which artery connects the two anterior cerebral arteries?

Anterior communicating artery

Epidural Hematoma

Middle Meningeal Artery

Usually from: Pterion fracture

Blood accumulates: Between skull and dura

more acute

Subdural Hematoma

Torn bridging veins

Blood accumulates: Between dura and arachnoid

• more chronic

• starts subtle and progresses

Subarachnoid Hematoma

Blood accumulates: Between arachnoid and pia

In the space where CSF normally circulates.

associated w/ anuerysms

frontal lobe

• Planning

• Personality

• Goals

• Movement

Parietal Lobe

• Awareness

• Sensation

• Location of objects

Temporal Lobe

• Memory

• Understanding

• Language

• Emotions

Occipital

Vision

Cerebellum

comparator for motor coordination

• training

brainstem

largely automatic functions and cranial nerve functions (midbrain, pons, medulla)

Medulla

respiratory centers

CN I

olfactory n.

CN II

Optic Nerve

CN III

oculomotor n

CN IV

trochlear n

CN V

trigemnial n

CN VI

abducens n

CN VII

facial nerve

CN VIII

vestibulocochlear n

CN IX

glossopharyngeal n

CN x

vagus n

CN XI

spinal accessory n

CN XII

Hypoglossal n

V1

ophthalmic n

v2

maxillary n

v3

mandibular n