Exam 1 Flashcards
(161 cards)
What is dynamic constancy
levels change over short periods of time but remain relatively constant over long periods of time
Is steady state or equilibrium more similar to homeostasis?
Steady state
What do paracrines target?
Local cells
What do autocrines target?
The same cell that secreted them
What determines the amplitude of normal range?
Threshold Stimulus (sensitivity)
What is the biggest difference in the homeostatic processes of the nervous system and endocrine system?
The endocrine system does not have an afferent pathway because the reflex receptor is already at the integrating center.
What is the effector in a systemic homeostatic process?
Any cell affected by the efferent pathway.
Is negative feedback or positive feedback part of homeostasis?
Negative feedback (maintains normal range)
Is hemostasis positive or negative feedback?
Positive (clotting cascade)
What part of the jaw unloading reflex involved negative feedback?
Shutting off the periodontal receptors once the pressure is off the teeth.
Are hydrophobic or hydrophilic substances permeable to phospholipid membranes?
hydrophobic (like lipids) (also water)
What levels of protein structure does denaturation and covalent/allosteric modulation affect?
2, 3, 4
As Kd increases, affinity
decreases
Cell junctions that prevent intercellular flow
Tight junctions
Cell junctions that provide structural support
Desmosomes
Substances with high intracellular [conc]
K+, Mg2+, PO3, Amino acids, proteins
Substances with high extracellular [conc]
Na+, Ca2+, Cl-, HCO3-, Glucose
Does bulk vesicular transport require energy input?
Yes
Is facilitated or simple diffusion rate decreased by resistance and distance?
Simple diffusion is slowed (cannot be selectively regulated)
Osmosis is determined by…
concentrations of impermeable solutes
Osmolarity is determined by…
concentrations of all permeable and impermeable solutes
Tonicity is determined by…
all impermeable solutes
Blood plasma is ___% of body water.
Interstitial fluid is ___% of body water.
Intracellular fluid is ___% of body water.
Blood plasma: 5%
Interstitial fluid: 15%
Intracellular fluid: 40%
What is primary active transport?
energy comes directly from breakdown of ATP