human systems Flashcards
metabolic rate
Rate at which the body converts stored energy into working energy
depends on age, sex, health, physical activity and hereditary factors
ectotherm vs endotherm
ectotherm = cold blooded, heated by the environment (lower metabolism; metabolism creates working energy/heat, since they get heated by their environment they do not require a faster metabolism)
endotherms = warm blooded, constant internal temp (higher metabolism, have to burn a larger quantity of fuel to keep steady internal body temperature)
How do we measure energy? what is a calorie?
we measure energy in joules and kilojoules (kj = 1000j )
CALORIE= AMOUNT OF ENERGY NEEDED TO INCREASE 1GR OF WATER BY 1 DEGREE CEL
kilocalorie (Cal)
1 Cal = 1000 cal = 4.2 kj
macro nutrients vs micro nutrients, organic vs inorganic food
Macro = carbohydrates, lipids, proteins micro = vitamins, minerals
organic = carbohydrates, proteins, lipids, vitamins inorganic = minerals, water
simple carbs, complex carbs
simple carbs : monosaccharide (single unit, ie. glucose, fructose)
complex carbs:
disaccharide (two monosaccharides, ie.sucrose, lactose)
polysacchride (three or more monosacchrides)
proteins
made from amino acids, joined by peptide bonds
saturated vs unsaturated fats
saturated = max number of hydrogen atoms, creates a straight molecule (stacks really easily, therefore can create solids; butter etc)
unsaturated = less number of hydrogen atoms, creates a triangle molecule (doesnt stack, therefore creates liquids such as oil)
water soluble vitamins
B and C
enzymes for fats, proteins, starch
fats = lipase proteins = protease starch = amylase
major organs in the digestive system
mouth pharynx esophagus liver gallblader pancreas stomach small intestine (doendeum, jenjenum, ileum) llarge intestine (ascending, transcending, descending, sigmoid) rectum
pharynx
part of the throat, gets food from the oral cavity to the esophagus
swallowing begins here by involuntary muscles
larynx (voicebox) moves up, covering the glottis (opening to trachea) with the epiglotis to prevent food from going into the airway
esophagus
tube going from the mouth to the stomach
gets food to the stomach through involuntary muscle contractions, PERISTALSIS
secretes mucus for lubrication
stomach,
LOWER ESOPHAGAEL SPHINCTER = pinching part leading to the stomach, prevents bolus from re entering the esophagus
PYLORIC SPHINCTER = pinching part leading out of the stomach, controls the flow of chyme into the doendeum ch
GASTRIC SECRETIONS = stomach walls contract to mix the food with the gastric secretions, which consist of MUCUS, GASTRIN, HCI, PEPSINOGEN
chyme
gastric juice and partially digested food
mesentry
attaches organs into place (small intestine)
