Anatomy Practical Flashcards
1
Q
What are the two divisions of the bones in the skull
A
- cranial bones
- facial bones
2
Q
name the bones of the cranium
A
frontal bone parietal bone occipital bone temporal bone sphenoid bone ethmoid bone
3
Q
Name the facial bones
A
mandible maxilla zygomatic bone nasal bone lacrimal bone palatine bone vomer
4
Q
name the cranial fossa parts
A
anterior cranial fossae
middle cranial fossae
posterior cranial fossae
5
Q
describe the structure of the temporal bone
A
- has a thicker part called the pertrous part
- has an external auditory meatus and an internal auditory meatus
- has the zygomatic process which forms the part of the zygomatic arch of the cheek bone
- mastoid process (anchoring site for some neck muscles
- styloid process
6
Q
What does the petrous part of the temporal bone house
A
The thicker part of the bone (the petrous part) houses the middle and inner ear.
7
Q
What two cranial nerves pass through the internal auditory meatus
A
the nerve of hearing and balance, the vestibulocochlear nerve CNVIII, and the facial nerve CNVII)
8
Q
What is the styloid process in the temporal bone an attachment site for
A
The needle like styloid process (often broken off) is an attachment for tongue and pharynx muscles.
9
Q
Describe the structure of the sphenoid bone
A
= The sphenoid bones is a butterfly shaped bone.
- It is made up of the central body, the greater wings and the lesser wings and 4 pterygoid plates.
- There are a number of important foramina in the sphenoid bone. These include the superior orbital fissure, the optic canals, the foramen rotundum, foramen ovale and foramen spinosum.
10
Q
what bone in the skull articulates with all other cranial bones
A
sphenoid
11
Q
Name the foramen in the sphenoid bone
A
superior orbital fissure, the optic canals, the foramen rotundum, foramen ovale foramen spinosum.
12
Q
What is the pterion
A
- marks where the frontal, parietal, temporal and sphenoid bones come together
- it is the thinnest part of the skull
13
Q
Why is the pterion clinically important
A
- marks the position of the anterior branches of the middle meningeal artery
- the middle meningeal artery supplies the dura and bone
- this is often implicated in intracranial haemorrhage
14
Q
from what artery does the middle meningeal artery branch of
A
maxillary artery from the ECA
15
Q
what foramen does the middle meningeal artery go through
A
foramen spinosum
16
Q
describe the ethmoid bone
A
- delicate and severe like a sieve through which the air can pass
- on the superior surface of the ethmoid bone is the cribriform plate where the olfactory bulbs of the olfactory nerve sit
17
Q
name the fontanelle present in the skull at birth
A
anterior fontanelle
posterior fontanelle
sphenoid fontanelle
mastoid fontanelle
18
Q
name the sutures present in the skull at birth
A
- sagittal
- coronal
- lambdoid
- squamous
19
Q
What three structures make up the nasal septum
A
- perpendicular plate of ethmoid bone.
- vomer bone.
- septal nasal cartilage
20
Q
Which bones make up the anterior, middle and posterior cranial fossa
A
Anterior - the frontal bone, ethmoid bone and sphenoid bone.
middle - the sphenoid bone and the two temporal bones.
posterior - the occipital bone and the two temporal bones.
21
Q
What brain structures are found in the anteiror, middle and posteiror cranial fossae
A
Anterior - lots of nerves
middle - the pituitary gland, and two lateral portions, which accommodate the temporal lobes of the brain.
posterior - the brainstem and cerebellum.
22
Q
what endocrine structure is found in the sella turcicia of the sphenoid bone
A
pituitary gland
23
Q
name the air sinuses and what they do
A
- frontal
- maxillary
- sphenoid
- ethmoid
- these lighten the skull and enhance the resonance of the voice
24
Q
How many vertebrae are in the spine
A
33
25
what do intervertebral discs do
- act as shock absorbers
26
How many vertebrae are present in each vertebral section
```
Cervical - 7
throacic - 12
lumbar 5
sacrum - 5 fused
coccyx - 4 fused
```
27
what is the common things that all vertebrae have
- The body
- The vertebral arch forms a vertebral foramen through which the spinal cord passes
- The transverse and spinous process is an attachment for the muscles of the back
28
describe C1 and C2
CI The Atlas articulates with occipital condyles of the skull (re: Greek Mythology)
C2 The Axis. More similar to a typical vertebra but has a dens process which acts like a pivot, and allows the atlas to pivot around the horizontal axis (ie shaking head to say no)
29
what are the differential features of the cervical, thoracic and lumbar vertebrae
Cervical
- Bifid spinous process
(Exceptions to this are C1 (no spinous process) and C7 )
- Transverse foramina – the vertebral arteries travel to the brain in this
- Triangular vertebral foramen
thoracic
- demi facets, they have facets superior and inferior as well as costal facets (on the transverse process) to articulate with the ribs
- The spinous processes of thoracic vertebrae are longer
- vertebral foramen is circular
lumbar
- large vertebral bodies
- triangular-shaped vertebral foramen
- spinous processes are shorter
30
what is the name of the foramen where the spinal nerves emerge from the vertebral column
vertebral foramen
31
what does the sacrum articulate with laterally
the 2 hip bones to form the sacroiliac joints
32
describe the foramina in the sacrum and what they do
The anterior and posterior sacral foramina transmit the anterior and the posterior rami of the sacral spinal nerves.
33
Name the parts of the development of the brain and what they develop into
- Telencephalon (cerebral hemispheres)
- Diencephalon (thalamus, hypothalamus)
- Mesencephalon (midbrain)
- Metencephalon (pons, cerebellum)
- Myelencephalon (medulla oblongata)
34
What structures make up the forebrain and hindbrain
The Hindbrain is composed of the medulla, the pons, and the cerebellum
the forebrain includes the thalamus, the hypothalamus, the limbic system, and the cerebrum.
35
which structure sits at the junction between the forebrain and hindbrain
midbrain
36
What makes up the brainstem
- medulla oblongata
- pons
- midbrain
37
What is the brainstem important for
- regulation of cardiac function
- regulation of respiratory function
- maintaining consciousness
- regulating sleep cycle
38
describe the ventral surface of the brainstem
- Midbrain is short and very little can be seen
- cerebral peduncles can be seen
- corticospinal tract is on the ventral surface
- pons has a birdge like surface
- medulla has pyramids on the ventral surface (the pyramids mark the decussation for the corticospinal tracts
- inferior olive - these are functionally asscoiated with the cerebellum
39
what cranial nerves are associated with the pons
CNV - VIII
40
What cranial nerves are associated with the medulla
IX - XII
41
What cranial nerves are associated with the midbrain
CNIII- IV
42
What cranial nerves emerge lateral to the inferior olive
X
IX
XI
43
which cranial nerves emerge between the inferior olive and pyramids
CN XII
44
name the cranial nerve general function and its exit opening
- olfactory
- optic
- oculomotor
- trochlear
- trigeminal
- abducens
- facial
- vestibulocochlear
- glossopharyngeal
- vagus
- accessory
- hypoglossal
- olfactory - smell - cribriform plate of ethmoid
- optic - sight, optic canal
- oculomotor - eye movement, superior orbital fissure
- trochlear - eye movement, superior orbital fissure
- trigeminal - sensory to the face, motor to the msucles of mastication, V1 - SOF, V2 - foraman rondtum, V3 - foramen ovale
- abducens - eye movement, superior orbital fissure
- facial - msucles of facial expression, taste of anterior 2/3 of the tongue, internal acoustic meatus
- vestibulocochlear - hearing and balance, internal acoustic meatus
- glossopharyngeal - sensory to pharynx, taste posterior 1/3 of the tongue, jugular foramen
- vagus - msucles of pharynx and layrnx, parasympathetic to abdomen, jugular foramen
- accessory - trapezius, SCM, jugular foramen
- hypoglossal - intrinsic tongue muscles, hypoglossal canal
45
describe the dorsal surface of the brainstem
- the dorsal surface of the midbrain has 2 paired swellings - inferior and superior colliculi
- gracile and cuneate tubercles like on either side of the most caudal part of the 4th ventricle, this opens to form the central canal about 1/3 of the way up the medulla - this is the point is called the obex
- rostral to this level is the dorsal surface of the medulla which is the floor of the caudal part of the 4th ventricle
-
46
what are the inferior and superior colliculi invovled in
- auditory and visual reflexes
47
what does the 4th ventricle contain
the 4th ventricle contains CSF that drains into the central canal of the spinal cord inferiorly and into the cerebral aqueduct superiorly
48
When is the medulla considered opened and closed
As the 4th ventricle is present, the medulla is considered ‘open’, as it opens up to the cerebellum via the 4th ventricle. This is the rostal medulla.
As the 4th ventricle closes and forms the central canal for the spinal cord, the medulla is considered ‘closed’ and is the most caudal point of the brainstem
49
in the midbrain what is visible at the ventral surface
cerebral peduncles
50
describe the blood supply to the brainstem
- arises from vertebral arteries
- these joint together to form the basilar artery
- basilar artery runs the length of the pons and splits into the posterior cerebral artery close to the pontine midbrain junction
- the posterior cerberal artery gives of several branches such as the anterior inferior cerebellar artery and the superior cerebellar artery
- the posterior inferior cerebellar artery is derived from the vertebral arteries
51
Where are the olfactory nerves
- these are in the olfactory epithelium in the roof of the nasal cavity
52
How do the oflactory nerves ascend into the nasal cavity
- They ascend through the cribiform plate of the ethmoid bone to reach the olfactory bulbs in the anterior cranial fossa.
- These nerves synapse on neurons in the bulbs.
53
What is loss of smell associated with
- it is frequently associated with upper respiratory tract infections, sinus diseases and head trauma
54
what does loss of olfactory fibres occur with
- this occurs with ageing
- injury to the nasal mucsoa or to the olfactory bulbs and tracts
- olfactory neurones can be torn away as they pass through the fractured cribiform plate
55
what are the optic nerves surrounded by
- extensions of the cranial meninges and subarachnoid space which is filled with CSF
56
where does the optic nerve pass
- passes posteromedially in the orbit through the optic canal to enter the middle cranial fossa where it forms the optic chiasm
- the fibres from the medial nasal half of each retina decussate and then join uncrossed fibres from the lateral nasal half of the retina to form the optic tract
57
If there was a direct trauma to the right orbit, with a fracture involving the optic canal, why might there be a loss of pupillary constriction? What type of blindness may result?
optic nerve is damaged - looses accomodation and light reflex
58
if a pituitary tumour compressed the optic chiasam what visual field defect would occur
loss of peripheral vision
59
if a berry aneruysm compressed the right optic tract what visual defect would occur
Homonygous hemiapnoia
60
describe the pathway of the oculomotor nerve
- the nerve exits the midbrain (medial to the cerebral peduncles), then runs anteriorly through the cavernous sinus on the lateral wall
- divides into superior and inferior branches - these both pass through the superior orbital fissure to innervate the extraocular muslces (excluding lateral rectus and superior oblique) and levator palpebrae superioris
-
61
What does the oculomotor nerve innervate
- extraocular muscles (excluding lateral rectus and superior oblique)
- levator palpebrae superioris
- also send pre synaptic parasympathetic fibres to the ciliary ganglion for innervations of the ciliary muscle (accommodation) and sphincter pupillae (constricts pupil)
62
What can lesions of an oculomotor nerve result from
- can result from pressure from a herniating uncus
- fracture involving the cavernous sinus
- aneurysms
63
Why may a herniating uncus result in a dilated pupil before it progresses to the deviated pupil in the “down and out” position with ptosis?
Damage to the oculomotor nerve
64
What is the smallest cranial nerve
Trochlear nerve
65
what has the longest intracranial course of the cranial nerves
- trochlear nerve
66
where does the trochlear nerve emerge from
It arises from the posterior (dorsal) surface of the midbrain (the only cranial nerve to do so), passing anteriorly around the brainstem.
67
where does the trochlear nerve pierce the dura matera
The trochlear nerve pierces the dura mater at the margin of the tentorium cerebella and passes on the lateral wall of the cavernous sinus, through the superior orbital fissure to the superior oblique muscle (the only extraocular muscle to use a pulley).
68
When is the trochlear nerve damaged and what happens with trochlear nerve damage
- rarely paralysed alone but may be torn when there are severe head injuries due to its long intracranial course
- characterstic sign of this is double vision when looking down
- the superior oblique assists the inferior rectus in depressing the pupil and is the only muscle to do so when the eye is adducted
69
where does the abducens nerve emerge from the brainstem and describe its route
- between the pons and medulla
- the nerves then pierce the dura and have a long intradural course to the superior orbital fissure
- abducens is somatic motor to one extraocular muslces - the lateral rectus
70
What does the abducens nerve innervate
lateral rectus
71
why is abducens affected by increased intracranial pressure
- because of its long intradural course and sharp bend along the petrosal part of the temporal bone therefore it can be effected by increased intracranial pressure
72
what does complete paralysis of abducens casue
- this causes medial deviation duet to the unopposed action of medial rectus
- diplopia is present in all ranges of movement except when looking away from the lesion
73
what can paralysis of abducens result from
- raised intracranial pressure
- pressure from atherosclerotic plaque in internal carotid arteries
- cerebral aneurysm of the circle of willis (85% occur in this region)
- septic thrombosis of the sinus subsequent to infection in the nasal cavities or paranasal air sinuses
74
which pharyngeal arch is the somatic nerve connected to
- it is somatic sensory and motor to derviates of the first pharyngeal arch
75
where does the trigeminal nerve arise from
- arises from the lateral aspect of the pons
76
what are the three branches of the trigeminal nerves
- ophthalmic nerve
- maxillary nerve
- mandibular nerve
77
describe where the motor root of the trigeminal nerve passes inferior to
- the motor root passes inferior to the trigeminal ganglion
| - the fibres join the mandibular division and supply the muscles of mastication
78
what does CNV1 (opthalmic) supply
sensory to cornea, upper conjunctiva, upper nasal mucosa, frontal and ethmoidal sinus, anterior dura, superior eyelid and forehead/scalp.
79
what does CNVII ( Maxillary) nerve supply
- sensory to dura middle cranial fossa, inferior conjunctiva, upper dentition and skin and mucous membranes associated with upper jaw.
80
What does CN3 (mandibular) nerve supply
– sensory to oral mucosa and anterior 2/3 of the tongue, lower teeth and jaw, temporal regions of face and external ear.
- Motor to muscles of mastication.
81
What does the V1 (ophthalmic) nerve divide into
- frontal nerve
- nasociliary nerve
- lacrimal nerve
82
What are the branches of V3 (mandibular nerve)
- lingual nerve
- inferior alveolar nerve
these are mainly sensoyr branches
83
which nerve hitches a lift with the lingual nerve
Chorda tympani (facial nerve brance)
84
which foramen does the inferior alveolar nerve pass through to enter the mandible
mandibular foramen
85
Name the 4 muscles of mastication
- lateral pterygoid
- medial pterygoid
- mandibular
- temporalis
86
what does the mandibular nrve innervate
- muscles of mastication
- mylohyoid
- anterior belly of digastric
- tesnor tympani
87
what is damaged caused by to CNV
- trauma
- tumours
- aneurysms
- meningeal infections
- The sensory and motor nuclei in the pons and medulla may be destroyed by intramedullary tumors or vascular lesions
88
How do you test for injury to CNV
Sensory
- Light touch is tested in each of the three divisions of the trigeminal nerve and on each side of the face using a cotton wool using a point stimulus
- For pain and temperature repeat the same steps as light touch but use a sharp object and a cold tuning fork respectively.
- Corneal reflex is conducted along with the facial nerve section of the test. - sensory innervation of the cornea is innervated by the trigeminal nerve
Motor
- Muscles of mastication (temporalis, masseter) should be inspected for atrophy.
- Palpate the temporalis and masseter as the patient clenches the jaw.
- The pterygoids can be tested by asking the patient to keep the mouth open against resistance, and move from side to side against resistance.
- A jaw jerk reflex can be tested by placing a finger over the patient's chin and then tapping the finger with a reflex hammer. Normally the jaw moves minimally.
89
Where does the facial nerve emerge from
- emerges from the pontine medullary junction lateral to abducens
90
what type of nerves does the facial nerve have in it
- a lagre motor root
| - smaller intermediate nerve that carries taste and parasympathetic fibres
91
describe the pathway of the facial nerve
- exits via the posterior cranial fossa through the internal auditory meatus
- courses through the temporal bone close to the tympanic cavity
- in the temporal bone it gives rise to the greater petrosal nerve and chorda tympani
- the facial nerve then exits the temporal bone through the stylomastoid foramen
- goes through the parotid gland and gives rise to the terminal branches
92
Name the 5 terminal branches of the facial nerve
```
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
```
93
which group of muscles do the branches of the facial nerve innervate
- muscles of facial expression
94
What does the greater petrosal nerve innervate
- parasympathetic to lacrimal gland
| - nerve to stapedius (a muscle that dampens vibrations of the stapes)
95
What does the chorda tympani nerve innervate
- special sensory (taste) to anterior 2/3 tongue
| - parasympathetic to submandibular ganglion (submandibular & sublingual gland)
96
what cranial nerve is the most frequently paralysed
CNVII - facial nerve
97
what does paralysis of the facial nerve cause
- can cause paralysis of facial muscles with or without loss of taste or altered secretion from the lacrimal or salivary glands
- bells palsy
98
What is bells palsy
- unilateral facial paralysis due to a lesion of CNVII
- a lesion of VII near its origin will result in paralysis of facial muscles on the ipsilateral side
- a central lesions (Upper motor lesion) results in paralysis on the contralateral inferior face
99
What does a central lesion result in
- a central lesions (Upper motor lesion) results in paralysis on the contralteral inferior face
100
How does damage to the facial nerve occur
- because the motor branches are superficial they can easily be damaged through cuts, birth injuries or to a fractured temporal bone
- also during parotid and submandibular surgery care must be taken to preserve the branches
101
Why is forehead wrinkling not impaired with a central lesion (UMN)? Use the diagram below to justify your answer.
because there is bilateral innervation
102
where does the vestibulocochlear nerve originate from
- originates from the pontine medullary junction
103
describe the route of the vestibulocochlear nerve
- originates from the pontine medullary junction and exits the posterior cranial fossa through the internal auditory meatus
- nerve divides into the cochlear and vestibular components
104
What does the cochlear and vestibular nerve supply
- the cochlear nerve is sensory to the spiral organ for hearing
- vestibular nerve is sensory to the semicircular ducts for sense of equlibration
105
Although the vestibular and cochlear nerves are independent.....
peripheral lesions often produce concurrent clinical effects.
106
what are the symptoms of CNVIII injuries
- hearing loss
- vertigo
- nystagmus
- tinnitus
- vestibular ataxia
107
Name 3 common causes of CNVIII problems?
benign paroxysmal positional vertigo (BPPV), Meniere's disease, and vestibular neuritis
108
Why can an acoustic neuroma lead to paralysis of muscles of facial expression?
because they both go through the internal auditory canal and it expands outwards
109
what nuclei send and receive fibres in the glossopharyngeal nerve
4 nuclei in the medulla send or receive firbes via IX
- 2 motor (nucleus ambiguss and inferior salviatory nucleus)
- 2 sensory (sensory of trigeminal nerve and solitary tract)
110
what three nuclei of the glossopharyngeal are shared with the vagus
- nucleus ambiguus (motor)
- sensory of trigeminal nerve (sensory)
- nucleus of solitary tract (sensory)
111
describe the route of the glossopharyngeal nerve
- exits the posterior cranial fossa through the jugular formane
- follows the stylopharyngeous (which it innervates)
- passes between the superior and middle pharyngeal constrictors
112
what does the glossopharyngeal nerve innervate
- parasympathetic fibres innervate the partoid gland via the optic ganglion
- the somatic sensory fibres and special sensory fibres are afferent to the posterior 1/3 of the tongue and the oropharynx
- there is also branch called the carotid sinus nerve, the nerve supplies the carotid (baroreceptor) and the carotid body (chemoreceptor) sensitive to blood gas
113
What causes injury to the glossopharyngeal
- injuries in IX in isolation are rare - usually accompanied by signs of involvement in IX, X and XI as well of these nerevs pass through the jugular foramen
- a tumour in this aea creates multiple cranial nerve palsies called jugular formane syndrome
114
In jugular foramen syndrome, what autonomic deficit is most likely present in your patient?
decrease in parotid secretion
115
How can you test the glossopharyngeal nerve and what is the efferent part of this reflex
- gag reflex
- afferent limb is the glossopharyngeal nerve
- efferent limb is the vagus nerve
116
where does the vagus nerve arise
- it arises from the lateral surface of the medulla
117
describe the root of the vagus nerve
- exits the posterior cranial fossa through the jugular foramen
- then descends through the neck in the carotid sheath to the root of the neck
- lies between the internal jugular vein and the common carotid artery
- in the neck the vagus nerve gives rise to the pharyngeal branch and the superior laryngeal nerve
118
describe what the vagus nerve innervates
- somatic sensory to laryngopharynx and larynx
- visceral sensory from the thoracic and abdominal organs
- somatic motor to palate, pharynx and larynx
- visceral motor (parasympathetic) to thoracic and abdominal organs
119
what are all the muscles of the pharynx and palate (except tensor veli palatini) supplied by
- they are supplied by the vagus vis the pharyngeal plexus and so injury to the pharyngeal branches of the vagus will result in dysphagia
120
In a patient with an injury to the pharyngeal branches of vagus, what would you expect to see if you inspected their mouth?
Uvula would be deviated away from the lesion to the opposite side
121
what reflex will be missing in damage to the pharyngeal branches of vagus
the pharyngeal reflex - (gag reflex)
122
What does the spinal accessory nerve innervate
- trapezius
| sternocleidomastoid
123
Where does the spinal accessory nerve arise from
The spinal accessory nerve is so called because it arises from a column of anterior horn motor neurons C1 to C5/6 of the spinal cord
124
describe the route of the spinal accessory nerve
- the spinal accessory nerve arises from a column of anterior horn motor neurones C1 to C5/C6
- they emerge as a series of rootlets and ascend into the cranial cavity via the foramen magnum and then exit through the jugular foramen
- the accessory nerve then descends in the carotid sheath which it pierces to innervate the SCM
- it emerges from the posterior border of SCM and crosses over the posterior triangle of the neck and passes deep into trapezius which it also innervates
125
What does the hypoglossal nerve innervate
- it has a somatic motor to the intrinsic and extrinsic muscles of the tongue
126
where does the hypoglossal nerve run
- it exits the cranium via the hypoglossal canal
- spirals behind the vagus to emerge between the internal carotid artery and the internal jugular vein
- lies on the carotid sheath deep to the muscles which attach to the styloid process(including the posterior belly of digastric)
127
what does injury to the hypoglossal nerve do
- it paralyses the ipsilateral half of the tongue
- after some time the tongue may appear shrunken and wrinkled
- tongue deviates to the same side as the lesion
128
describe the arterial blood supply to the brain
- the vertebral arteries join and this forms the basilar artery
- the vertebral arteries give of the anterior spinal arteries
- the basilar artery gives of the pontine arteries
- there are three inferior cerebellar arteries, these are the anterior inferior cerebellar artery and the posterior inferior cerebellar artery and the superior cerebellar artery
- the posterior inferior cerebellar artery branches of the vertebral artery
- the anterior inferior and posterior inferior cerebellar artery branches of the basilar artery
- at the end of the basilar artery splits into the posterior cerebral artery
- the posterior communicating artery joints the posterior cerebral artery to the middle cerebral artery
- the middle cerebral artery is joined to the anterior cerebral arteries
- the anterior cerebral arteries are connected to each other via the anterior communicating arteries
- the middle cerebral artery give of the internal carotid artery and the ophthalmic artery and the anterior chordal artery
129
What is the main supply of the blood to the brain
- main supply comes through the internal carotid arteries
130
what is the 3 branches of the internal carotid artery
- middle cerebral arteries
- anterior cerebral arteries (and there anterior communicating arteries)
these make up the anterior circulation
131
what gives rise to the posterior circulation
- the vertebral arteries
- basilar
- posterior cerebral artereis
132
what establises the circle of willis
The posterior communicating arteries establish the circle of Willis around the optic chiasm by linking the anterior and posterior circulation.
133
List the functional areas supplied by the
- anterior cerebral
- middle cerebral
- posterior cerebral
anterior cerebral - primary motor
middle cerebral - primary motor, broca and wernickes area, somatosensory cortex
posterior cerebral - visual and auditory?
134
describe the venous drainage of the brain
- drainage is by superficial and deep veins and dural sinus
| - these ultimately drain into the intenral jugular veins
135
where are the superficial veins and deep veins
The superficial veins in the arachnoid space and the deep veins from the centre of the brain eventually all drain into the dural sinuses.
136
What is the confluence of sinuses
- this is the junction of the straight, superior sagittal, and transverse sinuses
137
what does each transverse sinus do
- each transverse sinus makes an S shaped turn as the sigmoid sinuses which are continuous with the internal jugular veins
138
through which foramen do the jugular veins exit the skull
jugular foramen
- also exits here is the Cranial nerves IX (glossopharyngeal), X (vagus) and XI (accessory) and the inferior petrosal sinus and sigmoid sinus vein
139
The dural sinuses are found between which layers of the meninges?
between the endosteal and meningeal layers
140
What is the difference between a
- sulcus
- fissure
- gyrus
Sulcus - shallow grooves between folds
Fissure - deep grooves
Gyri - elevated folds
141
Each lobe can be divided by ....
each lobe can be divided into 3 gyri by 2 sulci.
142
What does the cerebral cortex enable us to do
- it allows us to be aware of ourselves and our sensations, to communicate, to remember, to understand and to initate voluntary movement
143
what is the cerebral cortex composed of
- grey matter cell bodies only
144
describe the concept of functional localization
1. ) Each hemisphere is chiefly concerned with sensory and motor functions of the opposite (contralateral) side of the body.
2. ) Although largely symmetrical in structure, the two hemispheres are not entirely equal in function. This is known as lateralization.
3. ) No functional area acts alone, and conscious behavior involves the entire cortex.
145
what is the main function and what is the lesion of
frontal
- primary motor cortex
- brocas area
parietal
- primary somatosensory cortex
temporal
- primary auditory cortex
occipital
- primary visual cortex
frontal
- primary motor cortex - primary motor control , deficit results in paralysis of the contralateral side of the body
- brocas area - speech production, defict results in expressive aphasia
parietal
- primary somatosensory cortex - somatic sensors that are responsible for detecting touch, proprioception, defcit results in loss of fine touch, proprioception, vibration
temporal
- primary auditory cortex - processes auditory information, loss results in hearing loss or cortical deafness depending on when the lesion is
occipital
- primary visual cortex - processes visual information, deficit results in vision loss
146
Where on the primary motor cortex do you find the motor control of the face
laterally?
147
Which 2 areas of the body have most of the primary motor cortex devoted to them?
- head and feet
