A&P: Unit 1 Body Organization

Anatomy Study of the structure and shape of the body “ana-” is apart, “-tomy” is to cut Subdivisions include Gross Anatomy: looking at large, easily observable structures of the body Microscopic Anatomy: looking at structures through a microscope (ex: cells and tissues) Usually studied in dead specimens

Physiology Study of how the body and its parts work or function “physio-” is nature, “-ology” is the study of Usually studied in living subjects

The two are related! Each part has a job to do to make your body work the way it’s supposed to! The structure of organs & systems determines what functions can take place

11 Organ Systems of the Body Integumentary System Includes: The skin Function: Protects deeper tissue, regulates body temperature, synthesizes Vitamin D

11 Organ Systems of the Body Muscular System Includes: Skeletal muscles, cardiac muscles, smooth muscles, and tendons Function: contract to allow movement, maintains posture

11 Organ Systems of the Body Skeletal System Includes: Bone, Cartilage, Ligaments, Joints Function: Supports body, Protects certain cavities, Stores minerals

11 Organ Systems of the Body Digestive System Includes: Mouth, Esophagus, Stomach, Small and Large Intestine, Rectum, and Liver Function: Breaks down food to deliver nutrients to the body cells; undigested food leaves body as feces

11 Organ Systems of the Body Respiratory System Includes: Nasal Passages, Pharynx, Larynx, Trachea, Bronchi, and Lungs Function: Supplies blood with oxygen and removes carbon dioxide

11 Organ Systems of the Body Cardiovascular System Includes: Heart, Blood Vessels (Veins, Arteries, and Capillaries) Function: Carries oxygen, carbon dioxide, nutrients, hormones, wastes, etc. through the body in blood

11 Organ Systems of the Body Nervous System Includes: Brain, Spinal Cord, Nerves, and Sensory Receptors Function: detect and respond to internal & external changes by activating appropriate muscles and glands

11 Organ Systems of the Body Urinary System Includes: Kidneys, Ureters, Bladder, and Urethra Function: Eliminates nitrogenous wastes from the body, maintains body’s water and salt balance, regulates pH of the blood

11 Organ Systems of the Body Lymphatic System Includes: Lymphatic vessels, Lymph Nodes, Spleen, Thymus, Tonsils Functions: Picks up fluid leaked from blood vessels and returns it to blood, cleanses blood, house white blood cells (involved with immunity)

11 Organ Systems of the Body Endocrine System Includes: Glands - including pineal, pituitary, thyroid, thymus, adrenal, pancreas, testis (males), and ovaries (females) Function: secretion of hormones that regulate body activities (growth, reproduction, and metabolism)

11 Organ Systems of the Body Reproductive System Males Includes: testes, scrotum, penis, glands, duct system Function: Produces sperm and carries to the outside of the body

11 Organ Systems of the Body Reproductive System, con’t Females Includes: uterus, ovaries, fallopian tubes, vagina Function: Produces eggs, serves as locations for fertilization and development of the fetus

Levels of Organization From smallest unit to largest unit: Chemical Level: atoms and compounds Cells: smallest unit of all living things Tissues: similar cells with common function There are 4 types of tissue – Epithelial, Connective, Muscle, and Nervous Organ: composed of two or more tissue types Organ System: organs that cooperate to accomplish a common goal Organism: highest level of organization

Necessary Life Functions Organ systems work together to promote the well-being of the entire body Some systems have a main function that they contribute There are 8 necessary life functions: Maintaining Boundaries - Metabolism Movement - Excretion Responsiveness - Reproduction Digestion - Growth

Necessary Life Functions Maintaining Boundaries “Insides” need to remain distinct from “Outsides” Ex: Integumentary – skin protects internal organs from bacteria, chemicals, drying out, heat, etc. Movement Get from one place to another Ex: Muscular and Skeletal – body Ex: Cardiovascular, Digestive, & Urinary – blood, nutrients, and urine

Necessary Life Functions Responsiveness (Irritability) Ability to sense changes and react to them Ex: Nervous system Digestion Break down food into molecules Ex: Digestive System

Necessary Life Functions Metabolism Chemical reactions which occur within body cells Breaking down complex molecules, building different larger molecules, producing energy (ATP) MANY systems contribute, including Digestive, Respiratory, & Cardiovascular Regulated mainly by Endocrine (hormones)

Necessary Life Functions Excretion Removing waste from the body Ex: Digestive and Urinary Reproduction Production of Offspring Ex: Reproductive, Endocrine (hormones) Growth Organism increase in size by increasing number of cells Every system experiences growth

Survival Needs Our body cannot continue to function if we do not have certain survival needs… Nutrients Needed for energy and cell building Oxygen Needed for chemical reactions in body 20% of air we breathe is oxygen

Survival Needs Water Most abundant chemical substance in the body 60 to 80% of body weight Provides fluid base for body secretions and excretions Body Temperature 98ºF (37ºC) ideal for body processes If go below, metabolic reactions too slow If go above, metabolic reactions too fast

Survival Needs Atmospheric Pressure Force exerted on surface of the body by weight of air Breathing and exchange of O2 / CO2 in lungs needs appropriate pressure

Homeostasis The body’s ability to maintain relatively stable internal conditions – needed for life “homeo-” is unchanging, “-stasis” is standing still This is another goal that your organ systems work together to achieve

Homeostasis With homeostasis, your body isn’t really “standing still”, but it’s trying to! It’s like a tight-rope walker – you want to stay on the wire, but sometimes other forces affect you (the wind, a slippery rope, noises, etc.) You must react to overcome the forces and re-balance yourself over the wire. Homeostasis works the same way… It attempts to keep an internal balance within your body.

Homeostasis Communication/coordination within the body is achieved mainly by the Nervous and Endocrine Systems, but many of the systems participate in some extent A response is triggered by some change in the norm

Homeostasis Most control mechanisms are “Negative Feedback Systems” – inhibit a change Examples include body temperature, heart rate, blood pressure, breathing rate, and blood levels of gases & nutrients

Homeostasis

Homeostasis “Positive Feedback Systems” are rare because they actually try to push your body out of the normal balance to react to an event that has occurred Examples include…

Homeostasis Birth Bleeding Oxytocin (causes contractions) is released due to pressure on the cervix Ends when the fetus is expelled Bleeding clotting yields more clotting, which is eventually stopped by stopped blood flow

Homeostasis