Chapter 24 Digestive System Flashcards
Gut
alimentary canal/gastrointestinal (GI) tract
Endocrine
no duct
Exocrine
exit
Foregut
mouth -> duodenum
Midgut
jejunum and ileum
Hindgut
colon -> rectum
bolus formation
swallow-able mass
Vestibule
space btw lips/cheeks & teeth
Gingiva
mucosa covering alveolar bone/hard palate
4 tonsils; how many paired salivary glands?
3
3 salivary glands:
parotid, submandibular, sublingual
Function of saliva
- cleanses teeth, moistens food
- contains enzyme amylase: break down starch
Tongue
- muscular hydrostat=constant volume
- anchored to hyoid and jaw
Tongue too tightly bound to floor of mouth?
ankyloglossia
Uvula acts as?
sealant
Hairy Tongue (Lingua Villosa)
- hypertrophy of filiform papillae
- Causes: smoking, dry-mouth, oral hygiene
Enamel (crown)
hardest substance in body (calcium phosphate)
Dentin (body of tooth)
forms roots & encloses the pulp cavity
Endodontic disease
- Root-canal procedure
- Goal: tooth ankylosis
Pulp cavity
contains blood vessels & nerves
Periodontal disease
- probe gingival pack
- damage to tooth/alveolus
Incisors
1 root, blade-shaped cusp
8
Cuspids
1 root, conical pointed cusp
4
Bicuspids
1-2 roots, blade-like cusps
8
Molars
3-4 roots, large flattened crowns
8-12
Edentulous
no teeth
deciduous teeth
- milk/baby teeth (20)
- no bicuspids
- erupt @ 6 months to 2yrs
adult teeth
- 28-32
- erupt @ 6-21 years
impacted molars
they rotated
How many layers of gut?
4
Mucosa
- innermost tunic
- secretes mucus which protects the lining of gut
- “pleated” appearance (plicae circularis or rugae)
- lamina propria (CT) supports overlying epithelium
Submucosa
- exocrine glands: enzyme secretion = digest food
- highly vascular = absorption of nutrients from food
- Meissner’s plexus of ANS fibers= controls the secretions of the submucosal glands
Muscularis
- 2 layers (peristalsis)
- inner layer: circular muscles = decreases diameter > increase in length
- outer layer: longitudinal muscles = decreases tube length > increases diameter
- myenteric plexus of ANS fibers = controls peristalsis (directional) and segmentation (mixing) of chyme
Serosa
- outermost layer (serous membrane)
- aka visceral peritoneum
Esophagus
- collapsible muscular tube (2 muscle layers)
- extends from pharynx to stomach through diaphragm
How many layers of muscles in stomach?
3
Gastric juices
HCL, pepsinogen/pepsin, rennin
Mucous
protects walls from gastric juices