Module 1A pt 2

Question 1

Homeostasis

Answer 1

• The maintenance of steady state by the bodys internal control system
  
  • The goal of treatment

Question 2

Cellular homeostasis

Answer 2

• Referes to the maintenance of a constant internal state in a changing environment
• A state of balance
  -Each cell in a multicellular organism needs to maintain homeostasis

Question 3

What does the cell need to survive

Answer 3

• Obtain and use energy
  
  • Make new cells
  • Exchange materials
  • Eliminate waste

Question 4

How is cellular homeostasis achieved

Answer 4

• Through diffusion, osmosis (passive transport)
  
  • Active transport which requires energy

Question 5

Diffusion

Answer 5

• The process of movement along a concentration gradient from high concentration to low concentration

Question 6

Two ways diffusion can happen

Answer 6

• Across the phospholipid bilayer (simple diffusion)
  
  • Through the protein channels (facilitated diffusion)

Question 7

How does diffusion maintain cellular homeostasis

Answer 7

• Cellular food (glucose, oxygen…) can diffusing into the cell
  
  • Waste products can diffuse out of the cell

Question 8

Osmosis

Answer 8

• The diffusion of water to balance out the concentration of other molecules
  
  • The water follows the concentration gradient

Question 9

How does osmosis maintain cellular homeostasis

Answer 9

• It maintains a specific water balance which is needed for chemical reactions
  -Balances out the concentration of other molecules

Question 10

Active transport

Answer 10

• Needs atp
  -Used when things need to move against concentration gradient

Question 11

How does active transport maintain cellular homeostasis

Answer 11

• To get needed materials into the cell that have a higher concentration within

Question 12

Are all the purposes of cells responding to change beneficial

Answer 12

No some can be detrimental

Question 13

Ways cells respond to change (5)

Answer 13

• Atrophy
• Hypertrophy / hyperplasia
• Metaplasia
• Dysplasia
  -Increased enzyme synthesis

Question 14

Atrophy

Answer 14

• A reduction in size of the cells
  
  • Response to diminished function, inadequate hormonal or neuronal stimulation, reduced blood supply
  • Example is how a muscle gets smaller after wearing a cast

Question 15

Hypertrophy

Answer 15

• An increase in sie of each cell without an increase in number of cells
  
  • Example is muscles getting bigger in weight lifters

Question 16

Hyperplasia

Answer 16

• An increase in the size of a tissue or organ caused by an increase in the number of cells
  
  • Example benign prostatic hyperplasia (BPH)

Question 17

BPH

Answer 17

• Benign prostatic hyperplasia
  
  • The prostate increases in size and leads to difficulty in urination

Question 18

What is more likely to result in an increase in the number of drug receptors

Answer 18

• Hyperplasic tissue (adds more cells

Question 19

Metaplasia

Answer 19

• A change from one type of cell to another that can tolerate a new environmental condition
  -Example: the ciliated columnar lining of the trachea turns into squamous epithelium to provide more protection in cig smokers (often the place where cancer can begin but not the cause of cancer

Question 20

Dysplasia

Answer 20

• The development and maturation of cellds that are disturbed and abnormal
• Associated with chronic irritation or inflammation
  -Can progress to neoplasia

Question 21

Neoplasia

Answer 21

• Formation of a tumour

Question 22

Increased enzyme synthesis

Answer 22

• A response to increased demand to cell to synthesize more enzyme from the smooth endoplasmic reticulum
  
  • Has an impact on other substances that enzyme also metabolizes
  • Example: alcoholics produce more enzymes to metabolize it so it can eliminate it faster

Question 23

Cell injury

Answer 23

• Can be reversed if the cause is removed and normal cell function restored
  
  • If the injury exceeds the ability of the cell to recover–> death

Question 24

Cell swelling

Answer 24

• Occurs when the transport mechanism fails (can be from no atp present) (sodium and water follows) into the cell which causes it to swell
  
  • Can be revered if energy production recommences

Question 25

Hydropic swelling

Answer 25

If the swelling continues fluid filled vacuoles accumulate

Question 26

Does water or sodium go into the cell first

Answer 26

sodium, water follows

Question 27

Steatosis

Answer 27

• Cell injury through fatty change
• Normal function through enzyme systems; fat is metabolized and exported
• Occurs when the enzyme systems are impaired leading to accumulation of fat droplets within the cytoplasm
  -Commonly occurs in liver

Question 28

Why is cell swelling and fatty change bad

Answer 28

• First sign of cellular injury
• Changes the structure of the cell
  -Swelling of multiple cells in an organ increase pallor (lighter colour), turgor (normal tension in living cells), and weight

Question 29

Necrosis

Answer 29

• Cell death
  -Cell death will occur when the injury is not reversible

Question 30

Infarction

Answer 30

Lack of blood supply

Question 31

What happens when cells die

Answer 31

• Mitochondria changes shape and developed calcium deposits
  
  • Lysosomal enzymes are released and digest the cell
  • Cell membrane ruptures
  • Nucleus shrinks and breaks into fragments or dissolves
  • May result in calcium deposition in tissue (can be used to detect necrosis)

Question 32

Apoptosis

Answer 32

• Programmed cellular self destruction
• Normal, if doesn’t happen when it should can cause disease
  -Doesn’t need to be injured to die, uterine tissue during menstruation is lost

Question 33

How is apoptosis begun and does it provoke a host response

Answer 33

• It can be started by an immune response, hormone response, number of cell divisions..
  -It does not provoke a host response (immune response or inflammation)

Question 34

Cell aging

Answer 34

• All cells age and then die
• Normal cells undergo the hayflick limit
• Once limit reached cell undergoes apoptosis
• Stem cells are immune to the hayflick limit
  -Some cancer cells activate repairing mechanism and can divide indefinitely

Question 35

Hayflick limit

Answer 35

The fixed number of divisions that normal cells undergo before they die

Question 36

Do all cells age the same

Answer 36

• No different organ systems are more susceptible
  
  • Neurons are incapable of division
  • Organs with constantly dividing cells are more prone to cancer
  • Enzyme systems become less active and the cells are less resilient to chemical influences like reactive oxygen species or environmental agents