Week 4 Flashcards
3 regions of brainstem=
midbrain, pons, medulla oblongata
controls automatic behaviors: breathing, heart rate, cardiac output etc
brain stems
provides the pathway for tracts between higher and lower brain centers
-associated with 10 of the 12 cranial nerves (1 and 2 aren’t associated)
brain stem
located between the diencephalon and the pons
Most superior part of brainstem
midbrain
2 bulging ventral structures that contain descending pyramidal motor tracks
Cerebral peduncles=
site of dopamine production
Substantia nigra=
hollow tube carries CSF from 3rd to 4th ventricle
cerebral aqueduct
the midbrain is associated with what nerves
Cranial nerves III [oculomotor] and IV [trochlear]
Rich blood supply and Fe pigment
Motor coordination of upper extremities
Red nucleus
the substantial nigra is in what part of the brain
midbrain
bulging brainstem region between the midbrain and the medulla oblongata
forms part of the anterior wall of the fourth ventricle
relay impulses between the motor cortex and the cerebellum
Respiratory control centeres
pons
Pons Cranial Nerves
- contains nuclei of the reticular formation V [trigeminal] VI [abducens] VII [facial] VIII [vestibulocochlear]
most inferior part of the brain stem
along with the pons, forms the ventral wall of the fourth ventricle
choroid plexus on the ventral wall of the fourth ventricle
medulla oblangata
crossover points of the corticospinal tracts (motor track crossover)
decussation
does decussation happen bin the medulla oblongata
yes
Heart control, breathing, messages to brain and spinal cord, sneezing, coughing, swallowing, sucking
Medulla Oblongata
Medullary Cranial Nerves
IX [glossopharyngeal]
X [vagus]
XI [accessory]
XII [hypoglossal]
= inability to swallow
DYSPHAGIA
complex, involving 4 cranial nerves, respiratory centers, phrenic nerve, diaphragm contraction and airway patency
sneeze reflex
irritation of trachea activates reflex to expel foreign material
cough reflex
initiated by touch receptors in pharynx, epiglottis closes, peristalsis, inhibit gag reflex [inability to swallow = DYSPHAGIA]
swallow reflex
drinking through straw, diaphragm contracts to expand lungs [↓ pressure]
suck reflex
complex, activated by chemoreceptors in medulla, incorporates abdominal muscles and lower esophageal sphincters
vomiting reflex
dorsal to the pons and medulla
protrudes under the occipital lobes of the cerebrum
11% of brain mass
Cerebellum
Precise timing and appropriate patterns of skeletal muscle contraction
Subconscious- no projections to somatosensory cortex
Cerebellum
connects two identical hemisphere of cerebellum
vermis
Fibers in cerebellum are contralateral or ipsilateral
ipsilateral (no crossover- R cerebellum works on R brain)
_______ receives impulses of the intent to initiate voluntary muscle contraction
cerebellum
dysmetria=
overestimation or underestimation of force
= irregular uncoordinated movement of limbs or trunk
ataxia
inability to perform rapid coordinated movement (affected by alcohol)
dysdiadochokinesia=
limbic system is associated with ______
emotions
ncludes the rhinencephalon, amygdala, hypothalamus, and anterior nucleus of the thalamus
limbic system
amygdla is associated with what emnotions
anger and fear
emotions via gestures
Cingulate gyrus
convert new information into long-term memories Spatial navigation (directions)
Hippocampus
- has diverse axonal connections with hypothalamus, thalamus, cerebellum, and spinal cord
-goes everywhere in the body- like fascia
-invovled in cortical arousal
filters out repetitive and weak stimuli (ie low buzzing of refrigerator)
alerts cortex to strong sensory signals (ie smoke alarm)
Controls coarse motor movement
Reticular Formation/. Reticular Activating System
what system is involved in cortical arrousal
Reticular Formation/. Reticular Activating System
_____records brain activity/ brain waves
EEG
- “Idling brain”
- relaxed and alert
- eyes closed, not thinking
alpha waves
- busy brain
- anxious thinking and active concentration
beta waves
- short duration
- common in children
- drowsiness and hypnosis, lucid dreaming, light sleep
- transitional states
theta waves
- low frequency, high amplitude
- deep sleep
- when reticular activating system is off
Delta Waves
2-15 seconds, blank stare, fluttering eyes; no
post-seizure confusion
absence seizures [petit mal]
1-2 minutes, LOC, usually falls with rigidity followed by jerking movements, loss of bowel and bladder control, and severe biting of the tongue; post-seizure confusion
tonic-clonic seizures [grand mal]
REM sleep =
= dreaming
one passes through four stages of NREM during the first ____- minutes of sleep
30-45
REM sleep occurs after the___ NREM stage; about 90 minutes in
4th
EEG pattern reverts through the NREM stages to the stage 1 pattern is called what
[backtrack]
During REM vital signs______ and dreaming rakes place
increase
____sleep may be a reverse learning process where superfluous information is purged from the brain
REM
lapsing abruptly into sleep from the awake state
narcolepsy=
chronic inability to obtain the amount or quality of sleep needed
insomnia=
temporary cessation of breathing during slee
sleep apnea=
sleep walking
somnambulism
- between brain and skull
- protect CNS
meninges
what meaning contains CSF
-subarachnoid contain CSF
Meninges of the brain
- Dura matter (tough matter)
- Arachnoid mater (spider matter)
- Pia matter (gentle matter)- most inner
- falx cerebri – fold that dips into the longitudinal fissure
- falx cerebelli – runs along the vermis of the cerebellum
- tentorium cerebelli – horizontal dural fold extends into the transverse fissure
dfgsdfg
in the middle
Separated by subdural space
arachnoid
CSF and large blood vessels in ________-
subarachnoid
is bleeding into the subarachnoid space surrounding the brain, i.e., the area between the arachnoid and the pia mater
SUBARACHNOID HEMORRHAGE [SAH]
form of traumatic brain injury in which blood collects between the dura [the outer protective covering of the brain] and the arachnoid [the middle layer of the meninges]
SUBDURAL HEMORRHAGE [SDH]=
- deep meninge
- delicate connective tissue
- clings tightly to the brain
pia matter
-similar comp to blood plasma; less protein
-160ml of CSF (6 ounces= half beer can)
gives buoyancy to the CNS organs
CSF
CSF is reaborded via ___________
arachnoid villi
CSF production blocked; water brain
hydrocephalus=
____________ help cleanse CSF by removing waste
Chord plexus
podocytes of_________ help form the blood brain barrier
astrocytes
BBB is selective or non selective
BBB is selective that allows some nutrients to pass
BBB is ineffective against what
Ineffective against substances than can diffuse through plasma membrane (some drugs)
where is the BBB absent
absent in some areas [vomiting center and the hypothalamus], allowing these areas to monitor the chemical composition of the blood
2 types of cerebrovascular accidents (CVA)
Ischemic
Hemorrhagic
-caused by blockage of cerebral artery
temporary episodes of reversible cerebral ischemia
transient ischemic attacks [TIAs]
contralateral left extremity sensory loss and weakness
Anterior Cerebral Artery [ACA]
contralateral homonymous hemianopia
Posterior Cerebral Artery [PCA]
most commonly affected, supplies largest area, contralateral upper extremity or face
Middle Cerebral Artery [MCA]
a progressive degenerative disease of the brain that results in dementia; m/c degenerative brain disorder
Alzheimer’s disease=
- degeneration of the dopamine-releasing neurons of the substantia nigra
- 2nd most common neurodenegrative disease in elderly
- onset in 50s (6th decade)
Parkinson’s disease=
Parkinson’s disease is associated with what system
extrapyramidal [involuntary] motor system
Diagnostic Criteria for parkinsons
- resting tremors pathognomonic [70%]
- bradykinesia [lead-pipe & cogwheel rigidity]
- abnormal gait [short-stepped & festinating]
- loss of postural reflexes [w/falling]
what is thew main sign of Parkinson’s
resting tremor (goes away with movement)
= fatal hereditary disorder caused by accumulation of the protein huntingtin that leads to degeneration of the basal nuclei
Huntington’s disease
autosomal dominant genetic
-on chromosome 4
huntingtons disease
movement disorder; brief irregular contractions that are non repetitive or rhythmic but appear to flow from one muscle to the next
Chorea-
