Human Body

Bones – 206 Functions Support/framework Protection Movement Storage – minerals (calcium and phosphorus), fats in internal cavities Blood cell formation – hematopoiesis – in marrow

Bone Classification Divided into 4 groups based on shape (1)Long bones Shaft with head at both ends Compact All limbs except wrist and ankles (2)Short bones Cube-shaped Spongy Ankles and wrists Sesamoid – form in tendons – ex. patella

(3)Flat bones Thin, flat, curved Compact layered around spongy Skull, ribs, sternum (4)Irregular bones Don’t fit into other three Vertebrae, hip bones

Fractures Closed (simple) fractures – clean break – under skin Open (compound) fractures – ends pierce skin

Heart Functions: transportation of oxygen, nutrients, cell wastes, hormones About the size of a fist Weighs < 1 lb Location btw lungs apex (pointed end) directed toward left hip and rests on diaphragm base points toward right shoulder and lies under 2 nd rib

Chambers 2 atria – receiving chambers 2 ventricles – discharging chambers Pumps – contract to expel blood Left ventricle forms apex Divided longitudinally by septum

Valves Atrioventricular (AV) valves – btw atria and ventricles Bicuspid – aka mitral valve – left side Tricuspid – right side Semilunar valves – btw ventricles and arteries Pulmonary semilunar valve Aortic semilunar valve Sounds Lub dup pause Lub = AV valves closing Dup = semilunar valves closing Murmurs – abnormal sounds May indicate a valve problem

Respiratory Sysem Pharynx (throat) Larynx (voice box) Composed of 8 hyaline cartilages and 1 elastic cartilage Largest – thyroid cartilage (Adam’s apple) – anterior Elastic – epiglottis – blocks entry of food Trachea (wind pipe) Blockage of trachea – choking Heimlich maneuver Tracheostomy

Main Bronchi (right & left) Lungs Left lung – 2 lobes Right lung – 3 lobes Bronchioles – smallest branches Alveoli – bulk of lungs – millions

Nervous System Neuron~ structural and functional unit Cell body~ nucelus and organelles Dendrites~ impulses from tips to neuron Axons~ impulses toward tips Myelin sheath~ supporting, insulating layer Node of Ranvier – gaps w/in the sheath Schwann cells~produce myelin sheath Synaptic (axon) terminals~ neurotransmitter releaser Synapse~ neuron junction

Integumentary System Aka integument – “covering” 2 layers – epidermis & dermis – usually very close Burns/friction may cause separation = blister Functions Insulates and cushions deeper organs Regulates body temp – capillaries, sweat glands Mini excretory system – urea, uric acid, salts, water released w/ sweat Synthesizes immunity proteins Synthesizes vitamin D Contains cutaneous receptors – touch, pressure, temp, pain

Epidermis Avascular Keratinocytes – majority of cells – produce keratin (tough protective) May have up to 5 strata (layers) Contains melanocytes – produce melanin (pigment) Sunlight stimulates production Concentrated in 1 spot = freckles, moles Cycle days

Dermis Hide – leathergoods May have Meissner’s corpuscles – touch receptors Form ridges – fingerprints Contains blood vessels, sweat glands, sebaceous (oil) glands, Pacinian corpuscles (pressure receptors) Blood vessels help maintain temp To release heat – vessels swell To conserve heat – vessels constrict, may bypass capillaries

Hypodermis Subcutaneous tissue – adipose tissue Not part of skin Acts as an anchor, shock absorber, insulator

Skin Color 3 pigments Melanin – yellow, brown, black Carotene – yellow-orange Oxygen-rich hemoglobin – red/pink

Digestive System Mouth – begins breakdown of food Pharynx Esophagus – about 25 cm long Stomach Length about 25cm Diameter varies May hold about 4L of food Forms rugae (folds) when empty

Small Intestine Average length 2.5-7m 3 divisions Duodenum – “12 finger lengths long” Jejunum – “empty” Ileum – “twisted intestine” Large Intestine About 1.5m long Absorbs water from indigestible food and gets rid of wastes Appendix – hangs from cecum Appendicitis – build up of bacteria

Rectum Anus Pancreas – produces digestion enzymes Also produces insulin and glucagen Liver – largest gland in body – 4 lobes Lies over stomach Produces bile Gallbladder - Small, green sac on the inferior surface of the liver Stores bile until needed