3. Body Communication and Homeostasis Flashcards
_ is the study of processes and functions in living organisms
Physiology
What is the maintenance of steady states in the body by coordinated physiological mechanisms?
Homeostasis
T/F Equilibrium and steady state are the same thing?
False
_ is the a condition in which opposing forces in adjacent compartments are balanced
Equilibrium
_ is a condition that doesn’t normally change with time and can apply to 1 or many compartments
Steady state
ATP may be required to maintain _
steady states
T/F a steady state indicates an equilibrium condition
False
What are the 4 regulatory mechanisms?
End-product inhibition
Negative feedback control
Feed forward control
Positive feedback
End-product inhibition involves _ reactions
enzymatic reactions
When there is too much G6P in muscle and adipose tissue, it blocks Hexokinase by _
end-product inhibition
_ involves non-enzymatic processes
Negative feedback
Insulin/glucagon, body temperature, and BP are types of _ control
Negative feedback
Open loop in which the regulated variable is not sensed by a sensor (acts on the effector)
Feed forward control
Type of feedback where a variable is changed and sensed, and action is taken to reinforce the change in the variable is _
positive feedback
Ferguson reflex is a type of _ feedback
positive
T/F Positive feedback systems are very common
False (they are rare, because hard to control and stop)
Gap junctions allows the spread of electrical currents that occur much _ than through channels
faster
_ allow small chemicals to pass through them
Gap junctions
T/F Gap junctions can not communicate with cells in different organs
True
Gap junctions communicate with _
neighboring cells
A paracrine response of histamine release by mast cells following soft tissue damage is a type of _ control
positive feedback (recruits more lymphocytes and Ab)
TMJ paracrine effects are a type of _ control in which TMJ fibroblasts release more NGF that travels down the neuron to release more neurotransmitter and CGRP which then comes back to act on more fibroblasts
positive feedback
T/F chemical messengers can be sent by more than 1 mechanism
True
_ have specific receptors genetically programmed for a specific cell ligand
Target tissues
T/F cytoplasmic receptors are also known as nuclear receptors
True (involved in intracellular communication)
Steroid hormones, vitamin A, and vitamin D are _ molecules that can cross the cell membrane
lipophilic
In _ receptors, the ligand is too large, has charge, or is not lipid-soluble
plasma membrane
Norepinephrine/epinephrine activate g-_ proteins to _ AC
stimulatory, activate
Acetylcholine activates g-_ proteins to _ AC
inhibitory, inhibit
_ is a substance besides the ligand that can activate the same receptor
Agonist
_ regulation increases receptor numbers when there is less than the normal hormone concentration
Up
_ regulation removes receptors when there is more than the normal hormone concentration
Down
T/F Second messengers work to amplify the signal
True
(allows conservation of energy and resources)
T/F Amplification of signal is usually observed with nuclear receptors
False (NRs provoke responses which need to be tightly regulated)
GABA, ACTH, Opioid are 2nd messengers that are indirect ion channel openers or _
metabotropic
Ach in muscle are 2nd messengers that are direct ion channel openers or _
ionotropic
Glycogen breakdown in the liver utilizes the conversion of ATP to _, which goes on to activate PKA
cAMP
G-protein activates _ to cut PIP2 into 2nd messengers _ and _
PLC, IP3, DAG
Arachidonic acid utilizes _ and _ to produce PGH2 which then goes on to produce _, _, and _
COX1, COX2
Prostacyclin, prostaglandins, thromboxane A2
Some anti-inflammatory drugs act on COX 1 and 2 such as _, _, _, and _ to prevent their formation
Aspirin, ibuprofen, celebrex, vioxx
Vascular endothelial cells produce _ which promotes _ of blood vessels
Prostacyclin, vasodilation
Platelets produce _ which promotes _ of blood vessels
Thromboxane A2, vasoconstriction
T/F P and TA2 prevent excessive clotting while limiting blood flow
False (increasing blood flow)
Aspirin inhibits COX formation, but in a few hours _ can again produce _ for prostacyclin production
Endothelial cells, COX
In platelets, COX is _ and new platelets must be formed before _ can be synthesized
Irreversibly inhibited, Thromboxane A2
12-HETE 15-HETE Lipoxins 5-HETE These are examples of _ that are formed from _ using _
leukotrienes, arachidonic acid, lipoxygenases
Boswelia plant extract is a _
LO inhibitor
_ are mediators of allergic and inflammatory reactions
Leukotrienes
Leukotrienes secreted by mast cells act (paracrine) to _
Attract neutrophils and eosinophils to the inflammation site
Some cells undergo _ to remove specific cells before they become cancerous or destructive
apoptosis
T/F Apoptosis provide cells at the peak of their performance
True
Necrosis results in _ while apoptosis does not
inflammation
Cells undergoing apoptosis utilize _ which are intracellular protein cutting enzymes
caspases
Alzheimer’s and AIDS have altered _ component
apoptosis
