organ systems

integumentary system

skin

  • forms the external body covering

  • prevents

    • losing blood

    • infection

      • oils and salt from sweat inhibit pathogenic growth (prevents bacteria from growing, but not 100% of the time) and prevent skin from drying out

  • protects deeper tissue from injury

    • protective barrier method

  • helps regulate body temperature

    • via adipose tissue (fat), which is a good insulator

      • as body creates heat, fat keeps the heat within the body

    • release of sweat lowers body temperature

  • location of cutaneous (sensory [i.e. hot, cold, etc.]) nerve receptors

  • different pigmentation via melanin

    • produced by a melanocyte (skin pigmentation cell)

      • when exposed to UV radiation (sunlight), you get a different pigmentation/darker skin

        • when your body is exposed to UV light, it synthesizes vitamin D

          • vitamin D is crucial in the absorption of calcium

          • vitamin D has a symbiotic relationship with the immune system

            • if you have a healthy vitamin D level, you are going to be able to fight off certain viruses and cancers

            • when you drop in vitamin D, immune system worsens

skeletal system

bones, cartilage, joints

  • protects and supports body organs

    • ex.)

      • skull protects brain

      • vertebrae protects spinal cord

      • rib cafe protects heart and lungs

  • provides muscle attachment for movement

  • site of blood cell formation

    • the center of certain bones is called marrow, and is where the blood cells are formed

  • stores minerals

    • calcium, potassium, magnesium, zinc, phosphorus

      • stored for a “rainy day”; a bank for when the body is lacking them and needs it

    • if you are nutrient-deficient in some things, your bones will also be nutrient-deficient

    • different disease processes will touch upon these deficiencies that can either cause an overgrowth of bones or weak, brittle bones





muscular system

skeletal muscles

  • produces movement

    • skeletal system doesn’t move; instead the muscles that attach onto the bones when they cross the joint and contract cause movement

  • maintains posture

  • produces heat

    • when you move muscles (ie when exercising), you get warm and start to perspire

  • multiple types of muscles

    • skeletal muscle: voluntary, move around 

      • ex.) biceps, quads

    • smooth muscle: involuntary, lines digestive tract

    • cardiac muscle: in the heart

nervous system

brain, spinal cord, nerves

  • fast-acting control system

    • brain sends electrical impulses out

      • sensory nerves: receives senses like touch, pain, light, vibration

      • motor types of nerves: responsible for attaching muscles and different glands

  • responds to internal and external change

    • anything chemical inside the body, or environmental outside of the body

  • activates muscles and glands


endocrine system

pineal gland (brain), pituitary gland (brain), thyroid gland (parathyroid on posterior aspect) (cervical neck region), thymus gland (above heart), adrenal glands (above kidney), pancreas (on top of abdomen), testis (male), ovary (female)

  • hormones

    • little concentrated chemicals that have a powerful effect

    • hormones are produced in one part of the body, and are circulated throughout the bloodstream

  • secretes regulatory hormones

    • growth

      • pituitary gland

      • growth hormones are produced in the pituitary gland and circulated throughout the body to grow legs and other parts

    • reproduction

    • metabolism

  • imbalance of hormones can result in diseases

cardiovascular system

heart, blood vessels, blood

  • transports materials in body via blood pumped by heart

    • heart acts like a pump (although is cardiac muscle), it’s essential to move the blood around

    • oxygen 

    • carbon dioxide

    • nutrients

    • (removes) wastes

      • as cells respirate (breathe) they go through a metabolic process that produces waste and gets filtered out through the kidneys

        • ex.) salt, urea, creatine

lymphatic (immune) system

thoracic duct, lymph nodes, lymphatic vessels, tonsils (powerful lymphatic gland), spleen (largest lymphatic organ)

  • returns fluids to blood vessels

    • it is another circulation system that carries fluid around the blood and dumps it back into the cardiovascular system to keep blood thin

  • cleanses the blood

  • involved in immunity

    • responsible for fighting off bacteria, fungi, and cancers

respiratory system

nasal cavity, pharynx, larynx, trachea, bronchus, left lung

*not made just up of the lungs

  • keeps blood supplied with oxygen

  • removes carbon dioxide

  • also affects acid-base balance (along with urinary system)

    • if the body overly tries to use glucose without oxygen, pH begins to drop





digestive system

oral cavity (mouth), esophagus (throat), stomach, small intestine, large intestine, rectum, anus

  • breaks down food

  • allows for nutrient absorption into blood

    • eating does not equate nutrient (ie calcium) absorption; a whole network of enzymes work together to break down these minerals and nutrients that the body can utilize

      • when there is a lack of certain enzymes or a problem with the pH, it results in a lot of disease processes

  • eliminates (undesirable,) indigestible materials as feces

    • the end of the digestive system


urinary system

kidney, ureter, urinary bladder (can expand + contract), urethra (eliminates urine out of the body)

  • eliminates nitrogenous wastes

    • waste products that have nitrogen in them and become toxic to the body

      • ex.) urine, urea

  • maintains acid-base balance

    • respiratory also affects acid-base balance

    • makes more acidic or more alkali

    • depending on what metabolic process is going on, acidosis or alkalosis occurs

      • can be good or bad, or can result in disease process

  • regulates water and electrolytes

    • salt


reproductive system

males: seminal vesicles, prostate gland, penis, vas deferens, testis, scrotum

females: mammary glands (in breasts), uterine tube, ovary, uterus, vagina

  • produces offspring

  • testes produce sperm and male hormone (testosterone)

    • testes part of both endocrine and reproductive system

      • testes product testosterone

  • ovaries produce eggs (ovum) and female hormones (estrogen, progesterone)

    • work in the development of secondary sex characteristics 

    • unification of sperm and ovum causes fertilization

  • only organ system that an individual can live without