Unit II – Animal Anatomy and Physiology

Study Notes

Anatomy: Study of body structure and parts' relationships.
Physiology: Focus on functions of living matter; includes behavior, biochemistry, and biophysics.

Skin Derivatives: Include sweat and oil glands, hair, wool, fur, and nails.
Functions:
- Physical protection by acting as a barrier.
- Prevents dehydration.
- Regulates body temperature.
- Provides sensory information via cutaneous receptors.
- Involved in metabolic ion regulation and waste excretion.

Eccrine Glands: Secretes hypotonic fluid from interstitial fluids; mainly water with dissolved substances.
Apocrine Glands: Located in specific body areas; secretes watery fluid containing fatty acids and proteins; influenced by sex steroids.

Known as oil glands; produces sebum.
Sebum Functions:
- Acts as natural skin cream and hair protector.
- Reduces evaporation and keeps skin soft.
- Exhibits bactericidal properties.

Hoof or Claw: Horny covering at the distal end of digits.
Chestnut: Horny mass on the forearm and hind leg of horses.
Ergot: Horny mass found in all four legs.
Feathers: Provide protection, temperature regulation, and facilitate flight in birds.

Functions:
- Protects vital organs.
- Provides rigidity and form to the body.
- Serves as levers for movement.
- Stores minerals and lipids.
- Site of blood formation.
Classification of Bones:
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sesamoid bones
Skeleton Division:
- Appendicular: Limbs and their attachments.
- Axial: Skull, vertebrae, and ribs.
- Visceral: Includes bones like os rostri (pig snout), os cordis (cattle heart), os penis (dog penis).

Functions:
- Produces movement.
- Maintains posture.
- Stabilizes joints.
- Generates heat.
Properties of Muscle:
- Excitability: Responsiveness to stimuli.
- Contractility: Ability to shorten forcibly.
- Extensibility: Can be stretched.
- Elasticity: Returns to original shape.
Muscle Classification:
- Voluntary Muscles: Striated (e.g., skeletal muscles).
- Involuntary Muscles: Cardiac (heart muscle) and smooth muscles.

Voluntary and Striated:
- Gastrocnemius: Chief muscle of the calf.
- Gluteus Maximus: Main extensor muscle of the hip.
Cardiac Muscle: Responsible for heart function.
Involuntary Smooth Muscle: Found in structures like the intestines.

Functions:
- Ingestion of food.
- Mastication (chewing).
- Digestion and absorption of nutrients.
- Excretion of waste.
Parts of Digestive System:
- Includes the mouth, tongue, lips, teeth, and salivary glands, crucial for food processing.