skin is the cutaneous membrane. it is the actual thin layer that covers the body. its purpose is to protect deeper tissue from bumps, chemicals, bacteria, UV rays, heat/cold, etc. functions (physiology): protects the body, aids in heat loss and retention, excretion of toxin, synthesizes vitamin D
negative vs positive feedbacknegative feedback: every time the body is high or low from normal level a signal tells the body to make changes to bring back normal levels. most mechanisms in human
positive feedback: a change in the body causes even more change in the same direction.reasons for homeostasisthe process by which organisms keep internal conditions relatively constant despite changes in external environments. concentration of salts, pH of internal environment, concentration of nutrients and waste, oxygen and co2 levels, vol + pressure of extracellular fluid. when these components are adequately controlled, homeostasis is maintained and the body is most likely healthy. organ systems must work together. when levels fluctuate feedback loops are the response to get us back to a set point. ex too hot = sweat to cool downisotonic, hypotonic, hypertonicisotonic: same amount of water inside and outside cell = no movement of water in/out of cell
hypotonic: less water outside cell = water moves inside cell
hypertonic: higher water outside cell = movement of water out of cellwhat is dialysis and why is it used?dialysis is a procedure that removes excess waste products and fluid from the blood when the kidneys stop working.what part of the cell cycle are non-dividing cells inthe inter-phase periodhyperthyroidexcessive activity of the thyroid gland. too many hormones. weight loss.hypothyroidunder active thyroid gland. cold, tired, starts as hyperthyroidism and progresses.hyperparathyroidoveractive parathyroid gland. over production of hormones.hypoparathyroidunderproduction of hormones by the parathyroidtraits of a cancersmall cytoplasm, multiple nuclei, coarse chromatin, multiple nucleoli. cells divide uncontrollably and tumors form. normal cells will stop dividing if there is a gene mutation, cancer cells continue to divide. when they continue to grow they cause tumors.skin disordersathletes foot: fungal infection, red and itchy
boils and carbuncles: inflammation of hair follicles and sebaceous glands
cold sores: caused by herpes simplex, viral infection, can be activated by UV rays, anxiety, fever
contact dermatitis: red and blistering skin reaction to an allergen- poison ivy, detergent, etc
psoriasis: over production of skin cells, red skin with silvery scales
burns: 1st, 2nd, and 3rd degree. tissue damage and cell death caused by heat, electricity, UV radiation, or chemicalshypothalamusgrowth hormone, dopamine. small, almond shape piece of the brain above the brain stem. controls homeostasis and tells pituitary what to do.pituitaryadrenocorticotropic hormone (ACTH), Thyroid-stimulating
hormone (TSH), Luteinising hormone (LH), Follicle-stimulating hormone (FSH), Prolactin (PRL), Growth hormone (GH), Melanocyte-stimulating
hormone (MSH)...tells hypothalamus what to dothyroida butterfly shaped gland in the neck. controls vitals like breathing, heart rate, central and peripheral nervous systems, body weight, muscle strength, menstrual cycles, body temp, and cholesterol levels. triiodothyronine (T3) and thyroxine (T4)parathyroidcalcium. located behind the thyroid containing 4 tiny glands. uses parathyroid hormones to control calcium levels in the blood, if more is needed its taken from the bonesadrenalslocated above the kidneys. the adrenal cortex is the outer layer that produces hormones that are vital to life. cortisol regulates metabolism and response to stress. aldosterone controls blood pressure.pinealposterior to the hypothalamus. regulates melatonin.reproductive organstestosterone, progesterone, estrogen. ovaries and testes.pancreasbehind the stomach. maintains sugar level. glucagon breaks down sugar to raise concentration. insulin decreases intake of sugar to decrease concentration.terms of position and directionsuperior (above) rostal (forehead area) posterior (back) medial (center) anterior (front) lateral (outer) proximal (close to center) distal (far from center) inferior (below) superficial (surface, skin) deep (muscles)how can you tell if a mole is cancerousABCD Rule to Recognize Melanoma
A - asymmetry, sides of mole don't match
B - border irregularity, no smooth borders
C - color, red, browns, tan, black
D - diameter larger than 6 mm
