Anatomy and Physiology Overview

Physiology

• Physiology is the study of the function of living organisms and their parts.

Anatomy

• Anatomy is the study of the structure of living organisms
• Both anatomy and physiology are interconnected and rely on each other for a complete understanding of a living organism.

Levels of Structural Organization

• Chemical Level: Atoms combine to form molecules.
• Cellular Level: Molecules assemble to form cells, the basic unit of life.
• Tissue Level: Similar cells group together to perform a specific function.
• Organ Level: Different tissues work together to form an organ.
• Organ System Level: Multiple organs collaborate to carry out a complex and coordinated bodily function.
• Organismal Level: The highest level of organization, comprised of all organ systems working together to support life.

The Cell

• The cell is the basic biological unit of life.
• It is often called the building block of life.
• Robert Hooke discovered the cell in 1665.
• The human body contains an estimated 75-100 trillion cells.
• Cells are microscopic, typically ranging in size from 10–100 µm.

Types of Cells

• Prokaryotic Cells:
  • Simpler in structure, small in size (0.1 – 5 μm).
  • Lack a nucleus and other membrane-bound organelles.
  • Have circular DNA.
• Eukaryotic Cells:
  • More complex, larger in size (10–100 μm).
  • Possess a nucleus and other membrane-bound organelles.
  • Have linear DNA.

Human Body Organization

• Organ Systems: Composed of a group of organs that work together to perform a major bodily function.
• Organs: Comprised of different tissues that function together to perform a particular task.
• Tissues: Composed of similar cells that perform a specific function.
• Cells: The building blocks of life.

Eleven Body Systems

• The Nervous System: Regulates behavior, maintains homeostasis, and controls sensory and motor functions. Organs: Brain, spinal cord, nerves, sense organs.
• The Endocrine System: Regulates body activities like temperature, metabolism, development, reproduction, and maintains homeostasis. Organs: Hypothalamus, pituitary, pancreas, adrenal, thyroid, testes, ovaries.
• The Lymphatic System: Plays a role in immunity and fluid balance. Organs: Lymph vessels, lymph nodes, spleen, thymus.
• The Circulatory System: Transports oxygen, nutrients, hormones, and removes waste products. Organs: Heart, blood vessels (arteries, veins, capillaries).
• The Respiratory System: Facilitates gas exchange between the blood and the lungs. Organs: Lungs, nose, mouth, trachea.
• The Digestive System: Breaks down food into smaller molecules for absorption and energy production. Organs: Mouth, esophagus, stomach, small intestine, large intestine.
• The Excretory System: Removes cellular waste products and helps regulate fluid balance. Organs: Kidneys, urinary bladder, ureters, urethra, skin, lungs.
• The Skeletal System: Provides support, protection, movement, and blood cell production. Organs: Bones, joints, cartilage.
• The Muscular System: Enables movement and provides support for the body. Organs: Skeletal muscles, smooth muscles, cardiac muscle.
• The Integumentary System: Acts as a barrier, protection, and sensation. Organs: Skin, hair, nails.
• The Reproductive System: Involved in the production of gametes and the continuation of the species. Organs: Ovaries, uterus, testes, penis.