Anatomy and Physiology: Homeostasis

Homeostasis

• Refers to the stable internal physical and chemical conditions maintained by organisms, despite fluctuations in their internal and external environments.

Musculoskeletal System

• Maintains homeostasis through thermoregulation by inducing shivering and sweating to control body temperature.
• Structure includes:
  • Skeletal muscle: Voluntary movements.
  • Smooth muscle: Involuntary movements.
  • Cardiac muscle: Mixed movements.
  • Bones: Provide structure and protection.
  • Cartilage: Offers flexible support.
  • Ligaments: Connect bones in joints.
  • Tendons: Link muscles to bones.

Respiratory System

• Maintains homeostasis by regulating blood pH through gas exchange.
• Key structures include:
  • Nose: Warms and moistens air.
  • Pharynx: Pathway for air and food.
  • Larynx: Aids in sound production.
  • Lungs: Site of gas exchange.
  • Trachea & Bronchi: Conduct air to the lungs.
  • Alveoli: Serve as the interface for gas exchange.

Circulatory System

• Delivers oxygen and nutrients to tissues, facilitating homeostasis.
• Important structures include:
  • Heart: Pumps blood throughout the body.
  • Atria & Ventricles: Chambers responsible for receiving and pumping blood.
  • Arteries & Veins: Carry blood away from and towards the heart, respectively.
  • Capillaries: Allow for nutrient and gas exchange at the tissue level.

Digestive System

• Responsible for nutrient absorption to maintain bodily functions.
• Major components:
  • Mouth: Site for ingestion and initial digestion.
  • Esophagus: Transports food to the stomach through peristalsis.
  • Stomach: Churns food and begins protein digestion.
  • Liver, Gall Bladder, Pancreas: Produce bile and digestive enzymes essential for chemical digestion.
  • Small Intestine: Main site for digestion and absorption.
  • Large Intestine: Reabsorbs water and compacts waste.

Excretory System

• Removes waste and regulates body temperature via sweating.
• Structures involved:
  • Skin: Excretes water and salt.
  • Lungs: Release carbon dioxide.
  • Liver: Converts ammonia to urea for safer transport.
  • Kidneys: Filter blood to produce urine, removing excess waste.

Key Concepts

• Feedback Inhibition: Mechanism where the response inhibits the original stimulus to maintain balance.
• Diffusion: Movement of particles from areas of higher concentration to lower concentration, crucial for gas exchange.
• Endothermic vs. Ectothermic: Endotherms generate internal heat while ectotherms rely on external temperature sources for body heat regulation.

Cellular Organization

• Cells: Basic unit of life.
• Tissues: Groups of similar cells performing specific functions.
• Organs: Structures formed from tissues working together for specific roles.
• Organ Systems: Combinations of organs cooperating to perform complex functions.

Blood Components

• Plasma: Liquid matrix transporting cells and substances.
• Red Blood Cells: Carry oxygen bound to hemoglobin.
• White Blood Cells: Integral to immune defense.
• Platelets: Essential for blood clotting.

Digestive Mechanisms

• Ingestion: Intake of food.
• Mechanical & Chemical Digestion: Breakdown of food particles for absorption.
• Absorption: Transfer of nutrients into the bloodstream.
• Elimination: Removal of indigestible substances from the body.

Organ Function

• Kidneys and Nephrons: Filter blood, regulate water and electrolyte balance.
• Bile Function: Emulsifies fats, aiding in their digestion and absorption in the small intestine.

Digestive Pathway

• Food travels through the Alimentary Canal, involving structures like the mouth, esophagus, stomach, and intestines before elimination through the anus.