Altered cell function

Question 1

Altered cellular and tissue biology happens because of (5)

Answer 1

(1) Adaptation
(2) Injury
(3) Neoplasia (malignant growth)
(4) Aging
(5) Death

Question 2

Name and define the two types of cell injury

Answer 2

Reversible - Prolonged stress and repeated injury

Irreversible - Point of no return, after which the cell dies.

Question 3

Characteristics about irreversible damage

Answer 3

(1) Lack of ATP because of mitochondrial damage

(2) Major damage in membrane function

Question 4

List some injurious stimuli of cells (8)

Answer 4

(1) chemical agents
(2) lack of sufficient oxygen (hypoxia)
(3) free radicals
(4) infectious agents
(5) physical and mechanical factors
(6) immunologic reactions
(7) genetic factors
(8) nutritional imbalances

Question 5

3 common forms of cell injury

Answer 5

(1) hypoxic
(2) free radicals and reactive oxygen species
(3) chemical

Question 6

What is the most common cause of hypoxia?

Answer 6

Ischemia

Question 7

What causesischemic injury?

Answer 7

Gradual narrowing of arteries (arteriosclerosis), and complete blockage by blood clots (thrombosis)

Question 8

Name the 4 adaptive changes in cells

Answer 8

(1) atrophy (decrease in cell size)
(2) hypertrophy (increase in cell size)
(3) hyperplasia (increase in cell number)
(4) metaplasia (reversible replacement of one mature cell type by another less mature cell type)

Question 9

Ischemia in Heart muscle - Response to cellular hypoxic injury

Answer 9

• 1 min: heart pale (no blood supply)
• 3 to 5 min: rapid decrease in mitochondrial phosphorylation - no ATP - no contraction
• Increased anaerobic metabolism (glycogen)

Question 10

What is atrophy?

What are its mechanisms?

Answer 10

Cellular size shrinkage due to:

(1) decreased protein synthesis
(2) increased protein catabolism

Question 11

What is Necrosis?

Answer 11

Irreversible injury and cellular dissolution due to hydrolytic enzyme activation

Question 12

What is Fat (enzymatic) Necrosis?

Answer 12

Cellular dissolution by lipases, which saponify fats

Question 13

What is Gangrenous Necrosis?

Answer 13

Death of tissue from severe hypoxic injury and bacteria.

Swollen and black, odorous coagulation

Question 14

What is Liquefactive Necrosis?

Answer 14

Ischaemic injury to brain nerve cells due to bacteria

Hydrolytic enzymes liquefy tissue (proteinaceous soup)

Question 15

What is Caseous Necrosis?

Answer 15

Combination of coagulative and liquefactive necrosis

Lung tissue becomes soft and liquefies due to infection

Question 16

What is Coagulation Necrosis?

Answer 16

When severe ischaemia leads to hypoxia in kidneys, heart, and adrenal glands
Loss of nuclei and cell but architecture remains as there are no enzymes for digestion

Question 17

What is dysplasia?

Answer 17

Abnormal change in cell size or shape and organisation of mature cells.

Question 18

What is hyperplasia?

Answer 18

Increase in the rate of cellular division