Digestion

1
Digestion

• Karen Kraus
• BIOL 204
• October 30, 2007

2
Doing it

• Physical and chemical breakdown of food molecules
• Absorption of nutrients
• Elimination of wastes

3
Pieces and Parts

• Gastrointestinal tract, aka alimentary canal
• Esophagus
• Stomach
• Duodenum
• Jejenum
• Ileum
• Colon (large intestine)

4
Accessorize

• Salivary glands
• Pancreas
• Liver
• Gall bladder

5
Vocabulary

• Ingestion
• Propulsion
• Deglutition, peristalsis
• Mechanical vs. chemical digestion
• Mastication, segmentation
• Absorption
• Defecation

6
Policing

• Mechanoreceptors (stretch receptors)
• Chemoreceptors
• Short reflexes
• Long reflexes

7
Covering everything

• Serous
• Falciform ligament
• Greater and lesser omenta
• Mesentery
• Mesocolon
• Retro, intra, and infraperitoneal

8
layering

• Serosa
• Muscularis
• Submuscosa
• Mucosa

9
Open up and say ahhh

• Labia
• Vestibule
• Hard and soft palates
• Uvula
• Palatoglossal arch
• Palatopharyngeal arch
• Fauces

10
Stick it out

• Taste
• Mixes food with saliva
• Compacts food
• Speech
• Papillae filiform, fungiform, vallate
• Intrinsic and extrinsic muscles

11
Drool drool

• Salivary functions
• Rinsing
• Dissolution
• Moisten food
• Salivary amylase
• Buccal glands
• Extrinsic glands

12
Spit!

• Mostly water
• Typical electrolytes (Na, K, Cl, phosphate,
  bicarbonate)
• Enzymes amylase, lysozyme
• Mucin and defensins
• IgA
• Metabolic wastes
• Controlled via PNS (IX and VII)
• Pons and upper medulla oblongata

13
Bite me!
14
Clickety-clack

• Deciduous vs. permanent
• Incisors
• Canines (cuspids)
• Premolars (bicuspids)
• Molars

15
Going down

• Mucosa
• Muscularis
• Adventitia

16
deeper

• Pharynx to hiatal sphincter
• Mucosa
• Submucosa
• Muscularis
• Sphincters
• Curvatures
• Innervation

17
Whats going on here?

• Chemical digestion
• Mechanical digestion
• Deglutition
• Oral phase
• Pharyngeal phase
• Esophageal phase

18
Down the hatch