Integument physiology

Question 1

What are the main functions of the integument?

Answer 1

Protection, sensory perception, thermoregulation, vitamin D synthesis, and excretion. It also serves as a barrier against mechanical, chemical, and microbial damage.

Question 2

What is thermoregulation and why is it important for homeostasis?

Answer 2

Thermoregulation is the maintenance of a stable internal body temperature despite environmental changes. It is vital for homeostasis because most biochemical processes require optimal temperatures to function properly.

Question 3

How does temperature regulation function as a negative feedback mechanism?

Answer 3

The hypothalamus acts as the control center. When body temperature deviates from its set point, thermoreceptors send signals to the hypothalamus, which activates effectors (e.g., blood vessels, sweat glands, muscles) to restore balance. Once normal temperature is reached, the response stops.

Question 4

What are the main mechanisms of heat production in animals?

Answer 4

Metabolic processes, muscle activity (shivering thermogenesis), non-shivering thermogenesis via brown adipose tissue, and hormonal regulation (thyroxine).

Question 5

How do animals conserve heat?

Answer 5

Vasoconstriction of peripheral vessels, piloerection (raising hairs/feathers), behavioral adaptations (seeking shelter, huddling), and insulation via fat or fur.

Question 6

How do animals lose heat?

Answer 6

Through radiation, conduction, convection, and evaporation. Evaporation occurs via sweating and panting when ambient temperature exceeds body temperature.

Question 7

What is the function and physiological significance of brown adipose tissue (BAT)?

Answer 7

BAT generates heat through non-shivering thermogenesis. It contains numerous mitochondria with cytochrome pigments that convert stored lipids directly into heat. It is crucial in neonates and hibernating species for maintaining body temperature.

Question 8

Where is brown adipose tissue typically located?

Answer 8

In the subcutaneous region between the scapulae and around the kidneys and heart in mammals.

Question 9

What are the key differences between brown and yellow adipose tissue?

Answer 9

Brown adipose tissue has numerous small lipid droplets and many mitochondria (brown color), while yellow adipose tissue has fewer mitochondria and a single large lipid droplet.

Question 10

What is counter-current heat exchange and how does it work?

Answer 10

A vascular arrangement where warm arterial blood transfers heat to cooler venous blood returning from extremities, preventing heat loss and maintaining core temperature in cold environments.