Chapter 1 Anatomy and Physiology Miss Plumley Introduction to Human Anatomy and Physiology

Introduction Where did Medicine come from? Early ancestors who were curious how our bodies worked Early ancestors who were also curious about illness What did our earliest ancestors do about illness? They took a visit to the witch doctor Eventually they looked at cadavers and soon knowledge of the human body expanded rapidly. Where Did it Come From: Ancient Egypt: Modern Medicine - Truveo Video Search Where Did it Come From: Ancient Egypt: Modern Medicine - Truveo Video Search

Anatomy and Physiology Anatomy The branch of science that deals with the structure of body parts, their forms and how they are organized. Physiology the function of body parts What they do and how they do it Why is it difficult to separate the topics of Anatomy and Physiology? Structures of body parts are so closely associated to their functions. Example: teeth are shaped to break solid foods into small pieces (the shape of the tooth is the structure and breaking down food is the function)

Levels of Organization Different Levels of Organization within the body Atomic  Molecular  Cellular  Tissues  Organs  Organ system  Organism Atom  Molecule  macromolecule  organelles  cell  Epithial Tissue  Small intestine  Digestive system  Human

Characteristics of Life Who is Mr. Drag Care??? M ovement: change in position of body or body part R esponsiveness: reaction to a change inside or outside D igestion: breakdown of food into simpler forms that can be used R eproduction: production of new organisms and new cells A bsorption: passage of substances through membranes and into fluids G rowth: increase in body size without changing shape C irculation: movement of substances into body fluids A ssimilation: changing absorbed substances into chemically different forms R espiration: obtaining oxygen, removing carbon dioxide, and releasing energy E xcretion: removal of wastes produced by metabolic reactions

This is Mr. Drag Care

Maintenance of Life Requirements of Organisms 1. Water 1. Most abundant chemical 2. Required for many metabolic processes 3. Transports substances within the organism 4. Regulates body temperature 2. Foods 1. Provides body with nutrients 2. Raw materials for building new living matter 3. Regulate vital chemical reactions 3. Oxygen 1. Makes up 1/5 of air 2. Used to release energy from food processes 3. Drives metabolic processes

Maintenance of Life 4. Heat 1. Product metabolic reactions 2. The more heat=the more rapidly chemical reactions take place 5. Pressure 1. Hydrostatic pressure: blood forced through blood vessels

Maintenance of Life Homeostasis Maintaining a stable internal environment Homeostatic mechanisms Self regulating control systems Three components 1. Receptors: notice a change in internal environment 2. Set point: tells what a particular value should be oExample: Body temperature should be 98.6˚F 3. Effectors: cause responses that alter conditions in the internal environment. oExample: muscles or glands

Maintenance of Life Homeostatic mechanisms Example: Calcium homeostasis (in blood - normal range is 9 to 11 mg%) Ca +2 is needed for nerve function, muscle contraction, blood clotting, etc. Calcium regulation functions by hormones Calcium levels rise above set point (receptors measure change in set point)  thyroid gland releases calcitonin (effectors)  Blood calcium level falls (response)  homeostasis: Correct blood calcium level

Maintenance of Life Negative Feedback Maintains the correction of the set point Prevents a correction from going to far Example: calcitonin is gradually slowed until the correct blood calcium level is reached. Negative feedback prevents too much calcitonin to be released, causing an overload of calcium in the blood. Homeostasis

Organization of the Human Body Body Cavities 1. Axial Portion: Head, neck and trunk 1. Cranial cavity: houses the skull 2. Vertebral canal: contains spinal cord 3. Thoracic cavity: Chest area (heart, lungs, diaphragm, esophagus, trachea and thymus gland). Medastinum (separates the cavity into two compartments) 4. Abdominal cavity: stomach, liver, spleen, gallbladder, kidneys, and most of the small and large intestine 5. Pelvic Cavity: enclosed by hip bones (urinary bladder, internal reproductive organs, and bottom part of large intestine)

Organization of the Human Body Axial Portion

Organization of the Human Body Body Cavities 2. Appendicular Portion: upper and lower limbs

Organization of the Human Body Appendicular Portion

Organization of the Human Body Thoracic and Abdominopelvic Membranes Thoracic Membranes Parietal pleura: membrane attached to the wall of a cavity (lines outside of the lungs) Visceral pleura: membrane that covers the interior of an organ (actually covers the lungs) Pleura cavity: space between the membranes Pericardial Membranes: Visceral pericardia: cover’s the heart’s surface Parietal pericardia: lines the heart Pericardial cavity: space between the membranes

Organization of the Human Body Thoracic and Abdominopelvic Membranes Abdominopelvic Cavity Membranes Peritoneal Membranes Parietal peritoneum: lines the walls of abdomen Visceral peritoneum: covers each organ in the abdominal cavity Peritoneal Cavity: space between these membranes

Organization of the Human Body Organ Systems 1. Body Covering Integumentary system: Include skin and various sensory organs (hair, nails, sweat glands and sebaceous glands).

Organization of the Human Body Organ System 2. Support and Movement Skeletal System: bones, and ligaments and cartilages that bind bones together. A place for muscles to attach. Muscular System: provide forces that move body parts by contracting and pulling their ends close together. Maintain posture and are a main source of body heat.

Organization of the Human Body Organ System 3. Integration and Coordination Nervous System: Brain, spinal cord, nerves and sense organs Endocrine System: include all glands that secrete chemical messengers called horomones

Organization of the Human Body Organ System 4. Transport Cardiovascular system: heart, veins, capillaries and blood. Transport of oxygen from the lungs to the heart to the rest of the body. Lymphatic system: Lymph nodes, spleen and thymus. Production of lymphocytes (defend body against infection).

Organization of the Human Body Organ System 5. Absorption and Excretion Digestive System: break down food into forms that can be absorbed by the body. Materials not absorbed are eliminated from the body (poop, pee) Respiratory System: move air in and out and exchange gases between the blood and the air. Urinary System: consists of kidneys, ureters, urinary bladder and urethra.

Organization of the Human Body Organ System 6. Reproduction Reproductive System: produces whole new organisms like itself.