The Human Body
Human Systems
o Circulatory
o Respiratory
o Immune
o Endocrine
o Digestive
o Nervous
o Excretory
o Reproductive
o Musculoskeletal
Circulatory
o Function: Pump OXYGEN to all body parts using blood.
o Red blood cells carry oxygen.
o Organs:
o Heart:
o pumps blood
o Exercise beats faster to move Oxygen faster.
o Circulatory
o Arteries: thick tubes that carry HIGH PRESSURE blood Away from heart.
o Veins: thin tubes that carry low pressure, low oxygen blood back to heart (have valves to stop backflow).
o Capillaries: very thin tubes that allow DIFFUSION.
o Oxygen & Nutrients
Circulatory: Diseases
o Heart disease: high fat & cholesterol diet clogs blood vessel and heart shuts down (heart attack)
o Hypertension: high blood pressure that can injure blood vessels
Respiratory
o Bring in O2 into lungs. Exhale CO2
o Alveoli = tiny air sacs for GAS EXCHANGE in lungs
o Breathing controlled by diaphragm
o Exercise Breathing increases
Respiratory: Diseases
o Asthma: narrowing of respiratory pathway (bronchi)
o Bronchitis: bacteria inflame bronchi & buildup mucus
o Emphysema: hardening/damage to alveoli by smoking
Immune
o Body defense system.
o Cells, viruses, bacteria have ANTIGENS (markers) with specific shapes.
o WBC’s like MACROPHAGES eat bacteria & viruses = PHAGOCYTOSIS
o Antibodies stick to antigens and kill bacteria & viruses.
Receptors that fit around antigens.
Immunity
o Active Immunity: get disease, body fights it, become immune.
o Vaccine = active
o Given a weakened/dead form of disease & body fights it…become immune without getting sick.
o Passive Immunity: antibodies “passed” to baby from mom without baby being exposed to disease.
Immune: Diseases
o HIV: Attacks WBC’s and changes viral coat (antigens) so can’t be detected by immune system. Leads to AIDS.
o Bird Flu/Swine Flu: Viruses originating from animals
Side note: Blood Types
Endocrine
o Glands make hormones. Hormones communicate with TARGET cells to maintain HOMEOSTASIS.
o Pancreas Insulin
o Blood sugar goes up after eating
o Insulin released, sugar level drops
o Liver Glucagon
o Blood sugar too low (Hypoglycemic)
o Releases stored sugar, blood sugar goes up
o Other examples: Adrenal glands adrenaline, Pituitary HGH, testes testosterone, ovaries estrogen
Negative Feedback = Homeostasis
Endocrine: Diseases
o Diabetes: blood sugar levels too high. Insulin not made or doesn’t work.
Digestive
o Break food nutrients down/hydrolysis
o Chew food (mechanical) in mouth > saliva with salivary amylase breaks down STARCH
o Esophagus > stomach
o Stomach acid and pepsin to break down protein (chemical)
o Digestive
o Small intestine and villi: lots of surface area (contact with food). Nutrients diffuse through villi into blood.
o Liver puts bile in small intestine to break down fat, gall bladder stores extra bile.
o Pancreas puts juices to reduce/buffer acid and break down nutrients
o Large intestine: indigestible food/roughage moves through and water absorbed to form feces.
Digestive: Diseases
o Appendicitis: infected appendix (organ with no function)
o Ulcer: hole in wall of stomach
o Diarrhea/constipation: water imbalance
Nervous
o Send electric messages/impulses to detect environment and make body function.
o Central Nervous System = brain and spinal cord
o Other nerves sense touch, pain, temperature
o Cause muscles, glands, and other organs to work
o Brain = controls nervous system
o Reflex = reaction without brain involved.
Neuron: nerve
Neurotransmitters: chemicals that speed up or slow down impulses between nerves.
Nervous: Diseases
o Lyme’s Disease: bacteria transferred from tick bites that destroys nervous system.
o Stroke: clog in blood vessel that cuts off O2 to part of brain and destroys it > paralysis
o Others: Parkinson’s, Alzheimer’s
Excretory
o Get rid of waste in blood.
o Liver filters blood and makes waste
o Kidneys filters waste from blood and make URINE
o URINE stored in bladder and exits through URETHRA
o Sweat glands > release waste to cool body
Excretory: Diseases
o Gout: uric acid (turn to urine) builds up in joints > painful
o Kidney stones
Reproductive
o Males: Testies make sperm ½ DNA
o Females: Ovaries make eggs ½ DNA
o Female 28 day menstrual cycle controlled by hormones.
HOW A BABY IS MADE:
o Ovulation: mid-cycle (day 14) . Release egg into Fallopian Tube/Oviduct
o Reproductive
o Sperm passes through Vagina > Uterus > and meets egg in Fallopian tube
o Fertilization: one sperm enters egg and becomes a ZYGOTE
o CLEAVAGE: egg divides
o Egg sticks to wall of uterus
o Placenta forms with umbilical cord:
Exchange of gases and nutrients between mom and baby
BLOOD DOES NOT MIX!!!
Smoking, drinking, medications can all pass through placenta and into baby
Negative effect on development
o No Fertilization?
If the egg is not fertilized…
MENSTRUATION occurs
Lining of uterus is shed with blood and exits through Vagina
Unfertilized egg exits
Menstrual CYCLE begins again
Reproductive: Diseases
o Miscarriage: fertilized egg does not stick to uterus wall.
o Birth defects: genetic or causes by chemicals during development.
o Fetal Alcohol Syndrome
Musculoskeletal
o Muscles:
pull on bones to move
Heart pumps blood
Move food in digestive system
Works with Nervous System
o Bones:
Bone marrow: makes RBC’s (carry oxygen), WBC’s, and PLATELETS which clot blood (stop bleeding)
Supports body and protects organs
Work with muscles to move
Musculoskeletal: Diseases
Osteoporosis: low calcium in bones, bones brittle and break easy (often in women).
Arthritis: inflamed joints due to overuse, disease or genetics.