Introduction to Human Physiology

Introduction to Human Physiology

• Human Physiology is the study of the functions of the human body
• When studying a function, consider "Why?" and "How?"
• Understand the goal and mechanism of the function
• Structure is related to function at multiple levels: whole body, systems, organs, tissues, and cells

Body Systems

• Circulatory: Organs: Heart, blood vessels, blood; Function: Transport of blood throughout the body's tissues
• Respiratory: Organs: Nose, pharynx, larynx, trachea, bronchi, lungs; Function: Exchange of carbon dioxide and oxygen, regulation of hydrogen ion concentration
• Digestive: Organs: Mouth, pharynx, esophagus, stomach, intestines, salivary glands, pancreas, liver, gallbladder; Function: Digestion and absorption of organic nutrients, salts, and water
• Urinary: Organs: Kidneys, ureters, bladder, urethra; Function: Regulation of plasma composition through controlled excretion of salts, water, and organic wastes
• Musculoskeletal: Organs: Bone, skeletal muscle, tendons, cartilage, ligaments, joints; Function: Support, protection, movement of the body, production of blood cells
• Immune: Organs: White blood cells, lymph vessels and nodes, spleen, thymus; Function: Defense against foreign invaders, return of extracellular fluid to blood, formation of white blood cells
• Nervous: Organs: Brain, spinal cord, peripheral nerves, special sense organs; Function: Regulation and coordination of body activities, detection of changes in internal and external environments, states of consciousness, learning, and cognition
• Endocrine: Organs: All glands secreting hormones (pancreas, pituitary, thyroid, parathyroid, adrenal); Function: Regulation and coordination of many body activities, including growth and metabolism
• Reproductive: Organs: Male: Testes, penis, associated ducts and glands; Female: Ovaries, fallopian tubes, uterus, vagina, mammary glands; Function: Production of sperm or ova, provision of a nutritive environment for the developing embryo and fetus
• Integumentary: Organs: Skin and sweat glands; Function: Protection against injury and dehydration, defense against foreign invaders, regulation of body temperature

The Cell

• Cells are the basic structural and functional units of all living organisms
• Cells contain a nucleus surrounded by a nuclear membrane and various organelles.

Cell Organelles

• Nucleus: Contains genetic material (DNA) and controls cellular activities.
• Mitochondria: Generate energy (ATP) for the cell. The inner membrane folds into cristae.
• Endoplasmic Reticulum (ER): Interconnected tubes and parallel membranes enclosing cisternae. Rough ER has ribosomes; smooth ER lacks ribosomes. SER and RER are involved in various synthetic and storage functions.
• Ribosomes: Granules containing protein and rRNA; responsible for protein synthesis.
• Golgi Apparatus: Modifies, sorts, and packages proteins.
• Lysosomes: Digest cellular waste and foreign materials.
• Peroxisomes: Break down hydrogen peroxide to prevent its harmful effects.
• Cell Membrane: Boundary of the cell; a fluid mosaic model of phospholipids, cholesterol, and proteins.