chapter 10

Question 1

GROWTH

Answer 1

• an increase in physical size of the body

Question 2

DEVELOPMENT

Answer 2

• an increase in the complexity of function

Question 3

GROWTH STUDY DESIGN

Answer 3

1. Cross Sectional
2. Longitudinal
3. Mixed Longitudinal

Question 4

WHAT IS GROWTH?

Answer 4

• change from a single cell to multicellular stages
• change in size, mass and shape
• change in function of organs and glands
• change in complexity of
structure

Question 5

THREE PRINCIPLES OF GROWTH

Answer 5

1. Growth is a Continuous Process
2. There are Inter-individual
   Differences in Growth Rates
3. There are Inter-individual
   Differences in Growth Rates

Question 6

what are the different ways we can illustrate growth:

Answer 6

• the growth curve
• the growth velocity curve
• changes in body shape

Question 7

GROWTH OF BONE

Answer 7

• Bone is formed by the deposition of crystals of
calcium in a matrix of fibres and carbohydrate.
• For bone to form properly there must be a constant
supply of matrix + calcium + vitamins C & D (all transported via the blood).
• Osteoblastic and osteoclastic activity are controlled by the influence of a number of hormones (later).

Question 8

GROWTH OF SHORT BONES

Answer 8

Growth of the cartilage model (chondrogenesis) precedes the formation of short bones in an indirect ossification process.

Question 9

GROWTH OF LONG BONES

Answer 9

• Ossification of the long bones begins at the periphery
  of the bone shaft to form a bone collar.
• The bone enlarges and elongates by adding bone to the surface (osteoblastic activity), after removing it from the interior of the shaft (osteoclastic activity).
• Secondary centres of ossification are formed at the ends and longitudinal growth continues at the epiphyseal plates.

Question 10

The embryonic period

Answer 10

1- fertilization
2- mitosis
3- further division of daughter cells
4- further division and organ development

Question 11

what do the organs develop into from the germ layers

Answer 11

Endoderm – digestive tract, liver, pancreas
Mesoderm – bone, muscle
Ectoderm – nervous tissue, skin epidermis, hair

Question 12

THE FOETAL PERIOD

Answer 12

From 2 months onwards, this period is characterised

by an increase in length, bulk and complexity.

Question 13

what is the 3-way interaction in the control of growth

Answer 13

• genes
• hormones
• environment

Question 14

When does the growth process begin & end?

Answer 14

fertilization of the ovum and continues through life

Question 15

What are the 3 principles of growth?

Answer 15

• Continuous process
  • Inter individual differences
  • Intra individual differences

Question 16

HORMONAL CONTROL

Answer 16

Hormones are produced by the endocrine glands.
The basic control over all glands is by the hypothalamus,
which is linked directly to the master gland - the hypophysis or pituitary gland.

Question 17

ACTH - Adrenocorticotropic Hormone

Answer 17

Responsible for triggering the growth spurt

Question 18

Hormones from Parathyroid Gland

Answer 18

Control the amount of calcium in the blood to assist ossification

Question 19

Effect of Hormones on Body Form

Answer 19

masculine - ‘android’ (wide shoulders - narrow hips,
muscle development, baldness, body hair, etc), or
feminine- ‘gynoid’, is partly determines by this hormonal mix (also genetic).

Question 20

ENVIRONMENTAL CONTROLS

Answer 20

Climate
Nutrition
Illness
Secular Trends
Exercise
Psychological Factors
Socio-economic Factors
Family Size