Zoology 100 Integumentary System PDF

ZOOT 1 100 – Principles of Animal Production and Economics UNIT 1 – Basic Anatomy and Physiology of Livestock and Poultry Animals Chapter I. Integumentary System Elfren F. Celestino Jr., MSc, PhD Unit Introduction Anim...

ZOOT 1 100 – Principles of Animal Production and Economics UNIT 1 – Basic Anatomy and Physiology of Livestock and Poultry Animals Chapter I. Integumentary System Elfren F. Celestino Jr., MSc, PhD Unit Introduction Animal Science The study of the biology of animals that live alongside humans. Concerned with the business aspects of producing livestock animals, but not limited to cattle for beef and milk, poultry, goat, sheep, swine, poultry and horses. Animal Husbandry Deals with breeding, farming and care of farm animals. Unit Introduction Anatomy Study of the structure of the body and the relation of its parts A branch of biological science that deals with the form, and structure of organisms Firm foundation of the whole art of medicine and has been inseparable from physiology Can be classified into several fields or specialization based on the methods employed in the study and their uses Unit Introduction Methods of Classifying Anatomy Based on Processes: Embryology - Developmental Anatomy Pathological Anatomy Based on Application: Surgical Anatomy Based on Methods Being Employed: Gross Anatomy Microscopic Anatomy/Microanatomy Unit Introduction Major Divisions of Anatomy Special Anatomy – description of the structure of a single type of species Veterinary Anatomy – deals with the form and structure of the principal domesticated animals, largely descriptive in character Unit Introduction Systematic Anatomy Divisions Osteology – the description of skeleton Syndesmology – the description of the joints Myology – muscles and accessory structures Splanchnology – the description of Unit Introduction Physiology The scientific study of the functions and mechanisms which work within a living system Focused on how organisms, organ systems, organs, cells, and biomolecules carry out the chemical and physical functions that exist in a living system Unit Introduction Directional Terms Dorsal structures (or positions) lie toward the back (dorsum) Ventral structures lie toward the belly (venter) or the corresponding surface of the head or tail Cranial structures lie toward the head (cranium) Caudal ones toward the tail (cauda) Within the head, structures toward the muzzle (rostrum) are said to be rostral; caudal remains appropriate. Unit Introduction Directional Terms Medial structures lie toward the median plane (medianus, in the middle) Lateral structures lie toward the side (latus, flank) Proximal structures lie toward the junction with the body Distal structures are those at a greater Unit Introduction Directional Terms In the limb – proximal part Cranial structures lie toward the “front” Caudal structures lie toward the “rear” In the limb – distal part Dorsal structures toward the “front Palmar structures toward the “rear” (forelimb) Plantar structures toward the “rear” Integumentary System Comprises the skin with its adnexal structures (e.g., hair and glands), horns, hoofs, claws, and other modifications of the epithelial covering of the body. Integumentary System Functions Physical protection and protective barrier Prevention of dehydration body temperature regulation Sensory information via cutaneous receptors metabolic actions Excretion of wastes Integumentary System Integumentary System Vit. D3 (cholecalciferol) synthesized from cholesterol in skin after exposure to the sun. Cholecalciferol is converted to calcidiol in the liver. Calcidiol is converted to Calcitriol (active Integumentary System Skin Covers the outside of the animal and is continuous with mucous membranes at oral, anal, and urogenital orifices, the vestibule of the nostril, and the palpebral fissure; these sites are characterized by a mucocutaneous junction. Thickness of skin varies both between species and on a given individual. Adheres tightly to underlying structures in some locations, but in others is loosely attached to allow for considerable movement. Integumentary System Epidermis - the outer layer of skin, the epidermis, is an avascular stratified squamous epithelium that is nearly free of nerve endings. Dermis - or corium; primarily consists of dense irregular connective tissue and cushions the body from stress and strain; contains mechanoreceptors and thermoreceptors; contains hair follicles, sweat glands, sebaceous glands (oil glands), lymphatic vessels, nerves and blood vessels Hypodermis – or superficial fascia, subcutis; consists primarily of loose  Integumentary System 1. Stratum corneum - consists of layers of dead, flattened cells 2. Stratum lucidum - variably present, comprises cells that are poorly stainable 3. Stratum granulosum - consists of spindle- shaped cells containing basophilic kerato- hyalin granules (keratinocytes). 4. Stratum spinosum - has a spiny appearance because of its desmosomes (intercellular bridges) connecting adjacent cells. Integumentary System Skin – Epidermis Keratinization and cornification - the drying and hardening of the superficial cells; renders the surface of the skin tough and resistant to drying. Rate at which this occurs can be influenced by trauma or disease processes Callus is a local increase in thickness in response to continuous trauma. Integumentary System Skin – Dermis Integumentary System Skin – Hypodermis Variable amounts of fat, the panniculus adiposus, are present in the hypodermis, with species dependent distribution and relative Integumentary System Hair 3 Types: Guard hairs - which form the smooth outer coat Wool hairs - also called the undercoat, which are fine and often curly Tactile hairs - long stiff hairs with specialized innervation that renders them effective as organs of touch Integumentary System Hair Adnexa of Skin Hair Hair follicle – modification of the epidermis Hair bulb – base of the follicle where living cells divide and grow to build the Sebaceous glands are classified as shaft. holocrine glands because their oily secretory product, sebum, is produced by disintegration of epithelial cells within the glands. Arrector pili muscle is a tiny bundle of smooth muscle fibers that extends from the deep portion of the hair follicle at an angle toward the epidermis Adnexa of Skin Hair Medulla at its center, surrounded by a scaly cortex, outside of which is a thin cuticle. Internal epithelial root sheath - intimately covers the root of the hair and is continuous with the epithelial cells covering the dermal papilla. External epithelial root sheath - surrounds the internal root sheath, is continuous with the Adnexa of Skin Hooves Corium - the dermis of hoofs and horns Periople - thin, waxy layer that covers the outside of the hoof Laminae - the connection between hoof wall and corium is characterized by interdigitating sheets of hoof wall and Adnexa of Skin Hooves Part of the hoof in contact with the ground features a horny sole and a softer bulb of the hoof. Deep to the bulb of the hoof is a shock- absorbing modification of the subcutis called Adnexa of Skin Horns Formed over the cornual process, a bony core that projects from the frontal bone of the skull --soft type of horn called the epikeras covers the surface of the Adnexa of Skin Dewclaws Accessory digits Do not bear weight and as a rule have little clinical significance Adnexa of Skin Dewclaws Correspond to digits II (medial) and V (lateral) Adnexa of Skin Chesnuts Hornlike growths on the medial sides of horses’ limbs Front chestnuts are proximal to the carpus, Hind chestnuts are Adnexa of Skin Ergots Small projections of cornified epithelium in the center of the palmar (plantar) part of the fetlock of the horse. Adnexa of Skin Feather Epidermal growths that form the distinctive outer covering, or plumage. Adnexa of Skin Feather  Adnexa of Skin Bill/Beak External anatomical structure of birds that is used for eating and for preening, manipulating objects, killing prey, fighting, probing for food, courtship and Adnexa of Skin Comb and Wattle Comb- Fleshy growth or crest on the top of the head of gallinaceous birds, such as turkeys, pheasants, and domestic chickens Wattle- Fleshy caruncle hanging from various parts of the head or neck in several groups of birds and mammals Adnexa of Skin Snood An erectile, fleshy protuberance on the forehead of turkeys Thank you..