Digestive System

The Gastric/Digestive System

• The digestive system is also called the digestive tract, the alimentary system, or the gastrointestinal (GI) system/tract.
• This system is a long, muscular tube that starts at the mouth and ends at the anus.

Functions of Digestive System

• Intake and digestion of food and water.
• Absorption of nutrients, using aliment/o as the combining form for nourishment.
• Elimination of solid wastes.

Digestive Structures

• The digestive structures are:
• Mouth or oral cavity
• Pharynx
• Esophagus
• Stomach
• Small and large intestines
• Accessory organs: pancreas

The Mouth

• The mouth uses or/o and stomat/o as combining forms.
• Lips form the oral cavity opening, with cheil/o and labi/o as combining forms.
• Cheeks form the oral cavity walls, using bucc/o as the combining form.

The Palate

• The palate forms the mouth roof, using palat/o as the combining form.
• Rugae are wrinkles or folds in the mouth.
• The hard palate is the bony rostral part covered by specialized mucous membrane.
• The soft palate is the flexible caudal part that closes off the nasal passage when swallowing.

The Tongue

• The tongue is a movable muscular organ, using gloss/o and lingu/o as combining forms.
• Papillae are the elevations on the tongue, with filiform (threadlike), fungiform (mushroom-like), and vallate (cup-shaped) types.
• Tastebuds are located on fungiform and vallate papillae.
• The tongue is connected to the oral cavity's ventral surface by the frenulum.

Jaw

• The maxilla and mandible form mouth boundaries, using gnath/o as combining forms for jaw.
• Prognathia: elongated (overshot) mandible, commonly known as an "underbite".
• Brachygnathia: shortened (undershot) mandible, commonly known as an "overbite".

Teeth

• Teeth are arranged in the maxillary and mandibular arcade and identified using the triadan system.
• The combining forms are dent/o, dent/i, and odont/o with dentition referring to teeth.
• Primary dentition is temporary/deciduous, sheds, while secondary is permanent.

Types of Teeth

• Incisors are front cutting teeth.
• Canines: long, pointed grasping/tearing teeth, also known as fangs/cuspids.
• Premolars: cheek teeth grinding food, also known as bicuspids.
• Molars: caudal cheek teeth that grind food.

Common Terms for Teeth

• Cheek teeth: premolars and molars
• Needle teeth: deciduous canines and third incisors of pigs
• Wolf teeth: rudimentary premolar 1 in horses
• Milk teeth: first set of teeth
• Tusks: permanent canine teeth of pigs

Tooth Classification Based on Ridges

• Carnassial tooth: large, shearing cheek tooth (upper P4 and lower M1 in dogs, upper P3 and lower M1 in cats)
• Fighting teeth: 6 teeth in llamas (upper vestigial incisors, upper/lower canines)
• Selenodont: animals with crescent grinding surfaces (ruminants).
• Lophodont: animals with ridge occlusal surfaces (equine).
• Bunodont: animals with worn, rounded surfaces (swine).
• Hypsodont: animals with continuously erupting teeth (ruminants).
• Pleurodont: animals with teeth attached to the inner jaw surface.
• Brachydont: animals with rooted teeth (carnivores).

Dental Formula

• This formula is the number/type of each tooth in a species
• Adult dog: 2(I 3/3, C 1/1, P 4/4, M 2/3) = 42 teeth
• Adult cat: 2(I 3/3, C 1/1, P 3/2, M 1/1) = 30 teeth

Anatomy of a Tooth

• Enamel: outer surface of the crown.
• Cementum: outer surface of the root.
• Dentin: connective tissue surrounding the pulp.
• Pulp: contains nerves, vessels, and loose connective tissue.
• Apical foramen: the hole where nerves/vessels enter.
• Alveoli: the sockets teeth are in.
• Alveolar bone: thin bone layer forming tooth socket.
• Periodontal ligament: fibrous structure holding tooth in alveolus.

Accessory Structures to Help with Digestion

• Gingiva is the mucous membrane around teeth. The combining form is gingiv/o. The gingival sulcus is the space around the tooth.
• Salivary glands secrete saliva, which contains digestive enzymes. The combining forms: sialaden/o and sial/o.

Functions of Saliva

• It moistens food, aids in bolus formation, starts digestion, and cleanses the mouth.
• Excessive saliva production: hypersalivation, also called ptyalism and hypersialosis.
• Salivary glands are named by location: mandibular (near mandible), sublingual (under tongue), zygomatic (medial to zygomatic arch), parotid (near ear). Para means near and ot/o means ear.

Branches of Dentistry

• Endodontics: treats diseases affecting the tooth pulp.
• Exodontics: tooth extraction and related procedures.
• Oral surgery: surgical correction of jaw, gums, and mouth
• Orthodontics: guidance and correction of malocclusion.
• Periodontics: studies/treats tooth-supporting structures.

Pharynx/Esophagus

• The pharynx is the cavity in the caudal oral cavity that joins the respiratory and gastrointestinal systems, also known as the throat. The combining form is pharyng/o.
• The esophagus is a collapsible, muscular tube from the oral cavity to the stomach, also known as the gullet. Esophag/o is the combining form.
• Ingesta is material taken in orally.
• Mastication is chewing.
• Deglutition is swallowing.

The Abdomen

• Remaining digestive organs are found in the abdomen, also known as the peritoneal or abdominal cavity, located between the diaphragm and pelvis. Combining forms: abdomin/o, celi/o, and lapar/o.
• The peritoneum lines the abdominal cavity and covers some organs with two layers.

Two Layers of Peritoneum

• Parietal peritoneum: lines the abdominal/pelvic cavities.
• Visceral peritoneum: covers abdominal organs.
• The omentum connects the stomach to other visceral organs.
• The mesentery connects the intestines to the abdominal wall.

Monogastric Stomach

• This stomach is a saclike organ for food digestion, using gastr/o as the combining form.
• Animals are classified as monogastric (one glandular stomach) or ruminant (one glandular stomach and three forestomachs).

Monogastric Stomach Parts

• Cardia: Entrance near esophagus.
• Fundus: Cranial, rounded part.
• Body: Main body.
• Antrum: Caudal part.
• Pylorus: Narrow passage between stomach and duodenum.
• Pyloric sphincter: Muscle ring controlling material flow from stomach to small intestine.
• Rugae: Mucosa folds.
• Lesser omentum: Connects the stomach to other visceral organs.
• Greater omentum: Connects stomach to dorsal abdominal wall.

Ruminant Stomach

• Ruminants regurgitate and remasticate their food and regurgitated food particles, fiber, rumen fluid and rumen microorganisms are called cud.

Ruminant Stomach Parts

• Rumen: Largest part serving as a fermentation vat.
• Reticulum: Most cranial portion.
• Omasum: Third part squeezing fluid out of the food bolus.
• Abomasum: The true glandular stomach.
• Intestinal flora is normal microorganisms residing in the gastrointestinal tract, producing enzymes that digest plant cells through fermentation.

Small Intestine

• This extends from the pylorus to the large intestine. The combining form is enter/o.
• Has 3 segments: Duodenum (proximal), Jejunum (middle), Ileum (distal)
• Contains tiny hairlike projections called villi.
• The crypts are the blind sacs.

Large Intestine

• Extends from the ileum to the anus.
• Has 4 segments: Cecum (pouch taking food from the ileum, cec/o as combining form), Colon (varies among species, col/o as combining form), Rectum (caudal portion, rect/o as combining form), Anus (caudal opening, an/o as combining form). Proct/o is the combining form for anus and rectum together.

Accessory Organs

• Salivary glands
• Liver: Caudal to the diaphragm, with hepat/o as combining form, storing excess glucose as glycogen, acts as a filter, composed of hepatocytes, sinusoids are channels in the liver, and produces bile. Bile alkalinizes the small intestine, and bile salts play a part in fat digestion. Emulsification is the process of fat digestion. Bilirubin pigment from hemoglobin destruction is released by the bile.
• Gallbladder: stores bile but does not make it with chol/e = bile, cyst/o = sac, Choledochus = common bile duct
• Pancreas: pancreat/o as combining form, it has endocrine and exocrine functions. Trypsin digests protein. Lipase digests fat. Amylase digests carbohydrates.

Digestion and Metabolism

• Digestion is the food breakdown into usable nutrients.
• Metabolism involves using nutrients, meta- means change or beyond.
• Anabolism builds body cells and catabolism breaks down body cells.
• Absorption (aka assimilation) intakes digested nutrients into the circulatory system. It occurs in the small intestine. Villi increase the small intestine's surface area and absorbs more nutrients.
• Pepsin digests protein.

Path of Digestion

• Prehension grasps/collects food in the oral cavity.
• Mastication (chewing) breaks down food.
• Deglutition moves food to the pharynx and esophagus.
• The epiglottis closes off the trachea for the process of breathing.

Following Food

• Food moves down the esophagus by gravity and peristalsis and peristalsis is a wavelike smooth muscle contraction (stalsis means contraction).
• Food moves through the small intestine by peristalsis and segmentation but segmentation mixes ingesta side to side.
• Chyme is the semifluid mass passing from the stomach.

GI Pathology

• Preprandial: before a meal
• Postprandial: after a meal
• Anorexia: not eating
• Ascites: fluid accumulation in the abdomen
• Borborygmus: stomach rumbling noises
• Cachexia: severe weight loss
• Colitis: colon inflammation
• Coprophagia: eating feces
• Enteritis: small intestine inflammation
• Gastroenteritis: stomach/small intestine inflammation
• Hematochezia: blood in the stool (bright red)
• Melena: black stool from digested blood.

Urinary System Functions

• Removal of waste from the body by filtering blood.
• Urea is the major waste product of protein metabolism and is filtered by the kidney
• Helps determine the health status of the kidney
• Maintains homeostasis (stable internal environment)
• Urin/o and ur/o are combining forms for the urinary system

Urinary System Structures

• A pair of kidneys (ren/o and nephr/o)
• A pair of ureters (ureter/o)
• A single urinary bladder (cyst/o)
• A single urethra (urethr/o)

Kidneys

• The kidneys are located behind the abdnominal cavity lining, or retroperitoneally
• THe Renal cortex is the outer part: cortic/o means outer region
• The renal medulla is the inner part: Medull/o means inner
• Hilus: Concave depression where blood vessels, nerves, and ureter attach.
• Renal pelvis: Area where urine collects, pyel/o means renal pelvis.
• Nephron: Functional unit of kidney.
• Millions of microscopic structures that do the work
• The Glomerulus (cluster of capillaries) is a structure of the Nephron
• Other structures that make up the Nephron are Bowmans capsule (cup shaped structure that contains the glomerulus), Proximal Convoluted Tubules (hollow tubes involved in reabsorbtion), Distal Convoluted Tubules (hollow tubes involved in secreation), Collecting Tubules (hollow tubes carrying urine from the cortex to the renal pelvis), Loop of Henle (U shaped turn involved in reabsorbtion)

Ureters

• Each kidney has a pair of narrow tubes, that transport urine to the urinary bladder
• The ureters enter the bladder at the trigone

Bladder and Urethra

• The urinary bladder is a hollow organ that hold urine
• The Urethra extends the urinary bladder to the outside of the body
• The external opening of the urethra is the urethral meatus or urinary meatus
• Meat/o means opening

Kidney Location

• The kidneys are located retroperitoneally behind the abdominal cavity lining
• One kidney is located on each side of the vertebral column below the diaphragm
• The renal artery carries blood to the kidney and the renal vein drains the blood
• Blood filtration depends on blood flow and filtration rate is affected by pressure

Internal Structures of Kidney

• There are two layers that surround the renal pelvis
• Cortex: the outer layer, which contains the majority of the nephron
• Medulla: inner layer, which contains most of the collecting tubules
• The nephron is the functional unit of the kidney

Nephron Processes

• Consists of glomerulus, Bowman's capsule, proximal/distal convoluted tubule, loop of Henle, collecting duct
• The nephron's process of forming urine is filtration, reabsorption, and secretion
• The calyces are irregular cuplike spaces
• The hilus is the concave depression for blood vessels, nerves, and ureter attachment

Species Variation in Kidneys

• Not all species have bean shaped kidneys
• Cattle have lobulated kidneys and no renal pelvis
• The right kidney of horses is heart shaped

Trigone

• The ureters are a pair of narrow tubes that carry urine from the kidneys to the urinary bladder, and they enter the bladder at the trigone.
• The trigone is a triangular portion at the base of the bladder with 3 angles marked by the 2 ureteral openings and 1 urethral opening

Urinary Bladder

• The urinary bladder is a hollow muscular organ that holds urine, which is very elastic, so its size/shape is depending on how much urine it is holding
• The flow of urine enters from the ureters and its position serves as a natural valve to control backflow
• Sphincters control the flow of urine out of the bladder to the urethra

Urinalysis

• Examination of urine components. Abbreviated UA.

Three Parts of UA

-Macroscopic/gross exam: observation of color, transparency (turbidity/cloudiness), odor, and foam. -Chemical analysis: reagent strip tests for pH, leukocytes, erythrocytes, protein, glucose, and specific gravity. -Microscopic analysis/urine sediment exam: detects cellular material in centrifuged urine under a microscope.

What is Urine?

• Uropoiesis is the process of urine production.
• Normal urine is clear and pale yellow when tested, though, turbid means cloudy.
• Micturition is the excretion of urine (aka urinating)

Urinary Catheterization

• This is inserting a tube through the urethra into the urinary bladder, also known as a u-cath.
• A catheter is a hollow tube inserted into a body cavity to inject/remove fluid.

Urine Descriptive Terms

• Albuminuria: albumin (major blood proteins) in urine.
• Anuria: complete urine suppression.
• Bacteriuria: presence of bacteria in urine.
• Crystalluria: urine contains naturally produced angular solid of definitive form (crystals).
• Dysuria: difficult/painful urination.
• Glucosuria/Glycosuria: glucose (sugar) in urine.
• Hematuria: blood in urine.
• Ketonuria: ketones in urine (increased fat metabolism).
• Nocturia: nightime excessive urination (nocti- means night).
• Oliguria: scanty or little urine.
• Pollakia: frequent urination (poll-laki means many times).
• Polyuria: excessive urination.
• Proteinuria: protein in urine.
• Pyuria: pus in urine.
• Stranguria: slow or painful urination.

Urine Test Strips

• Urobilinogen: liver and red blood cell diseases.
• Glucose: diabetes mellitus
• Ketones: uncontrolled diabetes mellitus.
• Bilirubin: liver or excessive blood cell breakdown.
• Protein: glomerular disease or urinary tract inflammation
• Blood: inflammation of urinary tract or bleeding disorders
• pH: influenced by diet/disease (acidic in meat diets, basis in cereal grain diet).

The Kidneys Produce Hormones

• Erythropoietin: stimulates red blood cell production in the bone marrow.
• Antidiuretic hormone (ADH): released by the posterior pituitary and suppresses urine formation.
• Aldosterone: secreted by the adrenal cortex; regulates electrolyte balance via sodium reabsorption.

Urinary System Tests

• Cystocentesis: surgical puncture of the urinary bladder, usually to collect urine that is usually performed with a needle and syringe.
• Cystography: radiographs of the bladder after water-soluble contrast material has been placed via a urethral catheter.
• Cystography can be single or double when either one or more contrast materials are used during contrast, and double contrast cystography, is when air and contrast material have been placed in the bladder via the urethral catheter. - A cystogram shows the radiographic film of the bladder after contrast.

Cystoscopic Procedures

Retrograde means going backward, describing the path of contrast material.

• Cytoscopy: internal bladder exam with a fiiberoptic instrument, a cystoscope.
• Intravenous pyelogram (IVP): radiograph of the kidney/ureters via dye to define clear structures.
• Pneumocystography: bladder radiograph after air is placed via catheter. -Radiography: creates images by using X-rays or a scout film (plain X-ray without contrast).
• Retrograde pyelogram: radiograph with contrast placed in the urinary bladder.
• Urinalysis (UA): Examination of urine components is a UA, and it has three parts.

Urinary System Pathology

• Azotemia: presence of urea/nitrogenous elements in the blood, uses azot/o mean urea/nitrogen
• Calculus: abnormal mineral deposit, Crystals are dissolved in urine, forms solids when the precipitate
• Lith/o is the combining form for stone or calculus, and -lith is the suffix for stone or calculus. When used in relation to the urinary system, calculus is modified to urinary calculus, lith is modified to urolith, and stone is modified to urinary stone or kidney stone to clarify which system is involved.

Disease of the Bladder

• Casts: fibrous/protein materials found in urine, signaling another abnormality
• Crystals: naturally produced angular solid of definitive form
• Cystalgia/cystodynia: urinary bladder pain
• Cystitis: bladder inflammation
• Cystocele: bladder displacement through vaginal wall
• Epispadias: Urethra opens on penis dorsum
• Feline lower urinary tract disease: common feline disease of cystitis/urethritis/crystalluria, formerly called feline urologic syndrome (FUS).
• FLUTD is also associated

Diseases of the Kidney

• Glomerulonephritis: inflammation of glomeruli
• Hydronephrosis: dilation of the renal pelvis a result of urine obstruction.
• Hydroureter: ureter distention caused by blockage.

Abnormalities

• Hypospadias: abnormal condition in which the urethra opens on the ventral surface of the penis.
• Inappropriate urination: eliminating urine at the wrong time or in the wrong place.
• Incontinence: inability to control excretory functions
• lithiasis: suffix meaning the presence of stones or calculi: Nephrolithiasis/urolithiasis/ureterolithiasis are the different diseases involving stones

Renal Pathologies Cont

• Nephrectasis is distention of the kidneys and suffix-ectasis means distention or stretching
• Nephritis: inflammation of the kidneys
• Nephrolith: kidney renal calculus
• Nephromalacia: abnormal softening of the kidney.
• Nephropathy: the disease of the kidneys.
• Nephrosclerosis: abnormal hardening of the kidney
• Nephrosis: abnormal condition of the kidney(s).
• Prerenal and Postrenal conditions affects the kidney before and after
• Prolapse: downward displacement of a body organ.
• ptosis means drooping or dropping down with Nephroptosis is describing a prolapsed kidney
• Pyelitis: inflammation of the renal pelvis
• Pyelonephritis: inflammation of the renal pelvis and kidney -Renal Failure: the inability for the kidney to function whether that is Acute, which is sudden or over shortly or chronic which is over a long period of time

Definitions of Urinary Terms

• Polydipsia/Polyuria indicates excessive thirst drinking and urine production, Polydipsia animals with renal failure often undergo diuresis and drugs that help with that are diuretics
• renal infarction obstructs blood flow to the kidney
• Uremia often leads to many types of kidney diseases
• Ureterectasis means diuresis of the urder
• Ureterolith is indicates a stone in the ureter, where are urethritis means there is an inflammation in the Urethra
• Urethrolithiasis means there is a disorder is characterized by the presence of stones
• a urethrolith is often the one with a urethral stone and Urinary tract infection in base a micro organisms in the local injury
• urolith is a often referred to as a urinary bladder often also sometimes called cystolith

Urinary System Procedures

• Cystectomy in which there is complete removal of all or part of the urinary bladder and often followed by a cystoplexy
• cystostomy is involved surgical creation of a opening with a new the skin and the urinary bladder and also can be reversed by cystotomy
• dialysis is a way of removing blood waste products when the kidneys no longer function by Hemodialysis/peritoneal dialysis
• Lithotripsy: destroying stones by ultrasonic waves (tripsy means to crush)
• Nephrectomy: kidney removal
• Nephropexy: fixation of kidney to body wall.
• Ureterectomy: surgical removal of the ureter
• Ureteroplsty: surgical repair of the ureter
• ureterotomy: surgical incision of the ureter
• Urethroplasty: surgical repair of the ureterm but Urethrostomy creates a permanent opening between the urethra and the skin

Urinary Acronyms

• all of the acronyms for the utinary system include adH or AKI or aRF, Bun, and CAF the more serious one often include FLUTD or Fush Gfr hD, iHD, and IVP as well with K or NA PU SG and UA and UTI

Cardiovascular System Functions

• The body’s tissues obtain oxygen, nutrients, and hormones from the blood
• Transport waste products to the appropriate waste removal systems
• Occasionally called the circulatory system
• Systemic Circulation: Blood Flow reaches all parts of the body, excluding lungs.
• Pulmonary Circulation: Blood Flow exits the heart, travels through the lungs, and returns to the heart.

Cardiovascular System Structures

• Cardiovascular is a term meaning, that it is involved with the heart and it's involving organ
• Heart is the main place where we see any of this happen
• and well-ordered blood vessels And lastly, there is typically flood as well

How The Heart Functions

• The heart is the hollow and the muscular organ that provides power to move blood through the body known to be located in the thoracic cavity
• It is further located in the mediastinum where the heart, lungs, and large blood vessels are situated

Cardiovascular Definition

• Is a double-walled membrane
• There are in place two layers of the pericardium The fibrous pericardium that often forms is the tough external layer, but on the interior is a serious layer dividing the body into two segments There is also in effect a parietal layer, and visceral laye
• Between the two serous layers of the pericardium, there is a space known as the pericardial space that contains an ideal amount amount of Pericardial fluid that prevent fiction between the heart and the walls as the heart beatz

Heart Wall

• Heart has three layers:
• Epicardium refers to external layer and is also the visceral layer of the pericardium
• Myocardium is the middle and thickest layer of the heart
• And Endocardium is the inner layer of the heart that also lines the heart

Blood Supply in the Heart

• It is known to give off a constant supply of oxygen
• The coronary arteries often serve the heart as the main source of oxygen in the nutrients however, the heart also has its is on such as themes and the coronary veins which are know to remove waste products from the Myocadia if blood supply to the heart is disrupted, it often times stops functioning that is known as a coronary occlusion can lead to ischemia is known in the area of necrosis is an infarction

Chamber Function

• The heart is generally divided into left and right sides which are then for the subdivided and too many chambers the best of what we see in mammalian and aviation heart is they haven't for chambers in which really the reptiles can only handle three of those the four chambers of the heart are: Atria
• Craniodorsal chambers.
• all the vessels are coming into the heart entry, and it's the left and right Art are always separated by the intertrial septum where as ventral calls or caudal ventral cambers often are are are pumping chambers that you see for the heart with a left ventricle always pumps blood to the internet body at such has to generate a lot of pumping force as a right ventricle only pumps blood to the light and is vessels always be the head through the ventricles

Rhythm and Beats Definition

• A rhythm is the recurrence of an action or a function, or regular and intervals here the heart's contractions are supposed to be red the rate on the quality of the quality of heart a heartbeat is modified electrical impulses from nerves, some the myocardium Cardiac output of how the work of blood pump to the heart per until time where stroke volumes the volume of blood ejected from the ventricles during each

Nodes

The electrical impulses are called the conduction system, they're controlled by Sino atrial node the atrial ventricular nodes, and the bundle of his, and the prinkie fiber Sino atrial node or SA node is located in the walls of the right atrium, near the entrance of the superior venal color

• purkinje fibers, typically are very typical cardiac muscular, muscular cells or left developed, at the area and are also associated with the ventricles which is a lot call the pacemaker for the heart

Electricity in the Heart

Electrical impulse from the SA node start waves of the muscle contractions with the impulse in the right atrium, spreading all over the muscle in both art causing them to contract to me in simultaneously which leads the contraction and forces a lot of blood into the ventricles Arial contraction, is always aerial systole with inotropy meaning for so contraction

Definition

• The Atrioventricular node often times in the area will be be found in the internet trial stuff to which contact impulses more slowly than the sinatorial nose but with the slower conducting what will cause a pause that allows the rest of of the art contraction to love the centric