Anatomy and Physiology Introduction

Introduction to Human Anatomy and Physiology

• Anatomy is the study of the structure and shape of the body and its parts, and their relationships to one another.
• Physiology is the study of how the body and its parts work or function.

Divisions of Anatomy

• Gross anatomy: study of large and easily observable structures like heart, brain, etc.
• Microscopic anatomy (Histology): study of small body structures like cells, tissues, etc.
• Embryology and Development: study of unborn human, development of human being.

Divisions of Physiology

• Systems physiology
• Evolutionary physiology
• Cell physiology
• Defence physiology

Relationship of Anatomy and Physiology

• Structure determines the functions of each organ.
• Anatomy and physiology are interconnected, and understanding one is essential for understanding the other.

Level of Organization

• Various levels of organization in the human body, from simple to complex.

Major Systems of the Body

• Integumentary system: forms external body covering, protects deeper tissue from injury, synthesizes vitamin D, regulates body temperature, etc.
• Skeletal system: protects and supports body organs, provides muscle attachment for movement, site of blood cell formation, stores minerals, etc.
• Muscular system: allows locomotion, maintains posture, produces body heat, etc.
• Nervous system: fast-acting control system, receives and interprets sensory information, responds to internal and external change, activates muscles and glands, etc.
• Endocrine system: secretes regulatory hormones for growth, reproduction, metabolism, etc.
• Cardiovascular system: transports materials in the body via blood pumped by the heart, supplying oxygen, nutrients, and removing waste products, etc.
• Lymphatic system: returns excess fluids to blood vessels, absorbs fats from the gastrointestinal tract, enhances immunity, etc.
• Respiratory system: facilitates gas exchange between air and blood, supplying oxygen and removing carbon dioxide, etc.
• Digestive system: receives and breaks down food, absorbs nutrients into blood, eliminates indigestible material, etc.
• Urinary system: eliminates nitrogenous wastes, maintains acid-base balance, regulates materials like water and electrolytes, stores and transports urine, etc.
• Reproductive system: produces offspring, develops embryos in females, produces sexual gametes (sperm and eggs) at puberty, etc.

Organ Systems Interrelationships

• Each system interacts with others to maintain homeostasis and ensure the survival of the organism.

Necessary Life Functions

• Maintaining boundaries: the internal environment remains distinct from the external.
• Movement: changes position or place (locomotion, propulsion, peristalsis).
• Sensitivity and responsiveness: senses changes in the environment and responds to them.
• Digestion: breaks down ingested foodstuff.
• Metabolism: all chemical reactions that occur in the body.
• Excretion: removal of wastes from the body.
• Reproduction: makes more of the same type of organisms (cellular and organismal levels).
• Growth: increase in size of a body part or the organism.

Survival Needs

• Nutrients: chemical substances used for energy and cell building.
• Oxygen: needed for metabolic reactions.
• Water: provides the necessary environment for chemical reactions.
• Maintaining normal body temperature: necessary for chemical reactions to occur at life-sustaining rates.
• Atmospheric pressure: required for proper breathing and gas exchange in the lungs.

Homeostasis

• The ability to maintain a relatively stable internal environment in an ever-changing outside world.
• Chemical, thermal, and neural factors interact to maintain homeostasis.

Homeostatic Control Mechanisms

• Variable (stimulus): internal conditions that could change.
• Receptor (sensor): monitors the environment and responds to changes (stimuli).
• Control center: matches data with normal values and sends signals to the effector.
• Effector: provides the means to respond to the stimulus.

Types of Feedback Mechanisms

• Negative feedback mechanisms: output shuts off the original stimulus (e.g., regulation of blood glucose levels).
• Positive feedback mechanisms: output enhances or exaggerates the original stimulus (e.g., regulation of blood clotting).

Important Biological Suffixes and Prefixes

• Various word parts with their meanings and examples, useful for understanding complex biological terms.