Biomed Test Review #5

mouth

consists of the oral cavity, labia (lips), cheeks, hard (front) and soft (back) palates, uvula, vestibule, tongue, and palatine (back) and lingual (front) tonsils

primary function is mechanical (mastication) and chemical (saliva) breakdown, ingestion and propulsion

pharynx/epiglottis

serves as a passageway for foods, fluids, and air through peristalsis (propulsion)

epiglottis covers windpipe when swallowing food to prevent it from entering the lungs

esophagus

around 10 inches, goes from pharynx to stomach through the diaphragm

passageway for food, performs peristalsis (propulsion) to help it move

stomach

a c-shaped sac on the left side of the abdomen, food enters and exits through sphincters into the small intestine

temporarily stores food, site of mechanical and chemical (HCl, pepsin, mucus) digestion, moves chyme to small intestine (propulsion)

chyme

processed food

small intestine

main site of nutrient absorption, consists of duodenum, jejunum, ileum, lined villi, microvilli, and circular folds to increase surface area, peyer's patches on internal walls, contains bile (breaks down fats) and pancreatic juice

duodenum

first part of the small intestine, connects to the stomach

jejunum

middle portion of the small intestine

ileum

last part of the small intestine, connects to the large intestine

peyer's patches

small clusters of lymphatic tissue in walls of small intestine

large intestine

larger diameter, around 1.5 m, consists of cecum, appendix, colon, rectum, and anal canal, main purpose is to absorb water

cecum

first part of large intestine, connects small and large intestines

appendix

small fingerlike extension of cecum, assists with fighting infections

colon

four parts: ascending (up the right side), transverse (across to the left), descending (down the left side), and sigmoid (across to the rectum)

rectum

the final section of the large intestine connecting to the anus

anus

end of the digestive tract

teeth

assists with mechanical digestion (mastication), two sets: deciduous and permanent

salivary glands

produces salivary amylase to start chemical breakdown (carbs), 3 locations: parotid, submandibular, and sublingual

pancreas

organ in the abdominal cavity that regulates blood sugar levels and produces digestive enzymes, as well as insulin (decreases blood sugar) and glycogen (increases blood sugar)

liver

located on the right side of the body beneath the diaphragm, produces bile to break down fats

gallbladder

attached to the liver, stores excess bile

overview of GI processes

ingestion, propulsion, breakdown (mechanical and chemical), absorption, defecation

ingestion

intake of food, involves the mouth

propulsion

movement of food through the GI tract, involves mouth, pharynx, esophagus, stomach, small intestine and large intestine

mechanical breakdown

food is physically broken down, involves mouth (chewing) and stomach (churning)

chemical breakdown

food is broken down through chemicals, involves the mouth (salivary amylase), stomach (pepsin), and small intestine (bile)

absorption

nutrients absorbed from the digestive system into the bloodstream, involves the small intestine (nutrients) and large intestine (water)

defecation

elimination of feces through the large intestine and anus

major nutrients

essential for life, carbs, lipids, proteins, and water

minor nutrients

essential but in small amounts, vitamins and minerals

metabolism

all chemical reactions necessary to maintain life, cellular energy (ATP) is produced via cellular respiration, liver plays key role as it helps convert nutrients to substances the body can use

basal metabolic rate

the body's resting rate of energy output

total metabolic rate

BMR + metabolism associated with physical activity

body temperature regulation

food is oxidized, warming the body, while sweat is released to cool the body

fever: controlled hyperthermia, used to warm body