ATI TEAS 6 EXAM STUDY GUIDE PREDICTOR

The stratum basale or stratum germinativum is always the bottom (deepest) layer. Continuous cell division occurs here and produces all the other layers. o The stratum spinosum is a layer of 8–10 keratinocytes o The non-dividing cells of the 3rd layer (stratum granulosum) are filled with granules of keratin. o The stratum lucidum is the 4th layer but is only present in thick skin (the skin of the fingertips, palms, and soles). o The stratum corneum is always outermost, composed of approximately 20 layers of flat cell-remnants that are like “bags of turtle wax” (dead keratinocytes with no cellular organelles filled with only keratin protein.) Skin’s involvement in temperature homeostasis Sweat glands to cool off body. Vasodilation of blood vessels. Shivering heats the body. Sebaceous & sweat glands are exocrine. Secret through ducts. Sebaceous are holocrine glands, and secrete sebum. o Inhibits water loss from the skin, protects against bacterial & fungal infections. Sweat glands are either eccrine or apocrine glands. Apocrine are located in the armpits, groin, palms, & soles of the feet. Endocrine system Adrenal cortex: Monitors blood sugar levels; helps in lipid & protein metabolism. Downloaded by denis munene () lOMoARcPSD| Adrenal medulla: Controls cardiac function; raises blood sugar & controls the size of blood vessels. Downloaded by denis munene () lOMoARcPSD| Thyroid gland: Helps regulate metabolism & functions in growth & development. Parathyroid: Regulates calcium levels in the blood. Pancreas islets: Raises & lowers blood sugar; active in carbohydrate metabolism. Thymus gland: Plays a role in immune responses. Pineal gland: Has an influence on daily biorhythms & sexual active maity. Pituitary gland: Plays an important role in growth & development. Endocrine functions of the Pancreas Pancreas: Produces insulin & glucagon Insulin lowers glucose Insulin affects fat metabolism, & can change livers ability to store fat. Thyroid & Parathyroid glands Thyroid & parathyroid are located below larynx Thyroid gland: regulates metabolism & secretes hormones Urinary System Consists of kidneys, urinary ducts, & bladder. Kidneys: bean-shaped structures located at the back of abdominal cavity o Has three layers: Renal cortex, renal medulla, & renal pelvis. o Kidney receives blood from renal arteries. o Kidneys filter the blood, reabsorb needed materials, secrete wastes & excess water in urine. o Blood flows from the renal arteries into arterioles into the glomerulus where its filtered. Glomerular filtrate enters the proximal convoluted tubule where water, glucose, ions, & Downloaded by denis munene () lOMoARcPSD|