Human Body Systems Class Notes

page 1 Human Body Systems: Class Notes Anatomy: Structure of Body Parts. Morphology Physiology: Function of body parts. What they do and how. A & P are very closely related; structure is closely related to function. Characteristics of Life • Movement - self initiated change in position, motion of internal parts • Responsiveness (irritability) - Ability to sense changes within or around the organism and react to them • Growth - increase in body size • Reproduction - Parents produce offspring / producing new individuals • Respiration - Obtaining oxygen (O2), using it to release energy from food substances, and getting rid of wastes • Digestion - Chemically changing (breaking down) food substances, and getting rid of wastes • Absorption - Passage of digested products (food substances) through membranes and into body fluids • Circulation - Movement of substances throughout the body • Assimilation - Changing absorbed substances into chemically different substances • Excretion - Removal of wastes METABOLISM:: All physical and chemical changes occurring in an organism Needs: Water, food, oxygen, heat, pressure. All must be regulated. HOMEOSTASIS: Tendency of the body to maintain a stable, balanced internal environment. Accomplished through self-regulating adjustments. Levels of Organization (from simplest to most complex) Atoms --> Molecules --> Macromolecules --> Organelles --> Cells --> Tissues --> Organs --> Organ Systems --> Organism • A group (mass) of cells working together to carry out certain common functions form a tissue. • A group of tissues working together to carry out certain common functions form an organ. • A group of organs… ORGAN SYSTEMS 1. Integumentary 2. Skeletal 3. Muscular 4. Nervous 5. Endocrine 6. Digestive 7. Circulatory = Cardiovascular and 7b. Lymphatic Body covering. Skin, hair, nails, sweat glands. Function: protect underlying tissues and regulate body temperature Bones, ligaments, cartilage Function: Support, movement, protection, and production of blood cells Muscles of the body Function: Movement, maintenance of posture, production of body heat Brain, spinal cord, nerves through the body Function: Communication throughout body, mental activities, maintaining homeostasis Ductless glands = pituitary, adrenal, thyroid, parathyroid, pancreas, ovaries, testes, thymus, pineal glands Function: Secretion of hormones, communication between body parts Mouth, teeth, pharynx, esophagus, stomach, small intestine, large intestine, liver, gall bladder, and many glands including the pancreas Function: Breakdown of food substances into simpler forms that can be absorbed (digestion). Heart, blood vessels, blood. Function: Transports materials throughout the body. *Lymphatic system usually included with the circulatory system page 2 Human Body Systems: Class Notes 8. Excretory = Urinary 9. Reproductive 10. Respiratory Kidneys, ureters, urinary bladder, urethra Function: Removes (filters) wastes from the blood and helps maintain the body's water and electrolyte balance Reproductive organs, primarily the ovaries (females) and testes (males) Function: Produce special reproductive cells for reproduction Nose, mouth, trachea, bronchi, LUNGS, alveoli Function: Brings O2 to the blood, takes CO2 away from blood. Skeletal System/Bones: • ALIVE • Help in movement and support, also protection • Honeycomb structure is strong. Bending prevents breaking. • Stronger with use and good nutrition. • More bones when born, later they fuse together • Form, protection and support Muscular System: • Voluntary muscles are connected to bones (skeletal) • Muscles of internal organs are not connected to skeleton • Actively contract (shorten), passively relax (lengthen) • Brain sends nerve signals to control movement • Muscle breaks or tears when goes beyond limit • External signals like shock can cause movement Skin: • largest organ of the body • perspires to cool body when water evaporates Digestive System: • breaks down food into molecules that are absorbed • Mechanical digestion: teeth/ stomach muscles • Chemical digestion: saliva/ stomach acids/ enzymes • Most absorption in the small intestine • After absorption, blood vessels carry nutrients to the body • Small intestine-- VERY long but small diameter • Large intestine reabsorbs water • Not enough lactase enzyme= lactose intolerant • Stomach is lined with mucus to protect from acid damage • Ulcers are caused when acid irritates lining of stomach • Tapeworms ingested- decrease food absorption • Peristalsis- movement of food by muscles in esophagus • Large intestine: absorbs too much water= constipation Absorbs too little water= diarrhea • Solid waste removal Excretory (Urinary) System: • Kidney is a filter system • Ureter carries filtered urine to bladder • 2 ureters (1 for each kidney) • 1 urethra (from the bladder) • Light yellow urine= enough fluids • Dark yellow urine= not enough fluids • • • • page 3 Human Body Systems: Class Notes Bladder has muscles to hold (little kids use thighs…not good) Urinalysis= tests run to see if sick o Glucose= diabetes o Protein= kidney disease o Nitrate= infection o White Blood Cells = infection Wastes= Carbon dioxide, water, urea liquid waste removal Respiratory System • Takes in oxygen, gives off carbon dioxide (gas exchange) • Bronchitis= inflammation in tubes • Pneumonia= lungs fill with fluid • Blocked trachea= choking • Epiglottis blocks tube so food will not enter • Larynx= voice box • Laryngitis= inflammation of larynx • Emphysema= damage of lung tissue, often from smoking • Tumor= blocks lung and reduces gas exchange • diaphragm = muscle that is used to help you breathe • Diaphragm spasms= hiccup Circulatory system or Cardiovascular system: • Movement of oxygen, nutrients, and wastes throughout body • Four chambers of heart • Pumps red and blue blood • Shock paddles are used to restart heart with pacemaker cells • Shock paddles STOP the heart from beating • Cholesterol (size of sand grain) can block the vessel= heart attack • Know the cyclical path of blood: o from heart, pushed to lung to pick up oxygen and drop off CO2, turns RED, o returns to heart, pumped to the rest of body where it drops off oxygen and picks up CO2 and turns BLUE, o then returns to the heart to start cycle again. Immune System is complex, so we will focus just on invasion by influenza virus: • “spiky virus” attaches to cell in the throat • Sore throat from special cells spraying toxin, kill bad and good cells • Fever because body turns up thermostat to fight invaders • Body tricked into thinking it is cold, so you shiver and feel very cold • Headache= vessels swell due to increased temp • Pain/aches due to the body sending chemical to slow you down • Medicines do not treat virus, they just make your symptoms lessen • 3 points of attack: barriers, inflammatory response, and immune response (T and B cells) Nervous System: • Brain is control center of all body activities • Sends out “chemical” signal in body • Neurons = nerve cell = axon, dendrites, terminal branches, cell body • Some nerves send signals from sensors (e.g. touch or heat or light) to brain; other nerves send signals from brain or spinal cord to muscles. • Synapse is a gap between neurons.