Digestive/Urinary System
Digestive System Function
Consists of organs that are involved in breaking down of food into molecules
It allows them to go through the wall of the digestive tract and can be taken by cells
Divisions of Digestive System
Gastrointestinal Tract Walls
Tube within a tube, open system
Continuous tube running from mouth to anus for passage of food.
Mucosa
Digestive Process
Ingestion-taking food through the mouth
Peristalsis- Propulsion of contraction and relaxation of smooth muscle lining and alimentary canal
Digestion- Process of breaking down larger food molecules into smaller molecules
Mechanical Digestion- Physical breakdown of food by cutting and grinding
Chemical Digestion- Requires enzymes
Absorption- Transport of digested end product into blood and lymph through the wall of GI tract.
Defacation- Elimination of indigestible substances from the body in the form of feces
Submucosa
Muscularis or muscular layer
Serosa
Mucosa
Mucous Membrane- Produces mucus for reduction of friction and protection.
Epithelium
Varies by location
Nonkeratinized stratifies squamous in mouth, esophagus, and anus, protection against friction
Simple columnar in intestine
Lamina Propria
Areolar connective tissue
Contains blood and lymph node for nourishment and immunity
Muscularis Mucosae
Two thin layers of smooth muscles
Submucosa
Areolar connective tissue containing major blood vessels
Many elastic fibers to retain shape
Submucosa Plexus - Autonomic nerve supply
Inner circular layer
Squeeze decrease size of lumen and some areas act as sphincter or valves
Outer longitunal layer- Shortens intestinal mouth, pharynx, superior esophagus and spinal sphincter- Voluntary muscle
Myenteric plexus- nerves
Serous
Outer covering of GI tract
Serous membrane
Composed of thin layer of areolar connective and simple squamous in epithelium
Gastrointestinal Tact
Mouth - Opening into oral cavity
Mechanical digestion- By the teeth by mastication
Chemical digestion- By saliva produced by salivary gland, digestion of starch begins
Mucosa produces mucus to coat bolus for easier transport
Initiates of deglutition (Swallowing)
Tongue allows for sense of taste
Immune function by the palatine tonsils
Pharynx
Oropharynx- Located posteriorly to mouth passage of food, water and air
Laryngopharynx- Inferior to oropharynx
Involved in deglutition, forcing bolus from mouth to esophagus
Esophagus
Collapsible tube runs from pharynx to stomach, pass through diaphragm
Only passage for food
Stomach
Located left to abdominal cavity in left hypochondriac region
Food enters at the cardioesophageal Sphincter
Food empties into duodenum of small intestine at the pyloric sphincter
Rugae- internal folds of stomach mucosa
Regions of stomach
Cardiac region
Fundus- Dome shaped filled with gas
Body- Main portion
Pylorus- Funnels shaped end
Pyloric Sphincter- Controls food leaving
Gastrointestinal Tract Part II
Small Intestine
Muscular tube extending from pyloric sphincter to the ileocecal valve
Chemical digestion where fat begins
Site of nutrition of absorption into blood and lymphatic vessels
Peristalsis and segment movement mix chyme with digestive enzymes
Regions of SI
Duodenum
Jejumum
Illeum
Vili of SI
Large Intestine
Site of absorption of water and electrolytes; Produces vitamins
Eliminates indigestible food from body and feces
Regions of LI
Cecum
Colon
Rectum
Anus
Eliminated feces from rectum to exterior
Internal- Made of involuntary smooth muscles
External- Voluntary skeletal muscle
Accessory Organ
Teeth- Hardest substance in body functions to mechanically breakdown into smaller pieces
Anatomy of teeth
Enamel
Dentin
Pulp
Supporting Ligament
Gingivi
Regions of teeth
Crown
Root
Types of teeth
Deciduos- Baby teeth
Permanent- Adult teeth
Incisors- Most anterior for cutting
Cuspids- Lateral incisor, for tearing and shredding
Premolars and molars- Sides and back for grinding
Salivary Glands
Amylase- Digest starch
Parotoid, Submandibular and Sublingal
Gastric Cells
Goblet cells- Produce mucus
Chief cells- Produce pepsinogen/ needs to be with hydrochloric acid to covert to pepsin
Pepsin- protein Digesting enzyme
Parietal cells- Produce HCL and intrinsic factor
Intrinsic factor- needed for absorption of vitamin b12 in stomach
Intestinal Glands
Secretes intestinal juice
Duodenal Glands- Alkaline Mucus to neutralize stomach acid
Enzymes in duodenum digest all food groups but require neutral ph to work
Pancreas
Located behind stomach Surrounded by duodenum
Produces digestive enzyme li[ase
Blood sugar by insulin
Liver
Largest gland in body; 4 lobes
Functions for storage of glycogen, fat soluble vitamins, and iron
removal of drugs, alcohol, and hormones
Gall Bladder
Pear- shaped organ; located underside of the liver on the right side of abdominal cavity
Stores bile and released into duodenum when needed
Urinary System
It regulates blood volume and pressure
Removes waste
Kidney
Regulating your water volume, , and ph levels
Influencing red blood cell production and blood pressure
Body keeps stuff it needs and takes away stuff it doesn't
3 Distinct layers
Renal cortex
Renal Medulla
Renal pelvis
Can hold over 20% of blood volume
Nephron
Glomerular Fitration
Tubular reabsorption
Tubular secretion
Microvili
Medulla
Urination
5% solutes , 95% water
All mammals and most animals in general, Urinate to remove toxins and help maintain water volume homeostasis or blood pressure
Urination disorders
Leukocytes- Urinary tract infection
Glucose- Diabetes mellitus
Erthrocytes- Bleeding in urinary tract
Proteins-working out too much, high Bp