Week 7 Part 2 Flashcards
(98 cards)
1
Q
Micturition center location
A
- pontine reticular formation
- lesser components in midbrain and medulla
2
Q
input to micturition center
A
- spinal cord
- cerebellum
- hypothalamus
- cerebral cortex
3
Q
input to micturition center from spinal cord
A
bladder distention
4
Q
input to micturition center from cerbellum
A
inhibitory
5
Q
input to micturition center from hypothalamus
A
control during sleeping
6
Q
input to micturition center from cerebral cortex
A
learned control of micturition (ie housebreaking)
7
Q
Neurons of micturition center
A
- contains UMNs that control symp and parasympathetic preganglionic neurons and somatic LMNs in spinal cord responsible for bladder filling and emptying
8
Q
micturition center fx
A
coordinates sympathetic, parasympathetic, and somatic components of micturition
9
Q
nerves involved in micturition
A
- pelvic nerves
- hypogastric nerve
- pudendal nerve
10
Q
pelvic nerves micturition
A
- VA info from bladder pressure receptors -> sacral spinal cord segments (info used locally for reflex components of voiding, also ascends spinal cord to brainstem micturition center, cerebral cortex and cerebellum)
- VEs (parasymp) -> detrusor muscle via pelvic plexsus (stimulation -> detrusor contraction)
11
Q
pelvic nerve arises from sacral spinal cord segments
A
S1-S3
12
Q
hypogastric nerves arise from what spinal cord segements
A
L1-L4
13
Q
hypogastric nerve carries
A
- VE (symp) -> detrusor muscle (stimulation -> detrusor muscle relaxation)
VE (symp) -> “internal uretheral sphincter” (proximal urethera) (stimulation -> contraction of internal uretheral sphincter)
14
Q
detrusor muscle
A
parasympathetic stimulation
-> detrusor contractoin
sympathetic stimulation -> detrusor relaxation
15
Q
pudendal nerve arises from
A
sacral spinal cord segments
16
Q
pudendal nerve innrevation
A
- SE information to striated external uretheral sphincter (in pelvic urethera)
- stimulation -> contraction of external sphincter
17
Q
bladder filling phase general
A
micturition center and local spinal reflexes ensure:
- detrusor relaxed
- internal and external uretheral sphincters are contracting
18
Q
bladder filling phase neurons
A
- parasympathetic VE neurons in segments S1-S3 inhibited -> prevent detrusor contraction
- sympathetic VE neurons(L1-L4 -> hypogastric nerves)= active, maintaining contraction of smooth muscle in proximal urethera (“internal urethreal sphincter”) and facilitate bladder filling bc further relax detrusor muscle
- SE LMNs in segments S1-S3 traveling in pudendal nerve= active -> contracting the external uretheral sphincter
- as bladder fills: info pertaining to bladder distention relayed to spinal cord via pelvic nerve and to brainstem via ascending spinal cord pathways
19
Q
bladder emptying basics
A
- occurs when bladder reaches a threshold level of distention
- process is initiated and controlled by descending pathways originating in brainstem micturition center
20
Q
bladder emptying nerves
A
- sacral VEs to detrusor via pelvic nerve facilitated -> detrusor contraction
- lumbar VEs control “int uretheral sphincter” via hypogastric nerve, inhibited
- > relaxation of internal uretheral sphinceter
- sacral SEs via pudendal nerve inhibited -> relaxation of external uretheral sphincter
21
Q
internal uretheral sphinceter
A
- innervated by hypogastric nerve
- inhibition hypogastricn nerve -> relaxed internal uretheral sphincter
- stimulation hypogastric nerve -> contraction of internal uretheral sphincter
22
Q
external urether sphincter
A
- innervated by pudendal nerve
- pudendal nerve inhibited -> relaxation external uretheral sphincter
- pudendal nerve activated
- > contraction of external uretheral sphincter
23
Q
micurition in absence of input from brain
A
- spinal cord segments can adapt fx to some degree in absence of brain input, but ability of bladder to fill to capacity w/o leaking and completely empty is dependent on micturition center in cd brainstem
24
Q
micturition center coordinaes
A
sympathetic, parasympathetic, and somatic components of voiding and imitates voiding when distention is adequate; this is involuntary and doesn’t require conscious or cerebral cortical input
25
cerebral cortical input to micturition center and spinal cord
ensures micturition occurs under proper circumstances; cerebral cortex can block micturition even if its been initiated by brainstem micturition center
26
cerebral cortex control micturition center
- UMNs from cerebral cortex control voluntary contraciton of external urethral sphinceter
27
damage to sacral spinal cord segments or sacral spinal roots in caudal equine and bladder
- cause LMN bladder dysfunction -> no voluntary control micturition
- detrusor muscle and ext urether sphincter flaccid bc lack LMN input
- bladder large and difficult to palpate bc soft
- dribble urine bc overflow, easy to express, complete bladder emptying never accomplished
- some patients maintain variable amount outflow resistance bc tone in int uretheral sphincter
- retention and stasis of urine -> bladder infections
28
spina cord contirbtiion to knowing when to urinate
- spinal cord knows how full bladder is
| - if just have this wait till bladder full then just go
29
lesions of cd brainstem or spinal cord segments C1-L7 can ->
- UMN bladder dysfunction
- no voluntary control of micturition
- LMNs to external uretheral sphincter cannot be inhibited by descending pathways so there is higher outflow resistance
- manual expression difficult
- bladder feels turgid bc increased tone in detrusor and fullness
- w/ time sacral reflexes may develop ability fo fx to some degree w/o input from brainstem (this will not be voluntarily controlled process)
30
lesions that produce UMN bladder dysfunction
MUST be severe lesions because desecending pathways that control micturition are bilateral (so unlikely to see UMN bladder in patent with paresis patient would be paralyzed, also unlikely to see in patient with pain response when pets stimulated)
31
cerebral disease and micturition
can result in normal ability to urinate but loss of learned behavior (house breaking)
32
T3-L3 lesion micturtion
- normally leads to retention of urine if lesion affects micturition center; animal with reduced nociception wills till have some intact spinal cord so should still have micturition fx
- must have severe lesion to -> UMN bladder dysfunction where can't void urine
- urine soaked legs can be a sign of inability to stand
33
functions mediated by hypothalamus
- Regulation of body temperature
- Regulation of metabolism and energy balance (hunger)
- Regulation of blood pressure and osmolarity (thirst, salt appetite, kidneys, vascular tone, cardiac output)
- Reproductive behaviors (circum annual rhythms)
- Sleep wake cycle
- Coordination of autonomic and somatomotor responses to threatening stimuli (fight or flight)
34
regulation of body temp afferents hypothalamus
- neurons in rostral hypothalamus and preoptic area fx as thermorecptors
- thermocreceptors in skin and viscera -> nucleus of the solitary tract and spinoreticular pathways -> hypothalamus
35
regulation of body temp if temp too high efferents hypothalamus
heat loss center in hypothalamus -> projections to medullary cardiovascular center -> control peripheral vasodilation
heat loss center in hypothalamus -> projections to brainstem respiratory center -> panting
heat loss center in hypothalamus -> projections to sympathetic preganglionics in spinal cord -> sweating
heat loss center in hypothalamus -> projections to forebrain -> shade seeking behavior
36
regulation of body temp if too low efferents hypothalamus
heat conservation center in hypothalamus -> projections to brainstem UMNs that control skeletal muscle -> shivering
heat conservation center in hypothalamus -> descending pathways to sympathetic preganglionic neurons in spinal cord -> piloerrection
heat conservation centers in hypothalamus -> sympathetic and thyroid hormone induced chemical thermogenesis -> increased metabolic rate
heat conservation centers in hypothalamus -> peripheral vasoconstriction
37
hypothalamic set point for temperature
can be altered during infectious, inflammatory, and physiologic processes (can be circumventricular organ -> hypothalamus to signal this); hypothalamus has mechanisms to limit magnitude of response
38
regulation of metabolism, energy balance, body tissue composition by hypothalamus
sensations of hunger, sanity, food seeking behaviors (exploring environment, sniffing, predatory behaviors), digestion (GIT secretion, peristalsis, dedication), tissue development and control of energy utilization at cellular level all controlled by hypothalamus
39
regulation of metabolism, energy balance, body tissue composition afferents hypothalamus
- hormonal feedback to brain from gut and tissues requiring glucose
- sensory receptors of gut
- amygdala (intimates fight of flight)
- other regions hypothalamus that process metabolism dependent fxs like repro and circadian rhythms
40
regulation of metabolism, energy balance, body tissue composition efferents hypothalamus
- hypothalamus -> control of brainstem somatic neurocircuits and motivational systems-> food seeking behavior
- hypothalamus -> autonomic control -> digestion
- hypothalamus -> endocrine mechanisms involving growth hormone and thyroid hormone -> cellular metabolism and proliferation
41
maintaining pregnancy and lactation hypothalamus
must tie regulation of energy balance and reproductive functions together to facilitate this
42
Regulation of fluid balance, osmolarity, and blood pressure afferents hypothalamus
- vascular baroreceptors
- osmoreceptors w/ in hypothalamus
- circulating hormones (released by organs including kidney and heart b/c change in blood pressure or blood or urine composition)
43
regulation of fluid balance efferents hypothalamus
- hypothalamus -> projections to cardiovascular regulatory centers in brainstem -> influence blood pressure and osmolar composition
- hypothalamus -> stimulating salt and water appetite
- hypothalamus -> investigating drinking behavior and releasing hormones-> influence vascular tone and/ or how plasma is modified by kidneys and gut
44
reproductive behaviors hypothalamus afferents
- inspired phernomes -> vomeronasal system -> hypothalamus -> reprobehaviors or estrus
- seasonal cycle -> melatonin release by pineal gland -> reproductive fx
45
reproductive behaviors hypothalamus efferents
- hypothalamus -> adenohypophysis -> release luteinizing hormone -> sex steroid production
- hypothalamus -> neurohypophysis -> oxytocin release -> milk letdown and promotion of birthing process
- hypothalamus -> autonomic fx related to mating and maintenance of pregnancy
- hypothalamus -> somatomotor maternal and mating behaviors
46
circadian rhythms/ sleep hypothalamus
- ambient light - retina -> suprachiasmatic nucleus -> hypothalamus-> histaminergic neurons -> diffuse projections throughout brain making up pt of ARAS
** Control of sleep/ wake cycle= intimately tied ot other hypothalamic fxs including thermoregulation, energy metabolism, and endocrine regulation
47
coordination of autonomic and somatomotor responses to threatening stimuli (ie fight or flight)
higher forebrain structures (amygdala and prefrontal cortex) -> hypothalamus -> periaquaductal grey and brainstem -> autonomic and behavioral responses to stimuli
48
sham rage
remove thalamus and cerebral hemispheres and mild stimuli will lead to coordinated defensive and offsenistive aggressive behaviors and accompanying autonomic response if you remove hypothalamus the coordinated response was not observed therefore hypothalamus was coordinating/ imitating emotional response; lesions to specific areas of hypothalamus can abolish these responses
49
pituitary abbess in cattle compressing hypothalamus causes
abnormal body temperature regulation, bradycardia, and depression
50
compression fo supraoptic nucleus in hypothalamus by tumor of pituitary gland ->
diabetes insipidus
51
Damage to supraoptic nucleus or infundibulum can result in
failure to produce or release ADH when decreased blood volume -> not concentrating urine -> PU/PD
52
neoplasms of adenohypohysis ->
over secretion of ACTH -> adrenal glands producing cortisol-> hyperadrenocorticisum -> PU/PD/PP (polyphasic) and dermatological abnormalities and muscle atrophy
53
lesions of hypothalamus can affect
- appetite -> ravenous appetite or loss of apetite
| - varrying degrees of depression or decreased consciousness due to interference with ARAS
54
Limic system
- hippocampus
- fornix
- mammillary nuclei
- cingulate gyrus
- prefrontal cortex
- piriform lobe
- septal nuclei
- amygdala
- other basal nuclei
- PAG
55
limbic structures are concerned with
behavior relevance of stimuli in contexts of external circumstances, memory, emotions, motivation, and threat to survival
56
our conscious experience of emotions depends on
neural activity in limbic structures
57
how does limbic system work (BROAD overview)
- based on its interpretation of a situation limbic system triggers coordinated autonomic, endocrine, and somatic response patterns designed to cope with situation
- control limbic system exerts upon behavior mediated via connections to hypothalamus, PAG, and cortical association areas
58
limbic structures are
richly innervated with axons that utilize monoamines as neurotransmitters (norepinephrine, dopamine, serotonin, histamine)
59
hippocampal formation location/ shape
- makes up much of archicortex
- c shaped
- curves around dorsal, cd, and ventral aspects of diencephalon
- v aspect of C deep to piriform lobe w/ amygdala at ventral and rostral tip of C
60
lateral ventricals and hippocampal formation
- surround lateral aspect of hippocampal formation
61
axons traveling between hippocampal formation and septal nuclei and mammillary nuclei travel in
fornix
62
hippocampal formation fx
- receives info from many cortical areas (via cingulate gyrus and regions of piriform lobe) and limbic structures (via fornix) and can influence cortex hypothalamus, and other limbic structures; INVOLVED IN MEMORY FORMATION AND SPATIAL MAPS OF ONE'S SURROUNDINGS
63
cingulate gyrus location
dorsal to corpus callosum
64
cingulate gyrus receives input from ___ and projects to ____
- receives diverse cortical input
| - projects to entorhinal cortex (piriform lobe) which feeds into hippocampal formation
65
cingulate gyrus plays role in
emotions, memory, and learning
66
prefrontal cortex location
- located in frontal lobe
67
prefrontal cortex involved in
- working memory
- decision making
- planning complex behavior (ie social interactions)
- expression of personality
68
septal nuclei location
- pt of basal nuclei group
- located in ventral septum pellucid rostral to anterior commissure; protrude laterally not md aspect of rostral horns of lat ventricles
69
septal nuclei interconnected with
- hippocampal formation and hypothalamus
70
appearance of hippocampal formation in transverse sections vs gross shape of hippocampal formation
- lateral ventricle is lateral to hippocampus in transverse sections and appears cd to it on gross structure
71
amygdala input
- minimally processed sensory info from thalamus
- highly processed sensory input from cortical areas
- limbic (recpirical interconnections with other basal nuclei, cortical areas, hippocampal formation, hypothalamus, and brainstem (including PAG, autonomic nuclei, and neuromodulatory neurons)
- neuromodulatory pathways (cholinergicc and monoamine pathways)
72
amygdala output
- cerebral cortex
- hypothalamus
- PAG
73
amygdala fx
- assesses emotional relevance of stimuli and generates appropriate autonomic, behavioral, and cognitive responses (basic stereotypical somatomotor response)
- emotional memory
74
location/ what is amagydala
- complex of nuclei; pt of basal nuclei
| - located rostral to ventral tip of hippocampal formation deep to piriform lobe
75
amygdala fast vs slow rxn
- minimally processed sensory input from thalamus allows it to make quick response to potentially or innately relevant visual, auditory, olfactory, or somatosensory stimuli while slower input form cortical areas can reinforce of cancel the response based on cortical interpretation of the threat
- also receives neuromodulatory input form cholinergic and monoamine pathway
76
amygdala autonomic and behavior responses
- involved in innate and learned fear response and in IDing stimuli that meet criteria for triggering autonomic and behavioral aspects of fight or flight
- stimulates autonomic and behavioral responses via projects to hypothalamus, PAG, neuromodulatory pathway
77
amygdala involved in
- fight or flight
- training
- physical manifestation of fear
- subconscious processing of stimuli
78
lesion in amygdala vs hippocampal formation w/ fear
- lesions affecting amygdala take away fear-associated behavioral and autonomic response; subject can recall details of stimuli but don't feel physical manifestations of emotions
- lesions affecting hippocamal formation leave autonomic and basic somatomotor responses in tact but abolish explicit memory of event
79
periaqueducatl grey location
- midbrain surrounding mesencephalic aquaduct
80
periaqueducatl grey input
- spinal nociceptors
- visceral afferents
- hypothalamus
- limbic forebrain structures (amygdala and prefrontal cortex)
81
periaqueductal grey projects to
- hypothalamus
- brainstem reticulospinal UMNs
- Locus coeruleus
- raphe nuclei
- LMNs
- sympathetic neurons
82
periaqueductal grey participates in
limbic network that generates coordinated autonomic and somatic responses to stimuli by
1. triggering basic somatomotor behavior patterns appropriate to current situation
2. triggering autonomic responses that support somatic response (symp or parasymp)
3. regulating flow of info in nociceptive pathway
83
basic somatomotor behavior patterns triggered by PAG
- engagement behaviors such as locomotion, vocalization, and attack
- disengagement heabviors such as freezing and becoming passive, imobile, and non reactive
- reproductive and micturition related posturing
- modifying respiratory patterns to match need of animal
84
psychological experience of fear/ emotions
- depends on activity in forebrain limbic structures especially cerebral cortical areas including
- cingulate gyrus
- prefrontal cortex
- these forebrain limbic structures can heighten, fine tune, or dampen activity in the subcortical circuits after evaluation of stimuli and considering context of situation and accessing learned behavior patterns encoded in forebrain structures
85
autonomic and behavioral reactions associated with psychological experiences of emotions
ARE NOT ACTUALLY FEELING THE EMOTION
- mediated by hypothalamus and PAG
- these are subcortical circuits which allow for quick stereotyped rxn to potentially threatening stimuli based on minimally processed sensory info
86
amygdala and psychological experience of fear
- amygdala most concerned with established positive and negative associations with stimuli that do not have innate relevance and with subconscious processing of innately relevant stimuli allowing for faster rxns to stimuli that cortical processing can allow
87
limbic structures relationships to each other
extensive interconnections as well as interconnection with areas of association and hypothalamus
88
limbic structures play a role in
- experience of emotins
- coordination of basic behavioral patterns
- learning and memory
- decision making and planning
- personality and social behavior
89
limbic structures receive information from
- highly processed :cortical areas
| - about more basic drives: hypothalamus
90
limbic structures can project to
- cortical areas to influence cognitive processing
| - hypothalamus and brainstem to control autonomic, endocrine, and somatic output from CNS
91
relationship between limbic system and hypothalamus
- means that psychological state of animal can influence many aspects of physiology and somatic behavior
- real or perceived threats and psychological stress and anxiety can -> sympathetic activation, endocrine alterations, and somatic behaviors that prep animal to cope with adversity but these can deleterious to animal over extended period of time
92
forebrain structures associated with limbic system controls
- behaviors including temperament, normal routine, mood, and motivational drives
93
forebrain structures associated with limbic system can produce
changes in characteristics but behavioral changes are not specific clinical findings bc can be caused by many things so have to be seen with other localizing signs to indicate forebrain
94
behavioral pharmacotherapy targets
neurocircuitry of limbic system bc they contain many receptors for monoamine neurotransmitter involved in behavior, social interaction, anxiety, and mood
95
damage to certain limbic structures can produce
-psychomotor seizures characterized by hallucinations, detachment from ones surroundings, visceral motor activity (urinating, drooling), bizarre somatic activity (running around wildly, expressions of emotions like barking, growling, piloerrection)
96
toxoplasma gondii
manipulates limbic system of rodents by altering domapinie neurotransmission and inducing rewiring of circuits in amygdala -> mice loosing innate fear of cat urine
97
psychosomatic interrelations limbic system
- psychological experience associated with stressors like chronic pain, anxiety, or fear likely b/c limbic structure activity
- connections form limbic structures to hypothalamus and brainstem autonomic centers can trigger increased symp and somatomotor output as result of this stress
- chronic activation of symp nervous system can be detrimental to health
98
physiological alterations that can occur due to chronic stress
- hypertension
- hyperventilation
- gastric ulcers
- ileus
