GIT MCQ (1)

Oral Cavity & Pharynx

• The oral cavity is a part of the digestive system that includes the oral mucous membranes, teeth, tonsils, salivary glands, and tongue
• Pharynx is the part of the digestive system that connects the oral cavity to the esophagus

Esophagus

• The esophagus is a muscular tube that connects the pharynx to the stomach

Stomach

• The stomach is a muscular sac that stores and mixes food
• There are two types of stomachs - Simple and complex stomachs

Intestines

• The intestines are a long, coiled tube that digests and absorbs food
• The intestines can be divided into two parts- the small intestine and the large intestine
• The small intestine is responsible for most of the digestion and absorption of nutrients.
• The large intestine absorbs water and electrolytes.

Liver & Pancreas

• The liver is a large organ that produces bile, which helps digest fats.
• The pancreas is a gland that produces enzymes that help digest food.

Peritoneum

• The peritoneum is a membrane that lines the abdominal cavity and covers the organs within it.

Signs of GI Disease

• Signs of GI disease can include vomiting, diarrhea, constipation, abdominal pain, and weight loss

Portals of entry of Pathogens

• The most common route of entry for pathogens is by ingestion
• Pathogens can enter the body through coughed up material that is swallowed
• They can also enter the body through systemic blood-borne infections
• Parasite migration can be a portal of entry for some pathogens.

Oral Cavity

• The oral cavity is the first part of the digestive system
• Oral cavity contains: oral mucous membranes, teeth, tonsils, salivary glands, and tongue
• Oral mucous membranes are a protective lining for the mouth
• The teeth are used for chewing food
• The tonsils are lymphatic tissues that help fight infection
• The salivary glands produce saliva, which helps moisten food and begin digestion
• The tongue helps move food around in the mouth and helps with swallowing

Palatoschisis (Cleft Palate)

• Palatoschisis is a fissure in the hard palate resulting in a connection between the oral and nasal cavities
• It can lead to aspiration pneumonia

Causes of Palatoschisis

• Palatoschisis can be caused by genetic factors and toxic plants such as Veratrum californicum

Cheiloschisis (Cleft Lip or Hare Lip)

• Cheiloschisis is a fissure in the lip

Stomatitis

• Stomatitis is an inflammation of the oral cavity
• Different types of stomatitis are: cheilitis (lips), glossitis (tongue), gingivitis (gums), pharyngitis (pharynx), tonsillitis (tonsils), and sialoadenitis (salivary glands)

Causes of Stomatitis

• Stomatitis can be caused by infectious agents, trauma, chemical injury, autoimmune diseases, and systemic diseases

Classification of Stomatitis

• Superficial stomatitis: Limited to the mucosa
  • Vesicular stomatitis
  • Erosive and ulcerative stomatitis
• Deep stomatitis: Extended to the submucosa
  • Necrotic stomatitis
  • Granulomatous stomatitis

Vesicular Stomatitis

• Characterized by vesicle formation - vesicle: Fluid-filled raised lesion
• It is caused by epithelial damage (viral)
• It leads to intracellular and intercellular edema, which results in erosion, ulcers, and cellular infiltration

Vesicular Stomatitis in Dogs & Cats

• It is mainly caused by autoimmune disease (in dogs & cats) and calicivirus infection (in cats)

Vesicular Stomatitis in Food Animals

• Foot and mouth disease (in cattle sheep, Pigs)
• Vesicular stomatitis (in Horse, cattle, Pig)

Foot and Mouth Disease

• It is highly contagious and affects mainly ruminants and pigs
• Caused by picornavirus
• It can lead to vesicles which rupture leading to ulcers
• It can also lead to gray/yellow myocardial necrosis (“tiger heart”) in animals less than 6 months of age

Erosive & Ulcerative Stomatitis

• Erosion: Loss of surface epithelium with intact basement membrane
• Ulcer: Loss of the epithelium with destruction of the basement membrane, revealing the underlying submucosa (blood vessels)
• Erosive & Ulcerative Stomatitis can be caused by: BVD, MCF, Rinderpest, Peste des petits ruminants, Bluetongue, FMD, Herpesvirus(Cattle, cats, horses, primates), and Uremia

Necrotizing Stomatitis

• Characterized by tissue necrosis
• Example: Calf diphtheria caused by Fusobacterium necrophorum

Granulomatous Stomatitis

• Characterized by granuloma formation
• Example: Actinobacillosis(wooden tongue) - caused by Actinobacillus lignieresii (Gram negative)
• Affects cattle, sheep
• Grossly: The tongue is firm, pale containing multifocal nodules, containing Yellow pus "sulfur granules," and has a massive amount of fibrous connective tissue
• Microscopically: a pyogranuloma - composed of mass of bacteria, radiating eosinophilic clubs, neutrophils, macrophages, giant cells, lymphocytes, plasma cells, and a fibrous connective tissue capsule

Feline Eosinophilic Granuloma

• It is a type of granulomatous stomatitis that affects cats

Lymphoplasmacytic Stomatitis

• Characterized by lymphocytes and plasma cells
• Example: Feline gingivostomatitis (FGS)

Benign Tumors and Tumor-like Masses

• Gingivial hyperplasia
• Epulis
• Papilloma (wart)

Malignant Tumors

• Squamous cell carcinoma
• Malignant melanoma
• Fibrosarcoma

Teeth

• Teeth are used for chewing food
• Anomalies in teeth can cause malocclusion

Anomalies of Teeth

• Prognathia: Protrusion of the mandible
• Brachygnathia: Short mandible, which can lead to malocclusion

Enamel Dysplasia

• Enamel dysplasia can be caused by canine distemper in puppies and BVD intra-uterine infection.

Attrition & Abnormal Wear

• Attrition and Abnormal wear can lead to dental infection and dental trauma.

Caries

• Caries is the acid demineralization of tooth and enzymatic digestion of dental organic matrix followed by inflammation
• Dental plaque (bacterial film + food + organic matrix) can lead to caries
• Dental calculus or tartar (mineralized plaque) can also lead to Caries
• Sequelae of carries: Loss of tooth, Alveolar osteomyelitis, Tooth abscess, Pulpitis, Bacteremia

Esophagus

• The esophagus is a muscular tube that connects the pharynx to the stomach
• Choke is when the esophagus is blocked usually by food
• It can lead to stenosis, rupture, perforation, and bloat

Esophagitis

• Esophagitis is inflammation of the esophagus
• Reflux esophagitis: due to repeated gastric acid reflux
• Ulcerative esophagitis: caused by BVD, bovine popular stomatitis
• Parasitic esophagitis: caused by Sarcocystosis (Cow), Spirocerca lupi (Dog)

Megaesophagus

• Megaesophagus is a condition where the esophagus is enlarged
• It can be congenital or acquired