NU545 PATHO STUDY GUIDE UNIT #1
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
What is cell communication? How does it occur? (p.20) - Answer-• Required for
homeostasis, regulate cellular growth/division & development/organization into tissues,
& coordinate cellular function.
• Occurs in 3 ways:
-via protein channels & gap junctions that directly coordinate activities of adjacent cells
(must be touching)
-via plasma membrane-based signaling molecules (receptors) that affect the cell itself
& cells that come in direct contact
-via chemical signals that must enter the distant cells to affect the receptors inside of
the distant cell (the most common means of communication).
• Primary modes of intercellular signaling are hormonal, neurohormonal, paracrine,
contact-dependent, & neurotransmitters. There is also Autocrine signaling where the
cell signals itself.
What is chemical signaling? (p.20) - Answer-Involves the secretion of chemicals, such
as hormones, neurohormones, paracrine, autocrine, and neurotransmitters. Chemical
signaling may occur through the bloodstream or in small discrete spaces
How is glucose transported from the blood to the cell? (p. 33) - Answer-Passive protein
channels.
Passive mediated transport or facilitated diffusion moves the glucose via a uniport
mechanism into the cell. When all glucose-specific receptors are occupied, the transport
system is saturated and operating at maximal capacity. Direction of movement is the
same as passive simple diffusion-down the concentration gradient, from an area of high
concentration to low concentration until equilibrium is achieved.
Understand the transportation of potassium and sodium across plasma membranes. (p.
29-32) - Answer-• The Na+ K+ antiport (opposite directions) system uses direct energy
of ATP to move cations.
• ATPase is transporter protein.
• Concentration of ATPase in plasma membranes is directly related to Na+ K+ transport
activity.
• Process:
- 3 Na+ ions bind to Na-binding sites on carrier's inner face.
- ATP molecule produced by cell's mitochondria binds to carrier.
- Carrier changes shape, releases 3 Na+ ions to outside of cell, & attracts 2 K+ ions to
K-binding sites.
- Carrier returns to original shape, releasing 2 K+ ions & the leftover ATP molecule to
inside of cell.
,- Carrier can now repeat cycle.
What is active transport? (p. 31-33) ch.1 - Answer-• The movement of a substance
across a membrane by a carrier protein. Requires metabolic energy (ATP) to move the
molecules against the concentration gradient.
• Active transport also occurs by endocytosis (vesicle formation), where substances are
engulfed by a segment of the plasma membrane, forming a vesicle that moves into the
cell.
What are cytokines? (p.38-39)
Or cytokinesis? (p.37) - Answer-• Cytokines are peptides that transmit signals
within/between cells to stimulate tissue growth & development.
Do all cells continue to replicate or divide? (p. 39) - Answer-• No, all types of cells
undergo mitosis during formation of the embryo, but adult cells including: nerve cells,
lens cells, & muscle cells, lose the ability to replicate.
• When a need arises for new cells, as in the repair of injured cells, previously non-
dividing cells must be rapidly triggered to reenter the cell cycle.
• Neurons are fixed at birth & are unable to be replaced.
When normal columnar ciliated epithelial cells of the bronchial lining are replaced by
stratified squamous cells, the process is called? (p. 54) - Answer-• Metaplasia: the
reversible replacement of one mature cell by another, sometimes less differentiated cell
type.
• However, lose protective ability, because new cells don't secrete mucus or have cilia.
• Bronchial metaplasia can be reversed if inducing stimulus is removed, such as
cigarette smoking.
What is the relationship between ischemia and ATP? (p. 55-57) - Answer-• When a
hypoxic injury occurs to myocardium, which causes an abrupt lack of contraction
(caused by quick decline in mitochondrial phosphorylation), causing insufficient ATP
production.
• Lack of ATP leads to increase in anaerobic metabolism, which generates ATP from
glycogen when there is insufficient oxygen.
• When glycogen stores are depleted, even anaerobic metabolism ceases.
When does sodium enter the cell and cause swelling? (p. 57) - Answer-• A reduction in
ATP levels cause the plasma membrane's Na-K pump & Na-Ca exchange to fail.
• Causes intracellular accumulation of Na & Ca & diffusion of K out of cell.
• Na & H2O enter cell freely, leading to cellular swelling.
What are free radicals in relation to cell damage? Progression of diseases? (p. 59-61) -
Answer-Membrane damage is initiated by injury induced by free radicals, primarily by
excess reactive oxygen species (ROS) called oxidated stress. Free radical is an
electrically uncharged atom or group of atoms having an unpaired electron; thus
causing the molecule to be unstable. To stabilize the molecule, it gives up an electron or
, steals one. This process is capable of injuries through chemical bond formation with
proteins, lipids, & carbs. Free radicals aren't easily controlled & they initiate chain
reactions. These reactive species are important in regard to cell injury by lipid
peroxidation, alterations of proteins causing fragmentation of polypeptide chains, &
alterations of DNA (breaking single strands). Diseases & disorders have been linked
directly & indirectly to these reactive species.
Know all about lead poisoning. How does it cause damage within the cell? (p. 65-67) -
Answer-• A heavy metal, primary hazard to children.
• Can cause learning disabilities, hyperactivity, & ADD
• Found in paint, soil, dust, debris from houses, baby formula mixed with lead
contaminated water, newsprint, water that flows through lead pipes, hair dyes, gasoline,
& tin cans or pottery made with lead based glaze.
• Nervous system, hematopoietic system, & kidneys are primarily affected
• Interferes with Ca. Can increase intracellular Ca concentrations & become a substitute
& some Ca-binding proteins are capable of binding with lead. PKC (protein kinase C)
mediated lead induced rise in intracellular free Ca causing cellular disruption.
• Inhibits enzymes involved in hemoglobin synthesis (ie anemia)
• Other s/s: convulsions, delirium, & peripheral nerve involvement to the wrist, fingers, &
feet, glycosuria, aminoaciduria, & hyperphosphaturia, n/v, loss of appetite, wt loss, &
abd cramps.
Know about the affects of fetal alcohol syndrome on infants. (p. 68-69) - Answer-• Can
lead to growth retardation, cognitive impairment, facial anomalies, & ocular
disturbances.
How does alcohol affect the nervous system? (p.67-68) - Answer-• Acts as a depressant
affecting the subcortical structures first (brainstem reticular formation). Motor and
intellectual activities then become distorted. At high levels, medullar centers become
depressed, affecting respirations.
Where do lipids accumulate? (p. 63, 75, 84-85) - Answer-• During chemical injury lipids
accumulate within the cytoplasm, starting within cisternae of the endoplasmic reticulum
(p.63).
• Lipids primarily accumulate in the cells of the spleen, liver, CNS (p.84).
• The most common site of intracellular lipid accumulation also known as fatty change is
liver cells (p.85).
• Heart, liver, & muscle in hyperlipidemia (p.75).
What is hemosiderosis? (p. 86) - Answer-• Excess iron is stored as hemosiderin in the
cells of many organs & tissues. Common w/multiple blood transfusions or prolonged
parenteral administration of iron or excessive alcohol
What causes free calcium in the cytosol? (p. 87 figure 2-24) - Answer-• Calcium is
usually stored in the mitochondria and endoplasmic reticulum and then pumped to
extracellular space bound to calcium-binding proteins.
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
What is cell communication? How does it occur? (p.20) - Answer-• Required for
homeostasis, regulate cellular growth/division & development/organization into tissues,
& coordinate cellular function.
• Occurs in 3 ways:
-via protein channels & gap junctions that directly coordinate activities of adjacent cells
(must be touching)
-via plasma membrane-based signaling molecules (receptors) that affect the cell itself
& cells that come in direct contact
-via chemical signals that must enter the distant cells to affect the receptors inside of
the distant cell (the most common means of communication).
• Primary modes of intercellular signaling are hormonal, neurohormonal, paracrine,
contact-dependent, & neurotransmitters. There is also Autocrine signaling where the
cell signals itself.
What is chemical signaling? (p.20) - Answer-Involves the secretion of chemicals, such
as hormones, neurohormones, paracrine, autocrine, and neurotransmitters. Chemical
signaling may occur through the bloodstream or in small discrete spaces
How is glucose transported from the blood to the cell? (p. 33) - Answer-Passive protein
channels.
Passive mediated transport or facilitated diffusion moves the glucose via a uniport
mechanism into the cell. When all glucose-specific receptors are occupied, the transport
system is saturated and operating at maximal capacity. Direction of movement is the
same as passive simple diffusion-down the concentration gradient, from an area of high
concentration to low concentration until equilibrium is achieved.
Understand the transportation of potassium and sodium across plasma membranes. (p.
29-32) - Answer-• The Na+ K+ antiport (opposite directions) system uses direct energy
of ATP to move cations.
• ATPase is transporter protein.
• Concentration of ATPase in plasma membranes is directly related to Na+ K+ transport
activity.
• Process:
- 3 Na+ ions bind to Na-binding sites on carrier's inner face.
- ATP molecule produced by cell's mitochondria binds to carrier.
- Carrier changes shape, releases 3 Na+ ions to outside of cell, & attracts 2 K+ ions to
K-binding sites.
- Carrier returns to original shape, releasing 2 K+ ions & the leftover ATP molecule to
inside of cell.
,- Carrier can now repeat cycle.
What is active transport? (p. 31-33) ch.1 - Answer-• The movement of a substance
across a membrane by a carrier protein. Requires metabolic energy (ATP) to move the
molecules against the concentration gradient.
• Active transport also occurs by endocytosis (vesicle formation), where substances are
engulfed by a segment of the plasma membrane, forming a vesicle that moves into the
cell.
What are cytokines? (p.38-39)
Or cytokinesis? (p.37) - Answer-• Cytokines are peptides that transmit signals
within/between cells to stimulate tissue growth & development.
Do all cells continue to replicate or divide? (p. 39) - Answer-• No, all types of cells
undergo mitosis during formation of the embryo, but adult cells including: nerve cells,
lens cells, & muscle cells, lose the ability to replicate.
• When a need arises for new cells, as in the repair of injured cells, previously non-
dividing cells must be rapidly triggered to reenter the cell cycle.
• Neurons are fixed at birth & are unable to be replaced.
When normal columnar ciliated epithelial cells of the bronchial lining are replaced by
stratified squamous cells, the process is called? (p. 54) - Answer-• Metaplasia: the
reversible replacement of one mature cell by another, sometimes less differentiated cell
type.
• However, lose protective ability, because new cells don't secrete mucus or have cilia.
• Bronchial metaplasia can be reversed if inducing stimulus is removed, such as
cigarette smoking.
What is the relationship between ischemia and ATP? (p. 55-57) - Answer-• When a
hypoxic injury occurs to myocardium, which causes an abrupt lack of contraction
(caused by quick decline in mitochondrial phosphorylation), causing insufficient ATP
production.
• Lack of ATP leads to increase in anaerobic metabolism, which generates ATP from
glycogen when there is insufficient oxygen.
• When glycogen stores are depleted, even anaerobic metabolism ceases.
When does sodium enter the cell and cause swelling? (p. 57) - Answer-• A reduction in
ATP levels cause the plasma membrane's Na-K pump & Na-Ca exchange to fail.
• Causes intracellular accumulation of Na & Ca & diffusion of K out of cell.
• Na & H2O enter cell freely, leading to cellular swelling.
What are free radicals in relation to cell damage? Progression of diseases? (p. 59-61) -
Answer-Membrane damage is initiated by injury induced by free radicals, primarily by
excess reactive oxygen species (ROS) called oxidated stress. Free radical is an
electrically uncharged atom or group of atoms having an unpaired electron; thus
causing the molecule to be unstable. To stabilize the molecule, it gives up an electron or
, steals one. This process is capable of injuries through chemical bond formation with
proteins, lipids, & carbs. Free radicals aren't easily controlled & they initiate chain
reactions. These reactive species are important in regard to cell injury by lipid
peroxidation, alterations of proteins causing fragmentation of polypeptide chains, &
alterations of DNA (breaking single strands). Diseases & disorders have been linked
directly & indirectly to these reactive species.
Know all about lead poisoning. How does it cause damage within the cell? (p. 65-67) -
Answer-• A heavy metal, primary hazard to children.
• Can cause learning disabilities, hyperactivity, & ADD
• Found in paint, soil, dust, debris from houses, baby formula mixed with lead
contaminated water, newsprint, water that flows through lead pipes, hair dyes, gasoline,
& tin cans or pottery made with lead based glaze.
• Nervous system, hematopoietic system, & kidneys are primarily affected
• Interferes with Ca. Can increase intracellular Ca concentrations & become a substitute
& some Ca-binding proteins are capable of binding with lead. PKC (protein kinase C)
mediated lead induced rise in intracellular free Ca causing cellular disruption.
• Inhibits enzymes involved in hemoglobin synthesis (ie anemia)
• Other s/s: convulsions, delirium, & peripheral nerve involvement to the wrist, fingers, &
feet, glycosuria, aminoaciduria, & hyperphosphaturia, n/v, loss of appetite, wt loss, &
abd cramps.
Know about the affects of fetal alcohol syndrome on infants. (p. 68-69) - Answer-• Can
lead to growth retardation, cognitive impairment, facial anomalies, & ocular
disturbances.
How does alcohol affect the nervous system? (p.67-68) - Answer-• Acts as a depressant
affecting the subcortical structures first (brainstem reticular formation). Motor and
intellectual activities then become distorted. At high levels, medullar centers become
depressed, affecting respirations.
Where do lipids accumulate? (p. 63, 75, 84-85) - Answer-• During chemical injury lipids
accumulate within the cytoplasm, starting within cisternae of the endoplasmic reticulum
(p.63).
• Lipids primarily accumulate in the cells of the spleen, liver, CNS (p.84).
• The most common site of intracellular lipid accumulation also known as fatty change is
liver cells (p.85).
• Heart, liver, & muscle in hyperlipidemia (p.75).
What is hemosiderosis? (p. 86) - Answer-• Excess iron is stored as hemosiderin in the
cells of many organs & tissues. Common w/multiple blood transfusions or prolonged
parenteral administration of iron or excessive alcohol
What causes free calcium in the cytosol? (p. 87 figure 2-24) - Answer-• Calcium is
usually stored in the mitochondria and endoplasmic reticulum and then pumped to
extracellular space bound to calcium-binding proteins.
