week 2 lecture

Question 1

define perfusion

Answer 1

-delivery of oxygen, nutrients
-removal of waste
-bathing cells in fluid

Question 2

define ischemia

Answer 2

stoppage of blood flow

Question 3

define hypoxia

Answer 3

low oxygen state

Question 4

what is the most common cause of cellular injury? what does it lead to

Answer 4

-ischemia
-leads to cellular and tissue hypoxia (lack of oxygen & poor blood flow)

Question 5

what is the key intervention for a hypoxic injury?

Answer 5

remove the source of injury and allow the cell to correct itself

Question 6

what does “-megaly” mean?

Answer 6

swelling on the organ level

Question 7

what is hepatomegaly?

Answer 7

swelling of the liver

Question 8

what is splenomegaly?

Answer 8

swelling of the spleen

Question 9

When our cells experience stressors it causes proteins to become misfolded but luckily our body respond well to an excess of misfolded proteins. What are two ways that our body responds?

Answer 9

-Increased synthesis of chaperones = ability to fix and REPAIR damaged proteins
-Activation of ubiquitin-proteasome pathway → leads to degranulation (break-down) of unfolded proteins to less harmful forms

Question 10

cellular adaptation: hyperplasia & example & medication

Answer 10

-increases in cell number
-repeated friction or cell injury → ex: corns and calluses development
-Medication SE: dilantin → gingival hyperplasia

Question 11

cellular adaptation: atrophy & example

Answer 11

-decrease in cell size
ex: disuse following a cast

Question 12

cellular adaptation: hypertrophy & example

Answer 12

-increase in cell size
ex: workout → muscle growth

Question 13

cellular adaptation: dysplasia

Answer 13

-disorderly change to cell shape, size, and arrangement
-precursor to cancer

Question 14

cellular adaptation: metaplasia & example

Answer 14

-change of cell shape, response to repeated cell injury
-Ex: Barrett’s esophagus: change from squamous epithelial cells to columnar epithelial cells

Question 15

Which type of irreversible cell injury is “messy”? Why might we describe it like this? How does it happen?

Answer 15

necrosis! it is accompanied by inflammation that continues to affect neighboring cells
Membrane rupture → cell will explode → cells contents leakage → inflammation

Question 16

Which type of irreversible cell injury is “neat”? Why might we describe it like this?

Answer 16

apoptosis is “programmed cell death” → neat and tidy process, with NO inflammation

Question 17

Is apoptosis always pathological? Explain and give an example.

Answer 17

No, it is a normal part of the body processes
ex: shedding of uterine lining during menstruation

Question 18

what are two types of environmental signals a cell can receive that induce apoptosis?

Answer 18

1. withdrawal of “survival” signals that normally suppress apoptotic pathways (AKA cells are no longer getting signals)
2. extracellular signals such as the fas ligand will bind to cell and trigger death cascade = “death receptors” (AKA receive signals from outside that tell them to self destruct)

Question 19

what is the internal pathway that can also induce apoptosis?

Answer 19

severe cell damage can trigger p53 to trigger cell death
ex: protective against cancer development

Question 20

what are the two factors that cause cellular and molecular damage (relating to cellular aging)? give an example for each.

Answer 20

1. progressive decline in the proliferation and reparative capacity of cells
   ex: not as good as repairing cells and making new cells
2. exposure to damaging environmental and metabolic factors
   ex: accumulation of damage to cells

Question 21

describe two theories of cellular aging

Answer 21

1. Free Radical Theory = accumulated cell damage over time
2. Programmed Senescence Theory = cells have a limited number of divisions, limited by telmores (ends of chromosomes) once they reach a critical limit

Question 22

what is somatic death?

Answer 22

death of an entire organism

Question 23

what do we use as proof of somatic death?

Answer 23

cessation of respirations and heartbeat

Question 24

what is rigor mortis? when does it occur and end?

Answer 24

stiffened muscles following death due to influx of calcium from muscle cells
-body remains rigid for 0-6 hours
-then flaccid 24-48 hours