Pathophysiology DNP South Alabama NU 545
Questions With Complete Solutions
Cell membranes contain which major chemical components? - ANSWER -Lipids
& Proteins act as the "molecular glue" for the structural integrity of the membrane.
(pg 11)
4 phases of the cell cycle - ANSWER -The four phases of the cell cycle are (1)
the G1 phase (G = gap), which is the period between the M phase and the start of
DNA synthesis; (2) the S phase (S =synthesis), in which DNA is synthesized in the
cell nucleus; (3) the G2 phase, in which RNA and protein synthesis occurs, the
period between the completion of DNA synthesis and the next phase (M); and (4)
the M phase (M = mitosis), which includes both nuclear and cytoplasmic division.
The M phase (mitosis) involves four stages: prophase, metaphase, anaphase, and
telophase. (pg 32)
What allows potassium to diffuse in and out of cells? - ANSWER -The NA-K
antiport system (Na moves out, K moves in) uses the direct energy of ATP to move
these cations. The transporter protein in an enzyme, ATPAse, which has a
requirement for Na, K, and Mg ions. The concentration of ATPase in plasma
membranes is directly related to Na-K transport activity. For every ATP molecule
hydrolyzed, three molecules of Na re transported out and two of K are transported
in. However, the exact mechanism for transport is uncertain.
(Sodium moves out and potassium moves into the cell through active transport -
for every 3 molecules of sodium that exit, 2 potassium enter the cell.) (pg 31)
How is the cell protected from injury? - ANSWER -The cell membrane and lipid
bilayer. It controls what comes in and out of the cell, gives structure.. cellular
adaption?
Protection Plasma membrane: barrier to toxic molecules and macromolecules
(proteins, nucleic acid, polysaccharides).
(pg. 12)
,What is the platelet-derived growth factor? - ANSWER -Stimulates proliferation
of connective tissue and neuroglial cells.
(p 39)
What is cell communication? How does it occur? - ANSWER -Cells need to
communicate to maintain a stable internal environment (homeostasis) to regulate
their growth and division, development and organization into tissues, and to
coordinate their functions.
How does it occur? 3 ways
1. Display signaling molecules (receptors) that affect the cell itself and other cells
in direct contact
2. Affect receptor proteins inside the target cell (enter the cell).
3. Protein channels (gap junctions) coordinate activities of adjacent cells. (p 19)
What is chemical signaling? - ANSWER -Communication at a distance,
hormonal, neurohormonal, paracrine, autocrine, and neurotransmitter
Paracrine signaling: secrete mediators that are absorbed or destroyed. Involves
different cell types. Secretes to adjacent target cells (next to)
Autocrine signaling: produce signals that they themselves respond to. Secreting
hormones to stimulate self (i.e. Cancer).
Hormonal signaling: endocrine cells secrete hormones to produce a response in
another set of cells GO THROUGH BLOODSTREAM to a target cell (i.e. thyroid-
stimulating hormone).
Neurohormonal signaling: hormones released by neurosecretory neurons ex: fight
or flight response(epi/nor) through the bloodstream to target. (pf 21)
How is glucose transported from the blood to the cell? - ANSWER -Passive
protein channel: passive mediated (facilitated diffusion) using protein transporter
down concentration gradient with no energy expenditure. Happens by a uniport
transporter. It demonstrates saturation kinetics, transport system is saturated when
all glucose specific receptors are occupied. (p.31)
Understand the transportation of K+ and Na across plasma membranes. -
ANSWER -Active transport potassium and sodium use direct energy of ATP in
plasma membrane; for every 3 molecules of Na that move out, 2 K+ molecules
, enter. This causes the inside of the cell to be more negative than the outside. The 3
Na bind to carrier and at the same time ATP binds to the carrier. ATP breaks, the
carrier changes shape and releases Na. The carrier attracts 2 K, the carrier returns
to original shape and releases K and ATP remnant. (32)
Understand membrane transport. - ANSWER -Membrane transport protein
sometimes called mediated transport. Movement of a substance across a membrane
in which a protein transport moves molecules against (or up) the concentration
gradient. This requires the expenditure of energy. (pg 32).
Understand the function of cAMP. - ANSWER -Cyclic adenosine
monophosphate-one of the 2 major messenger pathways. Binding of the ligand to
its surface receptor eventually activates the enzyme adenylyl cyclase on the inner
surface of the membrane. (pg 22)
Know the causes of electrolyte abnormalities (hypermagnesemia,
hypomagnesemia, hypokalemia, hypocalcemia). - ANSWER -Hypermagnesemia-
Usually renal insufficiency or failure: also excessive intake of magnesium-
containing antacids, adrenal insufficiency.
Hypomagnesemia- Malnutrition, malabsorption syndromes, alcoholism, urinary
losses (renal tubular dysfunction, loop diuretics).
Hypokalemia- The most common causes of hypokalemia are abnormal losses from
either the kidneys or the GI tract are associated with diarrhea, laxative misuse,
vomiting, and ileostomy drainage.
-Renal losses occur when the patient has a low magnesium level or is diuresing,
particularly in the patient with an elevated aldosterone level. Aldosterone is
released when the circulating blood volume is low; causing sodium retention in the
kidneys resulting in loss of potassium in the urine.
Hypocalcemia-inadequate intestinal absorption, deposition of ionized calcium into
the bone or soft tissue, blood administration, or decreases in PTH and vitamin D
levels, nutritional deficiencies.
(pg 120)
Questions With Complete Solutions
Cell membranes contain which major chemical components? - ANSWER -Lipids
& Proteins act as the "molecular glue" for the structural integrity of the membrane.
(pg 11)
4 phases of the cell cycle - ANSWER -The four phases of the cell cycle are (1)
the G1 phase (G = gap), which is the period between the M phase and the start of
DNA synthesis; (2) the S phase (S =synthesis), in which DNA is synthesized in the
cell nucleus; (3) the G2 phase, in which RNA and protein synthesis occurs, the
period between the completion of DNA synthesis and the next phase (M); and (4)
the M phase (M = mitosis), which includes both nuclear and cytoplasmic division.
The M phase (mitosis) involves four stages: prophase, metaphase, anaphase, and
telophase. (pg 32)
What allows potassium to diffuse in and out of cells? - ANSWER -The NA-K
antiport system (Na moves out, K moves in) uses the direct energy of ATP to move
these cations. The transporter protein in an enzyme, ATPAse, which has a
requirement for Na, K, and Mg ions. The concentration of ATPase in plasma
membranes is directly related to Na-K transport activity. For every ATP molecule
hydrolyzed, three molecules of Na re transported out and two of K are transported
in. However, the exact mechanism for transport is uncertain.
(Sodium moves out and potassium moves into the cell through active transport -
for every 3 molecules of sodium that exit, 2 potassium enter the cell.) (pg 31)
How is the cell protected from injury? - ANSWER -The cell membrane and lipid
bilayer. It controls what comes in and out of the cell, gives structure.. cellular
adaption?
Protection Plasma membrane: barrier to toxic molecules and macromolecules
(proteins, nucleic acid, polysaccharides).
(pg. 12)
,What is the platelet-derived growth factor? - ANSWER -Stimulates proliferation
of connective tissue and neuroglial cells.
(p 39)
What is cell communication? How does it occur? - ANSWER -Cells need to
communicate to maintain a stable internal environment (homeostasis) to regulate
their growth and division, development and organization into tissues, and to
coordinate their functions.
How does it occur? 3 ways
1. Display signaling molecules (receptors) that affect the cell itself and other cells
in direct contact
2. Affect receptor proteins inside the target cell (enter the cell).
3. Protein channels (gap junctions) coordinate activities of adjacent cells. (p 19)
What is chemical signaling? - ANSWER -Communication at a distance,
hormonal, neurohormonal, paracrine, autocrine, and neurotransmitter
Paracrine signaling: secrete mediators that are absorbed or destroyed. Involves
different cell types. Secretes to adjacent target cells (next to)
Autocrine signaling: produce signals that they themselves respond to. Secreting
hormones to stimulate self (i.e. Cancer).
Hormonal signaling: endocrine cells secrete hormones to produce a response in
another set of cells GO THROUGH BLOODSTREAM to a target cell (i.e. thyroid-
stimulating hormone).
Neurohormonal signaling: hormones released by neurosecretory neurons ex: fight
or flight response(epi/nor) through the bloodstream to target. (pf 21)
How is glucose transported from the blood to the cell? - ANSWER -Passive
protein channel: passive mediated (facilitated diffusion) using protein transporter
down concentration gradient with no energy expenditure. Happens by a uniport
transporter. It demonstrates saturation kinetics, transport system is saturated when
all glucose specific receptors are occupied. (p.31)
Understand the transportation of K+ and Na across plasma membranes. -
ANSWER -Active transport potassium and sodium use direct energy of ATP in
plasma membrane; for every 3 molecules of Na that move out, 2 K+ molecules
, enter. This causes the inside of the cell to be more negative than the outside. The 3
Na bind to carrier and at the same time ATP binds to the carrier. ATP breaks, the
carrier changes shape and releases Na. The carrier attracts 2 K, the carrier returns
to original shape and releases K and ATP remnant. (32)
Understand membrane transport. - ANSWER -Membrane transport protein
sometimes called mediated transport. Movement of a substance across a membrane
in which a protein transport moves molecules against (or up) the concentration
gradient. This requires the expenditure of energy. (pg 32).
Understand the function of cAMP. - ANSWER -Cyclic adenosine
monophosphate-one of the 2 major messenger pathways. Binding of the ligand to
its surface receptor eventually activates the enzyme adenylyl cyclase on the inner
surface of the membrane. (pg 22)
Know the causes of electrolyte abnormalities (hypermagnesemia,
hypomagnesemia, hypokalemia, hypocalcemia). - ANSWER -Hypermagnesemia-
Usually renal insufficiency or failure: also excessive intake of magnesium-
containing antacids, adrenal insufficiency.
Hypomagnesemia- Malnutrition, malabsorption syndromes, alcoholism, urinary
losses (renal tubular dysfunction, loop diuretics).
Hypokalemia- The most common causes of hypokalemia are abnormal losses from
either the kidneys or the GI tract are associated with diarrhea, laxative misuse,
vomiting, and ileostomy drainage.
-Renal losses occur when the patient has a low magnesium level or is diuresing,
particularly in the patient with an elevated aldosterone level. Aldosterone is
released when the circulating blood volume is low; causing sodium retention in the
kidneys resulting in loss of potassium in the urine.
Hypocalcemia-inadequate intestinal absorption, deposition of ionized calcium into
the bone or soft tissue, blood administration, or decreases in PTH and vitamin D
levels, nutritional deficiencies.
(pg 120)
