unit 4 Flashcards
organ systems
3 main compartments in the body that store food
- cytoplasm inside cells
- fluid between cells (interstitial fluid)
- fluid in the blood
macromolecules are in 4 major groups
- carbohydrates
- lipids
- proteins
- nucleic acids
all 4 together are called essential nutrients
carbohydrates
- Monomer: monosacerides
- CHO
- gets digested in the mouth
lipids
- monomer: fatty acids and gycogen
- CHO
- gets absorbed in small intestine
proteins
- monomer: amino acids
- CHON
- gets absorbed in the stomach
nucleic acids
- monomer: nucelotides
- CHONP
- gets absorbed in the small intestine
4 stages of food processing
- indigestion
–> take in or eating of food - digestion
–> breakdown of food by mechanical or chemical processes into small molecules for body to absorb - absorbtion
–> transporting productions of digestion into circulatory system, distributing to body - elimination (egestion)
–> removal of undigested solid waste from body
alimentary canal
- a tube that has a mouth at one end to ingest food and an anus in the other end to excrete waste
- along this tube - different organs will process food differently
mechanical digestion vs chemical digestion
mechanical:
- the physical breakdown of large pieces of food into small pieces
- mouth by action of teeth
- contractions
chemical digestion:
- chemical breakdown of nutrient molecules into small molecules by enzymes
amylase
- enzyme that breaks down starches in food into simple sugars
- dissolves water-soluble food particles
- stimulates taste buds to allow us to taste flavour in foods
- lubricates food to make food easier to swallow
upper part of digestive system
- starts with the mouth
- salivary glands are triggered by the smell or sight of food
- the glands in the mouth produce saliva to begin the chemical digestion of food
- mechanical - is when you bite and grind food
- the smaller pieces increase surface area of food and allow more exposure for saliva to chemically digest it
the esophagus
- when chewing ur tonge shapes food into a bolus and pushes in to back of the mouth
- bolus moves to esophagus
- the epiglottis is the cartilage valve that closes the trachea during the swallowing motion
- bolus is transported through esophagus, a muscular tube that connects the mouth to the stomach by peristalsis
- the esophageal sphincter is the transition between esophagus and stomach which allows bolus to enter the stomach (prevents heatburn and acid reflex) (closed to prevents stomach acid from backing up)
stomach
- stores food temporaily and helps with mechanical and chemical digestion
- the lining of the stomach secretes gastric acid (made of HCL and chemicaly digests food)
- stomach is coated with mucous that prevents damage from PH in acid
- micture of food and gastric juice produces chyme
- chyme leaves stomach through pyloric sphincter to small intestine
duodenum
- first part of the small intestine
- area for absorbing nutrients because the walls are covered in villi
- each villi is covered by microvilli
- acessory organs all support digestion in this area (pancreas and gallbladder)
jejunum and ileum
Jejunum:
- right after the duodennum
- breaks down proteins and carbohydrates to enter the blood stream
Ileum:
- after jejunum
- contains smaller villi than the other two sections
- absorbs nutrients and pushes undigested material to the large intestine
Large intestine
also known as colon
- absorbs any of the water in the food and leaves the undigested matter
- the leftover matter forms feces and is pushed by contractions to the rectum