wk 1- cell adaptation, stress and death

Question 1

LO: give examples of cell types that are considered under epithelial, connective tissue and others

Answer 1

1. epithelial- 1) simple squamous; 2) simple cuboidal; 3) simple columnar; and 4) pseudostratified
2. connective tissue- myocytes (muscle cells) - in skeletal muscle, smooth muscle, cardiac, fibroblasts, collagen and fat cells, endothelium, cartilage, bone.
3. Others- mesothelial cells, melanocytes, germ cells, haemopoeitic cells,

Question 2

LO: what is meant by labile, stable and permanent cells, give examples

Answer 2

1. labile (continuously dividing) - epithelial cells, haemopoietic stem cells
2. stable (quiescent) - epithelial cells, smooth muscle/fibroblasts, endothelial
3. permanent (non-dividing) - cardiac, skeletal myocytes, CNS neurons (if cells don’t divide, no primary cancers- secondary cancers can migrate)

Question 3

what occurs after stress on the cell?

Answer 3

cell adaptation or inability to adapt leads to cell injury and then (nercrosis or apoptosis) - cell death

Question 4

LO: define types of cellular adaptation and understand when these processes are not possible/reversible

Answer 4

1. autophagy- self eating, engulfs damaged or dangerous material to remove
2. hypertrophy- increased size of cell
3. hyperplasia- increased number of cells
4. metaplasia- the change from one cell type to another cell type where it is not normally found

all reversible except atrophy in permanent tissue (cell death)

Question 5

what is apoptosis definition

Answer 5

apoptosis- a programmed cell death, cell suicide so that neighbouring cells are not induced and inflammation does not occur

Question 6

what is nercosis? and what does it cause

Answer 6

necrosis- a sudden, messy death due to lack of supply etc (contents spilled out) causing:
1. neighbouring cells induced to undergo nercosis also (area of nercotic tissue - infarct
2. stimulation of acute inflammation
3. loss/reduced function of tissue (scarring, calcification, death

Question 7

LO: describe the main differences between apoptosis and necrosis 4

Answer 7

1. apoptosis occurs in physiology and pathology, nercosis is pathological
2. apoptosis is active (requires energy), necrosis is passive
3. a single cell can die by apoptosis, a necrotic cell kills neighbouring cells
4. apoptosis doesnt cause inflammation, necrosis does

Question 8

LO: what is an infarct and how does it occur?

Answer 8

Infarction is tissue death or necrosis due to inadequate blood supply to the affected area. It may be caused by artery blockage, rupture, mechanical compression, or vasoconstriction

Question 9

LO: what determines whether a stimulus causes atrophy or infarction?

Answer 9

atrophy- slow, gradual stress on cells (apoptosis/autophagy)

infarction- sudden severe stress. eg complete blockage of blood.

depends on stressor

Question 10

LO: what effect does aging have on cells and organs?

Answer 10

less likely to undergo autophagy, therefore more cell death occurring as a result

Question 11

what cellular adaptations would occur in a pregnant uterus?

Answer 11

epthithial layer (endometrium) undergoes HYPERPLASIA- increased number of cells

the deeper smooth muscle layer (mypmetrium) undergoes HYPERTROPHY- increased size of cells

Question 12

what cellular adaptations would occur in the uterus post menopause

Answer 12

apoptosis - active programmed cell death leading to atrophy of the tissue

Question 13

during embryogenesis, what cellular adaptation occurs and does it lead to inflammation

Answer 13

apoptosis and no, active programmed cell death so it is contained

Question 14

after birth of a child what cellular adaptations would the uterus undergo?

Answer 14

the epithelial cells that has undergone hyperplasia would undergo apoptosis- programmed cell death

the deeper smooth muscle cells that had undergone hypertrophy would undergo autophagy- decrease in cell size

Question 15

necrosis is (4)

Answer 15

passive form of cell death- doesnt use energy to contain

kills neighbouring cells from an infarct

does not occur in physiology

stimulates an acute inflammatory response

Question 16

apoptosis is (4)

Answer 16

active form of cell death

contained death that doesn’t kill neighbouring cells

occurs in physiology and pathology

does not cause acute inflammation

Question 17

where is the prostate gland located and what are its functions

Answer 17

epithelial gland that surrounds the male uretha just below the bladder.

the secretions from the prostate gland form part of the ejaculate, which provide nutrients to the sperm and show antibacterial properties

Question 18

what cellular processes can occur within the prostate gland and bladder?

Answer 18

prostate- believed to originally be prostatic hyperplasia, however it is now believed to be failure of apoptosis. old cells that should be dying are being kept alive leading to an increase in size of the gland.

bladder- the enlarged prostate causes contriction on the uretha leading to urinary retention within the bladder. hypertrophy occurs in the bladder due to this.

Question 19

what could cause the testicle to atrophy and what cellular adaptations are involved?

Answer 19

cyst, tumour, arterial disease atherosclerosis, hormonal abnormalities

anything that slowly puts pressure on the tissue to reduce blood or nerve supply, this will cause the cells to shrink through autophagy and die by apoptosis

Question 20

what type of cell type are most metaplasia cells turning into and why

Answer 20

stratified squamous as they are more resistant to irritation

Question 21

is metaplasia an active and passive process

Answer 21

active

Question 22

is metaplsia reversible?

Answer 22

yes if the environment changes back or the stress is removed

Question 23

what is the difference between young and old people and tissue atrophy

Answer 23

for young it often includes both autphagy and apoptosis, whereas old its just apoptosis

Question 24

if a permanent cell type organ atrophies, can it be reversed?

Answer 24

no, the cells are unable to proliferate, therefore the cells lost through apoptosis will not be replaced

however, the cells that had shrunk through autophagy could undergo hypertrophy to restore the size of the organ, but will not have the same functional reserve it once had. this is also dependent on age if autophagy occurs.

Question 25

what tissues in the human body atrophies with age?

Answer 25

all but the prostate gland in men

senile atrophy

Question 26

senile atrophy is caused by

Answer 26

reduced hormones/growth factors and is exacerbated by vascular disease

Question 27

why is pathological hypertrophy of the heart a bad thing?

Answer 27

the heart is less dynamic and there is further for
oxygen, nutrients and wastes to diffuse to get to and from cells.

As hypertrophy increases, muscle
contraction becomes less efficient and the valves of the heart may malfunction all of which
increases the risk of myocardial infarction &/or failure

Question 28

what is the difference between this and an exercise induced hypertrophied heart?

Answer 28

more uniformly hypertrophied across the chambers.
increases in cardiac output during their workout but their resting heart rate is usually lower than average. increase in elastic fibres, capillary density,
mitochondrial number and energy efficiency

Question 29

atrophy is

Answer 29

tissue/organ shrinkage through cellular apoptosis or apoptosis and autophage (opposite of hypertrophy)

Question 30

what is autophagy

Answer 30

cell reduces in size by eating itself (still alive, not cell death)

Question 31

infarction is

Answer 31

area of necrosis

Question 32

ischaemia

Answer 32

lack of blood supply, might be partial or complete.
partial can be reversed

Question 33

examples of permenant tissues/non dividing cells

Answer 33

cardiac/skeletal myocyctes, CNS neurons

Question 34

examples of stable tissues

Answer 34

some epithelial cells: eg liver, kidney, lungs and pancreas
smooth muscle cells,
fibroblasts, endothelial cells

Question 35

examples of labile tissues

Answer 35

some epithelial cells eg lining of skin, GIT, reproductive and urinary tracts
haemopoietic stem cells

Question 36

what cellular adaptations lead to an increase in overall size of an organ

Answer 36

hyperplasia and hypertrophy

Question 37

when is atrophy not reversible?

Answer 37

in permanent cells

Question 38

what cellular adaptations lead to a decrease in overall size of an organ

Answer 38

apoptosis and autophagy

Question 39

what is the term given to secretory epithelial cells

Answer 39

glandular

Question 40

what type of epithelium is best at withstanding physical stress

Answer 40

straitified squamous epithelium

Question 41

what cellular adaptation will occur in a heart that is forced to work harder

Answer 41

hypertrophy

Question 42

will there be an inflammatory response if an infarct occurs to the heart or brain

Answer 42

yes if theyre still alive

Question 43

when cells undergo metaplasia are they conidered normal or abnormal

Answer 43

theyre still normal cells