S & F: Last Chunk

• Here is an updated list of study notes

Ruminant Gastrointestinal & Anatomy

• The abomasum is the "true stomach" in ruminants.
• Traumatic Reticuloperitonitis in cattle is commonly called Hardware Disease.
• Actinomycosis ("Lumpy Jaw") is caused by Gram-positive anaerobic bacteria.
• Actinobacillosis is characterized by a very hard, swollen, and painful tongue in cattle.
• A "ping" sound auscultated on the left side of a fresh dairy cow indicates a Left Displaced Abomasum (LDA).
• Abomasal hypomotility is a prerequisite for the development of a displaced abomasum.
• Hemorrhagic Bowel Syndrome in dairy cows is associated with Clostridium perfringens type A and Aspergillus fumigatus.
• Omentopexy is the surgical fixation and anchoring of the abomasum to correct an LDA, often via a right flank approach.
• Cecal dilation refers to the distention of the cecum without a twist.
• Type I rectal prolapse involves only the rectal mucosa.
• Rumination is the rechewing of cud to break down plant matter.
• Traumatic pericarditis occurs when a foreign body penetrates from the reticulum through the diaphragm.
• The abomasum is NOT part of the ruminant forestomach.
• The omasum is primarily located on the right side of the bovine abdomen.
• The reticular mucosa in ruminants has a honeycomb appearance.

Gastrointestinal Physiology

• Production of red blood cells is NOT a main function of the gastrointestinal tract (GIT).
• The Enteric Nervous System (ENS) is often referred to as the "Little Brain".
• The cephalic phase of digestion is initiated by the anticipation, sight, or smell of food.
• Gastrin stimulates parietal cells in the stomach to secrete HCl and pepsinogen.
• Secretin is released in response to acid in the duodenum and stimulates bicarbonate secretion from the pancreas.
• The hepatic portal system transports nutrient-rich blood from the digestive tract primarily to the liver.
• Fermentation is the metabolic action of microorganisms in the GIT and is particularly important in herbivores.
• In ruminants, Volatile Fatty Acids (VFAs) are primarily absorbed through the epithelium of the rumen.
• The enzyme carbonic anhydrase in red blood cells primarily catalyzes the hydration of CO2 to form carbonic acid.
• The "first pass effect" relates to the metabolism of substances absorbed from the GIT primarily by the liver before reaching systemic circulation.

Small Animal Gl Anatomy

• In a dog, the oral cavity proper is the space inside the dental arches.
• The zygomatic salivary gland is specific to carnivores.
• Brachydont dentition, characterized by short crowns and well-developed roots, is found in carnivores like dogs.
• The permanent dental formula for a dog is 2(I 3/3, C 1/1, P 4/4, M 2/3) = 42.
• In the Triadan numbering system, 104 represents the permanent upper right canine tooth in a dog.
• The pharynx serves as a common passageway for the respiratory and digestive systems.
• In a dog, the stomach is the dilated part of the digestive system located between the esophagus and the duodenum.
• In the dog, the jejunum is the longest part of the small intestine, forming numerous coils.
• In the dog, the ileum typically opens into the ascending colon, part of the large intestine.
• The canine liver has six distinct lobes.

Large Animal Gl Anatomy

• A dental pad (replacing upper incisors) is characteristic of the oral cavity in ruminants but absent in horses. Hypsodont dentition, characterized by high crowns and enamel extending below the gum line, is found in horses and ruminants.
• The diastema is the wide gap separating the incisors from the cheek teeth in horses.
• The permanent dental formula for cattle is 2(I 0/3, C 0/1, P 3/3, M 3/3) = 32.
• The margo plicatus is the distinct border separating the non-glandular and glandular parts of the equine stomach lining.
• The reticulum is the compartment of the bovine stomach located furthest cranially and has a honeycomb-patterned mucosa.
• The equine large colon consists of the ascending and transverse colon and the ascending colon characterized by having four parallel limbs and three flexures.
• In ruminants, the ascending colon characterized by its flat spiral aspect (proximal, spiral, and distal loops).
• Horses typically lack a gallbladder.
• In cattle (ox), the accessory pancreatic duct is typically present and functional.

Acid-Base Balance

• According to the Brønsted-Lowry definition, an acid is a substance that can donate a proton (H+).
• The normal approximate pH range of arterial blood plasma in mammals is 7.35 – 7.45.
• A decrease in blood pH below the normal range is termed acidosis.
• Chemical buffer systems act as the body's first line of defense against pH changes, acting within seconds but not removing H+ from the body.
• The bicarbonate buffer system is the most important extracellular chemical buffer system in the body.
• Hemoglobin acts as an important intracellular buffer, particularly within red blood cells (erythrocytes).
• Carbonic anhydrase is the enzyme crucial for rapidly catalyzing the reaction between CO2 and H2O to form H2CO3, especially in RBCs and renal tubules.
• The phosphate buffer system (H2PO4- / HPO42-) plays a significant buffering role primarily in intracellular fluid and renal tubular filtrate.

Respiratory Anatomy & Physiology

• Alveoli are NOT part of the airways (involved in air conduction).
• Gas exchange (O2 and CO2 diffusion) primarily occurs in alveoli.
• In the dog, the ethmoconchae is where the olfactory mucosa responsible for the sense of smell is mainly located.
• The nasopharynx is located dorsal to the soft palate.
• Thyroid and Cricoid laryngeal cartilages are unpaired, as is the Epiglottis, the Arytenoid is paired.
• The trachea is characterized by C-shaped cartilaginous rings completed dorsally by the trachealis muscle.
• The correct order of branching in the bronchial tree after the principal bronchi is: Lobar bronchi -> Segmental bronchi -> Bronchioles.
• The right lung in the dog is divided into four lobes (Cranial, Middle, Caudal, Accessory).
• The pulmonary trunk carries deoxygenated blood to the lungs.
• The visceral (pulmonary) pleura is the serous membrane directly adhering to the surface of the lungs.
• The conducting zone of the respiratory system, where no significant gas exchange occurs, is also known as the anatomic dead space.
• Type II pneumocytes are the alveolar cells responsible for producing pulmonary surfactant.
• During normal quiet exhalation, the process is passive, due to elastic recoil of the lungs and thorax.
• Lung compliance refers to the ease with which the lungs can be expanded or stretched.
• Hypoxic Pulmonary Vasoconstriction (HPV) is a mechanism where low oxygen in alveoli causes constriction of nearby pulmonary arteries.

Avian Anatomy

• The uropygial gland in birds, located at the tail base, is primarily involved in waterproofing feathers.
• The fusion of several thoracic vertebrae in birds is known as the notarium.
• The furcula (wishbone) is formed by the fusion of the right and left clavicles in birds.
• The avian syrinx, located at the tracheal bifurcation, functions in vocalization.
• Birds possess air sacs which act as reservoirs for air, facilitating unidirectional flow through the lungs.
• In birds, the glandular stomach is the proventriculus, and the muscular stomach is the gizzard (ventriculus).
• The cloaca is the common chamber receiving products from the digestive, urinary, and reproductive tracts in birds.

Introduction to Radiology

• Air is the most radiolucent substance on a standard radiograph (appears blackest).
• Metal is the most radiopaque substance on a standard radiograph (appears whitest).
• Ionizing radiation, like X-rays, has the potential to cause harm primarily by creating ions within tissues, potentially altering cells.
• When naming a radiographic view, the convention is based on the direction the primary X-ray beam travels (entry point to exit point).
• A ventrodorsal (VD) view of the canine thorax means the primary beam enters the ventral aspect and exits the dorsal aspect of the patient.