Growth and development

Question 1

prenatal development stages

Answer 1

Ovum
Embryonic
Fetal

Question 2

Ovum Phase

Answer 2

Shortest phase
cleavage-massive increase in cell # and decrease in cell size
increase in DNA, with no protein synthesis

Question 3

Embryonic phase

Answer 3

formation of ectoderm, mesoderm, and endoderm
starts to take form

Question 4

Fetal phase

Answer 4

Starts to look like something else, organ and tissue development

Question 5

Muscle cells

Answer 5

cells that are designed for a specific type of tissue or structure are called determined or committed cells

Question 6

myoblasts (muscle regulatory genes)

Answer 6

capable of making new myoblasts
don’t contain contractile proteins

Question 7

differentiate

Answer 7

stop dividing

Question 8

align

Answer 8

membrane fuse to form an immature muscle fiber (myotube)

Question 9

myotube (more=bigger muscle)

Answer 9

Scaffolding for the formation of muscle fibers

Question 10

What will myoblasts do to the myotubes

Answer 10

myoblasts will align themselves along the primary myotubes

Question 11

What do myotubes and myoblasts do together

Answer 11

fuse together to form secondary tube

Question 12

What happens after formation of secondary tube

Answer 12

intervention occurs
splinter away (receives a nerve)
forms myofibers

Question 13

Myogenesis

Answer 13

occurs during the firs 2/3 of prenatal development

Question 14

What matures quicker and slower?

Answer 14

bone and muscle - quicker
fat - slower

Question 15

Determinant growth

Answer 15

grow to a given size (mammals)

Question 16

Indeterminate growth

Answer 16

no predetermined size, will grow to available nutrients and environment, can create muscle fibers

Question 17

Post natal growth

Answer 17

Phase 1-4 and myogenesis

Question 18

Phase I

Answer 18

15-20% total growth
slow growth of all tissue
organs, bone, muscle

Question 19

Phase II

Answer 19

75% of total growth
organ and bone growth complete
muscle hitting maximal growth
fat accumulates slowly

Question 20

Phase III

Answer 20

80-90% of growth complete and of muscle deposited
rapid accumulation of fat

Question 21

Phase IV

Answer 21

90-95% of additional growth is fat
5-10% of gain is muscle

Question 22

Myogensis

Answer 22

Muscle coming to be
Hypertrophy
Hyperplasia

Question 23

Hypertrophy

Answer 23

Increase in cell size (post natal)

Question 24

Hyperplasia

Answer 24

Increase in cell # (prenatal)

Question 25

Muscle growth

Answer 25

increase in muscle fiber radial longitudinal

Question 26

radial muscle growth

Answer 26

fibers split to form new myofibers induced hypertrophy

Question 27

longitudinal muscle growth

Answer 27

stretch induced hypertrophy bone growth add sarcomeres growth occurs at the end of the muscle

Question 28

Protein turnover

Answer 28

process of building protein replacing it with newly synthesized protein

Question 29

protein accretion

Answer 29

more synthesis than degradation

Question 30

atrophy

Answer 30

more degradation than synthesis

Question 31

protein degradation

Answer 31

proteolysis breaking down proteins into peptides and amino acids

Question 32

lysosomal system

Answer 32

sarcoplasmic proteins 25-30%

Question 33

calpain system

Answer 33

post mortem tenderness majority of protein degradation

Question 34

ubiquitin-proteosome proticolytic pathway

Answer 34

binds to protein, targets the protein for degradation

Question 35

Satellite cells

Answer 35

differentiate and enter the cell create more DNA units more protein synthesis hypertrophy

Question 36

factors that affect growth

Answer 36

genetics, nutrition, hormones, growth promotants

Question 37

Genetics

Answer 37

double muscled, increases in fibers and myotubes, mutation of myostatin gene

Question 38

Nutrition

Answer 38

Poor nutrition can affect muscle size

Question 39

Sex hormones

Answer 39

testosterone, increase bone growth, increase protein synthesis

Question 40

estrogen

Answer 40

facilitates fat deposition, stimulates muscle growth, very anabolic in ruminants

Question 41

Growth hormone or somatropin

Answer 41

production of insulin, increase protein synthesis and decrease protein degradation, increases lipolysis

Question 42

Insulin

Answer 42

increases storage of glucose and glycogen, fatty acids, amino acids

Question 43

Leptin

Answer 43

decrease food intake, increase energy expenditure, decrease fat mass

Question 44

Growth promotants

Answer 44

increase muscle cell size, beef and swine implants