Phgy 215 Midterm Examination with
Complete Answers.
homeostasis - Answer the ability of a cell or organism to regulate and maintain its internal
environment
set point - Answer the range or point at which a physiological state tends to stabilize
3 components of homeotic control - Answer sensor, integrator, effector
Intrinsic regulation - Answer local or autoregulation
extrinsic regulation - Answer regulation mechanisms are outside the tissue or organ
Negative feedback - Answer changes cause an effector to respond in the opposite direction
i.e. food causes blood sugar to go up, pancreas creates insulin to make the blood sugar go down
Roles of the plasma membrane - Answer regulate fluid composition
allows nutrients in, waste out
enables communication
joins cells together
3 primary functions of the plasma membrane - Answer ensure survival
protection
cooperation and coordination with other cells
3 components of the plasma membrane - Answer phospholipids
cholesterol
ion channels
3 things that hold cells together - Answer Extracellular matrix
cell adhesion molecules
cell junctions
,what is are the main protein fibers in the extracellular matrix - Answer elastin, collagen,
fibronectin
What is the purpose of fibronectin? - Answer promotes cell adhesion
cell junction types - Answer tight junctions, desmosomes, gap junctons
desmosomes - Answer anchor adjacent cells
tight junctions - Answer tight seal, found in epithelial cells
gap junction - Answer allows passage of material through, communication
common in smooth and cardiac muscle
What kind of substances can readily cross the plasma membrane? - Answer uncharged, small
molecules
What are the transport methods? - Answer passive
active
Example of passive transport - Answer diffusion, facilitated diffusion
Example of active transport - Answer carrier mediated transport, vesicular transport
Two forces underlying the movement of water - Answer osmotic pressure
hydro-static pressure
What is osmotic pressure - Answer pressure coming from a gradient/concentration difference
what is hydrostatic pressure? - Answer pressure from water volume
Facilitated diffusion - Answer no energy needed, carrier needed
active transport - Answer energy needed, often against a gradient
, What are the characteristics of carrier mediated transport? - Answer specificity
saturation
competition
specificity - Answer each carrier protein is specialized to recognize and transport a specific
substance
saturation - Answer there is only so many of each type of carrier protein, so they can be
vesicoverwhelmed
competition - Answer sometimes several substances use the same carrier protein
types of vesicular transport - Answer pinocytosis
receptor-mediated
phagocytosis
exocytosis
pinocytosis - Answer cell membrane engulfs and internalizes extracellular fluid
small pouch formed, pinched off by dynamin
receptor-mediated endocytosis - Answer vesicle creation trigger by bonding of a substance to
specific-receptor on the cell surface
phagocytosis - Answer internalization of large multi-molecular particles
exocytosis - Answer membrane formed within the cell fuses with plasma membrane and
releases its contents
mechanism to release large polar molecules, allows cell to move proteins
what causes excitable cells? - Answer difference in ion concentrations (Na, K) between inside
and outside of cells
ion channels - Answer large transmembrane protein, allows ions to enter or exit
voltage gated ion channels - Answer open and close in response to changes in membrane
potential
Complete Answers.
homeostasis - Answer the ability of a cell or organism to regulate and maintain its internal
environment
set point - Answer the range or point at which a physiological state tends to stabilize
3 components of homeotic control - Answer sensor, integrator, effector
Intrinsic regulation - Answer local or autoregulation
extrinsic regulation - Answer regulation mechanisms are outside the tissue or organ
Negative feedback - Answer changes cause an effector to respond in the opposite direction
i.e. food causes blood sugar to go up, pancreas creates insulin to make the blood sugar go down
Roles of the plasma membrane - Answer regulate fluid composition
allows nutrients in, waste out
enables communication
joins cells together
3 primary functions of the plasma membrane - Answer ensure survival
protection
cooperation and coordination with other cells
3 components of the plasma membrane - Answer phospholipids
cholesterol
ion channels
3 things that hold cells together - Answer Extracellular matrix
cell adhesion molecules
cell junctions
,what is are the main protein fibers in the extracellular matrix - Answer elastin, collagen,
fibronectin
What is the purpose of fibronectin? - Answer promotes cell adhesion
cell junction types - Answer tight junctions, desmosomes, gap junctons
desmosomes - Answer anchor adjacent cells
tight junctions - Answer tight seal, found in epithelial cells
gap junction - Answer allows passage of material through, communication
common in smooth and cardiac muscle
What kind of substances can readily cross the plasma membrane? - Answer uncharged, small
molecules
What are the transport methods? - Answer passive
active
Example of passive transport - Answer diffusion, facilitated diffusion
Example of active transport - Answer carrier mediated transport, vesicular transport
Two forces underlying the movement of water - Answer osmotic pressure
hydro-static pressure
What is osmotic pressure - Answer pressure coming from a gradient/concentration difference
what is hydrostatic pressure? - Answer pressure from water volume
Facilitated diffusion - Answer no energy needed, carrier needed
active transport - Answer energy needed, often against a gradient
, What are the characteristics of carrier mediated transport? - Answer specificity
saturation
competition
specificity - Answer each carrier protein is specialized to recognize and transport a specific
substance
saturation - Answer there is only so many of each type of carrier protein, so they can be
vesicoverwhelmed
competition - Answer sometimes several substances use the same carrier protein
types of vesicular transport - Answer pinocytosis
receptor-mediated
phagocytosis
exocytosis
pinocytosis - Answer cell membrane engulfs and internalizes extracellular fluid
small pouch formed, pinched off by dynamin
receptor-mediated endocytosis - Answer vesicle creation trigger by bonding of a substance to
specific-receptor on the cell surface
phagocytosis - Answer internalization of large multi-molecular particles
exocytosis - Answer membrane formed within the cell fuses with plasma membrane and
releases its contents
mechanism to release large polar molecules, allows cell to move proteins
what causes excitable cells? - Answer difference in ion concentrations (Na, K) between inside
and outside of cells
ion channels - Answer large transmembrane protein, allows ions to enter or exit
voltage gated ion channels - Answer open and close in response to changes in membrane
potential
