Gross Veterinary Anatomy - Digestive and Respiratory Organs

Flashcards for Veterinary Anatomy focusing on the digestive and respiratory systems.

Splanchnology

Deals with the visceral organs of digestive, respiratory, and urogenital systems

Mouth / Oral Cavity

The first segment of the digestive tract, bounded by the hard and soft palate, teeth, cheeks, lips, tongue, and oropharynx.

Pharynx

Connects the mouth to the esophagus and serves as a common passageway for food, water, and air.

Oropharynx

Aperture of the pharynx that opens into the mouth.

Nasopharynx

Aperture of the pharynx that opens into the nasal cavity dorsal to the oral cavity.

Laryngopharynx

Aperture of the pharynx that opens into the larynx and esophagus ventrally.

Pharyngeal proper

Serves as a common passageway for digestive and respiratory tract

Esophagus

Long, muscular tube serving as a passageway for bolus.

Bolus

Ingesta passing along the esophagus; pH is slightly acidic or alkaline.

Cervical Esophagus

Part of the esophagus adjacent to cervical vertebrae.

Thoracic Esophagus

Part of esophagus adjacent to thoracic vertebrae.

Abdominal Esophagus

Part of the esophagus that is passing across the hiatus esophageal of the diaphragm.

Diaphragm

Muscle which separates the thoracic from the abdominal cavity

4 concentric layers of esophagus

• tunica mucosa

• tunica submucosa

• tunica muscularis

• tunica adventitia

Tunica Mucosa

The inner layer of the esophagus.

Tunica Adventitia

The outer layer of esophagus; made of thick connective tissue.

Glandular Stomach

Muscular bag which temporarily stores chyme.

Chyme

Ingesta in stomach upon mixing of bolus with gastric juice; pH is strongly acidic.

4 parts of stomach

• cardia

• fundus

• body

• pylorus

Cardiac Sphincter

Between the esophagus and cardiac region.

Pyloric Sphincter

Between the pylorus and duodenum (small intestine).

Spincters

Prevents backflow of ingesta

4 concentric layers of stomach

• tunica mucosa

• tunica submucosa

• tunica muscularis

• tunica serosa

Gastric glands

At the region of the fundus; made up of chief cells and parietal cells

Chief Cells

Secrete pepsinogen (inactive form of pepsin).

Parietal Cells

Secrete hydrochloric acid (HCl).

Components of gastric / digestive juice

HCL + pepsinogen

Tunica Serosa

Made of thinner connective tissue compared to t. adventitia.

2 surfaces of the stomach

• Parietal

• Visceral

Parietal surface

convex; facing outside of the abdomen

Visceral surface

facing other internal organs

2 curvatures of the stomach

• greater

• lesser

Greater curvature

along parietal surface

Lesser curvature

along visceral surface

Entrance of stomach

cardia; to the left

Exit of stomach

pylorus, to the right

Small intestine

• Named after its relative diameter (smaller than large intestine)

  • But in terms of length, small intestine is relatively longer

• Tube which connects the stomach with the large intestine

Duodenum

First segment of the small intestine where bile and pancreatic juices empty.

Jejunum

Longest and most absorptive segment of the small intestine.

Ileum

Terminal/last segment of the small intestine involved in intestinal defense, containing Peyer's patches.

Peyer's Patches

Lymphoid nodules in the ileum involved in intestinal defense.

Fixed part

duodenum

Mesenteric part

jejunum and illeum

Large instestine

• Extends from the termination of the ileum to the anus

• It has a much greater diameter than the small intestine

Cecum

Counterpart of appendix in humans; site of fermentation in some animals.

Colon

Longest segment of the large intestine, main site for water and electrolyte reabsorption.

Transit time

how long it takes for ingesta to pass through large intestine

Rectum

Terminal segment of large intestine; temporary storage site for feces.

Defecation

Act of expelling waste products/feces.

Anus

Terminal segment of the alimentary canal.

Muscles of anus

Sphinter ani externi et interni

Salivary gland

Refer to three pairs of large glands situated on the sides of the face and the adjacent part of the neck

4 types of salivary glands

• Parotid

• Submandibular

• Sublingual

• Zygomatic / orbital

Serous

Watery consistency (type of secretion).

Mucous

Thick consistency due to presence of mucin granules (type of secretion).

Mixed

Combination of serous and mucous type (type of secretion).

Parotid

serous except in the dog where it is mixed

Mixed

Submandibular and sublingual

Zygomatic / orbital gland in the dog

Accessory salivary gland situated in the interior part of the pterygopalatine fossa; it is mixed

Liver

nutritional guardian of the body; largest gland in the body

Hepatic Lobule

Six-sided structural unit of the liver.

3 - 4 lobes of liver

• Left hepatic

• Right hepatic

• Median/quadrate

• Caudate lobe (has papillary process)

7 - 8

Number of lobes in dogs

Surfaces of liver

• parietal

• visceral

Gallbladder

Temporarily stores bile from the liver.

Exocrine Portion of Pancreas (Pancreatic Acinar Cells)

Secretes pancreatic amylase, lipase, trypsinogen, and chymotrypsinogen.

Endocrine Portion of Pancreas (Islet of Langerhans)

Secretes glucagon (alpha cells) and insulin (beta cells).

Glucagon

Increases blood sugar levels.

Insulin

Decreases blood sugar levels.

Teeth

Essential for chopping, grinding, and chewing the food.

4 types of teeth

• Incisor

• Canine

• Premolar

• Molar

Deciduous dentition

Only incisor, canine, and premolars are present

Permanent dentition

molars are present

3 surfaces of teeth

• Occlusal

• Labial

• Lingual

Layers of teeth

• Cementum

• Enamel

• Dentine

• Pulp cavity

3 regions of tooth

• Crown

• Neck

• Root

Cementum

Outer layer of neck and root of the teeth..

Enamel

Outer layer of the crown of the teeth.

Dentine

Inner layer of teeth.

Pulp cavity

Inside the tooth.

Carnassial Teeth (Shearing Teeth)

Have 3 roots.

Dogs have 2 pairs of carnassial teeth

• Last upper premolar

• First lower molar

Tongue

It is supported in a muscular sling formed by the mylohyoid muscles

Tongue is said to have

• A root

• A body

• An apex

Dorsum of the tongue

• Free dorsal surface

  • The mucous membrane of the dorsum is papillated

Filiform Papillae

Bristle-like papillae on the tongue.

Fungiform Papillae

Mushroom-shaped papillae on the tongue.

Foliate Papillae

Leaf-shaped papillae on the tongue.

Vallate Papillae

V-shaped papillae on the dorsum of the tongue.

Soft palate described as having

• base

• free border

Soft palate has 2 surfaces

• oral

• aboral

Anterior pillars

Two short, thick folds which run from the free border of the oral surface to either side of the tongue

Posterior pillar

From the free border of the aboral surface to meet over the commencement of the esophagus

Hard palate

• Bounded in front and on either side by the alveolar arches

• It is continuous with the soft palate behind

Bony basis of the hard palate is formed by palatine processes of

• Premaxillae

• Maxillae

• Horizontal part of the palatine bones

Respiration

Exchange of oxygen and carbon dioxide.

Phonation

Voice production.

Olfaction

Sense of smell.

Nasal cavity

• Cylindrical passage enclosed by facial bones

• Bounded dorsally by nasal bone

  • Laterally, by premaxilla and maxilla

  • Ventrally, by palatine

  • Rostrally, by anterior nares or nostril

  • Caudally, by posterior nares or choanae

Nasal cavity is divided into 2 cavities

• Left cavity

• Right cavity