Digestive System Flashcards
Mechanical digestion
Physical breakdown of food particles
Chemical digestion
Enzymatic cleavage of chemical bonds
Digestive pathway
Oral cavity -> Pharynx -> Esophagus -> Stomach -> Small intestine -> Large intestine -> Rectum -> Anus
Accessory organs of digestion
Salivary glands, pancreas, liver, gallbladder
Enteric nervous system
Govern function of digestive system
Location of enteric nervous system
Walls of digestive tract
Hormones that trigger thirst
Aldosterone, ADH
Hormones that trigger hunger
Glucagon and ghrelin
Hormones that promote satiety
Leptin and cholecystokinin
Salivary amylase
Hydrolyze starch into smaller sugars
Salivary lipase
Hydrolylze lipids
Fat soluble vitamins
A, D, E, K
Peristalsis
Muscle contraction that moves food toward the stomach
Swallowing occurs through the
Upper esophageal sphincter
Food enters the stomach through the
Lower esophageal sphincter
The stomach is divided into
Fundus, body, antrum, pylorus
Fundus and body contain
Gastric glands
Antrum and pylorus contain
Pyloric glands
Rugae
Lining of stomach
Internal curvature of the stomach is called
Lesser curvature
External curvature of stomach
Greater curvature
Gastric glands respond to signals from the
Vagus nerve of the parasympathetic neurons
Mucous cells
Produce bicarbonate mucus that protects the muscular wall from acid
Gastric gland cell types
Chief cells and parietal cells
Chief cells secrete
Pepsinongen
Parietal cells secrete
HCl and intrinsic factors
H+ ions cleave
Pepsinogen to pepsin
Pepsin
Cleaves peptide bonds
Intrinsic factor
Needed for Vitamin B absorption, secreted in stomach
Pyloric glands
G-cells secrete gastrin
Gastrin
Increases HCl secretion and gastric motility
Pepsin is activated by
Acid
Chyme
Food after mechanical and chemical digestion in stomach
Food leaves the stomach and enters the duodenum through
Pyloric sphincter
Segments of the small intestine
Duodenum, Jejunum, ileum
Duodenum releases
Brush-border enzymes
Bile salts
Derived from cholesterol, emulsify fats into micelles
Pancreatic juices are secreted into the
Duodenum
Pancreatic juice enzymes can digest
Carbs, fats, proteins
Duodenum pH conditions
Basic
Acinar cells produce
Pancreatic juices
Jejunum and ileum are involved in
Absorption
Villi components
Capillary bed and lacteal
Lacteal
Lymphatic system vessel
Large intestine components
Cecum, colon, rectum
Capillaries in the small intestine absorb
Water-soluble nutrients e.g. monosaccharides, amino acids, short-chain fatty acids
Lacteals in the small intestine absorb
Fat-soluble nutrients e.g. fats, cholesterol
Bile contains
Bile salt, cholesterol, pigments
Liver functions
- Bile production 2. Process nutrients 3. Detox 4. Synthesize albumin and clotting factor
Gallbladder
Stores and concentrates bile
Part of large intestine that absorbs water and salt
Colon
Peptidase, enteropeptidase, and secretin are found in
Duodenum
Secretin (hormone)
Stimulates release of pancreatic juices and slows motility
Cholecystokinin (hormone)
Stimulates bile and pancreatic juice release and promotes satiety