Cellular Adaption Lecture

Question 1

What causes cellular adaptions?

Answer 1

Increased demand, reduced nutrients supply or other forms of “stress”

Question 2

What causes cellular injury?

Answer 2

Limits of the adaptive response are reached or if adaptation is not possible

Question 3

What is ischemia/hypoxia?

Answer 3

Oxygen deprivation

Question 4

What are physical agents that cause injury?

Answer 4

Mechanical trauma, extremes of temperature

Changes in atmospheric pressure, radiation, shock (electricity)

Question 5

What is cellular adaptation?

Answer 5

Cells response to excessive physiological stresses or pathological stimuli –> cell reaches steady state where it maintains viability and function

Question 6

What is autocrine signaling?

Answer 6

Cell responds to signaling substances that they themselves secrete

Question 7

What is paracrine signaling?

Answer 7

Cell produces substances that affect only a target cell in close proximity

Question 8

What is endocrine signaling?

Answer 8

Hormones are synthesized by cells of the endocrine organs and act on target cells distant from their site of synthesis

Question 9

What are subcellular adaptations?

Answer 9

Mitochondria increase in number to better meet the metabolic needs of organisms
but under different stresses these can take on abnormal sizes and shapes

Question 10

What are lysosomes?

Answer 10

Membrane-bound intracellular organelles that contain a variety of hydrolytic enzymes
Take unwanted materials from the outside and move tehm within the cytosol

Question 11

What are primary lysosomes?

Answer 11

Synthesized in the rER and packaged in the golgi
They fuse with membrane bound vacuoles containing material to be digested forming a secondary lysosomes or phagolysosomes

Question 12

What is the cytoskeleton consist of and what is it critical for?

Answer 12

Microtubules, actin filaments, myosin filaments, and other intermediate filaments
Critical for cell locomotion, transport, and movement of intracellular organelles

Question 13

What disease are caused via the disruption of the cytoskeleton?

Answer 13

Alzheimer’s where neurofibrillary tangles become common in neurons via microtubule-associated proteins and neurofilaents –> loses ability to communicate

Question 14

What is hyperplasia?

Answer 14

increase in number

Question 15

What is hypertrophy?

Answer 15

Increase in size

Question 16

What are the three ways cellular adaptions occur?

Answer 16

Cell growth and differentiation
Atrophy (skrinkage)
Metaplasia (reversible replacement)

Question 17

What are the three types of cells?

Answer 17

Continuously dividing (skin, oral cavity)
Quiescent (stable) cell (liver, kidney)
Nondividing (permanent) cells (neurons, cardiac)

Question 18

What stimulates cell growth?

Answer 18

Injury, mechanical forces acting on a tissue, or cell death

Question 19

What is cellular hyperplasia?

Answer 19

Physiologically: hormonal (increase in function) and compensatory (increase tissue mass)
Pathologically: Hormonal (abnormal menstrual bleeding), growth factors and viral infections

Question 20

Define atrophy

Answer 20

Reduction in cell size and number

Question 21

Physiological Atrophy during fetal development?

Answer 21

Notochord –> vertebral column
Tonsils –> after puberty
Thymus –> during puberty

Question 22

Pathological atrophy is caused by?

Answer 22

Decrease workload, loss of innervation, diminished blood supply, inadequate nutrition, aging, pressure

Question 23

What is metaplasia?

Answer 23

Change in cell type –> reprogramming tissue cells via growth factors, cytokines and

Question 24

What does the cell membrane help maintain?

Answer 24

Ionic gradients and osmotic homeostatsis

Question 25

What does aerobic respiration help maintain?

Answer 25

oxidative metabolism and ATP

Question 26

What are the six common biochemical mechanisms important to the mediation of cell injury and death?

Answer 26

1. Decrease ATP synthesis and ATP depletion
2. Defects in membrane permeability
3. Loss of calcium homeostasis and increased intracellular calcium
4. Oxygen and oxygen derived free radicals
5. Irreversible mitochondrial damage
6. Protein misfolding and DNA damage

Question 27

What are the consequences of decreasing intracellular ATP?

Answer 27

Increase anaerobic glycolysis which decreases glycogen and pH and increase lactic acid
Decrease in protein synthesis, ER swelling, cellular swelling, etc

Question 28

What are the consequences of loss of calcium homeostatsis?

Answer 28

Intracellular calcium when increased can activate a number of ezymes (ATPase, endonucleases, phopholipiases, etc)

Question 29

What are the pathologic effects of ROS?

Answer 29

Cell injury and death
ROS reacts with FA to induce oxidation which genrates lipid peroxidases that disrupt the plasma membrane
ROS reacts with proteins to cause abnormal folding and DNA causing mutations and breaks

Question 30

What are the ROS removal techniques?

Answer 30

Antioxidants
SOD converts O2- to H2O2
Glutathione peroxidase converts OH to H20
Catalase converst H2O2 to H20

Question 31

Define reperfusion injury

Answer 31

Detrimental changes that occur upon reistatement of blood flow to the tissue
Cells die after blood flow resumes

Question 32

What are some examples of reperfusion injury?

Answer 32

Increase ROS

Release of cytokines and cell adhesion molecules