Flashcards in Digestive System Deck (65)
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31
Saliva
Moistens, dissolves food for taste, begins starch and fat digestion, cleanses teeth, inhibits bacteria, and binds food together into bolus
32
Amylase
Begins starch digestion
33
Lingual Lipase
Digests fat after it reaches the stomach
34
Lysozyme
Enzyme that kills bacteria
35
Immunoglobin A
Inhibits bacterial growth
36
Electrolytes
Na+, K+, Cl-, phosphate, and bicarbonate
37
Salivation
Salivary nuclei in the medulla oblongata and pons
Parasympathetic function
38
Mumps
Myxovirus that attacks the parotid gland
39
Pharynx
Funnel-shaped tube extending from internal nares to the esophagus (posteriorly) and the larynx (anteriorly)
40
Esophagus
Collapsed muscular tube
41
Histology of the Esophagus
Mucosa: stratified squamous
Submucosa: large mucous glands
Muscularis: upper 1/3 is skeletal, middle is mixed, lower 1/3 is smooth
Adventitia: connective tissue blending with surrounding connective tissue (no peritoneum)
42
Swallowing
Upper sphincter relaxes when larynx is lifted
Peristalsis pushes food down
Lower sphincter relaxes as food approaches
43
Swallowing: Oral Phase
Voluntary
Bolus formed in the mouth
Oropharynx-->Laryngopharynx
44
Pharyngeal Phase
Involuntary
Tongue and soft palate block food and drink
Esophagus widens
45
Esophageal Phase
Peristalsis
Brain swallowing center + myenteric plexus in esophageal wall
Muscle above bolus constricts
46
Anatomy of Stomach
Left side of stomach
Cardia, Fundus, Body, Pylorus
47
Pylorospasm
Muscle fibers of sphincter fail to relax, trapping food in the stomach
Vomiting occurs to relieve pressure
48
Pyloric Stenosis
Narrowing of sphincter indicated by projectile vomiting
Must be corrected surgically
49
Stomach Mucous Cell
Secretes mucous
Cardiac, pyloric glands
50
Stomach Regenerative Cells
Base of gastric pits
Divide rapidly
New cells migrate upward
51
Stomach Parietal Cells
Secrete HCl, intrinsic factor, ghrelin
Found mostly in gastric glands
52
Stomach Chief Cells
Most numerous
Secrete gastric lipase, pepsinogen
Lower 1/2 of gastric glands
53
Stomach Enteroendocrine Cells
Found in the lower end of the gland
Secrete hormones and paracrine messengers
At least 8 different kinds
54
Stomach Muscularis
Longitudinal, Circular, and Inner Oblique
55
Stomach Mechanical Digestion
Gentle mixing waves
More vigorous waves from body to pyloric region
Intense waves near the pylorus
56
Stomach Chemical Digestion
Protein digestion begins as HCl denatures protein, transforms pepsinogen into pepsin
Fat digestion continues as gastric lipase splits triglycerides in milk fat
57
Regulation of Gastric Secretion and Motility
1. Cephalic phase
2. Gastric phase
3. Intestinal phase
58
Cephalic Phase
Gets the stomach ready
Cerebral cortex stimulates parasympathetic nervous system
Vagus nerve increases stomach muscle and glandular activity
59
Gastric Phase
"Stomach Working"
Nervous control keeps stomach active
Endocrine system influences stomach activity
60
