Organization & Body Systems Unit 1: Intro to Anatomy Chapter 1.1

Anatomy & Physiology The study of the human body Anatomy is concerned with the structure of a part

Physiology is concerned with the function of the part

Levels of Organization Body is organized into levels from most simple to most complex

Atoms Most simple Compose all substances Chemicals elements

Molecules Atoms joined together form molecules Example: amino acids

Macromolecules Molecules joined together form macromolecules Example: protein

Organelles Tiny structures found in cells that perform cellular functions Example: mitochondria – supplies cell with energy

Cells Macromolecules found in all cells Basic unit of all living things

Tissue Composed of similar types of cells and performs a specific function Example: blood, muscle, fat

Organs Groups of tissues working together to perform a specific function Example: heart, stomach

Organ System Groups of organs that perform a particular function Example: digestive system: supply body with the nutrients needed for growth and repair

Organism All the body systems make up an organism Unicellular organism: made up of one cell Example: amoeba Multicellular organism: made up of many cells Example: gorillas

Review ________ is concerned with the structure or an organ or part, while ________ is concerned with the function. ANSWER: Anatomy, Physiology

___________ are groups of tissues working together to perform a specific function. Answer: Organs

3. ______________ organisms are made up of many cells, while ___________ organisms are made up of one cell. ANSWER: multicellular, unicellular

4. Basic unit of all living things are called ________. ANSWER: cells

Homeostasis Homeostasis is the relative constancy of the body’s internal environment Even when external conditions change, the body’s internal condition stays within a narrow range All systems of the body contribute toward maintaining homeostasis If the body’s internal conditions changes greatly, illness results

2 types of homeostasis mechanisms: Negative feedback – returns a variable back to a the set point

Positive feedback – mechanism that brings about an ever greater change in the same direction Example: Childbirth

Introduction Organs in the body work together in systems 11 organ systems in the body Organ systems can be divided into 4 categories based on function

Body Systems Support, Maintenance Movement, of the Body & Protection Integration & Coordination Maintenance of the Body Reproduction & Development

Support, Movement, & Protection Integumentary System: Organs: skin and accessory organs (hair & nails) Function: protects tissue, regulate body temperature & contains sense organs

Skeletal System Organs: bones, cartilage, & ligaments Function: protects body parts, produce blood cells, stores calcium & phosphorus salts

Muscular System Organs: skeletal, cardiac, and smooth muscles Function: move voluntarily, respond to stimuli, produce body heat

Integration & Coordination Nervous System Organs: brain, spinal cord & nerves Function: conducts nerve impulses from the sense organs to the brain and then to the muscles and gland

Endocrine System: Organs: Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, testes Function: secretes chemicals that are messengers between body part, maintain proper functioning of reproductive system

Maintenance of Body Circulatory (Cardiovascular) system: Organs: Heart, blood vessels, blood Function: transports nutrients and oxygen to cells through blood, removes wastes

Immune (Lymphatic) System: Organs: Lymph nodes, thymus, spleen Function: protects body from disease

Respiratory System: Organs: Nose, pharynx, larynx, trachea, lungs Function: bring oxygen into lungs and take carbon dioxide out of the lungs

Digestive System: Organs: mouth, pharynx, esophagus, stomach, small & large intestine, rectum Function: receive food and digest into nutrient molecules

Urinary System: Organs: kidneys and urinary bladder Function: gets rid of nitrogenous wastes, helps regulate fluid level and chemical content of the blood

Reproduction & Development Reproductive System: Organs: Male: testes, epididymis, vas deferens, urethra, penis Female: ovaries, Fallopian tubes, vagina, uterus Function: produce sex cells, nourish and protect fetus (female)