BIO 132 Exam 3 Questions With 100% Correct Answers | Verified | Latest Update

BIO 132 Exam 3 Questions With 100% Correct Answers | Verified | Latest Update Digestive System - Answer- the organ system that processes ingested food (both physically and chemically), extracts nutrients from it, and eliminates the residue What are the five stages/functions of the digestion system? - Answer- -ingestion -digestion -absorption -compaction -defecation Ingestion - Answer- selective intake of food Digestion - Answer- mechanical and chemical breakdown of food into a form usable/absorbable by the body Mechanical Digestion - Answer- mastication, rugae/churning, segmentation, emulsification Chemical Digestion - Answer- -HCl acid denaturation -enzymatic breakdown Enzymatic Breakdown - Answer- -carbohydrates (salivary amylase, pancreatic amylase) -proteins (peptidase: pepsin, trypsin, etc.) -lipids (linguinal lipase, gastric lipase, pancreatic lipase) Absorption - Answer- uptake of nutrient molecules into the epithelial cells of the digestive tract and then into the blood and lymph Compaction - Answer- absorbing water and consolidating the indigestible residue into feces Defecation - Answer- elimination of feces What are the two subdivision of the digestive tract? - Answer- -digestive tract -accessory organs Accessory Organs include? - Answer- -salivary glands -liver -gallbladder -pancreas What are the layers of the digestive tract? - Answer- -mucosa -submucosa -muscularis externa -serosa Mucosa - Answer- the innermost layer of the human digestive tract, lines the lumen; in some parts of the digestive system, it contains mucus-secreting cells and glands that secrete digestive enzymes Submucosa - Answer- the layer of connective tissue directly under the mucosa; that contains nerves, blood vessels, and lymph nodes Muscularis Externa - Answer- bilayer of smooth muscle which consists of a layer running circularly and another running longitudinally; responsible for segmentation and peristalsis Serosa - Answer- outermost layer; areolar loose connective tissue topped by simple squamous mesothelium The enteric nervous system helps control... - Answer- the smooth muscle The parasympathetic nervous system promotes... - Answer- digestion What are the structures of the alimentary canal? - Answer- -mouth -pharynx -esophagus -stomach -small intestine -large intestine -anus Dentition - Answer- functions to masticate; to increase the surface area of the food via mechanical digestion Tongue - Answer- composed of skeletal muscle -papillae -frenulum Papillae - Answer- rough projections that contain taste buds Taste Buds - Answer- sensory receptors Frenulum - Answer- small fold of tissue that attaches/secures/restricts tongue or lip Palate - Answer- separates oral and nasal cavities -hard palate -soft palate Hard Palate - Answer- anterior portion, supported by bone, keratinized Soft Palate - Answer- -posterior portion, not supported by bone, non-keratinized, muscular, uvula -blocks nasopharynx to prevent food stuffs from entering nasal cavity when swallowing Intrinsic Salivary Glands - Answer- small glands dispersed amid other oral tissues -lingual glands (in the tongue) -labial glands (inside of the lips) -palatine glands (roof of mouth) -buccal glands (inside of the cheek) External Salivary Glands - Answer- -parotid -submandibular -sublingual Saliva - Answer- produced by intrinsic salivary glands dispersed in oral tissue and extrinsic salivary glands What is the pH of saliva? - Answer- 6.8-7.0 Saliva contains... - Answer- -electrolytes -salivary amylase -lingual lipase -antibacterial lysozyme and IgA secretory antibodies -functions: to cleanse teeth and moistens food to perceive taste and prepares it for swallowing by forming a bolus Bolus - Answer- a moistened mass of food swallowed; formed as a result of saliva binding food particles pack into a soft, slippery, easily swallowed mass Pharynx (throat) - Answer- -three parts: nasopharynx, oropharynx, and laryngopharynx -palatine tonsils, lingual tonsils, pharyngeal tonsils -functions: swallowing Swallowing is also known as - Answer- deglutition Swallowing - Answer- -voluntary phase (in mouth) -reflex action Reflex Action - Answer- -involuntary swallowing center of medulla oblongata -once the food or drink is pushed back to the oropharynx (breathing stops to swallow and signals the stomach to relax) Esophagus - Answer- -functions: to transport food from pharynx to cardiac orifice of stomach passing through esophageal hiatus -peristalsis Esophageal Hiatus - Answer- a hole in the diaphragm through which the esophagus and the vagus nerves pass Peristalsis - Answer- wave of muscular contraction (muscularis externa) that pushes the food bolus ahead of it along the alimentary canal, entirely involuntary reflex What kind of tissue is found in the mucosa layer of the esophagus? - Answer- nonkeratinized stratified squamous epithelium What are the layers of the esophagus? - Answer- -mucosa -submucosa -muscularis externa -serosa/adventitia Submucosa layer of the esophagus - Answer- secretes mucus Muscularis Externa of the esophagus - Answer- -skeletal muscle superiorly -mixed in middle -smooth muscle inferiorly Lower Esophageal Sphincter - Answer- marks the entrance to the stomach; usually closed to prevent regurgitation of food and stomach acids; relaxes to let food pass into the stomach Heartburn - Answer- burning sensation that occurs when some of the stomach contents escape back into the esophagus Barrett's esophagus - Answer- the epithelial lining changes from stratified squamous to simple columnar epithelia as a result of acidic insult