Brain and Meninges Flashcards Preview

Anatomy Written 2 > Brain and Meninges > Flashcards

Flashcards in Brain and Meninges Deck (58):
1

Average mass of brain

1300 to 1400 grams

2

Telencephalon

Cerebrum
Cerebral hemispheres separated by the longitudinal fissure
Gyri and Sulci
Lobes - frontal, parietal, temporal, insula, and occipital

3

Diencephalon

Thalamus
Epithalamus
Hypothalamus

4

Mesencephalon

Midbrain

5

Metencephalon

Pons and Cerebellum

6

Myelencephalon

Medulla Oblongata

7

Cerebrum

Frontal
Parietal
Occipital
Temporal

8

Frontal Lobe

(motor control, personality, judgment, planning, language production)

9

Parietal Lobe

Sensation, body orientation

10

Occipital Lobe

Visual perception and interpretation

11

Temporal Lobe

Audition (hearing), language comprehension and memory

12

Cerebellum

coordination and control of movement

13

Brainstem

midbrain, pons, medulla oblongata
Breathing, reticular activation (consciousness) and cardiovascular control

14

Diencephalon

Relay of sensory info; feeding, emotion, fight or flight response, and sexual behavior

15

Meninges

Cranial meninges are continuous with the spinal meninges at the foramen magnum
Dura, arachnoid, pia

16

Cranial dura mater

Two layers
Periosteal
Meningeal

17

Periosteal Dura Mater

outer layer representing the periosteum of the cranial cavity
contains meningial arteries
NOT continuous with the spinal dura mater

18

Meningeal Layer of dura mater

Inner layer continuous with the spinal dura mater at the foramen magnum

19

The two layers separate and form...

1. Dural partitions (folds)
2. Venous Sinuses (important for drainage)

20

Dural Partitions

Falx Cerebri - separates cerebral hemispheres
Tentorum Cerebelli - separates cerebellum from posterior portions of cerebral hemispheres
Falx Cerebelli - short projection btw cerebellar hemispheres
Diaphragma sellae - forms a roof over the sella turcica

21

Primary arterial supply is from

Middle meningeal arteries (branches of the maxillary arter)

22

Innervation

Principally by the ophthalmic, maxillary, and mandibular divisions of triggeminal (CN V)
Dura of posterior cranial fossa - upper cervical nerves

23

Arachnoid Mater

Thin membrane lining the inner meningeal layer of the dura mater
Thin processes extend into the subarachnoid space and are continuous with the pia mater

24

Pia Mater

Thin, delicate membrane adherent to the surface of the brain

25

Meningial Spaces

Extradural (Epidural) Space
Subdural Space
Subarachnoid Space

26

Extradural (Epidural) Space

Potential space btw the skull and periosteal dural layer

27

Extradural (Epidural) Space Clinical Correlation

Becomes a real space when an extradural hematoma forms from either a rupture of the meningeal artery or a tear in a dural venous sinus

28

Subdural Space

Potential space btw menngeal dural layer and arachnoid mater

29

Subdural Space Clinical Correlation

Real space may result when a subdural hematoma forms from the tearing of a vein entering a dural venous sinus

30

Subarachnoid Space

Real space btw arachnoid mater and pia mater filled with CSF
CSF is formed by specialized vascular structures, the choroid plexuses, in the ventricles and is reabsorbed into the dural venous sinuses via arachnoid villi that form the arachnoid granulations and lateral lacunae

31

Subarachnoid Space Clinical Correlation

Subarachnoid hemorrhage - most result from ruptures aneurysm

32

Ventricular System

Cavities filled with CSF secreted by the choroid plexuses

33

Lateral Ventricles

Each communicates with 3rd ventricle via interventricular foramen (aka foramen of monro)

34

Third Ventricle

Communicates with 4th ventricle via cerebral aqueduct (of sylvius)

35

Fourth Ventricle

Communicates with subarachnoid space via the median aperture (foramen of Magendie) and lateral apertures (foramen of Luschka)

36

Ventricular System - Clinical Correlation

Hydrocephalus - dilation of the ventricular system of the brain due to
1. obstruction of CSF flow (most common)
2. CSF not being adequately reabsorbed (less common)
3. overproducation of CSF (rare)
Not in adults - fused bones

37

Arterial Supply

Two pairs of arteries supply the brain
1. Vertebral
2. Internal Carotid Arteries

38

Vertebral arteries join and form the

Basilar Artery
- it then divides into the posterior cerebral arteries

39

Internal carotid arteries divide into

Terminal branches
Anterior and middle cerebral arteries

40

Cerebral Arterial Circle (of Willis)

Internal Carotid Arteries
Anterior Cerebral Arteries
Anterior Communicating Artery
Posterior Communicating Arteries
Posterior Cerebral Arteries

41

Clinical Correlation Arterial Supply

strokes relate to a disruption in blood supply leading to tissue death
A Cerebral Infarction occurs when blood is obstructed, and can lead to an ischemic stroke
A Cerebral Aneurysm is a weak spot in cerebral vessel which can rupture causing a hemorrhagic stroke
Location will affect specific brain structures and thus affect specific functions

42

Venous Drainage

Small cerebral and other veins drain into dural venous sinuses, which (most) ultimately drain into the internal jugulars

43

Name Venous Drainage

Superior Sagittal Sinus
Inferior Sagittal Sinus
Confluence of Sinuses
Transverse Sinuses
Sigmoid Sinuses
Cavernous Sinuses
Superior and Inferior Petrosal Sinuses

44

Confluence of Sinuses

Meeting of superior sgaittal, straight, and occipital

45

Transverse Sinuses

Drain the confluence and continue distally as the sigmoid sinuses, emptying into the internal jugular veins

46

Cavernous sinuses

Relation to danger triangle

47

CN 1

Olfactory - sensory for smell

48

CN II

Optic - sensory for vision

49

CN III

Oculomotor - motor to levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, inferior oblique, sphincter pupillae, and ciliary muscles

50

CN IV

Trochler - motor to superior oblique

51

CN V

Trigeminal - sesnory from face and dura mater
Motor to muscles of mastication, anterior belly of digastric, and mylohyoid

52

CN VI

Abducens - motor to lateral rectus

53

CN VII

Facial - Sensory from external acoustic meatus portion of auricle
Taste from anterior 2/3 tongue
Motor to submandibular, sublingual, and lacrimal glands
Motor to muscles of facial expression, posterior belly of digastric, stylohyoid, and stapedius

54

CN VIII

Vestibulocochlear - sensory for balance and hearing

55

CN IX

Glossopharyngeal - sensory from carotid belly and sinus, posterior 1/3 tongue, palatine tonsils, oropharynx, and mucosa of middle ear and pharyngotympanic tube
Taste from posterior 1/3 of tongue
Motor to parotid gland and stylopharyngeus

56

CN X

Vagus - sensory from larynx, laryngopharynx, parts of auricle and external acoustic meatus, aortic body chemoreceptors and aortic arch baroreceptors, esophagus, bronchi, lungs, heart, and abdominal viscera
Taste from epiglottis and pharynx
Motor to GI viscera, throacic viscera, larynx, pharynx, palatoglossus, and palate

57

CN XI

Accessory - Motor to trap and SCM

58

CN XII

Hypoglossal - Motor to intrinsic tongue muscles, hypoglossus, genioglossis, styloglossus