Block 4 Shut the door Flashcards Preview

Hailey - Neuro > Block 4 Shut the door > Flashcards

Flashcards in Block 4 Shut the door Deck (105):
1

homeostasis example pathway

receptors: baroreceptors (peripheral) or temperature (central) > AFF > hypothalamus > EFF > hormones/ANS

2

homostasis fxn

integrates info for control of ENDOCRINE, ANS, and neural systems concerned with motivation (LIMBIC SYSTEM)

3

fornix

major projection from hypothalamus > mammillary bodies

4

pituitary structure

when head trauma...

lies at base of brain in sphenoid bone: sella turcica

infundibulum/stalk to pit can be severed = severs pit from thalamus >>> increase in prolactin (because under inhibitory control)

5

adenohypophysis

neurophypophysis

median eminence

anterior pituitary (more rostral)

posterior pituitary

infundibulum (intersection between hypothalamus and pit gland = impt relay)

6

posterior pituitary fxn

synthesis and secretion of VASOPRESSIN OR OXYTOCIN

synthesized in MAGNOCELLULUAR hypothalamic neurons in SUPRAOPTIC (SON) and PARAVENTRICULAR (PVN) nuclei (secrete directly into systemic circulation)
>
transported via axons to nerve terminals in posterior pituitary

7

Supraoptic nucleus (SON) and paraventricular nucleus (PVN) are where?

activated by

in medulla

limbic structures (motivation, emotions)
solitary nucleus (medulla) (requires AFF from baroreceptors and gi tract)

8

nerve terminals in posterior pituitary >

vasopression and oxytocin axonal transported > terminal > vesicles > released by AP activity

9

Vasopressin/ADH stimulus

1. increased BLOOD OSMOLALITY: too much NaCl > hypothalamus > VP > kidney > INC WATER RESORPTION by kidney

2. HYPOVOLEMIA: dec blood volume > receptors in heart > hypothalamus > VP > INC WATER RESORPTION

3. HYPOTENSION: dec blood pressure > baroreceptor > hypothalamus > VP > VASOCONSTRICTION > inc BP

10

Oxytocin stimulus

WOMEN

1. SUCKLING/nursing > inc OT > "milk ejection reflex" via smooth muscle contraction in breast

2. UTERINE SITMULATION > inc OT > uterine contraction > delivery of newborn

*bonding idea, delivered intranasally

11

anterior pituitary fxn
families

secretions of "families" of hormones into system circulation
1. somatomammotropins
GH
PROLACTIN

2. glycoproteins
TSH
FSH
LH

3. opiomelanocortin peptides
ACTH
B-EP

12

somatomammotropins
stimulus and effects

GH growth hormone
stimulus: EXERCISE, STRESS, SLEEP
effect: tissue growth, metabolism of fat, carbs, etc.

PROLACTIN
stimulus: SUCKING, STRESS
effect: development of mammary tissue, LACTATION (to be ejected by oxytocin)

13

glycoprotein
stimulus and effects

TSH thyroid-stimulating hormone
stimulus: COLD TEMPS
effects: increase TH > inc cell metabolism, inc metabolic rate, inc heat production *negative feedback

FSH follicle-stimulating hormone
gonadotropin regulated by hypothalamic peptide
effects:
MEN inc SPERMATOGENESIS
WOMEN development of ovarian FOLLICLE

LH luteinizing hormone
gonadotropin regulated by hypothalamic peptide
effects:
MEN *required for SPERATOGENESIS (with FSH), stimulates TESTOSTERONE
WOMEN initiates OVULATION "trigger," stimulates PROGESTERONE from spent follicle

14

opiomelanocortin peptides
stimulus and effects

opiate receptor binding, pigment action, adrenal cortex
common precursor: pro-imc: POMC

ACTH adrenocorticotropic hormone
stimulus: STRESS
effects: secretes CORTISOL/glucocorticoid from adrenal cortex

B-EP beta-endorphin
stimulus: STRESS (fight or flight)
effects: opiate-like ANALGESIA

15

POMC special because

when cleaved makes two biologically active peptides: ACTH and B-EP

16

test used clinically to asses anterior pituitary function?

stress common stimulus, so induce insulin-induced hypoglycemia
inject small insulin: decrease blood glucose >>> increase in ACTH, cortisol, prolactin, b-EP, GH

17

hypothalamus controls anterior pituitary by _______ neurons,

which secrete _______ to median eminence

parvocellular neurons

hypothalamic releasing hormones

18

hypothalamic releasing hormone
function/pathway

synthesized in parvocellular neurons > transported via axons to median eminence > released from nerve terminals into hypophyseal portal vein

19

hypothalamic releasing hormones
excitatory
inhibitory

4 excitatory:
TRH thryotropin-releasing hormone = INC TSH
GnRH gonadotropin-releasing hormone = INC FSH and LH
CRH corticotropin-releasing hormone = INC ACTH and B-EP
GHRH growth hormone-releasing hormone = INC GH

2 inhibitory:
SOMATOSTATIN decrease GH secretion
DOPAMINE decrease PROLACTIN

20

only pituitary hormone controlled by excitatory and inhibitor HRHs

GH

21

diabetes insipidus

bitter urine
LOSS OF VASOPRESSIN SECRETION
etiology: head trauma (sever pit stalk), autoimm, idiopathic

POLYURIA excess urine
POLYDYPSIA excess drinking

Tx: desaminovasopression

22

galactorrhea-amenorrhea

inappropriate lactation
cessation of menstruation
HYPERPROLACTINEMIA increased blood prolactin

etiology: tumor in pituitary = MICROADENOMA that release prolactin > dec LH and FSH > cessation of menstruatio > INFERTILITY

Tx: surgically remove microadenoma, block prolactin with DOPAMINE REC AGONIST

23

signals from periphery that cause us to stop eating

1. hormone CCK from gi tract thru vagus to brainstem
(SHORT-TERM SIGNAL)
2. LEPTIN from intestines from high fat content to hypothalamus
(LONG-TERM SIGNAL)

24

short term signals of satiety (decreased food intake)

a. oropharyngeal: TASTE
b. GASTRIC DISTENSION/STRETCH and INTENSTINAL NUTRIENT
c. POST-ABSROPTIVE SATIETY: gi > liver through portal vein; SENSORS FOR GLUCOSE AND FREE FAs in liver

25

satiety factors in CNS
a. gastric distention
b. CCK
c. ghrelin

a. gastric distenion: MECHANORECEPTORS on VAGAL AFFERENTS > solitary nucleus (NTS)
*add leptin, increased response to gastric stretch

b. cholecystokinin CCK: hormone released from duodenum in response to meals
-inc gallbladder contraction > inc bile release > inc fat digestion
-inc pyloric constriction
-inc gastric contractions
CCK Rec > inc VAGAL AFF response > NTS

c. ghrelin hormone: from stomach
increased by fasting
OREXIGENIC: INC APPETITE

26

Prader-Willi syndrome
Sx

fetal hypotonia
mental retardation
hypogonadotropic hypogonadism DEC FSH and LH
ghrelin secretion HYPERGHRELINEMIA
obesity
hyperphagia EXCESSIVE EATING

27

long-term CNS signals of satiety

LEPTIN: adipocytes release leptin
*morbid obesity: higher > normal amounts leptin
site of action:
1. solitary nucleus in brainstem
2. hypothalamus

MULTIPLE HYPOTHALAMIC NUCLIE implicated in control of food intake: LHA, PVN, ARC

28

CNS nuclei of satiety:
LHA lateral hypothalamic area
PVN paraventricular nucleus
ARC arcuate nucleus

activation of LHA > release of "anabolic" NT = OREXIN > increase in eating

activation of PVN > release of "catabolic" NT = CRH (corticotropin releasing hormone) > decrease in eating

ARC: integrates all this info
two populations of neurons:
i. NPY (neuropeptide Y) neurons project both to PVN and LHA to INC EATING
ii. MELANOCORTIN neurons project both to PVN and LHA to DEC EATING

29

LHA lesion

APHAGIA cessation of eating
1. aphagia due to damage to MEDIAL FOREBRAIN BUNDLE = MESOLIMBIC SYSTEM dopeminergic system

reduced MOTIVATION to eat
reduced MOTOR FUNCTION to eat

2. aphagia due to loss of neurons that synthesis "orexigenic" peptide = OREXIN

30

actions of leptin on ARC

i. leptin acts in ARC to inhibit NPY: DEC FOOD INTAKE

ii. leptin acts in ARC to activate melanocortin neurons: DEC FOOD INTAKE

31

actions of ghelin on ARC

ghrelin acts in ARC to activate NPY neurons: INC FOOD INTAKE

32

what type of drug could be promising candidates for treating hyperphagia-induced obesity?

activate melanocrtin receptors

33

___% treated for mood disorders

over 50%

34

limbic system related structures

amygdala
hippocampus
septal nuclei
nucleus accumbens
medial prefrontal cortex and anterior cingulate cortex
ventral segmental area
anterior and dorsomedial nuclei of thalamus
mamillary nuclei

35

limbic system pathways:

FORNIX: hippocampus > mammillary body and septal nuclei
MAMMILLO-THALAMIC TRACT: mammillary body > anterior n of thalamus
anterior n of thalamus > cingulate gyrus and prefrontal cortex
STRIA TERMINAULIS: amygdala > septal nucleus
MEDIAL FOREBRAIN BUNDLE: midbrain via hypothalamus > forebrain

36

all limbic areas receive rich innervation by _____ and _____ axons

monoaminergic and cholinergic axons
a. NE from locus ceruleus (LC) in pons
b. 5HT from raphe nuclei (Ra) midbrain, pons
c. DA from mesolimbic system***
d. ACh from nucleus baseless and septal nucleus

= general arousal, sleep wake cycles

37

ventral segmental area (VTA) projects to:
(DA neurons)

nucleus accumbens
medial prefrontal cortex
amygdala
septal nuclei

38

mesolimbic system (DA)

i. self-stimulation studies: VTA > REWARDING
ii. drug addiction
COCAINE block DA repute: inc DA in synapse

39

lesion VTA, NAcc

decreased drug seeking behavior
DA receptors permanently blocked
***has effects on our natural reward system (endorphins, natural opioids, nicotine, opioids)

40

natural rewards

SEX
FOOD

41

ACh neurons lost in AD in

nucleus basalis**
spetal nucleus

42

limbic system functions
AMYGDALA and lesion

amygdala fxns
a. role in fear conditioning/type of learning
Pavlovian classical conditioning

lesions to amygdala: prevent fear conditioning

43

limbic system functions
PREFRONTAL CORTEX and syndrome

prefrontal cortex
"The Case of Phineas Gage" rod through prefrontal while RR working

Prefrontal Lobe Syndrome:
GAAII
a. impaired GOAL directed behavior, no job
b. lack of emotion in decision-making APATHY
c. poor social judgment ANTISOCIAL behavior
d. poor emotional control INCREASED IMPULSIVITY

etiology:
dorsolateral PFC: working memory and executive function
orbital frontal cortex: projections to amygdala

44

limbic system functions
HIPPOCAMPUS and injury

patient H.M. fell off bike > seizures
*bilateral medial temporal lobectomy = removed hippocampus bilaterally
>>>
a. anterograde amnesia (no new memories)
b. temporally graded retrograde amnesia (lost old memories, post surgery, can remember prior to surgery)
c. explicity or declarative memory lost (semantic/facts and episodic/experiences)
d. IMPLICIT MEMORY MOTOR SKILLS NOT LOST

45

limbic system dysfunction
Urbach-Wiethe disease

AMYGDALA dysfunction

a. impaired recognition of emotion in facial expressions, INABILITY TO JUDGE "LIKE" EMOTIONS (fear vs anger, surprise vs. joy)
b. MEMORY LOSS especially w/ EMOTIONAL CONTENT

46

limbic system dysfunction
PTSD

AMYGDALA dysfunction
triad of symptoms:
1. re-experiencing phenomena/flashbacks
2. avoidance of situations that parallel initial trauma
3. hyperarousal: hypervigilance and increased anxiety

etiology:
increased amygdala activity in fMRI
increased medial prefrontal cortex activity which usually inhbitis amygdala

47

Korsakoff's syndrome triad

1. DISORDER of immediate memory > no new memories
2. DISORIENTATION > to space and time
3. CONFABULATION > fabrication

etiology:
chronic alcoholism and thiamine B1 deficiency
MAMMILLARY BODY DEGENERATION

48

Kluver-Bucy Syndrome

1. oral tendencies: all objects in mouth (Gary Busey has a big mouth)
2. changes in emotions ("k" is the most apathetic response)
3. hypersexuality ("luver")
4. visual agnosia: physchic blindness (Gary Busey has asymmetric eyes)

49

Alzheimer's Dementia AD

etiology:
-loss of CHOLINERGIC input (in nucleus basalis) to HIPPOCAMPUS
-presence of NFTs (intracellular, phosphorylated tau proteins) and beta-amyloid plaques (extracellular)

Sx:
1. loss of memory
2. mood disorders: anx and dep
3. loss of motor fxn: slow
4. complete loss of cognitive fxn

50

___% over 85yo have AD

over 50% over 85yo have AD

51

according to engeland, treat AD with

donepezil (Aricept)
AChE

52

Schizophrenia
Sx and incidence

fragmentation of mood, thought, and movement
Sx:
positive: delusions and hallucinations
negative: social withdrawal

1% US population diagnosed

53

Schizophrenia
neurochemical basis hypotheses

1. "dopamine hypothesis" increase in DA rec activity
> amphetamine psychosis
Tx:
antipsychotic: HALOPERIDOL
block DA receptors (SE: parkinsonian)
atypical anti-psychotic: CLOZAPINE
block DA receptors
block 5HT receptors
block glutamate repute: increase glutamate in synapse

2. "glutamate hypothesis"
PHENCYCLIDINE (PCP) "angel dust"
blocks NMDA glutamate receptor
Tx:
increase glutamate receptor activity

54

Depression
Sx and incidence

Sx:
lethargy, anhedonia, loss of sleep

15% US population
20% F, 13% M treated

55

Depression
neurochemical basis hypothesis

"monoamine hypothesis"
decreased NE and/or decreased 5HT receptor activity

Tx: increase NE and DA
1. MAOIs
2. TCAs: block repute of NE and/or 5HT
3. SSRIs: block repute of 5HT

56

Chronic Traumatic Encephalopathy (CTE)

progressive neurodegenerative disease cause by repeated head trauma

TRIAD Sx:
1. cognition: ANTEROGRADE AMNESIA and LOSS EXECUTIVE FXN (prefrontal cortex and hippocampus)
2. mood: DEP and APATHY
3. behavior: DEC IMPULSE CONTROL and INC AGRESSIVENESS

~age 30-50 yo
risk factors: HEAD TRAUMA

etiology: generalized BRAIN ATROPHY including prefrontal cortex, temporal lobes (amygdala, hippocampus), and parietal lobes
NFTs PRESENT

57

MCA stroke

weakness and snsory deficits to CONTRLATERAL side
lateral side frontal, parental and temporal
FACE and ARMS
HOMONYMOUS HEMIANOPSIA
"looking at their lesion"
dominant hem: aphasia > problems speaking
nondom hem: contralateral hemineglect

58

ACA stroke

weakness and sensory contralat SAME
anterior and medial frontal and parietal and temporal
LEGS
PERSONALITY CHANGES

59

Lenticulostriate stroke

branch of MCA to DEEP STRUX OF BRAIN
hallmark: LACK CORTICAL SIGNS
pure motor: POSTERIOR LIMB OF IC (hemiparesis of legs, arms, face)
pure sensory: LATERAL THALAMUS (numbness of legs, arms, face CONTRALAT)

60

Vertebral Artery stroke

supplies inferior cerebellum and lateral medulla
VERTIGO, BLURRED VISION, VOMITING, NYSTAGMUS, ATAXIA
WALLENBERG syndrome: numbness on one side of face and opposite side of body*****

61

Basilar artery stroke

supplies rostral brainstem and occipital lboes
CN PALSIES, GAZE ISSUES, HEMIANOPSIA, MIOSIS
may cause LOSS OF CONSCIOUSNESS

62

Posterior cerebral artery stroke (PICA)

supplies occipital lobes
HOMONYMOUS HEMIANOPSIA (of contralateral)
MACULAR SPARING
ACROMATOPSIA difficulty naming colors
nondom hem: neglect of affected vision field

63

intracerebral hemorrhage

HTN
decreased vascular elasticity

64

subarachnoid hemorrhage

rupture of intracranial aneurysms or trauma
thunderclap sudden HA, "worst headache ever"
N/V, nuchal rigidity, photophobia, change in consciousness

65

ischemia stroke

atherosclerosis via thrombosis of cerebral vessels OR embolism
> inadequate oxygen delivery to brain > neuronal death as soon as 4 min
sudden onset focal neurologic deficits, no HA

66

stroke imaging

non-contrast CT
for intracranial bleeding, including SAH, intracerebral bleeding or hematoma

MRI: ischemic stroke and focal cerebral ischemia

67

when is cerebral angiography indicated?

to evaluate patients with ischemic strokes in vertebrobasilar distribution and subarachnoid/intraparencymal hemorrhage

68

modifiable risk factors for stroke

HTN
DM
lipids
sympathomimetic abuse
smoking
EtOH
obesity
Afib

69

non modifiable risk factors for stroke

age***most imp
race
ethnicity
heredity
Hispanic Americans, American Indians, Alaska Natives > white Americans
African Americans 2X than white Americans**

70

tPA for stroke
MOA

enchances conversion of plasminogen to plamin by binding to fibrin > INITIATES FIBRINOLYSIS
*helps restore potency to thromboses vessels

considered for patients with ISCHEMIC stroke who can be treated WITHIN 3-4.5 HOURS OF SX ONSET

71

tPA contraindecations

HBP
INTRACRANIAL HEMORRHAGE
SAH
rapidly resolving symptoms
MI, stroke, head injury in past 3 mo
GIB past 3 weeks
active bleeding
anticoagulation therapy

72

hypothermia is resisted by

heat conservation: VASOCONSTRICTION
heat production: SHIVERING

73

hypothalamus received input from ____ and ____ temperature receptors

skin (local) and spinal cord (central)
***2 sensory receptors

74

local skin sensors cause release of ______

core SC temperature sensory send signals to CNS to activate _____

NO = VASODILATOR

SYMPATHETIC NERVE OUTFLOW (adrengergic and cholinergic)

75

cold skin sensors release _____

NE = VASOCONSTRICTOR

76

fever involves a pyrogen which stimulates the hypothalamus to produce _____

PGE2 = causes shivering

77

hypothalamic temperature is special because

does not change in temperature (receives sensors from elsewhere)

78

sympathetic receptors related to blood pressure regulation

NE interacts with:
Beta-1: stimulate HR, increase stroke volume
Alpha-1: increase total peripheral resistance

=increase BP

79

blood pressure regulation pathway

stretch receptors on carotid arteries and aortic arch > sense stretch/BP > as BP increases, firing rate incrases > glossopharyngeal IX and vagus X nere to medulla > solitary nucleus > rostral ventrolateral medulla suppressed

baroreceptors inhibit: sympathetic PREganglionic neurons which usually increase BP

80

baroreceptors

attenuate (decrease) high BP

81

if blood pressure drops >

less activation of IX and X > less stimulation of NTs > LESS INHIBITION of rostral ventrolateral medulla > GREATER STIMULATION of PREganglionic sympathetics in thoracic cord > INC HR, SV, RESISTANCE using a1 and b1 receptors

82

orthostatic hypotension

LBP when stand up from sitting or laying down
young people, most common cause: dehydration, not enough fluids

83

inspiration requires

a PUMP (diaphragm and external intercostals)
a PACEMAKER to initiate breathing (Pre-Boetzinger area of ventrolateral medulla)

84

stimulate _____ to innervate diaphragm

phrenic nerve (C3-5)
ACh and nicotinic receptor

85

inputs to Pre-Boetzinger area

parafacial respiratory center SENSES CO2 (ACTUALLY H+) and DIRECTLY EXCITES ABDOMINALS

86

BTW, how do you get H+ from CO2?

CA carbonic anhydrase

87

Ondyne's curse

lack of CO2 sensors >>> HYPOVENTILATION
FATAL

88

sympathetics control _______ of _______
parasympathetics affect ______ of _______

rate of breathing
dilation of bronchioles

89

urination is controlled by both

voluntary and involuntary mechanisms
1. external sphincter VOLUNTARY
ACh and NICOTINIC

2. internal sphincter INVOLUNTARY
ACh and MUSCARINIC
PARAsympathetic

90

bladder full > sends AFF signals to

medial prefrontal cortex (usually suppresses voiding)
detected by STRETCH MECHANORECEPTORS

91

Pontine micturition center activates

the sacral cord to stimulate PREganglionic PARAsympathetic nerves >
relaxation of external voluntary sphincter
contraction of urinary bladder

92

urination involves dis-inhibitor of the micturition center when bladder is full, controlled by activation of which nerve

pudendal nerve > relax external sphincter

93

incontinence Tx

ANTIMUSCARINICS
M3 antagonists

94

HYPOkinetic disorders

DIRECT pathway INHIBITED
INDIRECT pathway ACTIVE
= decreased motor activity

PARKINSON DISEASE = LOSS OF DOPAMINERGIC NEURONS

95

HYPERkineteic disorders

DIRECT pathway ACTIVE
INDIRECT pathway INHIBITED
= incrased motor activity

HUNTINGTON DISEASE = expanded CAG repeats

96

parkinson disease Tx

RESTORE dopaminergic activity (not slow progression of disease)

LEVODOPA (prodrug) plus CARBIDOPA (inh AAAD) = sinemet

97

adverse effects of L-DOPA

"peak dose" dyskinesia
high plasma level, activating DIRECT too much

diphasic sykinesia
at onset and offset of loop effect

"off" period dystonia
when levels all off: no relief
think morning/eve when dose is off

"wearing off" phenomenon
driven by progressive loss of DA neurons

PRIMARY SIDE EFFECTS BECAUSE DA RECEPTORS IN ALL OF BODY

98

L-DOPA primary adverse effects

-confusion, anxiety, agitation, insomnia, nightmares, depression
-psychotic reactions: schizophrenia-like delusions and hallucinations (because increased DA in limbic system) REVERSIBLE
-orthostatic hypotension
-nausea, vomiting, anorexia

99

COMT inhibitors

ENTACAPONE

decrease peripheral metabolism of L-DOPA
(like AAAD, but not into DA, will be excreted instead)

smoother response
longer on time

100

MAOI

SELEGINE

MAO-a: metabolizes NE and 5HT
MAO-b: priary metabolism of dopamine: USEFUL PD TX

can be mono therapy in early stages

smoothes out dosing

101

Dopaine receptor agonists

PRAMIPEXOLE D3 agonist

ROPINIROLE D2 agonist

direct action on D2 receptors in stiatum
becoming more first line
less SE

102

muscarinic antagonists

Ach is NT for a small amount of striatal interneurons

TRIHEXYPHENIDYL

103

Amantadine

antiviral

104

PD Tx tissue transplantation?

human fetal adrenal medullary tissue into caudate nucleus

105

PD surgery

pallidotomy: allieviates akinesia