Adipose Growth

Question 1

For adipose growth, what is critical for the formation of visceral/subcutaneous adipocytes?

Answer 1

Fetal hyperplasia

Question 2

For adipose growth, what establishes the potential of intramuscular fat?

Answer 2

Perinatal hyperplasia

Question 3

In prenatal growth, does hyperplasia or hypertrophy happen?

Answer 3

Hyperplasia

Question 4

True or False: Postnatal growth of fat depots relies mainly on hypertrophy and hypertrophy happens

Answer 4

FALSE - Postnatal growth of fat depots relies mainly on hypertrophy but hyperplasia happens

Question 5

Postnatal adipose growth is through increasing….

Answer 5

…diamter and volume of adipocytes (hypertrophy)

Question 6

Adipoblast ___________ is limited and continues after birth.

Answer 6

hyperplasia

Question 7

New adipocytes differentiate from ___________ that are found in _______ __________ ________ from which fat originally develops.

Answer 7

adipoblasts, loose connective tissue

Question 8

Name the factors affecting adipose tissue composition and metabolism.

Answer 8

• Age
• Anatomical location
• Species
• breed/strain
• Sex
• Hormones
• Nutrition
• Environmental temperature
• physical activity

Question 9

Changes occur in fat tissue composition with age.

What’s the composition of fat tissue in young animals? In old animals?

Answer 9

• Young animals:
  Small adipocytes, low % lipid, and high % protein and water
• Old animals:
  Large adipocytes, high % lipid, low % protein and water

Question 10

How does anatomical location affect adipose tissue composition and metabolism?

Answer 10

Different fat depots throughout the body accumulate at different rates during development.

For instance, adipose tissue that develop early usually accumulate more fat compared to those that develop late.

Question 11

How do species affect adipose tissue composition and metabolism?

Answer 11

There is variability in adipose composition due to differences in lipid metabolism.

For instance, species with different environmental needs have evolved adipocytes of different size, number, and composition.

Question 12

How does breed/strain affect adipose tissue composition and metabolism?

Answer 12

Different breeds or genetic lines within a species vary in their ability to deposit adipose tissue. They also exhibit distribution of fat between adipose tissues.

Question 13

How does sex affect adipose tissue composition and metabolism?

Answer 13

Sex just influences fat distribution.

Question 14

How do hormones affect adipose tissue composition and metabolism? Name them and what they affect.

Answer 14

Hormones have significant effects on adipose tissue composition and metabolism:

1) Insulin - lipogenic (promotes lipid synthesis)
2) Growth Hormone - lipolytic (promotes lipid breakdown)
3) Glucagon - lipolytic
4) Insulin-like growth factor (IGF) - lipogenic/lipolytic
5) Glucocorticoids - lipolytic
6) Catecholamines - lipolytic
7) Thyroid hormones - lipolytic
8) Leptin - reduces appetite and feed intake

Question 15

How does nutrition affect adipose tissue composition and metabolism?

Answer 15

Reduced energy intake induces lipolysis so that fatty acids are released for oxidation.

Amino acid/protein deficiencies will result in increased lipogenesis because lean tissue accretion cannot be maximized.

Question 16

How does environmental temperature affect adipose tissue composition and metabolism?

Answer 16

When temperatures drop below the thermoneutral zone, adipose tissue will be mobilized to produce heat.

Question 17

How does physical activity affect adipose tissue composition and metabolism?

Answer 17

Work and exercise modify the amount of lipid contained in the body. It also promotes lipolysis to meet increased energy requirements.