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BODY SYSTEMS NOTESDigestive SystemMain Purpose: Break down food to absorb nutrients for energy.Two types of digestionphysical or mechanical (through actual breaking apart and tearing of food)chemical (enzymes breaking down the food)Mouth site of physical digestion from teeth and tongue)chemical digestion from salivamastication=chewingEsophagustube that connects mouth to stomachperistalsis- the movement of muscles in the digestive tract that constantly pushes food from mouth to anusreverse peristalsis = vomiting or throwing upStomachChemically breaks down proteins with pepsin and HCl (hydrochloric acid)Physically breaks down food through churningSmall IntestineAbsorption of nutrientsLarge intestine/ColonAbsorption of waterRectum and AnusCollects and release fecal wasteSome of the organs that aren’t in the actual digestive tube, but are helpful:Gall Bladdersecretes bile (used to break down fats in the small intestine)Liversecretes bileconverts extra sugar to glycogen for storagedetoxifies poisons (alcohols, toxins, pesticides, etc.)Circulatory Systemmain job: transport body fluids throughout body3 types of blood vesselsarteries- carry blood away from the heartcapillaries- tiny blood vessels where blood diffuses into the body tissues to deliver nutrients and oxygenveins- carry blood toward the heartComponents of BloodRed Blood Cells- Carry oxygenWhite Blood Cells- Fight off infectionsPlatelets- Clotting and wound healing43434008382000Process (use picture to the right)red = oxygen rich bloodblue = oxygen depleted bloodHeart pumps oxygen rich blood to body tissuesCapillaries help exchange oxygen and CO2 in body tissuesVeins transport oxygen depleted blood back to heartHeart pumps oxygen depleted blood to lungsIn lungs, the oxygen depleted blood is dropped off in capillaries (and we exhale)When we inhale, the oxygen rich blood is picked up in capillaries and transported to the heartRepeat steps 1-6 for each breath/heart beatCO2 being picked up in body tissues is a byproduct of cellular respiration. O2 is a necessary reactant for cellular respiration. Cellular respiration makes ATP, which our bodies use for energy.Respiratory Systemmain job: gas exchangeWe inhale (breathe in) oxygen (O2) to deliver to our body cells for cellular respirationWe exhale (breathe out) carbon dioxide (CO2) which is a byproduct from cellular respirationProcess:1. Breathe in through either the nasal cavity or the mouth2. Air passes through trachea3. Air splits into two bronchi to enter each lung4. Bronchi split into even smaller bronchioles5. Air eventually makes it to tiny air filled sacs called alveoliCapillaries that will pick up oxygen to be delivered to the heart surround alveoli.The heart will pump the oxygen rich blood to the bodyDeoxygenated blood will be delivered back to the alveoli through the circulatory system6. Deoxygenated blood delivers CO2 to the alveoli7. CO2 travels back up the bronchioles, bronchi, trachea, and out through either the mouth or the nasal passages The diaphragm is a muscle under the lungs that controls breathingAs it contracts or relaxes it makes more or less room for the lungs which causes air to either rush into the body or be pushed outExcretory SystemMain job: Rid body of wastes made through metabolic processesExcretion is the process of ridding the body of toxic chemicals, excess water, salts, and carbon dioxide while maintaining osmotic pressure and pH balanceMain organsLungs: excrete carbon dioxide and water vaporSkin: excretes water, salts, and small amounts of nitrogen wastes in sweat Kidneys: excrete nitrogen wastes, salts, water, and other substances in urine Each kidney has 1 million tiny tubes called nephronsEach tube has a ball surrounded by capillaries to help remove waste from the bloodUrine is produced in kidneysUrine is composed of urea, salts, and waters left over after useful molecules have been reabsorbed into the bloodUreters are tubes that carry urine from the kidneys to the bladderThe bladder is a hollow sac that holds urineWhen the bladder becomes full, the nervous system signals the brain, and you feel the urge to urinateUrine passes from the bladder through a urethra to exit the bodyFemale urethra is separate from the reproduction systemMale urethra passes both urine and semen from the reproduction system3429000-11430000Endocrine SystemMain job: produce and secrete hormones in the bodyHormones can do the following things by sending chemical messages to cellsregulate growth, development, behavior, and reproductioncoordinate the production, use, and storage of energymaintain homeostasis (temperature regulation, metabolism, excretion, and water and salt balance)respond to stimuli from outside the bodyGlands are responsible for producing and secreting hormones (all glands and tissues that are in the endocrine system are show to the right)How hormones work:Each hormone is secreted by a cell into the blood streamIt has a special shapeThe cell it wants to signal have receptors with special shapesWhen the hormone attaches to the cell, it tells the cell what to change about its activities (shown below)The endocrine system helps maintain homeostasis through feedback mechanismsThe body detects how much of a hormone is in the bloodWhen there is not enough, it helps the body produce moreWhen there is too much, it tells the body to stop producingBlood Glucose levels are controlled by a feedback mechanismA lot of glucose in the blood causes the production of insulinInsulin is a hormone that causes muscles to take up glucose and convert it to glycogen for storage in the liverWhen there is not enough glucose in the blood, glucagon is producedGlucagon is a hormone that causes the liver to release glucose into the bloodPeople with diabetes cannot covert glucose into glycogen because they can’t produce insulinSkeletal Systemmain job: protect internal organs, support your body, and enable movementboneshard outer covering of compact boneinner spongy bone corebone marrow: fills the spongy area of the boneproduces both red and white blood cells and plateletsjoints: where two bones meetcushioned by pads of cartilage to help with the pressuretypes of jointsimmovable: little to no movement between bonesjoints of the skullslightly movable joints: allow limited movementvertebrae of the skeletonfreely movable joints: allows movementball-and-socket: all types of movement: hips and shoulderspivot joint: allows for rotation: top of spine (turning of head)hinge joint: bending and straightening (elbows, knuckles)gliding joint: sliding motion (wrists and ankles)saddle joint: rotation, bending, straightening (base of thumbs)ligaments: strong bands of connective tissue that hold joints togetherdisorders of the skeletal system42291008318500osteoporosis: “porous bones” causes brittle and easily fractured bonesarthritis: swelling of joints Muscular Systemmain job: move the body by pulling on bonesmuscles are connected to bones by connective tissue called tendonsMuscle Structureprotein filaments that are stretchyactinmyosinsarcomeres are the units of muscles linked end to endMuscle Contractionsarcomere is relaxed; actin and myosin are partially overlappednerves stimulate the muscle to contractcauses the sliding of actin and myosin so they overlap even moresarcomere is completely contracted; actin and myosin are completely overlappedthe sarcomere is shorter in length, which makes the muscle shorten and causes the bones to pull in a directionthe movement of actin and myosin requires ATPATP is made during cellular respiration, which requires oxygenincreased muscle movement causes a higher heart rate and breathing rate so that more oxygen can be delivered to the muscle cells to maintain homeostasisImmune SystemNonspecific defensesskin and mucus membranes protect against pathogens entering the bodypathogen: any disease causing agentinflammatory response (inflammation/swelling)skin is puncturedpathogens enter bodywhite blood cells exit capillaries to attack and destroy pathogensthe extra cells in the area causes swelling and rednessfeverbody increases temperature because many bacteria cannot withstand high temperaturesSpecific defenesesantigen: substance that triggers an immune responsepresent on the surface of an infected body cellproteins on the outside of helpter T cells called receptors bind to antigens targeting them for destructionpg 928 in book explains the process of how our bodies attack infected body cellsHIV infects Helper T cellsbecause it attacks the immune system, it is very hard for the body to fight off other infections like the common cold, flu, etc.Nervous System34290004254500Main job: transmit informationneuron: nerve cellssend electrical signals called nerve impulsesdendrites-extend from cell body (like antennae)receive information from other cellscell body- collects information from dendritesaxon- carries the signal from the cell body to other neurons transmitting through the axon terminalbundles of axons are called nervescovered in myelin sheath which helps the nerve impulses move fasterwhen a neuron meets another cell, they do not touchthere is a gap called the synapsewhen the signal reaches the gap, neurotransmitters (special molecules) are signaled to exit and enter the surrounding cells to cause a response to a stimulusCentral Nervous SystemBrain and Spinal Cordbrain is the main processing centercontains 100 billion neuronsspinal cord: dense cable of nerves running down the vertebral column (backbone)controls reflexes: sudden involuntary contraction of muscles in response to a stimulusPeripheral Nervous Systemconnects brain and spinal cord to rest of body with many nervessensory division: directs sensory information to central nervous system (CNS)sight, smell, feelingmotor divison: carries out responses to sensory information how the body reacts to a sensory stimulusLook at table on 961 to see how drugs affect the nervous systemIntegumentary Systemskin is largest organ in bodyprotects body from injuryfirst line of defense against diseaseregulates body temperatureprevents body from drying out due to evaporation2 layersEpidermisoutermost layer of skinconstantly being regenerated because it is constantly falling off due to damagedermislayer just beneath epidermiscontains hair follicles, nerve cells, blood vesselstemperature regulationwhen hot: blood vessels dilate and push blood to surface so heat will leave bodywhen cold: blood vessels constrict and keep blood deep within skin to prevent heat from leaving bodyHairhelps protect and insulate the bodymade of mostly dead keratin-filled cellsNailskeratin filled cells on fingertips and toes to help protectReproductive SystemMale Systemsperm cells are produced by meiosis in the testessperm mature and are stored in the epididymis (a coiled tube above the testes)a mature sperm cell has a head, a midpiece, and a powerful tail for swimmingsperm move through the epididymis and the vas deferens (long tube that meets up with the urethra) and exit the body through the urethraFemale SystemEgg cells are produced through meiosis in the ovariesAn egg cell matures in a 28-day cycleThe menstrual cycle prepares the uterus for pregnancythese cycles are regulated by hormonesIf no fertilization occurs, the prepares uterus sheds its lining (menstruation)DevelopmentAfter a sperm fertilizes an egg, cleavage (cell division) begins and then it implants in the uterine wallIt takes 9 months for the child to completely developFirst three months (trimester) have the most crucial stagesbaby is fed through a placenta (a series of tissues that diffuse nutrients to baby)Sexual Transmitted Infectionsmany caused by bacteria and virusessyphilis: bacterial; can destroy bones, nervous system, and skin if untreatedgonorrhea and chlamydia: common bacterials STIs; can scar fallopian tubes and cause infertilitygenital herpes is viral; causes blistering ................
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