Chapter 9 Flashcards
TorF: Body systems are influenced by extrinsic factors.
True
TorF: Ossification begins at primary ossification centres in the midportions of long bones.
True
TorF: Growth in bone length occurs at primary ossification centres.
False. Growth in bone length occurs at secondary ossification centres at the ends of a bone shaft (epiphyses).
What is bone growth called?
Appositional bone growth
Loss of muscle mass is minimal until what age?
Age 50
At what age does adipose tissue first appear in the fetus?
3.5 months
What is hyperplasia?
The increase in growth of organs and tissues by cell development
What is hypertrophy?
The increase in size of skeletal muscle through a growth in size of its component cells
Which is more significant after puberty? Hyperplasia or hypertrophy?
Hypertrophy
Define the endocrine system
Plays a role in regulating growth and maturation through chemical substances - hormones
What are the major hormones involved in growth? What do these hormones do?
Growth hormones (GH)
Thyroid hormones (TH)
Gonadal hormones (estrogen, androgens, and testosterone)
These hormones stimulate protein anabolism (constructive metabolsim/tissue building)
Where is the growth hormone secreted?
Anterior pituitary gland
What is the role of gonadal hormones?
They influence growth and sexual maturation - sex organs and secondary sex characteristics
What is an important role of the placenta in relation to hormones?
The placenta produces its own hormone and serves as a barrier to prevent the mother’s hormones from impacting the fetus’ system
Growth after birth involves these factors:
- Increases in size of neurons
- Prolific branching to form synapses
- Increases in glial cells for support and nourishment of neurons
- Increases in myelin to insulate axons
