Digestive and Urinary System
Sarah Hernandez P.6

Digestive Enzymes

Digestion and absorption of macromolecules

Layers of GI Tract (+ stomach)

Disorders of digestive/urinary systems

Major organs of urinary system

Major functions of urinary system

Major organs of digestive system: alimentary canal and accessory organs

Major functions of digestive system

Nephron anatomy and physiology

  • salivary amylase: of salivary glands; begins carbohydrate digestion by breaking starches to disaccharides
  • pepsin: of gastric chief cells; begins protein digestion
  • pancreatic amylase: of pancreas; breaks starch to disaccharides
  • pancreatic lipase: breaks fats to fatty acids/ glycerol
  • proteolytic enzymes- trypsin, chymotrypsin, carbopeptidase: of pancreas; breaks proteins into peptides
  • nucleases: of pancreas; breaks nucleic acids to nucleotides
  • peptidase: of intestinal mucosal cells; breaks peptides to amino acids
  • sucrase, maltase, lactase: of intestinal mucosal cells; break dissacharides to monosaccharides
  • intestinal lipase: intestinal mucosal cells; brekas fats to fatty acids/ glycerol
  • enterokinase: of intestinal mucosal cells; breaks trypsinogen to trypsin
  • filters salts/waste from the blood
  • maintains normal concentrations of electrolytes/water
  • helps control RBC production and blood pressure
  • regulates pH and body fluid volume
  • kidneys: filter blood
    -kidneys: regulates volume, composition, and pH of body fluids
    -remove metabolic wastes from blood, forming urine
    -help control the rate of rbc formation
  • ureters: transport urine from kidneys to bladder
    -due to ureter angle entering urinary bladder, urine is propelled towards bladder, preventing backflow
  • urinary bladder: stores urine, lies in pelvic cavity
  • urethra: conveys urine to outside of the body
    -tubular organ that transfers urine outside the body; contains internal urethral sphincter (smooth muscle) and external urethral sphincter (skeletal muscle)

alimentary canal

accessory organs

salivary glands (parotid, submandibular, sublingual glands): secretes saliva and mositens/dissolves food particles, binds together, aids in tasting and begins carbohydrate digestion

  • salivary glands contain serous cells that produce watery fluid containing salivary amylase and mucous cells, producing binding mucous
    liver: located upper right quadrant of abdominal cavity, largest internal organ
    functions:
    -responsible for metabolic activities{ of carbs, lipids, proteins
    -stores glycogen, vitamins A/D/B12 + iron
    -synthesizes lipoproteins, phospholipids, cholesterol
    -filters blood: removes damaged rbcs, foreign substances and toxins
    digestion role= secrete bile
    gallbladder: stores bile between meals and reabsorbs water to concentrate bile
    pancreas: both endocrine/exocrine gland
    -exocrine function: produce pancreatic juice ending in digestion
  • pancreatic juices contain bicarbonate ions; creates alkaline environment in duodenum for enzyme function
  • pancreatic juices: contains enzymes digesting carbs, fats, proteins, nucleic acids

mouth: first portion of the alimentary canal, surrounded by lips, cheeks, tongue, and palate

  • receives food and begins mechanical digestion via mastication
    pharynx: (throat) connects basal/oral cavities with larynx and esophagus
  • divided into 3 portions: nasopharynx, oropharynx, laryngopharynx
    esophagus: muscular tube from pharynx to stomach, extends through diaphragm opening
  • mucous glands lubricate inner tubal lining
  • lower esophageal (cardica, cardioesophageal) sphincter: helps prevent regurgitation of stomach contents into esophagus
    stomach: located in upper left abdominal quadrant
  • rugae: gastric folds of mucosa/submucosa, allows for digestion
  • parts of the stomach: cardiac, fundus, body region, phylorus
  • gastric secretions: in thick mucosa of stomach open to lumen as gastric pits- mucus cells (mucous), chief cells (protein digestion), pareital cells (hydrochloric acids, activates pepsinogen/ intrinsic factor)
  • consists of same 4 layers throughout length with variations based on functions to specific sections of the canal} layers= mucosa, submucosa, muscularis, serosa
    mucosa: mucous membrane surrounding lumen of the tube; inner layer of wall
  • protects tissues of canal and carries on secretion/absorption of dietary nutrients
  • consists of epithelium, connective tissue and smooth muscle
    submucosa: beneath mucosa; houses blood, lymphatic vessels, nerves, glands
  • of loos connective tissue, nourishing canal layers and transporting absorbed nutrients away from digestive organs
    muscularis: propels food through canal
  • 2 layers of smooth muscle
    -inner=circular
    -outer-longitudinal layers
    serosa: outer serous layer or visceral peritoneum
  • protects underlying tissues an secretes serous fluid to reduce friction

Large Intestine:

  • Vitamin K and B
  • other 5% of water absorption

Small Intestine:

  • vitamin A,D,E,K diffuse into absorptive cells
  • Vitamin C and B diffused by passive/active transports
  • Vitamin B12 absorbed by endocytosis

small intestine: long, tubular organ that runs from stomach to beginning of large intestine

  • functions: receives chyme from stomach, bile of liver/gallbladder and pancreatic juices from pancreas, finish nutrient digestion of chyme, and transfers residue to large intestine
  • small intestine consists of : duodenum, jejunum, ileum and mesentery- double layerd peritoneum folds containing blood vessels, nerves, lymphatic vessels of intestinal wall + villi
  • small intestine secretes= mucous, watery fluids, peptidases, sucrase/maltase/lactase and intestinal lipase enzymes
    large intestine: parts of the large intestine consist of the cecum, colon, rectum, anal canal
  • does not digest/absorb nutrients but absorbs electrolytes/water
    rectum: straight section of large intestine, lies next to sacrum
  • cholecystitis: inflammation of the gallbladder
  • gastroesophageal reflux disease (GERD): chronic disease that occurs when esophageal sphincter relaxes, allowing contents of stomach to move back to esophagus
  • inflammatory bowel disease (IBD): chronic complex intestinal condition causing digestive tract inflammation- includes crohnis disease/ ulcerate colitis
  • peptic ulcers: sores that develop in stomach lining or duodenum
  • colon diseases:
    -polyps= growths
    -hemorrhoids= inflamed veins in rectum/anus
  • bladder cancer: when cells of the bladder grow out of control and eventually lead to bladder cancer
  • urinary tract infection: abnormal growth of bacteria anywhere along urinary tract combined with symptoms
  • kidney stones: stones formed from high levels of minerals and salts in urine

Renal Corpuscle

  • glomerulus: filtration of water and dissolved plasma substances
  • glomerular capsule: recipient of glomerular filtrate

Renal Tubule

  • Proximal convoluted tubule:
    -reabsorption of glucose, amino acids, creatine, lactic/uric/citric/absorbic acids; phosphate, sulfate, calcium, potassium, and sodium ions via active transport
    -reabsorption of water via osmosis
    -reabsorption of negatively charged ions via electrochemical attraction
  • Descending limb of nephron loop: reabsorption of water via osmosis
  • Ascending limb of nephron loop: reabsorption of sodium ions via active transport
  • Distal convoluted tubule: reabsorp. water via osmosis
  • secretion of hydrogen/potassium ions via active and passive transport

The digestive system consists of 10 organs that absorb and digest nutrients via mechanical and chemical breakdown. Accessory organs assist in the chemical breakdown of nutrients for proper ingestion of essential nutrients such as carbohydrates, fats, proteins, and nucleic acids, as well as other essential food molecules for nutrient absorption through the bloodstream