Chapter1a (1)
The Human Body: An Orientation
Chapter 1 Overview
Overview of Anatomy and Physiology
Anatomy
Definition: The study of structure.
Subdivisions:
Gross or macroscopic anatomy: Includes regional, surface, and systemic anatomy.
Microscopic anatomy: Includes cytology (study of cells) and histology (study of tissues).
Developmental anatomy: Focuses on embryology (growth and development of an organism).
Essential Tools for Studying Anatomy
Mastery of anatomical terminology: Understanding terms used in anatomy.
Observation: Noting physical characteristics and structures.
Manipulation: Physically examining body structures.
Palpation: Feeling body parts with hands to determine their condition.
Auscultation: Listening to the internal sounds of the body, often using a stethoscope.
Physiology
Definition: The study of function at various levels.
Subdivisions: Based primarily on organ systems, such as renal (kidneys) and cardiovascular physiology.
Essential Tools for Studying Physiology
Focus on multiple levels: From systemic to cellular and molecular functions.
Basic physical principles: Understanding concepts like electrical currents, pressure, and movement.
Basic chemical principles: Importance of chemical interactions in bodily functions.
Principle of Complementarity
Inseparability of Anatomy and Physiology: Structure (anatomy) and function (physiology) are deeply intertwined.
Form Follows Function: A structure's form is determined by its function.
Examples: Specific forms of anatomical structures enable specific functions.
Levels of Structural Organization
Chemical level: Atoms and molecules.
Cellular level: Cells and their organelles.
Tissue level: Tissues made up of similar types of cells.
Organ level: Organs composed of different tissue types.
Organ system level: Different organs working together.
Organismal level: The entire human organism made up of many organ systems.
Organ Systems of the Body
11 Organ Systems: Need to know the name, structures involved, and functions of each system:
Integumentary System
Skeletal System
Muscular System
Nervous System
Endocrine System
Cardiovascular System
Lymphatic System/Immunity
Respiratory System
Digestive System
Urinary System
Reproductive System
Integumentary System
Components: Skin, nails, hair.
Functions: Protects deeper tissues, synthesizes vitamin D, houses receptors and glands.
Skeletal System
Components: Bones, joints.
Functions: Protects body organs, provides framework for movement, blood cell formation, mineral storage.
Muscular System
Components: Skeletal muscles.
Functions: Facilitates movement and locomotion, maintains posture, produces heat.
Nervous System
Components: Brain, nerves, spinal cord.
Functions: Fast-acting control system, responds to changes in the body by activating muscles and glands.
Endocrine System
Components: Various glands (e.g., pituitary, thyroid, adrenal).
Functions: Secretes hormones regulating growth, reproduction, and metabolism.
Cardiovascular System
Components: Heart, blood vessels.
Functions: Transports blood carrying oxygen, carbon dioxide, nutrients, and wastes.
Lymphatic System/Immunity
Components: Lymphatic vessels, lymph nodes, spleen.
Functions: Returns fluid leaked from blood vessels, disposes of debris, houses lymphocytes for immunity.
Respiratory System
Components: Lungs, airways (e.g., trachea, bronchus).
Functions: Supplies blood with oxygen and removes carbon dioxide through gas exchange in lungs.
Digestive System
Components: Stomach, intestines, liver.
Functions: Breaks down food for absorption; eliminates indigestible waste.
Urinary System
Components: Kidneys, urinary bladder.
Functions: Eliminates nitrogenous wastes, regulates water, electrolytes, and acid-base balance.
Male Reproductive System
Components: Testes, prostate, penis.
Functions: Production of offspring, sperm production, and delivery.
Female Reproductive System
Components: Ovaries, uterus, mammary glands.
Functions: Production of eggs, support for fertilization and fetal development.
Organ Systems Interrelationships
All organ systems are interconnected.
Cells depend on organ systems for survival.
Organ systems cooperate to perform essential life functions.
Necessary Life Functions
Maintaining boundaries: Between internal and external environments (e.g., skin).
Movement: Includes body parts and substance movement.
Responsiveness: Ability to sense and respond to stimuli.
Digestion: Breakdown and absorption of nutrients.
Metabolism: All chemical reactions, involving catabolism and anabolism.
Excretion: Removal of wastes from metabolism and digestion.
Reproduction: Cellular division and offspring production.
Growth: Increase in size of body parts or organism.
Survival Needs
Nutrients: Chemicals for energy and cell building (carbohydrates, fats, proteins, vitamins).
Oxygen: Essential for energy release.
Water: Most abundant chemical; site of reactions.
Normal body temperature: Affects reaction rates.
Appropriate atmospheric pressure: Essential for breathing and gas exchange.
Homeostasis
Definition: Maintenance of a stable internal environment despite external changes.
A dynamic state of equilibrium vital for health.
Homeostatic Control Mechanisms
Continuous monitoring and regulation of variables.
Nervous and endocrine systems facilitate communication.
Components of a Control Mechanism
Receptor (sensor): Monitors and responds to stimuli.
Control center: Determines set point and response to stimuli.
Effector: Carries out response to restore equilibrium.
Feedback Mechanisms
Negative Feedback: Reduces the original stimulus, maintaining homeostasis.
Example: Body temperature regulation.
Positive Feedback: Enhances the original stimulus, often leading to a change.
Example: Labor contractions during childbirth, blood clotting.
Homeostatic Imbalance
Any disturbance of homeostasis may result in disease or death.