Body Communication Flashcards
______ is the study of processes and functions of living organisms
Physiology
______ is the maintenance of steady states in body by coordinated physiological mechanisms
Homeostasis
who introduced homeostasis?
Walter B Cannon
______ is a condition in which opposing forces in adjacent compartments are balanced (no net transfer), but
_________ is a condition that doest change with time and can apply to single or several compartments
Equilibrium, Steady state
does steady state necessarily indicate an equilibrium condition?
NO
________ involves enzymatic reactions. a example of this is G6P inhibiting Hexokinase II
End-product inhibition
_____________ involves non-enzymatic processes where a sensor acts on a feedback controller
Negative feedback control
___________ is an open loop where regulated variable is NOT sensed by a sensor; it anticipates changes and pushes the body to respond in anticipation
feed-forward control
what are examples of feed-forward controls?
-your stomach growling and releasing stomach acid in response to seeing/smelling food
-your HR, BP increasing in anticipation of a race
_______ occurs when a variable is changed/sensed and action is taken to reinforce the change in that variable
Positive feedback
what are different forms of cell communication?
- direct links (gap/transient)
- local chemical responses
- neuronal synapses
advantages and disadvantages of gap junctions?
Advantages:
-Not a general body response
-Fast transmission to neighboring cells
-Reliable transmission
-Coordinated activity between cells
Disadvantages
-Can’t communicate with cells in different organs
-Can’t communicate efficiently with cells located far in same tissue
Transient direct linkup of cells are mainly between _______ cells and other cells
immune
when would down-regulation of receptors happen?
If there are a high number of ligands, receptor number goes down so we don’t have too much of a response
when would up-regulation of receptors happen?
If there are not enough ligands/hormones, receptor number will increase so we can have enough binding for the correct effect
is amplification of signals usually seen with nuclear receptors?
no because nuclear receptors are used for substances that are highly regulated (testosterone, estrogen, retinoic acid)
what are the ways ions can enter the cell?
- direct/ionotropic
- indirect/metabotropic
- leaky channel, voltage gated
_______ catalyzes reaction to produce cAMP → cAMP (cAMP can then activate PKA)
Adenylyl cyclase
Most cases: cAMP production associated with _____ muscle relaxation (removal of Ca+ from cells)
smooth
________ is a family of enzymes that breakdown cAMP → AMP
Phosphodiesterase
_______ cleaves PiP2 → IP3 + Diacylglycerol
Phospholipase C
___ is involved in Ca++ mediated signaling (mechanism of activation for smooth muscle) and Calmodulin
IP3
_________ activates PKC
Diacylglycerol (DAG)
________ enzymes are involved in pathway production of Prostaglandins, prostacyclin, Thromboxane A2
(easy target for drugs such as NSAIDS and Vioxx Celebrex)
Cyclo-oxygenase (COX)
COX-1 or COX-2 → PGH2 → ______enzyme_____ → PGI2 (prostacyclin) → Vasodilation
Prostacyclin synthase
COX-1 or COX-2 → PGH2 → _____enzyme______→ Thromboxane A → Vasoconstriction
Thromboxane synthetase
_______ are mediators of allergic reactions and inflammation, secreted by mast cells when allergens combine with IgE
Leukotrienes
________ are the enzymes that catalyze the reactions that create leukotrienes
Lipoxygenases enzymes
what are some diseases leukotrienes are associated with?
-TMJ inflammation
-Rheumatoid arthritis
-Asthma
-Allergic rhinitis
-Crohn’s disease
-Ulcerative colitis
does apoptosis induce inflammation?
NO
are caspases a part of necrosis?
NO only apoptosis
alzheimers is associated with _____ apoptosis and cancer is associated with ______ apoptosis
too much
cells escaping
what are some reasons for cells going through apoptosis?
-Self-destruction for the greater good of remaining cells
-Self-elimination of selected cells = a normal part of development
-Tissue turnover in the adult body
-Cellular elements in human blood and immune system
_____ causes cells to disintegrate and release intracellular content into interstitial area which produces inflammation
Necrosis
