HNS 1 Flashcards
Label the following
A- Parietal bone
B- Frontal Bone
C- Sphenoid bone
D- Zygomatic Bone
E- Mandible
F- Temporal Bone
G- Occipital bone
label the following
A- Anterior fonatelle
B- Sagital Suture
C- Bregma
D- Coronal Suture
E- Metopic suture
F- Naison
G- Pterion
H- Squamous suture
I- Asterion
J- Posterior Fonatelle
K- Lambda
Label the following
A- Anterior Cranial Fossa
B- Medial Cranial Fossa
C- Posterior Cranial Fossa
Label The Following
Anterior Fonatelle
soft spot on babies head
Unfused bone
Closes up 18-24 months
Label the following
A- cribiform plate- part of ethmoid bone and where olfactory nerve passes through
B- Optic canal- optic nerve, opthalmic artery
C- Superior orbital fissure- opthalmic division of trigeminal nerve, occularmotor nerve, trochlear nerve, abducent neve, superior opthalmic vein (CN V1, 3, 4, 6)
D- Foramen rotundum- maxillary division of trigeminal nerve
E- Foramen Ovale- mandibular division of trigeminal passes through here
F- Foramen spinosum- middle meningeal artery passes through here
Label the following
A- Internal acoustic meatus- cranial nerves 7 and 8 pass through here
B- Jugular foramen- CN 9, 10, 11 pass through here
C- Hyperglossal canal- CN 12
D- Foramen magnum- spinal chord and brainstem come together here
Label the following
A- Coronal (fronta plane)
B- Horizital (transverse)
C- Saggital (middle of brain)
D- Midsaggital (middle of body)
Label the following
A- Frontal Lobe
B- Parietal Lobe
C- Occipital Lobe
D- Temporal Lobe
Label the following
A- primary motor area
B- primary sensory area
C- sensory motor and sensory area
D- posteriro speach area (Wernike’s area)
E- Secorndary visual area
F- primary visual area
G- secondary auditory area
H- primary audit area
I- anterior speach area (Broca’s area)
What are the 3 layers of the meninges?
Dura mater- thick inelastic
Arachnoid mater- elastic, spider-like projections
Pia Mater- innermost, thin, delicate
What is the role of the meninges?
stabilize and protect the brain
form the sinuses - how venous blood criculates through cranial cavity
What is the outer surface of the brain seen in the dissection room and why?
collapsed arachnoid mater
because CSF has drained away
pia is beneath it when you peel away the archnoid
What 2 layers is the dura mater divided into?
Periosteal- closer to skull
Meningeal- closer to arachnoid mater
What do the 2 layers of the dura mater come together to form?
Falx cerebri
Divides the 2 hemespheres of the brain
Whats the largest venous sinus in the brain?
Superior saggital sinus
How do the meninges change when they come out of the foramen magnum?
Forms extra dural space between dura mater and vertebral column- the spinal dural space
This is where extradural or epidural anesthesia is administered
What is found between unfused periosteal and meningeal layers of dura mater?
Dural venous sinus
What space is found between the dura mater and arachnoid mater?
Subdural space
What space is found between the arachnoid mater and pia mater?
Subarachnoid space
This is where cerebrospinal fluid accumulates
What divides the cerebellum from the occipital lobe?
Tentorium cerebelli
Provides structure and support for the brain and stops it moving too much
What is the most significant bood vessel that supplies the meninges?
Middle meningeal artery
Branches of the maxillary artery
What supplies blood to the brain and where do they enter the cranial cavity?
Internal carotid arteries (80%) - enter at carotid canal
vertebral arteries (20%) - enter at foramen magnum
They form the circle of willis at base of brain
Label the following
What does the anterior communicating artery supply?
Middle and superior parts of frontal lobe and anterior parietal lobe
What does the posterior communication artery supply?
Supplies medial thalamic surface and walls of 3rd ventricle
What deos the basilar artery supply?
Directly supplies the brainstem and cerebellum and provides distal flow to thalami and medial temporal and parietal lobes
What does the vertebral artery supply?
Supplies posterior fossa and occipital lobes and provides vertebral column blood supply
What does the posterior inferior cerebellar artery supply
Provides blood flow to cerebellum
If blockage of CSF did occur what would be seen on a brain scan and why
Enlarged ventricles
because they are unable to drain CSF so fluid would accumlate in them causing hydrocephalus
What is an extra-dural haematoma?
Cuased by arterial damage- tearing of branches of middle meningeal artery
Blood collects between periosteal layer and calvaria
Typically occurs in region of pterion
What is a subdural haematoma?
Results from venous bleeding, usually from torn cerebral veins where they enter superior sagital sinus.
Bleeing is below the dura mater between the arachnoid mater and dura mater
What do the venous sinuses drain in to?
Internal jugular vein
Label the following
What are the layers of the scalp?
Skin
Connective tissue (dense)- contains arteries, veins and nerves supplying scalp. When scalp is cut, dense connective tissue holds cut vessels open- perfuse bleeding
Aponeurotic layer
Loose connective tissue- facilitates movement of scalp over calvaria. Infections tend to localise and spread through here
Pericranium- periosteum on outer surfce of calvaria
What arteries supply the scalp?
Branches of external carotid artery or opthalmic artery (a branch of internal carotid artery)
What occurs if there is a lasceration to the scalp?
The scalp has extremely rich blood supply from external carotid artery so lascerations tend to bleed profusely.
If lasceration damages loose connective tissue, infection can easily spread in this layer.
Emissery vein can spread infection from scalp into cranial cavity
What is the anatomical course of the olfactory nerve?
Sense of smell detected by olfactory nerve receptors in nasal epithelium
Thier axons form olfactory nerves which enter intra-cranial cavity by passing through cribiform plate in ethmoid bone
Sensory information reaches primary olfactory cortex in temperal lobe of brain
How do you test the olfactory nerve?
- Ask patient if theyve had noticible changes to sense of smell
- Test each nostril seperately with stong smell e.g. mint or vanilla
Patient’s eyes should be shut
What is the function of the optic nerve?
Pupillary light reflex- controls size of pupils in response to change in lght strength
Each pupillary light reflex has afferent limb (optic nerve) and 2 efferent limbs (parasympathetic fibres)
What is the anatomical course of the optic nerve?
- Light travel throughs pupil and turned into impulse by rods and cones
- Impulses are transmitted from retina through intra-cranial cavity to the brain by optic nerve through optic canal
- Impulses pass through visual pathway to the primary visual cortex
What is the course of the pupillary light reflex?
Optic nerve sends sensory impulases to mid brain nuclei to trigger motor impulses through parasympathetic axons runing along occularmotor neve to innervate pupillary sphincter muscle causing pupil contraction
How is the optic nerve tested?
- ask patient to stare at distant tager
- Inspect pupils
- Shine one eye with pen light and look for pupil constriction
- Take light away
- Shin light into same eye and look for constriction in contralateral eye
