VEM 017: Comparative Anatomy of Domestic Animals - Digestive & Respiratory Systems - PDF

VEM 017: Comparative Anatomy of Domestic Animals DR. ZANTHOPE CZARINA B. PEREZ Assistant Professor I FUNCTION Responsible for the breakdown of food into smaller portions Ø Utilized for energy, growth, and cellular rene...

VEM 017: Comparative Anatomy of Domestic Animals DR. ZANTHOPE CZARINA B. PEREZ Assistant Professor I FUNCTION Responsible for the breakdown of food into smaller portions Ø Utilized for energy, growth, and cellular renewal Eliminate unabsorbed and excreted residues VEM 017: Comparative Anatomy of Domestic Animals  DIGESTIVE SYSTEM Alimentary canal Accessory glands Mouth and pharynx Salivary glands Esophagus and stomach Liver Small intestine Large intestine pancreas Anal canal VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX ORAL CAVITY Labial vestibule: space between the teeth and lips. Vestibule: Buccal vestibule: space between teeth and cheeks. Proper oral cavity: space within the dental arcades VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX ORAL CAVITY Vestibule Communicate by means of interdental spaces ~ INTERALVEOLAR MARGIN Proper oral cavity VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX LIPS Labia oris Frame the opening of the mouth Form the rostral and parts of the lateral borders of the vestibule Used for prehension of food, communication, and suckling in newborn animals. VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX LIPS Form of lips is determined by diet and feeding habits. Horse: for collecting food and introducing it into the mouth Sensitive and mobile Cat: prehension Less mobile and reduced in size VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX LIPS Innervated by cranial nerve VII ~ facial nerve Dog: communication, aggression (lips can be drawn back from teeth) Incapable of food intake Cattle & Pig: upper lip is modified to form = nasolabial plate in ox & rostral disc in pig Insensitive + backward oriented papillae on the palate & tongue = prone to swallow foreign body VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX Partition that separates the digestive and respiratory passages PALATE of the head. HARD PALATE SOFT PALATE VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX PALATE In horses, hard palate is divided into two equal portions by the median raphe Palatine rugae extend to the whole length of the palate VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX TONGUE Responsible for lapping water, prehension of food, manipulating the food within the mouth and swallowing. Used to enhance heat loss VEM 017: Comparative Anatomy of Domestic Animals  Tongue of the horse is shaped like a spatula Strengthened by cartilage within the dorsal part of the tongue. VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals  LINGUAL PAPILLAE MECHANICAL PAPILLAE Cornified, no taste buds 1. Filiform papillae: smallest, most common, present at the rostral 2/3 2. Conical papillae: bigger but less frequent, at the caudal 1/3 3. Marginal papillae: rostral half of new born-carnivores; aids in sucking; suckling; disappears when diet changes to solid VEM 017: Comparative Anatomy of Domestic Animals  LINGUAL PAPILLAE MECHANICAL PAPILLAE Cornified, no taste buds 1. Filiform papillae: smallest, most common, present at the rostral 2/3 2. Conical papillae: bigger but less frequent, at the caudal 1/3 3. Marginal papillae: rostral half of new born-carnivores; aids in sucking; suckling; disappears when diet changes to solid VEM 017: Comparative Anatomy of Domestic Animals  LINGUAL PAPILLAE GUSTATORY PAPILLAE With taste buds 1. Fungiform papillae: looks like mushroom 2. Foliate papillae: leaf-shaped ridges 3. Vallate papillae: largest and least numerous, with circular projections VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX TEETH VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX TEETH TYPE POSITION FUNCTION - At the rostral end of the upper and lower jaw Responsible for cutting grass Incisors - There are 12 incisors – 6 in each jaw - Rudimentary teeth & often fail to erupt in Holding food firmly in the mouth mares Canines - In stallions, these tushes develop at age of 5 years - Erupt in the space ~ diastema - Flattened teeth Primarily used for chewing and Premolars and - Wolf teeth develop at between 18 months grinding up the food into particles and 5 years of age. Often removed because Molars they can cause pain and interference. VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals  TEETH SURFACES Distal surface – contact adjacent to the caudal or next lateral tooth 1. Vestibular Surface - Faces the lip or check - Labial or buccal surface 2. Lingual Surface - Faces the tongue 3. Contact Surface - Faces the adjacent teeth in the dental arch Mesial surface - Further classified to mesial and – contact adjacent to the next rostral or medial tooth distal surface VEM 017: Comparative Anatomy of Domestic Animals  TEETH SURFACES 4. Occlusal Surface - Faces the ipsilateral opposite upper and lower arch. VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals DENTAL FORMULA Deciduous dentition Permanent dentition Species I C PM M T I C PM M T Dog 2 3/3 1/1 3/3 0/0 28 3/3 1/1 4/4 2/3 42 Ruminant 0/4 0/0 3/3 0/0 20 0/4 0/0 3/3 3/3 32 Horse 3/3 0/0 3/3 0/0 24 3/3 1/1 3(4)/3 3/3 40-42 Pig 3/3 1/1 4/4 0/0 32 3/3 1/1 4/4 3/3 44 Cat 3/3 1/1 3/2 0/0 26 3/3 1/1 3/2 1/1 30 Birds No teeth VEM 017: Comparative Anatomy of Domestic Animals A. MOUTH AND PHARYNX SALIVARY GLANDS 1. Parotid salivary gland 2. Mandibular salivary gland 3. Sublingual salivary gland VEM 017: Comparative Anatomy of Domestic Animals  A. MOUTH AND PHARYNX SALIVARY GLANDS Opening of parotid duct: Horse: level at the 3rd cheek teeth Sublingual gland: Horse: Only polystomatic part is present VEM 017: Comparative Anatomy of Domestic Animals B. ESOPHAGUS AND STOMACH ESOPHAGUS Has four layers (from inner to outer): 1. Tunica mucosa 2. Tunica submucosa 3. Tunica muscularis 4. Tunica adventitia/serosa VEM 017: Comparative Anatomy of Domestic Animals B. ESOPHAGUS AND STOMACH ESOPHAGUS Dog and ruminant: Entirely striated Pig: Horse: Striated at only near Striated at the cardia smooth first 2/3 muscle/caudal part VEM 017: Comparative Anatomy of Domestic Animals B. ESOPHAGUS AND STOMACH STOMACH Major divisions of stomach: 1. Cardiac 2. Fundus 3. Body 4. Pyloric VEM 017: Comparative Anatomy of Domestic Animals B. ESOPHAGUS AND STOMACH VEM 017: Comparative Anatomy of Domestic Animals B. ESOPHAGUS AND STOMACH STOMACH In horse: Small compared to other species Fundus is extended to form the saccus caecus Well developed cardiac sphincter + oblique entrance of esophagus = inability to vomit VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE SMALL INTESTINE Begins at the pylorus and ends at the caecocolic junction Three parts: Main functions: 1. Duodenum 1. Digestion – enzymatic destruction of 2. Jejunum ingested material 3. Ileum 2. Absorption 1. pP VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE SMALL INTESTINE - connected to the dorsal abdominal wall by dorsal mesentery over its whole length. Allows a great degree of mobility to the small intestine. VEM 017: Comparative Anatomy of Domestic Animals C. INTESTINE DUODENUM In horse and ruminants, the duodenum is fixed in its position by a short mesoduodenum. VEM 017: Comparative Anatomy of Domestic Animals C. INTESTINE JEJUNUM In the horse most of the jejunum is found within the left dorsal part of the abdomen. A considerable degree of mobility is provided to the jejunum by its long mesentery VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE ILEUM The distinction between the jejunum and the ileum is defined by the proximal extent of the ILEOCAECAL FOLD. In the horse, dysfunction of the nervous supply to the ileum leads to a permanent contraction of the muscular coat of the ileum, which can result in impaction and thus colic. VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE LARGE INTESTINE From caecum to anus Three parts: 1. Caecum a) Ascending colon 2. Colon b) Transverse colon c) Descending colon 3. Rectum Horseshoe shaped colon VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE First part of the large intestine; lies at the right CAECUM half of the abdomen. Blind tube demarcated from the colon Function in horse: by the entrance of the ileum ~ Responsible for the digestion of ileocaecal fold complex carbohydrates such as cellulose Communicates with the ileum through the ileal orifice and with the colon through the caecocolic orifice. VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE CAECUM OF HORSE Consists of: 1. Base 2. Curved tapering body 3. Blind-ending apex VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE CAECUM OF HORSE Comma-shaped Oriented cranially VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE CAECUM OF HORSE Smooth muscle bands are present ~ taenia - Cause sacculation of the gut ~ haustra VEM 017: Comparative Anatomy of Domestic Animals C. INTESTINE COLON Three parts: 1. Ascending colon 2. Transverse colon 3. Descending colon VEM 017: Comparative Anatomy of Domestic Animals C. INTESTINE COLON Ascending colon consists of four parts: 1. Right ventral colon 2. Left ventral colon 3. Left dorsal colon 4. Right dorsal colon VEM 017: Comparative Anatomy of Domestic Animals  C. INTESTINE COLON Can also be distinguished by the number of taenia: 1. Right ventral colon - 4 2. Left ventral colon - 3 3. Left dorsal colon - none 4. Right dorsal colon -3 VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals GLANDS ASSOCIATED WITH THE ALIMENTARY TRACT LIVER PANCREAS VEM 017: Comparative Anatomy of Domestic Animals  D. GLANDS ASSOCIATED Located in the thoracic part of the abdomen, immediately behind LIVER the diaphragm. Four main lobes: a. Left hepatic lobe b. Right hepatic lobe c. Caudate lobe d. Quadrate lobe VEM 017: Comparative Anatomy of Domestic Animals D. GLANDS ASSOCIATED LIVER Dog Horse Papillary process is absent in horse Horse lack gallbladder Right hepatic lobe is undivided in horse VEM 017: Comparative Anatomy of Domestic Animals  D. GLANDS ASSOCIATED Located in the dorsal part of the abdominal cavity in close relationship to the PANCREAS proximal part of the duodenum. Three parts: Function: Exocrine and endocrine function a. Body of the pancreas b. Right lobe c. Left lobe VEM 017: Comparative Anatomy of Domestic Animals  D. GLANDS ASSOCIATED PANCREAS Compared based on appearance in general: Dog: letter V Horse: Massive and triangular Pig: left lobe is larger Ruminant: Irregular to quadrilateral in shape VEM 017: Comparative Anatomy of Domestic Animals  D. GLANDS ASSOCIATED PANCREAS Compared based on presence or absence of pancreatic duct/accessory duct. Pancreatic duct: Duct of Wirsung Accessory pancreatic duct: Duct of Santorini VEM 017: Comparative Anatomy of Domestic Animals D. GLANDS ASSOCIATED PANCREAS Pancreatic Accessory Dogs / / Cats / Cattle / Goat / Horse / / Pigs / VEM 017: Comparative Anatomy of Domestic Animals RESPIRATORY SYSTEM Upper respiratory tract Lower respiratory tract Main function: Essential for gaseous exchange between air and blood. VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT NOSE The integument around the nostrils is hairless and sharply demarcated from the unmodified skin in all domestic mammals except in horse. Unmodified skin with some tactile hairs surrounds the nostrils. VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT NOSE Variation also exists with regards to the shape of nostrils. Shape is dictated by the nasal cartilage VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT - Planum nasale - Planum nasolabiale (nasal plate + upper - Nasal diverticulum (false nostril) lip) - Philtrum is absent - Presence of philtrum - Philtrum is absent - Planum nasale - Planum nasale - Planum rostrale - Presence of philtrum - Philtrum is present - Philtrum is absent VEM 017: Comparative Anatomy of Domestic Animals VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT NASAL MEATUS Leads to olfactory mucosa VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT NASAL MEATUS Leads to the paranasal sinuses VEM 017: Comparative Anatomy of Domestic Animals UPPER RESPIRATORY TRACT NASAL MEATUS Leads to the pharynx VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT LARYNX Connects pharynx to the trachea. Protects the entrance to the trachea thus preventing aspiration of foreign material into the lower respiratory tract Important in vocalization VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT LARYNX The skeleton of the larynx is composed of the following bilaterally symmetrical laryngeal cartilages: 1. Epiglottic cartilage 2. Thyroid cartilage 3. Arytenoid cartilage 4. Cricoid cartilage VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT TRACHEA Extends from the cricoid cartilage of larynx to its bifurcation Consists of a series of C-shaped hyaline cartilages connected by ligaments VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT TRACHEA Number of the tracheal cartilages varies among species: Horse 48-60 Ruminants 48-60 Pig 29-36 Dog 42-46 Cat 38-43 Birds 120 VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT TRACHEA Location of tracheal muscle: all are located inside tracheal rings except dog. VEM 017: Comparative Anatomy of Domestic Animals LOWER RESPIRATORY TRACT LUNGS Occupy most of the thoracic cavity and each lung is invaginated in the corresponding pleural sac. Left cranial lobe Left lung Right lung (cranial part) Cranial Cranial Left cranial lobe Caudal Middle (caudal part) Accessory Caudal Left caudal lobe VEM 017: Comparative Anatomy of Domestic Animals  LOWER RESPIRATORY TRACT LUNGS Horse: has the least number of lobes Left lung Right lung Cranial- undivided Cranial Caudal Middle - missing Accessory Caudal VEM 017: Comparative Anatomy of Domestic Animals