Cell Growth, Differentiation, Adaptation

Question 1

What is development?

Answer 1

the successive process of systemic gene-directed changes throughout an organisms life cycle

Question 2

What are the 4 subprocesses of development?

Answer 2

1. growth 2. differentiation 3. pattern forming 4. morphogenesis

Question 3

What is the cell cycle?

Answer 3

growth + synthesis + mitosis

Question 4

Define growth?

Answer 4

the increase in cellular mass as a result of metabolism

Question 5

Define synthesis?

Answer 5

the production of DNA and RNA to regulate cellular activity

Question 6

Define mitosis?

Answer 6

division of nucleus and cytoplasm of cell resulting in the formation of 2 daughter cells with identical DNA to the parent cell

Question 7

What are the 2 major phases of the cell cycle?

Answer 7

interphase and mitosis

Question 8

What limits cell growth?

Answer 8

1. stress on DNA 2. difficulty moving nutrients/waste across membrane

Question 9

What is cell growth?

Answer 9

increase in the number of cells, length, girth through cell division and cleavage

Question 10

What is cleavage?

Answer 10

rapid mitotic cell division of the diploid zygote after fertilization to form blastomeres

Question 11

What is alometric growth?

Answer 11

different growth rates of parts within the same organsim e.g. legs grow faster than head

Question 12

What is a stem cell?

Answer 12

unspecialized cells from which differentiated cells develop

Question 13

What are adult stem cells?

Answer 13

cells that differentiate to renew and replace cells in the adult body - have limited potential

Question 14

What are the types of stem cells? TEMP

Answer 14

1. multipotent 2. pluripotent 3. totipotent 4. embryonic

Question 15

What are pluripotent stem cells?

Answer 15

cells that can develop into most but not all cell types

Question 16

What are multipotent stem cells?

Answer 16

stem cells that can differentiate into a limited number of cell types

Question 17

What are totipotent stem cells?

Answer 17

stem cells that can differentiate into every type of cell e.g. fertilized egg

Question 18

What are embryonic stem cells?

Answer 18

can make different types of cells e.g. pluripotent or multipotent

Question 19

What are the 3 types of tissues?

Answer 19

1. stable 2. labile 3. permanent

Question 20

What is labile tissue?

Answer 20

has high cell turnover, cells have short life span, shows continuous mitotic division - have high regenerative capacity e.g. skin

Question 21

What is stable tissue?

Answer 21

has low cell turnover, cells have a long life span, mitosis is rare or absent e.g. liver cells (hepatocytes)

Question 22

What is permanent tissue?

Answer 22

cell division does not take place e.g. neurons

Question 23

What is regeneration?

Answer 23

replacing of dead/damaged cells

Question 24

What is cellular differentiation?

Answer 24

the process by which cells become specialized

Question 25

What are the stages of cellular differentiation?

Answer 25

1. differential inheritance of cytoplasmic determinants 2. cell to cell interaction - induction

Question 26

What are the 3 germ cell layers?

Answer 26

1. ectoderm 2. mesoderm 3. endoderm

Question 27

What are the 4 primary tissues?

Answer 27

1. epithelial tissue (endoderm, mesoderm, ectoderm) 2. connective tissue (from mesoderm) 3. muscle (from mesoderm) 4. nervous (from ectoderm)

Question 28

Explain the process of celluar differentiation?

Answer 28

1. differential inheritance of cytoplasmic determinants - transcription factors turn genes off and on and are located in a certain area of the cell so when the cell divides and become part of one of the cells they decide what that cell will specialize into 2. cell to cell interaction - the change in fate of a cell due to interaction with an adjacent cell (induction), either through physical contact or signals

Question 29

What is cell adaption?

Answer 29

cell changes in response to the environment/stimuli

Question 30

What are the 4 main adaptive phases?

Answer 30

1. atrophy 2. hypertrophy 3. hyperplasia 4. metaplasia

Question 31

What is atrophy?

Answer 31

shrinkage of an organ as a result of a decrease in cell size and/or number after normal growth has been reached

Question 32

Causes of atrophy? DOID

Answer 32

1. gradual and continuous injury 2. organelles decrease 3. deficient nutrient supply e.g. liver atrophy due to decreased blood flow through the portal vein 4. decreased workload e.g. muscle fiber atrophy

Question 33

What is hypertrophy?

Answer 33

enlargement of an organ as a result of increased cell size

Question 34

Causes of hypertrophy?

Answer 34

1. increases in size due to synthesis of more structural elements 2. increased functional demand e.g. pregnant uterus enlarges due to hormone-induced increase 3. endocrine stimulation of reproductive organs e.g. prolactin and estrogen cause mammary hypertrophy during lactation

Question 35

What is hyperplasia?

Answer 35

enlargement of an organ through an increase in cell number

Question 36

Causes of hyperplasia?

Answer 36

induced by hormonal stimuli or chronic irritation

Question 37

What is metaplasia?

Answer 37

change in tissue type due to replacement of one differentiated cell by another

Question 38

What is apoptosis?

Answer 38

cell death as a part of normal controlled development

Question 39

What is necrosis?

Answer 39

cell death due to disease or injury