Thermoregulation and Fever 9/12/05
Terms
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copy deck
- ___ feedback is when any deviation from set point is returned back to set pt. Stable
- Negative
- ____ feedback any deviation from set pt drives further from set pt. no true set pt. UNSTABLE
- positive
- ___ systems no input needed about controlled variable for initiation. Pre-emptive strike. Anticipation prevents occurence
- Feed forward system
- Rapid upsweep AP(inactivation gate), labor delivery, ovulation, blood clotting-(thrombosis if no control) are types of________
- positive feedback
-
What is the sensor?
controller?
Effector?
Controlled variable? -
Thermoreceptors
hypothalamus
heat prod/heat loss
core temp - Majority of control systems in body are _______
- negative feedback
- THe _______potential is graded, depol of AFFERENT SENSORY neuron
- Generator
- _____ is needed to make an action potential
- voltage gated sodium channels
- Thermoreceptors are found in what three places in body and how do they work?
- skin, gut, brain (pre opticof hypothalamus) change firing rate
- ____ use C fibers (small unmyel) are TRP-V1-4,vanilloid, Capsaicin hotpeppers. 30-45 C
- Warm sensitive
- _____ is the only warm receptor that is voltage gated
- TRPV1 Temp increase->threshold moves closer to Vm (Vm no change)
- _____ receptors use menthol,TRVPM8, Potassium leak closing or sodium opening 10-38 C
- Cold sensitive
-
Anterior hypothalamus:
Posterior hypothalamus: -
responses to heat
responses to cooling
hypo: has strong ties to ANS -
Oral is ___than rectal
Skin is 2 degrees ____ than core
Core temp is lowest at____ -
less than
cooler
6:00 A.M. - Each thermoregulatory behavior (sweating,shivering) has a specific ______ and wont be activated until its reached
- set point
-
Cutaneous:
Viscera:
Hypothalamus:(thermostat)
pre-optic and superoptic -
environment
core and environment
core - ____ is activated when cold
-
sympathetic
thyroxin releases (inc metab)
epi/norep rele. increases hydolysis ATP ANS adrenal m
shivering
increases food intake/behavior
hyp rel TRH to pit rel TSH to thyroid rel thyroxine to every cell - _____ activated when hot
-
parasympathetic
insensible water loss (not controlled (respir)
sweating (sympath cholinergic bc T and L SSL Ach = increase vasodilation to duct - ___adipose only in infants hydrolysis ATP (uncouples)
- brown
-
If cutan change but core same _____ system. to increase heat loss _______
decrease heat loss_______ -
feed forward
vasodilation
vasoconstriction - Catecholamines,epi/nor/aldosterone decrease sodium part of heat acclimation can lead to _______
- sweat inducing
-
Primary secretion : sodium, Cl back to blood, cause reabsor of water very concentrated
Increase ROS:________
Low ROS_______ -
similar to plasma but no protein, high in water, sodium
lots water litle sodium
little water, lots sodium -
Purpose goosebumps-
increase heat prod -
prevent conduction
increase hunger
TSH
catecholamines from adrenals
nonshivering thermogenesis -
Fever- must be driven by______
made by cytokines cant cross _____
exert effects on____, this produces ____ acts on_____ cause setpt change at _____ receptor. make ____, during___, Resolution -
hypothalamus
BBB
OVLT
Prostaglandin E2
hypothalamic neurons
EP3
Tb<Tset
Tb=Tset
Tb>Tset -
____ body temps less than 85F
low rate chemical rxns, can be used clinically to reduce metab and O2 demand for heart or neurosurgery - Hypothermia