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Karen Morales period 6 Digestive & Urinary System - Coggle Diagram
Karen Morales period 6
Digestive & Urinary System
Main functions of the digestive system
– Absorb molecules into the bloodstream
– Rid body of any indigestible remains
– Break it down into nutrient molecules
– Take in food
Organs of the digestive system
accessory organs
Teeth:Mastication: process of chewing that tears and grinds food into smaller fragments
Tongue
– Gripps, repositions, and mixes food during chewing
– Forms bolus, a mixture of food and saliva
– Initiation of swallowing, speech, and taste
Liver: digestive function is production of bile
Bile duct s
Cystic duct connects to gallbladder
Common hepatic duct leaves liver
Bile duct formed by union of common hepatic and cystic ducts
Largest gland in the body
Digestive glands: produce secretions that help break down foodstuffs. salivary glands, liver and pancreas
functions of saliva
– Cleanses mouth
– Dissolves food chemicals for taste
– Moistens food; compacts into bolus
– Begins breakdown of starch with enzyme amylase
Mouth:where food is chewed and mixed with enzyme-containing saliva that begins process of digestion, and swallowing process is initiated
Lips and cheeks
Palate forms the roof of the mouth and has two distinct parts
Soft palate: fold formed mostly of skeletal muscle.Closes off nasopharynx during swallowing
Hard palate: formed by palatine bones and palatine processes of maxillae with a midline ridge called raphe
Gallbladder:a thin-walled muscular sac on ventral surface of liver. store bile
Pancreas: supplies most of enzymes needed to digest chyme, as well as bicarbonate to neutralize stomach acid. produce pancreac juice
Anal Canal
Continuous muscular tube that runs from the mouth to anus
Digests food: breaks down into smaller fragments
Absorbs fragments through lining into blood
Organs: mouth, pharynx, esophagus, stomach, small intestine, large intestine,anus
Esophagus
Flat muscular tube that runs from laryngopharynx to stomach
– Is collapsed when not involved in food propulsion
Gastroesophageal (cardiac) sphincter surrounds cardial orifice.Keeps orifice closed when food is not being swallowed
Stomach is a temporary storage tank that starts chemical breakdown of protein digestion
pharynx
Food passes from mouth into oropharynx and then into laryngopharynx
– Allows passage of food, fluids, and air
– External muscle layers consists of two skeletal muscle layers
Small intestine is the major organ of digestion and absorption
Jejunum: ~2.5 m (8 ft) long; attached posteriorly by mesentery
Duodenum: mostly retroperitoneal; ~25.0 cm (10.0 in) long; curves around head of pancreas
Ileum: ~3.6 m (12 ft) long; attached posteriorly by mesentery; joins large intestine
Large intestine
– Teniae coli: three bands of longitudinal smooth muscle in muscularis
– Haustra: pocketlike sacs caused by tone of teniae coli
– Epiploic appendages: fat-filled pouches of visceral peritoneum
subdivisions
Appendix: masses of lymphoid tissue
Colon
Transverse colon: travels across abdominal cavity
Descending colon: travels down left side of abdominal cavity
Ascending colon: travels up right side of abdominal cavity to level of right kidney
Sigmoid colon: S-shaped portion that travels through pelvis
Cecum: first part of large intestine
Rectum: three rectal valves stop feces from being passed with gas
Anal canal: last segment of large intestine that opens to body exterior at anus
**Digestive Processes
Ingestion: eating
Propulsion: movement of food through the alimentary canal, which includes:Swallowing.Peristalsis: major means of propulsion of food that involves alternating waves of contraction and relaxation
Mechanical breakdown: includes chewing, mixing food with saliva, churning food in stomach, and segmentation. Segmentation: local constriction of intestine that mixes food with digestive juices
Digestion: series of catabolic steps that involves enzymes that break down complex food molecules into chemical building blocks
Absorption: passage of digested fragments from lumen of GI tract into blood or lymph
Defecation: elimination of indigestible substances via anus in form of feces
DIgestive process in stomach
Carries out breakdown of food
Serves as holding area for food
Delivers chyme to small intestine
Denatures proteins by HCl
Pepsin carries out enzymatic digestion of proteins
Lipid-soluble alcohol and aspirin are absorbed into blood
Only stomach function essential to life is secretion of intrinsic factor for vitamin B12 absorption
small intestine
Takes 3–6 hours in small intestine to absorb all nutrients and most water
between meals
Peristalsis increases, initiated by rise in hormone motilin in late intestinal phase.Meal remnants, bacteria, and debris are moved toward large intestine
after a meal
Segmentation is most common motion of small intestine
Chyme from stomach contains partially digested carbohydrates and proteins and
undigested fats
Large Intestine
Residue remains in large intestine 12–24 hours
No food breakdown occurs except what enteric bacteria digest
• Major functions of large intestine: Propulsion of feces to anus and defecation.Reabsorption of vitamins (made by bacterial flora), water, and electrolytes
Defacation: expel feces
digestion of macromolecules
carbohydrate digestion occurs at mouth and small intestine
Fructose passes via facilitated diffusion
All monosaccharides leave the epithelial cells via facilitated diffusion,enter the capillary blood in the villi, and are transported to the liver via the hepatic portal vein.
glucose and galactose are absorbed via cotransport with Na+.
fat digestion occurs in mouth, stomach, small intestine
fatty acids and monoglycerides are recombined to form triglycerides and hen combined with other lipids and proteins
the chylomicrons enter the lacteals of the villi and are transported to the systemic circulation
Some short chain fatty acids are absorbed and enter the capillary blood in the villi, and are transported to the liver via the hepatic portal vein.
fatty acids and monoglycerides enter the intestinal cells via diffusion.
protein digestion occurs at stomach, small intestine
Some dipeptides and tripeptides are absorbed via cotransport with H+ and hydrolyzed to amino acids within the cells
frequently, transcytosis( transcellular transport in which various macromolecules are transported across the interior of a cell) of small peptides occur
Amino acids are absorbed via cotransport with Na+.
amino acids leave the epithelial cells by facilitated diffusion, enter the capillary blood in the villi, and are transported to the liver via the hepatic portal vein.
histology of anal canal
Submucosa
– Consists of areolar connective tissue
– Contains blood and lymphatic vessels, lymphoid follicles, and submucosal nerve
plexus that supply surrounding GI tract tissues
– Has abundant amount of elastic tissues that help organs to regain shape after storing large meal
Muscularis externa
– Muscle layer responsible for segmentation and peristalsis
– Contains inner circular muscle layer and outer longitudinal layers
Mucosa
– Tunic layer that lines lumen
– Functions: different layers perform one or all three
Absorbs end products of digestion
Protects against infectious disease
Secretes mucus, digestive enzymes, and hormones
Serosa outer most layer
Stomach
Lesser curvature: concave medial surface of stomach
lesser omentum:runs from lesser curvature to liver
Greater curvature: convex lateral surface of stomach
greater omentum: drapes inferiorly from greater curvature over intestine, spleen, and transverse colon
Stomach wall contains regular four tunics; however, muscularis and mucosa are modified
Mucosa layer is also modified.Secrete two-layer coat of alkaline mucus.Dotted with gastric pits, which lead into gastric glands.Gastric glands produce gastric juice
Muscularis externa has circular and longitudinal smooth muscle layers, as well as extra third layer, the oblique (diagonal) layer
small intestine: Small intestine’s length and other structural modifications provide huge surface area for nutrient absorption
Mircovilli :Cytoplasmic extensions of mucosal cell that give fuzzy appearance called the brush border that contains membrane-bound enzymes brush border enzymes, used for final carbohydrate and protein digestion
Villi:Fingerlike projections of mucosa (~1 mm high) with a core that contains dense capillary bed and lymphatic capillary called a lacteal for absorption
Major functions of the urinary system
Eliminate waste products from the blood.
Maintain water balance in the body.
Regulate the levels of electrolytes in the body.
digestive enzymes
– Proteases (for proteins): secreted in inactive form to prevent self-digestion
– Amylase (for carbohydrates)
– Lipases (for lipids)
– Nucleases (for nucleic acids)
Mucous neck cells:Secrete thin, acidic mucus of unknown function
Parietal cells:Hydrochloric acid (HCl),pH 1.5–3.5; denatures protein, activates pepsin, breaks down plant cell walls, and kills many bacteria. intrinsic factor:Glycoprotein required for absorption of vitamin B12 in small
Chiefs cells: Pepsinogen: inactive enzyme that is activated to pepsin by HCl and by pepsin itself (a positive feedback mechanism) Lipases: digests 15% lipids
Enteroendocrine cells:Secrete chemical messengers into lamina propria
Major organs of the urinary systems
Ureters: transport urine from kidneys to urinary bladder
Urinary bladder: temporary storage reservoir for urine
Kidneys, a major excretory organ, maintain the body’s internal environment
– Regulating total water volume and total solute concentration in water
– Regulating ion concentrations in extracellular fluid (ECF)
– Excreting metabolic wastes, toxins, drugs
– Producing erythropoietin (regulates blood pressure and renin (regulates RBC production)
gross anatomy
Renal medulla: deep to cortex, composed of cone-shaped medullary (renal) pyramids
Renal pelvis, funnel shaped tube continuous with ureter
Renal cortex: granular-appearing superficial region
Urethra: transports urine out of body
Nephron are the structural and functional units that forms urine in the Kidneys
Renal tubule
Nephron loop:U-shaped structure consisting of two limbs.Proximal part of descending limb is continuous with proximal tubule.ascending limb
Distal convoluted tubule:farthest from renal corpuscle.Distal convoluted tubule drains into collecting duct.Function more in secretion than reabsorption
Proximal convoluted tubule: closest to renal corpuscle. functions in reabsorption and secretion
Renal corpuscle
Glomerular capsule:cup-shaped, hollow structure surrounding glomerulus
Glomerulus:Tuft of capillaries composed of fenestrated endothelium
Physiology of nephron
The proximal tubule is the first site of water reabsorption into the bloodstream, and the site where the majority of water and salt reabsorption takes place.
The loop of Henle is a U-shaped tube that consists of a descending limb and ascending limb. It transfers fluid from the proximal to the distal tubule.
The glomerulus is a capillary tuft that receives its blood supply from an afferent arteriole of the renal circulation. Here, fluid and solutes are filtered out of the blood and into the space made by Bowman’s capsule.
The distal convoluted tubule and collecting duct is the final site of reabsorption in the nephron.
After passage through the collecting duct, the fluid is brought into the ureter, where it leaves the kidney as urine.
Disorders of the digestive and urinary systems
peptic ulcers
:open sores that develop on the inside lining of your stomach and the upper portion of your small intestine
colon cancer
:A cancer of the colon or rectum, located at the digestive tract's lower end
inflammatory bowel disease
: ongoing inflammation of all or part of the digestive tract
Ulcerative colitis
is a chronic inflammatory bowel disease in which abnormal reactions of the immune system cause inflammation and ulcers on the inner lining of your large intestine
Gastroesophageal Reflux Disease
a digestive disorder that occurs when acidic stomach juices, or food and fluids back up from the stomach into the esophagus
Bladder
:Cancer that begins in the bladder, a sign is blood in urine
Cholecystitis
is a redness and swelling of the gallbladder, occurs when bile gets trapped in the gallbladder
Urinary Tract Infection
An infection in any part of the urinary system, the kidneys, bladder, or urethra. A sign is lower pelvic pain, more common in women
kidney stones
:A small, hard deposit that forms in the kidneys and is often painful when passed.
