The Brain Flashcards
0
Q
CNS includes?
A
the brain + the spinal cord
1
Q
The brain includes?
A
-cerebrum, brainstem & cerebellum
2
Q
What is the spinal cord?
A
-cylindrical bundle of nerves that extends from foramen magnum (upper border of atlas) to first or second lumbar vertebrae
3
Q
What is the narrowing of the cord called?
A
the Conus Medullaris
4
Q
Spinal nerves continue along what?
A
Cauda Equina
5
Q
How many enlargements of the spinal cord? What are they?
A
- 2
- cervical & lumbar regionals
- enlarges the motor & sensory nerves that come in & out of the spinal cord to supply the arms & legs respectively
6
Q
After the apex of the conus medullaris? What is it called & what does it do?
A
from apex of conus medullaris there is a CT filament called the filum terminale that anchors the cord to the first coccygeal segment
7
Q
What are the 5 parts that make up the spinal cord?
A
- white matter
- grey matter
- central canal
- dorsal horns
- ventral horns
8
Q
What is white matter?
A
myelinated, outer layer of spinal cord
9
Q
What is grey matter?
A
unmyelinated, inner H-shaped portion of spinal cord
10
Q
What is the central canal?
A
filled with CSF, runs longitudinally along length of spinal cord, continuous with ventricular system of brain
11
Q
What are the dorsal horns?
A
sensory nerve tracts
12
Q
What are the ventral horns?
A
motor neurons
13
Q
What does the brainstem include?
A
- midbrain
- pons
- medulla oblongata
14
Q
What is the medulla oblongata good for?
A
several centers for autonomic function:
-respiration, cardiac center, vasomotor center, reflex centers for vomiting, swallowing, coughing, sneezing
part of it forms the fourth ventricle
15
Q
What does the medulla oblongata contain?
A
- pyramids (corticospinal tracts)
- decussation of the pyramids (where motor fibers from L hemisphere cross to the right and vice versa)
- nuclei for CN IX, X, XI & XII
16
Q
What is the pons? What does it contain?
A
- ‘bridge’
- contains fiber tracts connecting the medulla & cerebellum with upper portions of the brain
- contains respiratory centers that work with those in the medulla
- contains nuclei for CN V (motor) VI, VII, part of VIII
17
Q
What is the midbrain? What does it contain?
A
- cerebral peduncles
- substantia nigra
- corpora quadrigemina
- nuclei for CN III, IV & V (sensory)
- cerebral aqueduct passes through midbrain
18
Q
What are the cerebral peduncles?
A
-connecting tracts from pons to cerebellum
19
Q
What is the substantia nigra?
A
-dopamine producing regions associated with reward, addiction & movment
20
Q
What are the corpora quadrigemina?
A
-the masses that make up the superior & inferior colliculi
21
Q
What is the cerebellum responsible for?
A
- balance/posture, learning of motions, cognitive functions & motor coordination
- does not initiate motions, but responsible for fine tuning motions
- damage to the cerebellum will result in lack of coordination in gait, speech, etc.
22
Q
What are the parts of the cerebrum?
A
- hemispheres (connected by corpus collosum)
- sulci (valleys) & gyri (hills)
- lobes: frontal, parietal, occipital, temporal
23
Q
Cerebral hemispheres include…
A
- cerebral cortex
- basal ganglia
24
Cerebral cortex is a site for?
-site for sensorimotor integration & perceptive qualities of our experiences
25
What is a gyrus?
-convolution of cortex
26
What is a sulcus/fissure? What are the 3 fissues/sulci?
- gap between gyri
- longitudinal fissure: divides brain into L & R halves
- lateral (sylvian) sulcus: separates temporal from frontal lobes
- central sulcus: separates frontal from parietal lobes
27
What are the lobes of the brain? What do they do?
- frontal: primary, motor activity, behavior, speech production
- parietal: primary somatosensory & proprioception; association of somatosensory, vision, audition; formation of egocentric space & sense of self
- occipital: vision
- temporal: audition, olfaction, memory
28
What is the homunculus?
- 'little human'
- image of the body imprinted on the brain; two types: sensory & motor
- sensory homunuclus is represented on postcentral gyrus of parietal lobe
- motor homunculus represented on the precentral gyrus of the frontal lobe
29
What sensory information is received in the thalamus? Where is it integrated and relayed to?
- all sensory stimuli, except for olfaction are received here
- integrated & relayed through thalamocortical radiations to specific cortical areas
30
What does the hypothalamus comprise? What is the chief region for? What does it regulate? What does it produce?
- comprises the wall & floor of the 3rd ventricle
- chief region for integration of autonomic NS
- regulates H2O balance, BT & thirst
- produces antidiuretic hormone & oxytocin
31
What are the 12 cranial nerves?
```
CN I= olfactory
CN II= optic
CN III= oculomotor
CN IV= trochlear
CN V= trigeminal
CN VI= abducens
CN VII= facial
CN VIII= vestibulocochlear
CN IX= glossopharyngeal
CN X= vagus
CN XI= accessory
CN XII= hypoglossal
```
32
What is CN I for? How do you test it?
- olfactory n.
- smell
- testing done by waving a nonirritating scent under pts nose
33
What is CN II for? How do you test it?
- optic n.
- sense of sight, transmits retinal images back to the occipital lobe of the brain
- tested in office w/Snellen chart & fundoscopic examination
34
What is CN III for? What does it innervate? How do you test it?
- occulomotor n.
- innervates superior, inferior & medial rectus, inferior oblique muscles that control the movements of the eye as well as the levator palpebrae superioris muscle of the eyelid & the muscles that control pupillary constriction
- have pt. follow a moving object, look at alignment of the eyes, shine a light in their eyes & look for pupillary constriction
35
What is CN IV for? What does it innervate? How do you test it?
- trochlear n.
- innervates the superior oblique muscle of the eye
- observe the alignment of the eye & have pt. follow moving object with their eyes
36
What is CN V for? It provides sensory innervation to what and motor innervation to what? How do you test it?
- trigeminal n.
- provides sensory innervation to most of the face & motor innervation to the muscles of mastication, corneal reflex
- testing done by lightly touching the face and cornea w/cotton swab & observing bite strength
37
What is CN VI for? What does it innervate? How do you test it?
- abducens n.
- innervates lateral rectus muscle of eye
- look at alignment of the eyes, have pt. follow a moving object with their eyes
38
What is CN VII for? What does it innervate? What are the 2 notable branches? How do you test it?
- facial n.
- motor innervation to muscles of facial expression & parasympathetic motor innervation to lacrimal gland & most of sinuses
- 2 notable branches: n. to stapedius muscle (innervates stapedius muscle of inner ear) & chorda tympani which provides special sense innervation from anterior 2/3 of tongue
- testing done by observing the ability of the patient to make various facial expressions: cotton swab dipped in flavored substance & place on anterior 2/3 of tongue
- corneal reflex tests the afferent (sensory) path of CN V, but efferent response is activated by CN VII
39
What is CN VIII? What are the 2 major divisions? How do you test it?
- vestibulocochlear n.
- splits into 2 major divisions:
* vestibular n. which determines head position/acceleration information from inner ear
* cochlear n. processes sensation of sound information from inner ear
- test by using a tuning fork (Weber & Rinne tests) for cochlear part, to test vestibule part move head & observe eyes for nystagmus
40
What is CN IX? What does CN IX provide innervation to & what kind? How do you test?
- glossopharyngeal
- provides sensory info for carotid bodies/sinus, posterior 1/3 of tongue, pharynx & middle ear as well as taste for posterior 1/3 of tongue
- provides motor innervation to stylopharyngeus muscle & parotid gland
- testing of this nerve usually done by assessing ability to taste on posterior 1/3 of tongue & determining if sensation is intact on arches of palate
41
What is CN X? What does CN X do? What does it provide innervation to? What kind?
- vagus
- provides efferent parasympathetic innervation to all organs below the neck down to proximal 1/2 of transverse colon (with exception of adrenal glands)
- provides motor innervation to several muscles important to speech such as muscles of larynx, cricothyroid & pharyngeal constrictors
- test by asking the to say "Ahhh" and observing the uvula; if both are working the uvula should stay midline; if pt. can speak normally vagus is intact
42
What is CN XI? What does CN XI do? How do you test?
- accessory
- motor innervation to sternocleidomastoid & trapezius muscles
- test by asking pt to contract those muscles against resistance
43
What is CN XII? What does CN XII innervate? What kind? How do you test?
- hypoglossal
- motor innervation to all muscles of tongue except for palatoglossu muscle
- test by asking pt to stick tongue out straight, if deviates that indicates a dysfnction
44
Most simplistic, what are each of the cranial nerves and what is each responsible for?
CN I: olfactory= smell
CN II: optic= sight
CN III: oculomotor= eye movements, pupil constriction
CN IV: trochlear= superior oblique muscle
CN V: trigeminal= sensory to face, motor to muscles of mastication
CN VI: abducens= lateral rectus muscle
CN VII: facial= muscles of facial expression, taste
CN VIII: vestibulococchlear= hearing, balance
CN IX: glossopharyngeal= taste, secremotor to parotid, stylopharyngeus muscle
CN X: vagus= motor to laryngeal/pharyngeal muscles, parasympathetic to everything north of splenic flexure
CN XI: accessory= sternocleidomastoid & trapezius
CN XII: hypoglossal= muscles of tongue
