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Flashcards in growth and ageing Deck (24)
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1

growth can involve 2 cellular changes, what are these?

- increase in cell numbers (hyperplasia)
- increase in cell size (hypertrophy)

2

which cells cannot regenerate?

neurons

3

growth can be affected by which 2 factors?

- genetic
- environmental

4

humans have 2 main growth phases, when are these?

- birth
- around 12

5

name hormones that influence growth

- thyroid hormone
- growth hormones
- sex hormones
- insulin
- cortisol
- parathyroid hormone

6

thyroid hormone is essential for normal growth and development, what role does it play?

- essential fro protein synthesis in foetal/infant brain
- required for normal development of neurons
- necessary for childhood growth
- facilitate action of growth hormone and sympathetic nervous system

7

what effect might hypothyroidism have on a growing child?

- impede brain and skeletal growth
- delayed tooth eruption
- growth defects

8

what re the metabolic actions of growth hormone?

- increase blood glucose
- decrease glucose uptake by cells
-increased lipolysis (make fatty acids available)
- facilitate uptake of amino acids for proteins synthesis
- cartilage/bone/soft tissue/viscera growth

9

describe hypothyroid dwarfism

- missing thyroid hormone
- infant proportions

10

describe hypopituitary dwarfism

- missing growth hormone
- normal proportions

11

which 2 hormones are responsible for the pubertal growth spurt?

oestrogen and testosterone

12

the effects of oestrogen and testosterone are mediated by an increase in which 2 hormones?

GH and IGF-1

13

what effects do oestrogen and progesterone have on bone growth?

- stimulate bone growth
- accelerate closure of epiphyseal growth plates

14

describe the anabolic effect of testosterone

-effect on protein synthesis increasing muscle bulk

15

insulin has no direct effect on growth, how does it contribute indirectly?

- promote foetal growth
- promote post-natal growth by stimulating IGF-1
- facilitate protein synthesis

16

cortisol, when present in high levels, has what effect on growth?

inhibits it

17

what effects does cortisol have on growth?

- stimulate protein catabolism
- suppress bone growth and promotes resorption

18

what role do Vii D and parathyroid hormone play in growth?

- ensure adequate amounts of calcium and phosphate areavaailable for bone formation
- Vit D absorbs calcium from gut
- PTH raises plasma calcium levels

19

what effect does excess growth hormone have on children?

accelerates growth - gigantism

20


what effect does excess growth hormone have on adults?

acromegaly

21

which bone enlargens due to pituitary tumour?

sella turcica

22

what is the name for defective cartilage growth?

achondroplasia

23

what is the definition for ageing?

gradual deterioration of all parts of the body

24

what happens to cells during ageing?

- decline in the ability of them to divide
- as they divide there is an accumulation of damage (error in DNA, abnormal proteins, damaged organelles)
- free radicals