human bio II

• Digestion


  The process of breaking down all ingested food into small molecules (nutrients) for absorption into the bloodstream to be used by body cells
• Parts of the digestive tract/alimentary canal

  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine

  
• Digestive system


  • Consists of a digestive tract/alimentary canal and several accessory organs
  • Accessory organs aid in chemical digestion (teeth, tongue, 3 pairs of salivary glands, liver, gallbladder, bile ducts, pancreas)

  
• Functions and processes of the digestive system

  • Ingestion
  • Secretion
  • Motility
  • Digestion
  • Absorption
  • Defecation

  
• Genito-urinary system


  The system responsible for the production, storage, and elimination of urine
• Motility


  1. Mixing

  2. Propulsion

  3. Segmentation

  4. Peristalsis
• Mechanical digestion


  Breaks large pieces of food into smaller ones without altering their chemical composition
• Chemical digestion


  Breaks down larger nutrient molecules into simpler chemicals (organic and inorganic molecules) suitable for absorption by the digestive epithelium
• Layers of the digestive canal

  • Mucosa or mucous membrane
  • Submucosa
  • Muscular layer
  • Serosa/adventitia

  
• Functions of the kidneys

  • Regulation of blood ionic composition
  • Regulation of blood pH
  • Regulation of blood volume
  • Enzymatic regulation of blood pressure
  • Maintenance of blood osmolarity
  • Production of hormones
  • Regulation of blood glucose level
  • Excretion of wastes and foreign substances

  
• Mucosa or mucous membrane

  • A moist epithelial membrane that lines the alimentary canal lumen from mouth to anus
  • Secretes mucus, digestive enzymes, and hormones
  • Absorbs the end products of digestion into the blood
  • Protects against infectious disease

  
• Excretion


  The process of separating wastes from the body fluids and eliminating them from the body
• Submucosa


  • Contains a rich supply of blood and lymphatic vessels, lymphoid follicles
  • Contains an extensive network of neurons known as the submucosal neural plexus

  
• Systems that excrete wastes

  • Respiratory system
  • Integumentary system
  • Digestive system
  • Urinary system
• Muscular layer


  • The mouth, pharynx, and superior and middle parts of the esophagus contains skeletal muscle that produces voluntary swallowing
  • Responsible for segmentation and peristalsis

  
• Nitrogenous wastes


  Wastes containing nitrogen, such as ammonia and urea
• Serosa/Serous layer


  • The outermost layer, a serous membrane composed of areolar connective tissue and simple squamous epithelium (mesothelium)
  • Secretes serous fluid to moisten and lubricate the tube's outer surface
• Organs of the urinary system

  • Two kidneys
  • Two ureters
  • Urinary bladder
  • Urethra

  
• Parts of the peritoneum

  • Visceral peritoneum
  • Parietal peritoneum
  • Peritoneal cavity
• Kidneys


  • Bean-shaped organs
  • Lie in a retroperitoneal position
  • Protected by the lower rib cage
• Renal hilum


  The medial border of each kidney, occupied by the ureter, renal blood vessels, lymphatics, and nerves

  
• Retroperitoneal organ


  Organs that lie on the posterior abdominal wall, covered by peritoneum only on their anterior surfaces and not in the peritoneal cavity

  
• Renal pelvis


  The funnel-shaped area within each kidney where urine collects and is funneled into the ureter

  
• Major peritoneal folds


  • Lesser omentum
  • Falciform ligament
  • Greater omentum
  • Mesentery proper
  • Mesocolon
• Adrenal gland


  An endocrine gland located at the top of each kidney

  
• Peritonitis


  Inflammation of the peritoneum, often caused by a piercing abdominal wound, perforating ulcer, burst appendix, or poor sterile technique during abdominal surgery
• Renal cortex


  The light-colored, outermost region of the kidney that contains over one million microscopic nephrons

  
• Ascites


  Accumulation of several liters of fluid in the peritoneal cavity in certain diseases
• Renal medulla


  The dark, inner portion of the kidney that consists of several cone-shaped renal pyramids

  
• Enteric nervous system


  • The "brain of the gut", consists of ~100 million neurons that extend from the esophagus to the anus
  • Controls motility of the digestive canal (movement: peristalsis/segmentation)
  • Controls the secretions of the mucosal epithelium

  
• Renal papilla


  The narrower end of the renal pyramids where the urine drains into the minor calyces

  
• Autonomic nervous system


  • Regulates the enteric nervous system
  • Parasympathetic nerves stimulate increased digestive canal secretion and motility
  • Sympathetic nerves cause a decrease in digestive canal secretion and motility

  
• Renal column


  Tissue extending from the renal cortex between the renal pyramids, separating them

  
• The alimentary canal is a muscular tube ~8 m long that passes through the body's thoracic and abdominopelvic cavities
• Renal lobe


  One pyramid and its surrounding cortical tissue, making up about eight lobes of a kidney

  
• Mouth/oral cavity


  • Also called the buccal cavity
  • Anterior opening is the oral orifice
  • Posterior opening is the oropharynx
  • Lined by a thick stratified squamous epithelium
• Path of draining urine

  Nephrons → papillary ducts → minor calyces → major calyces → renal pelvis → ureter → bladder

  
• Lips and cheeks


  • Lips are highly mobile structures with skeletal muscles and sensory receptors
  • Cheeks form the lateral walls of the mouth, associated with expression and chewing
• Renal blood supply


  • Kidneys receive 20-25% of resting cardiac output
  • Renal blood flow ~1200 mL/min
  • Urine output ~1-3 L/day

  
• Major salivary glands


  • Parotid gland
  • Submandibular gland
  • Sublingual gland