Ch. 26 Anatomy Lecture

Hard palate

Soft palate

Uvula

Fauces

Tongue

Teeth

Gingivae

Vestibule

Crown

Neck

Root

• Enamel

• Hardest substance in the body

• Made with calcium phosphate

Dentin

• Pulp and pulp cavity

• Consists of nerves, blood vessels, and soft connective tissue

Root canal

Cementum

• Periodontal ligaments

• Hold teeth in bone

Deciduous teeth

20 temporary teeth

Adult teeth

32 permanent teeth

Papillae

Houses taste buds

Sublingual salivary gland

Submandibular salivary gland

Parotid salivary gland

What is saliva made of?

• Mucin

• Electrolytes

• Antibodies

• Enzymes

Salivary amylase

Begins chemical digestion of complex carbohydrates

Lingual lipase

Begins chemical digestion of triglycerides

Mucosa

Mucosal epithelium

• Lamina propia

• Mostly areola connective tissue

• Muscularis mucosae

• Smooth muscle

• Submucosa

• Mostly areolar connective tissue

• Houses many nerves, blood vessels, and lymphatic vessels

Muscularis externa

• Longitudinal muscle

• Allows shortening and lengthening

• Circular muscle

• Allows constriction and dilation

Serosa

• Epithelial layer of serosa aka visceral peritoneum

• Mostly simple squamous epithelium

• Connective tissue layer of serosa

• Mostly areola connective tissue

Lumen

Esophagus

• Muscular tube leading from mouth to stomach

• Function: movement of food by peristalsis; does not contribute to digestion

• Muscular externa

• Upper third = skeletal muscle; lower third = smooth muscle

• Adventitia

• Only connective tissue; therefore, not serosa

Esophageal sphincter

Regulates the entrance and exit from the esophagus

Upper esophageal sphincter

• Lower esophageal sphincter

• Aka gastroesophageal or cardiac sphincter

GERD

• Gastroesophageal reflux disease

• Lower esophageal sphincter does not close properly, allowing stomach acid to enter the esophagus

Parietal peritoneum

Membrane lining of the abdominal cavity

• Mesenteries

• Folds of the peritoneum that support and stabilize organs, holds fat, and houses vessels

• Greater omentum

• Mesentery that hangs over abdominal organs

• Oblique muscle layer

• Allows the stomach to twist for churning

• Stomach has 3 layers of muscle

What is the rugae made of?

Mucosa and submucosa

Gastric pit

Simple columnar epithelium

Lamina propia

Gastric gland

• Surface mucus cells

• Secretes alkaline mucus to protect from stomach acid

• Parietal cells

• Secret hydrochloric acid and intrinsic factor

Function of hydrochloric acid secreted by parietal cells

• Kills microorganisms

• Denatures proteins

Function of intrinsic factor secreted by parietal cells

Necessary for the absorption of vit b12 in the small intenstines

• Chief cells

• Secretes pepsinogen

Pepsinogen

• Precursor to pepsin

• Pepsin breaks down proteins

• Enteroendocrine cells

• Secretes gastrin, somatostatin, histamine, and other hormones (coordinates digestion)

Chyme

Stomach secretions and food

Digestive functions of stomach

• Chemical breakdown of proteins

• No absorption of nutrients (except alcohol and some drugs)

Duodenum

• Mixes chyme, pancreatic secretions, and bile

• Shallow plicae

Plicae

• Circular folds of the submucosa

• Increase surface area of small intestine for absorption

Jejunum

• Where final chemical digestion and most absorption of nutrients occurs

• Deep plicae and villi

Villi

Fingerlike folds in the mucosa layer

• Contains microvilli

Microvilli

• Folds on the apical surface of epithelial cells of small intestine

• Increases surface area and absorption on the cellular level

• Lacteal

• Absorbs fats

• Capillary network

• Absorbs nutrients

Ileum

• Absorption of vit B12

• Has vili and less prominent plicae

• Has peyer’s patches (MALT) to protect from bacteria in large intestine

Large intestine

• No folds

• Lots of goblet cells for mucus

• Function: absorbs water, vit K, biotin, and vit B5; stores fecal matter

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• Smooth muscle (involuntary contraction)

• Skeletal muscle (voluntary contraction)

Pancreas

• Dual glandular

• Pancreatic acini: cells that make digestive enzymes and dumps them into duodenum via pancreatic duct

Lobules

• Functional unit of liver

• Filters blood from the hepatic portal veins

Liver functions

• Metabolic regulation

• Hematological regulation

• Bile production

Galbladder

Stores bile

Cholelithiasis

• Gallstones

• Composed of cholesterol