Quiz #5 Flashcards
(41 cards)
1
Q
Thalamus
A
- two hemispheres, size walnut, sits above brain stem
- a relay station; gateway to cerebral cortex
2
Q
Functions of thalamus
A
- relays sensory (except smell)
- perception of pain, temperature, and touch
- imparts sense of pleasantness and noxiousness
- maintains cortical arousal, attention, and sleep-wake cycle
3
Q
Medial geniculate body
A
relays auditory information from subcortical midbrain structures to auditory cortex and temporal lobe (hearing)
4
Q
Lateral geniculate body
A
information from optic nerve to primary visual cortex in occipital lobe (visual)
5
Q
Ventral posterior medial
A
input (pain, temperature, and touch) form trigeminothalamic tract from CN associated with the face (V, VII, IX, X)
6
Q
Ventral lateral & ventral anterior
A
- both receive input from basal ganglia & cerebellum and send information to motor cortex
- VL - motor planning
- VL & VA - involved in speech production
7
Q
Blood supply to thalamus
A
the posterior communicating artery (PCA) is very important to the blood supply for the thalamus
8
Q
Cushing disease
A
- endocrine (hormone) disorder caused by tumor on the pituitary
- results in high levels of cortisol
- symptoms include moon facies, emotional disturbances, osteoporosis, hypertension, buffalo hump, obesity, amenorrhea (loss of menstruation), muscle weakness, and abdominal stripes
9
Q
Acromelagy
A
- “extreme largeness”
- caused by pituitary tumor
- results in pituitary producing too much human growth hormone
- symptoms: large stature, large nose and jaw, large hands, hypertension, and peripheral neuropathy
10
Q
Epithalamus
A
- lies superior & posterior to thalamus
- connects limbic system to forebrain and other parts of the brain
11
Q
Parts of the epithalamus
A
pineal gland
habenula
stria medullaris
12
Q
Pineal gland
A
- pinecone
- produces melatonin, sleep-wake cycle, circadian rhythms
13
Q
Habenula
A
olfactory reflexes & stress (limbic system)
14
Q
Stria medullaris
A
white matter tract connects habenula to limbic system
15
Q
Epithalamus
A
functions:
- sleep-wake cycle, olfactory reflexes, and reward and aversion
- key function is connection of limbic system to other parts of the brain
16
Q
Subthalamus
A
- lies below the thalamus
- connects basal ganglia to the motor cortex, thus more related to basal ganglia than thalamus
- important for modulation of movement outside basal ganglia
17
Q
Damage to the subthalamus can result in:
A
- hemiballismus: one-sided involuntary flinging of limbs
- tremors
- obsessive compulsive
- impulsivity
- deep brain stimulation: success to relieve tremors and involuntary movements
18
Q
Basal ganglia
A
- caudate nucleus - C shaped
- regulate emotions: fear and aggression, emotional meaning to memories, reward processing, and decision making
- three large nuclei: caudate nucleus - c-shaped, globus pallidus, and putamen
- functionally together called striatum
- anatomically together called lenticular muscles
19
Q
Two major pathways of the basal ganglia
A
- direct pathway: facilitates movement
- indirect pathway: inhibits movement
20
Q
Connections of the cortical motor areas
A
- using dopamine (produced in substantia nigra) regulates posture, balance, swinging arm movements, walking
- activating, sustaining, and inhibiting motor movements
21
Q
Dyskinesias
A
- involuntary, erratic movements, often fluid and dance like
- tremors
- athetosis: slow & writhing; limbs, trunk, neck, face, and tongue
- chorea: involuntary, unpredictable, rapid contractions of face, arms, legs
- ballismus
- tics
22
Q
Akinesias
A
- lose ability to move muscles on my own, “frozen”
- rigidity: muscles stiffen & tighten involuntarily
- dystonia: involuntary muscle contractions, repetitive movement or abnormal postures
- bradykinesia: slowness of movement, difficulty initiating movement
23
Q
Parkinson’s disease
A
- caused by degeneration of midbrain’s substantia nigra and loss of dopamine to BG
- symptoms: muscle rigidity, dyskinesias, resting and pill-rolling tremors, shuffling gait, weak voice, dysarthria, flat affect, poor posture, and dysphagia
24
Q
Medication for Parkinson’s
A
- Levodopa/carbidopa medications: sinemet, parcopa, stalevo
- dopamine agonists: mirapex, requip, parlodel
- anticholinergics: artane and cogentin
- MAO-B inhibitors: eldepryl and zelapar
- COMT inhibitors: comtan and tasmar
25
Deep brain stimulation
- type of Parkinson's treatment (surgery)
- surgical insertion of a brain pacemaker that stimulates the basal ganglia, reducing Parkinsonian symptoms
26
Pallidotomy
- type of Parkinson's treatment (surgery)
- cells in the globus pallidusare selectively destroyed using a heated probe, reducing Parkinsonian symptoms
27
Huntington's disease
- a progressive, hereditary neurological disease due to degeneration of the basal ganglia
- average onset is around 35 years of age
- autosomal dominant pattern of inheritance
- symptoms: severe chorea, athetosis, emotional and personality changes, torticollis (twisting of the neck), dysarthria, dysphagia, and dementia
28
Ventricles
- fluid-filled spaces in brain
- 4 types of ventricles:
right lateral ventricle, left lateral ventricle, third ventricle, fourth ventricle; located in each hemisphere, paired, c-shaped
- each ventricle has a structure called the choroid plexus that produces cerebral spinal fluid
29
Third ventricle
- from diencephalon
- single structure
- slit like structure between two thalami & part of hypothalamus
- may be absent in 30% of humans
30
Fourth ventricle
- most inferiorly located
- lies within brainstem
31
Where do the ventricles drain to?
- lateral ventricles drain to 3rd ventricle via forman of monroe (interventricular foramen)
- 3rd ventricle drains to the 4th ventricle
- 4th ventricle has drains to central spinal canal - bathes spinal column drains to subarachnoid cisterns - lie between arachnoid and pia mater
- CSF is reabsorbed from here
32
Function of CSF
- provides mechanical protection/cushioning
- facilitates homeostasis
- facilitates communication between CNS & peripheral nervous system & immune systems
33
What is CSF?
- cerebrospinal fluid
- clear/colorless fluid
- choroid plexus: located in each ventricle
- found in ventricular system, cerebral, spinal, and arachnoid spaces and perivascular spaces in CNS
34
CSF components
- water
- protein 9 (low concentrations)
- neurotransmitters - helpful diagnostic purposes
- glucose
35
CSF Production
- secretion varies over the duration of the day
- average 650 ml/day
- 140-270 mL volume in CNS at given moment
- 25 mL housed in the ventricles at a given movement
- maximal production is after midnight
36
CSF production changes with
aging
hypertension
atherosclerosis
sleep deprivation
37
CSF impact of dementia/alzheimer's
- aging process lead to hypo secretions of CSF because increased connective tissue and changes in vascular system causes CSF to "back up"
- interferes with the brain waste clearance system
38
Hydrocephalus
- subarachnoid hemorrhage complication
- excess CSF builds up in ventricles
- thought to be an obstruction
- now idea is hemorrhage caused an inflammation response in the brain that causes hypersecretion
39
Normal pressure hydrocephalus
- gradual blockage CSF drainage pathways, ventricles enlarge to hold excess CSF resulting in compression of brain tissue
- ventricles become enlarged but may not have increase actual pressure
- occurs from CVA, tumor, meningitis, hemorrhage, or brain
- majority cases over 60
- symptoms primary unsteady gait wide based, short, slow, and shuffling, forgetfulness/dementia, as progresses bladder control problems arise
40
How can you diagnose hydrocephalus
- CT scan, MRI, lumbar puncture (spinal tap)
- spinal tap: local anesthetic, inject needle into lower back, remove about 50cc of CSF to see if symptoms improve
- shunt placement surgeons choice: anterior horn lateral ventricles or occipital horn lateral ventricle then drains into abdomen
41
Holes in meninges
- decrease CSF pressure
- postural headaches: patient worse seated, better supine
- related to buoyance of brain and difficulty keeping brain supported if not enough CSF
