Growth and Development

Question 1

What is growth?

Answer 1

Positive change in size, often over a period of time.

Question 2

What is development?

Answer 2

The process of growth to maturity.

Question 3

What are the life stages?

Answer 3

• Infancy: birth to 1 year.
• Early childhood: 1-6 years.
• Late childhood: 6-12 years.
• Adolescence: 12-20 years.
• Early adulthood: 20-40 years.
• Middle adulthood: 40-65 years.
• Late adulthood: 65 years.
• Death.

Question 4

What factors affect growth and development?

Answer 4

1) . Prenatal and birth factors.
2) . Genetic/chromosomal factors –> inherited.
3) . Racial factors.
4) . Endocrine system.
5) .Drugs.
6) . Illness - children grow slower during illness.
7) . Nutrition.
8) . Environment.
9) . Stress.

Question 5

What are the developmental stages of embryology?

Answer 5

1) . Fertilisation.
2) . Cleavage.
3) . Gastrulation.
4) . Neurulation.
5) . Organogenesis.

Question 6

What is the stage of fertilisation?

Answer 6

Day 1.

• Sperm and ovum join together to form a zygote.

Question 7

What is the stage of cleavage?

Answer 7

Week 1-2.

• Mitotic cell division of the fertilised egg which produces the blastocyst, a hollow ball of cells.

Question 8

What is the stage of gastrulation?

Answer 8

Week 3.

• Cell movement in which 3 layers develop –> 3 layered embryo.

Question 9

What is the stage of neurulation?

Answer 9

Week 3-4.

• Neural plate fold in upon itself to form the neural tube –> this will form the brain and spinal cord.

Question 10

What is the stage of organogenesis?

Answer 10

Weeks 3-8.

• The internal organs develop from the ectodern, endoderm and mesoderm.

Question 11

What are the 3 germ layers that develop during the gastrulation stage?

Answer 11

1) . Ectoderm –> outside layer.
2) , Endoderm –> inside layer.
3) . Mesoderm –> middle layer.

Question 12

What do the 3 germ layers produce?

Answer 12

1) . Ectoderm
- Skin cells of epidermis.
- Neuron of brain.
- Pigment cell.
2) . Endoderm
- Lung cell (alveolar cell).
- Thyroid cell.
- Pancreatic cell.
3) . Mesoderm
- Cardiac muscle.
- Skeletal muscle cells.
- Tubule cell of the kidney.
- red blood cells.

Question 13

What are the 4 types of growth and development?

Answer 13

1) . Physical: body growth.
2) . Mental: mind development.
3) . Emotional: feelings.
4) . Social: interactions and relationships with others.

Question 14

When do the 4 types of development occur?

Answer 14

In each stage of growth and development.

Question 15

What is human physical growth?

Answer 15

Increase in size/number of cells –> increase in overall size.

Question 16

When does most rapid growth take place?

Answer 16

In utero –> first 2 years of life and adolescence.

Question 17

How is growth measured?

Answer 17

• Weight.
• Length.
• Head circumference.
• Skinfold thickness.

Question 18

How does the growth velocity change in the first 2 years?

Answer 18

Growth velocity is high, but falls from over 200 to 90mm/year.

Question 19

How does the growth velocity change 12 to 14 years?

Answer 19

Sharp increase in growth velocity from 70 to 100mm/year.

Question 20

What are the main hormones responsible for the 2 growth spurts?

Answer 20

Growth hormone

• sex hormones (testosterone, oestrogen) are responsible for the adolescence growth spurt.

Question 21

What are the 2 growth trends?

Answer 21

• Cephalocaudal.

- Proximodistal.

Question 22

What is the cephalocaudal trend in growth?

Answer 22

• Grow from head down.

- Head and chest grow first before legs.

Question 23

What is the proximodistal trend in growth?

Answer 23

• Center of the body grows outward.

- Arms and legs grow before hands.

Question 24

What gland/hormones are important in growth?

Answer 24

1) . Thyroid –> thyroxine.
2) . Adrenal –> adrenal androgen.
3) . Testes –> testosterone.
4) . Ovaries –> Estradiol.
5) . Pituitary –> growth hormone + activating hormones.

Question 25

How does thyroxine affect growth?

Answer 25

Normal brain development and overall rate of growth.

Question 26

How does adrenal androgen affect growth?

Answer 26

Involved in some changes at puberty –>

• particularly the development of secondary sex characteristics in girls.

Question 27

How does testosterone affect growth?

Answer 27

• Formation of male genitals.

- Triggers changes in primary/secondary sex characteristics at puberty in males.

Question 28

How does estradiol affect growth?

Answer 28

Development of menstrual cycle and breasts in girls.

Question 29

How does the growth hormone + activating hormone affect growth?

Answer 29

• Rate of physical maturation.

- Signals other glands activating to secrete hormones.

Question 30

What is experience-expectant growth in the brain?

Answer 30

• Ordinary experiences “expected” by brain to grow normally.

Question 31

What is experience-dependent growth in the brain?

Answer 31

• Specific experience, varies widely.