CNS anatomy Flashcards
1
Q
Falx cerebri
A
- projects downwards to separate the right and left cerebral hemispheres.
2
Q
Tentorium cerebelli
A
- separates the occipital lobes from the cerebellum
- contains tentorial notch
3
Q
Periosteal dura mater
A
- Outermost layer of dura mater
- Dura mater is thick, tough and inextensible
- lines the inner surface of the bones of the cranium.
4
Q
Meningeal dura mater
A
- located deep to the periosteal layer
- continuous with the dura mater of the spinal cord.
5
Q
Arachnoid mater
A
- Arachnoid mater is the middle layer of the meninges
- Lies directly underneath the dura mater
- Consists of layers of connective tissue
- Avascular
- Does not receive any innervation.
6
Q
Pia mater
A
- Located underneath the sub-arachnoid space
- Very thin, and tightly adhered to surface of brain and spinal cord.
- Follows contours of the brain (the gyri and fissures).
- Highly vascularised
7
Q
Subdural space
A
- a potential space that can be opened by the separation of the arachnoid mater from the dura mater
8
Q
Subarachnoid space
A
- contains cerebrospinal fluid, which cushions the brain. - small projections of arachnoid mater into the dura (arachnoid granulations)
- allow CSF to re-enter the circulation via the dural venous sinuses.
9
Q
Tentorial notch
A
- Space found anteromedially in tentorium cerebelli for passage of the midbrain.
10
Q
Superior sagittal sinus
A
- Dural venous sinus
- Runs through the groove for superior sagittal sinus
- Appears triangular in cross section
11
Q
Inferior sagittal sinus
A
The inferior sagittal sinus is a dural venous sinus found within the inferior, free margin of the falx cerebri
12
Q
Straight sinus
A
The inferior sagittal sinus and the great cerebral vein join together to form the straight sinus.
13
Q
Transverse sinuses
A
- runs through the tentorium cerebelli
- collect the blood from the veins of the cerebellum and inferior surface of the brain
14
Q
Cavernous sinus
A
- Contains several key structures: abducens nerve, carotid plexus, internal carotid artery
- Lateral wall contains: oculomotor nerve, trochlear nerve, ophthalmic and maxillary branches of trigeminal nerve
15
Q
Confluence of sinuses
A
- Straight, superior, and inferior sagittal sinuses converge at confluence of sinuses
- Overlies the internal occipital protuberance
16
Q
Sigmoid sinuses
A
- One of the dural venous sinuses
17
Q
Cerebrum
A
-Largest part of the brain, located superiorly and anteriorly in relation to the brainstem.
- It consists of two cerebral hemispheres (left and right), separated by the falx cerebri of the dura mater.
18
Q
Diencephalon
A
- Caudal part of forebrain
- Consists of thalamus and hypothalamus (and other structures but don’t need to know)
19
Q
Brainstem
A
- Distal part of brain that consists of midbrain pons, and medulla oblongata
20
Q
Cerebellum
A
- Important role in motor control
- Sits inferior to occipital and temporal lobes, within the posterior cranial fossa.
- It is separated from these lobes by the tentorium cerebelli, a tough layer of dura mater.
21
Q
Spinal cord
A
22
Q
Midbrain
A
- Acts as a conduit between the forebrain above and the pons and cerebellum below.
23
Q
Pons
A
- The pons is the largest part of the brainstem
- CN V, VI, VII, VIII emerge from the pons
- Houses main sensory nucleus, trigeminal motor nucleus, abducens nucleus, facial nucleus, cochlear and vestibular nuclei
24
Q
Medulla
A
- Houses essential ascending and descending nerve tracts as well as brainstem nuclei.
- Contains pyramids, through which upper motor neurones descend
25
Central sulcus
- Groove separating the frontal and parietal lobes.
26
Longitudinal fissure
- Separates cerebral hemispheres
27
Lateral fissure
- Separates frontal and parietal lobes
28
Frontal lobes
- Responsible for higher intellect, personality, mood, social conduct and language
29
Temporal lobes
- Responsible for memory and language including hearing (location of the primary auditory cortex).
30
Parietal lobes
- Responsible for language and calculation on the dominant hemisphere side, and visuospatial functions on the non-dominant hemisphere side
31
Occipital lobes
- The primary visual cortex (V1) is located within the occipital lobe
- Responsible for vision.
32
Pre- and postcentral gyri
- Precentral gyrus – location of primary motor cortex.
- Postcentral gyrus – location of primary somatosensory cortex.
33
Cingulate gyrus
- Part of limbic system
- Isthmus is continuous inferiorly with parahippocampal gyrus in the temporal lobe of the human brain.
34
Parahippocampal gyrus
- Part of limbic system
35
Uncus of temporal lobe
- Extremity of parahippocampal gyrus
- If it herniates, CN III can be compressed
- Contains olfactory cortex
36
Calcarine sulcus
- Location of primary visual cortex
37
Parieto-occipital sulcus
- Marks boundaries between parietal and occipital lobes
38
Corpus callosum
- Large white matter tract that connects the two hemispheres of the brain.
39
Anterior and posterior commissures
- Work together to link the cerebral hemispheres of the brain
- Interconnects amygdalae and temporal lobes
- Contributes to memory, emotion, speech and hearing.
40
Septum pellucidum
- A thin, triangular, vertical membrane separating the anterior horns of the left and right lateral ventricles of the brain.
41
Lateral ventricles
- The left and right lateral ventricles are located within their respective hemispheres of the cerebrum.
- They have ‘horns’ which project into the frontal, occipital and temporal lobes.
42
Third ventricle
- The lateral ventricles are connected to the third ventricle by the foramen of Monro.
- The third ventricle is situated in between the right and the left thalamus.
43
Cerebral aqueduct
- Connects third ventricle to fourth ventricle
44
Fourth ventricle
- Lies within the brainstem, at the junction between the pons and medulla oblongata.
- Fluid then drains into central spinal canal and subarachnoid cisterns
45
Thalamus
- Situated at core of diencephalon
- Grey matter
- Relays and integrates a myriad of motor and sensory impulses between the higher centres of the brain and the peripheries.
46
Hypothalamus
- Has connections with the endocrine, autonomic (visceral motor), somatic motor, and limbic systems, maintaining a state of homeostasis.
- Controls body temperature, blood circulation, food intake, fluid and electrolyte balance, the sleep-wake cycle, metabolism and sexual behaviour.
47
Pineal gland
- Produces melatonin
- Tucked in a groove where 2 halves of the thalamus join
48
Pituitary gland
- Located in sella turcica of sphenoid bone
- Anatomically and functionally closely related to the hypothalamus.
- Anterior portion secretes pituitary hormones
49
Optic chiasm
- Fibres of the optic nerve (CN II) extend posteriorly from each eye and intersect within the middle cranial fossa, forming the optic chiasm.
- Located at the base of the brain, just anterior and inferior to the location of the pituitary gland.
50
Fornix
- Found in the mesial aspect of the cerebral hemispheres, below the corpus callosum
- Connects hippocampus to various cortical structures
- Associated with the processes of cognition, memory consolidation, emotions and sexual responses
51
Cerebellar tonsils
- Can herniated through foramen magnum
52
Cerebellar peduncles
- Connect cerebellum to brainstem
53
Vermis
Found in the middle of the cerebellum
54
Olfactory nerve
Smell
55
Optic nerve
- Transmits special sensory information for vision
56
Oculomotor nerve
It provides motor and parasympathetic innervation to some of the structures within the bony orbit.
57
Trochlear nerve
- Innervates superior oblique (depresses and intorts eyeball)
58
Trigeminal nerve
- Innervate the skin, mucous membranes and sinuses of the face.
- Mandibular branch innervates muscles of mastication: medial pterygoid, lateral pterygoid, masseter and temporalis.
- Also supplies anterior belly of digastric and tensor tympani.
59
Abducens nerve
- Innervates lateral rectus muscle (abducts eyeball)
60
Facial nerve
- Supplies muscles of facial expression, posterior belly of the digastric, stylohyoid and stapedius muscles
- Provides special taste sensation to the anterior 2/3 of the tongue via the chorda tympani
61
Vestibulocochlear
- Hearing and balance
62
Glossopharyngeal
- Innervates the oropharynx, carotid body and sinus, posterior 1/3 of the tongue, middle ear cavity and Eustachian tube.
- Provides taste sensation to the posterior 1/3 of the tongue.
- Innervates parotid gland.
- Innervates the stylopharyngeus muscle of the pharynx.
63
Vagus
- Innervates skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera.
- Provides taste sensation to the epiglottis and root of the tongue.
- Provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx.
Parasympathetic: Innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm.
64
Accessory nerve
- Innervates sternocleidomastoid and trapezius muscles.
65
Hypoglossal nerve
- Innervates all the extrinsic and intrinsic muscles of the tongue
66
Cervical enlargement
- Located proximally, at the C4-T1 level.
- It represents the origin of the brachial plexus.
67
Lumbar enlargement
- Between T11 and L1 is the lumbar enlargement,
- It represents the origin of the lumbar and sacral plexi.
68
Conus medullaris
At the L2 vertebral level the spinal cord tapers off, forming the conus medullaris.
69
Filum terminale
- Formed distally by meninges
- Strand of fibrous tissue
- Attaches to the vertebral bodies of the coccyx
- Acts as an anchor for the spinal cord and meninges.
70
Lumbar cistern
- This space is accessed during a lumbar puncture (to obtain CSF fluid) and spinal anaesthesia.
71
Cauda equina
- A bundle of spinal nerves that arise from the distal end of the spinal cord.
- They run in the subarachnoid space, before exiting at their appropriate vertebral level.
