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Digestive & Urinary System, Emily Cronin, Period 1 - Coggle Diagram

- - - - Alimentary canal (gastrointestinal or GI tract or gut)
        
        Organs involved:
        mouth
        pharynx
        esophagus
        stomach
        small intestine
        large intestine
        anus
        
        Functions:
        
        Continuous muscular tube that runs from the mouth to anus
        
        Digests food: breaks down into smaller fragments
        
        Absorbs fragments through lining into blood
        
        Mouth: where food is chewed and mixed with enzyme-containing saliva that begins process of digestion, and swallowing process is initiated
        
        Teeth: lie in sockets in gum-covered margins of mandible and maxilla
        
        Classification:
        
        Molars: broad crowns, rounded cusps: best grinders
        
        Premolars (bicuspids): broad crowns with rounded cusps used to grind or crush
        
        Canines: fanglike teeth that tear or pierce
        
        Incisors: chisel shaped for cutting
        
        Structure:
        
        Crown: exposed part above gingiva (gum)
        (Covered by enamel, the hardest substance in body)
        
        Root: portion embedded in jawbone
        (Connected to crown by neck)
        
        Salivary glands:
        Function of Saliva:
        
        Cleanses mouth
        
        Dissolves food chemicals for taste
        
        Moistens food; compacts into bolus
        
        Begins breakdown of starch with enzyme amylase
        
        2 types of secretory cells
        
        Serous cells: produce watery secretion, enzymes, ions, bit of mucin
        
        Mucous cells: produce mucus
        
        Tongue: occupies floor of mouth
        
        Functions:
        
        -Initiation of swallowing, speech, and taste
        
        -Gripping, repositioning, and mixing of food during chewing
        
        -Formation of bolus, mixture of food and saliva
        
        Stomach: a temporary storage tank that starts chemical breakdown of protein digestion
        
        Regions of the stomach
        
        Body: midportion
        
        Pyloric part: wider and more superior portion of pyloric region
        
        Fundus: dome-shaped region beneath diaphragm
        
        Antrum: narrows into pyloric canal that terminates in pylorus
        
        Cardial part (cardia): surrounds cardial orifice
        
        (Pylorus: continuous with duodenum through pyloric valve)
        
        Small intestine: the major organ of digestion and absorption
        (from the pyloric sphincter to the ileocecal valve)
        (the point at which it joins the large intestine)
        
        Jejunum: attached posteriorly by mesentery
        
        Ileum: attached posteriorly by mesentery; joins large intestine at ileocecal valve
        
        Duodenum: mostly retroperitoneal; curves around head of pancreas
        
        Esophagus: Flat muscular tube that runs from laryngopharynx to stomach
        
        Is collapsed when not involved in food propulsion
        
        Gastroesophageal (cardiac) sphincter surrounds cardial orifice
        
        Large intestine -3 features:
        
        3 features
        
        Epiploic appendages: fat-filled pouches of visceral peritoneum
        
        Teniae coli: three bands of longitudinal smooth muscle in Muscularis
        
        Haustra: pocketlike sacs caused by tone of Teniae coli
        
        Functions:
        
        -Propulsion of feces to anus & defecation
        
        -Reabsorption of vitamins
        
        (made by bacterial flora), water, & electrolytes
        
        (especially Na+and Cl−)
        
        Subdivisions:
        
        Cecum: first part of large intestine
        
        Rectum: three rectal valves stop feces from being passed with gas (flatus)
        
        Anal canal: last segment of large intestine that opens to body exterior at anus
        
        Colon: has several regions, most which are retroperitoneal (except for transverse and sigmoid regions)
        
        Appendix: masses of lymphoid tissue
        
        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
      - Accessory digestive organs
        (teeth, tongue, & gallbladder)
        
        Gallbladder: a thin-walled muscular sac on ventral surface of liver
        
        Bile def.: (chief function is storage of bile)
        
        Function: to store & concentrate bile by absorbing water and ions
        
        Digestive glands: produce secretions that help break down foodstuffs
        
        Liver: largest organ in the body
        Consists of 4 primary lobes: right, left, caudate, & quadrate
        
        Bile ducts:
        
        Bile duct formed by union of common hepatic and cystic ducts
        
        Cystic duct connects to gallbladder
        
        Common hepatic duct leaves liver
        
        Bile def.: digestive function is production of bile)
        
        Pancreas: a thin-walled muscular sac on ventral surface of liver
        Function: to store and concentrate bile by absorbing water and ions
        
        Exocrine function: produce pancreatic juice
        Endocrine function: secretion of insulin and glucagon by pancreatic islet cells
        
        Bile def.: supplies most of enzymes needed to digest chyme, as well as bicarbonate to neutralize stomach acid
- - - - Renal corpuscle
        
        2 parts
        
        2 layers
        
        Renal tubule:
        consists of a single layer of epithelial cells but each region has its own unique histology and function
        
        Visceral layer: clings to glomerular capillaries; branching epithelial
        
        Parietal layer: simple squamous epithelium
        
        Glomerulus: Tuft of capillaries composed of fenestrated endothelium
        Filtrate: plasma-derived fluid that renal tubules process to form urine
        
        Glomerular (Bowman's) capsule: cup-shaped, hollow structures surrounding the glomerulus
  - - - Proximal convoluted tubule:
        cuboidal cells with dense microvilli that form a brush border
        Function: reabsorption and secretion
        
        Nephron Loop "loop of Heule":
        U-shaped structure consisting of 2 limbs
        
        Descending limb: Proximal part of descending limb is continuous with proximal tubule
        
        Ascending limb: thick ascending limb (Cuboidal or columnar cells)
        
        Distal convoluted tubule:
        Cuboidal cell with very few microvilli
        Function: more in secretion than reabsorption
        
        Principal cells: sparse with short microvilli & Maintain water and 𝑁𝑎+ balance
        
        Intercalated cells: Cuboidal cells with abundant microvilli & consists of 2 types:
        A & B cells (both help maintain acid-base balance of blood
- - - - Urinary bladder: temporary storage reservoir for urine
        
        Urethra: transports urine out of body
  - - - Maintain body's internal environment by:
        
        Ensuring long-term acid-base balance
        
        Excreting metabolic wastes, toxins, drugs
        
        Regulating ion concentrations in extra cellular fluid (ECF)
        
        Producing erythropoietin (regulates blood pressure and renin (regulates RBC production))
        
        Regulating total water volume and solute concentration in water
        
        Activating vitamin D
        
        Carrying out gluconeogenesis, if needed