Skin - Integumentary and Appendages Skin is the largest organ in the body Combining forms for skin: a. cutane b. derm c. dermat d. derma I. Functions of the skin: a. Protective membrane b. Glands which produce secretions c. Nerve fibers for sensation d. Maintain body temperature II. Structure of the skin A. Epidermis (epi- above, dermis - skin)- outer membrane Takes 21 days for normal mitosis of an animal’s skin Animals have thinner epidermis layers than humans Made up of squamous epithelium (flat, platelike cells) Lacks major blood vessels - avascular Depends on capillaries for nourishment Melanocytes - cells that contain Melanin (Black pigment) Keratin (Kerat – horny) is a protein that provides skin with its waterproofing properties B. Dermis Composed of blood, lymph vessels, nerve Fibroblasts - fiber producing cells for repair. Histocytes (macrophages) - phagocytic cells Mast cells - cells that produce histamine and heparin Arrector pili - muscles attached to hair follicles to stiffen the hair - “raising the hackles” Sebaceous gland - oil gland
16
Embed
2016utah19951997currrr18881928.weebly.com2016utah19951997currrr18881928.weebly.com/uploads/7/9/9/... · Web viewAcne - plugged sebaceous glands. Cats are prone to feline acne. Scrub
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Skin - Integumentary and Appendages
Skin is the largest organ in the body
Combining forms for skin:
a. cutaneb. dermc. dermatd. derma
I. Functions of the skin:a. Protective membraneb. Glands which produce secretionsc. Nerve fibers for sensationd. Maintain body temperature
II. Structure of the skinA. Epidermis (epi- above, dermis - skin)- outer membrane
Takes 21 days for normal mitosis of an animal’s skin Animals have thinner epidermis layers than humans Made up of squamous epithelium (flat, platelike cells) Lacks major blood vessels - avascular Depends on capillaries for nourishment Melanocytes - cells that contain Melanin (Black pigment) Keratin (Kerat – horny) is a protein that provides skin with its waterproofing
properties
B. Dermis Composed of blood, lymph vessels, nerve Fibroblasts - fiber producing cells for repair. Histocytes (macrophages) - phagocytic cells Mast cells - cells that produce histamine and heparin Arrector pili - muscles attached to hair follicles to stiffen the hair - “raising the
C. Subcutaneous LayerLocated under the dermis and is composed of connective tissue - fat or lipid or adipose tissue.
III. HairRodlike fibers made of dead protein cells filled with keratin.
A. Types of hair1. Fur - short, fine, soft hair2. Guard hairs - long, straight, stiff hairs that form the outer coat; primary hair or top coat. 3. Secondary Hairs - finer, softer, and wavy hair; undercoat. 4. Tactile Hair - long, brittle, extremely sensitive hairs usually located on the face
B. Hair development1. Simple - guard hairs that grow from separate follicular openings, as in cattle2. Compound - multiple guard hairs that grow from a single follicle, as in dogs.
C. Color of hair3 primary pigments - black, brown, yellowGray hair - loss of pigmentWhite hair - absence of pigment and presence of air in the hair shaft
D. Shedding/MoltingControlled by temperature, hormones, photoperiod, and nutrition
IV. Nails, Horns, Hooves
Quick - blood supply for nails/claws
Coronary band (Coronet) - growth of the hoof
Chestnuts/Ergots - vestigal pads in horses. Chestnuts are located on the medial surface of the leg above the knee or hock. Chestnuts correspond to carpal pads in the dog. Ergots are located in the tuft of hair on the fetlock joint. Ergots correspond to metacarpal and metarsal pads in the dog.
Horn - permanent structure that grows continuously after birth. Breeds that are naturally hornless are called polled.
Antler - not permanent and are shed and regrown annually. Antlers are initially covered with skin called velvet. When the animal rubs off the velvet, the bone is exposed, the antlers lose their blood supply and are shed off.
V. FeathersA. Types of feathers
1. Contour - covers a bird’s body and constitutes the flight feathersa. Remigies - wing flight feathersb. Rectricies - tail flight feathers
2. Semiplume - found under contour feathers; provides insulation; help with buoyancy in water birds.
3. Down - soft feathers located near the skin to provide insulation4. Filoplume - located on the neck and head5. Bristles - around the eyes, nares, mouth; provides a sensory response
B. Wing trimsLarger birds - trim the first 4 primary remigiesSmaller birds - trim the first 5-6 primary remigies
V. Pathology1. Abrasion - injury to superficial skin layers
7. Contusion - injury that does not break the skin; redness and inflammation
8. Dermatitis - inflammation of the skin
9. Discoid lupus erythematosus (Collie nose or solar dermatitis) -canine autoimmune disease. The bridge of the nose exhibits depigmentation, erythema, scaling and erosions. Commonly seen in Collies, German Shepherds, Huskies, Labs, and Sheep dogs.
10. Ecchymosis (bruise) - bleeding into the skin from a broken blood vessel.
29. Demodectic Mange - “cigar shape mite”Mites live within the hair follicle Signs: patches of alopecia, variable erythema, secondary bacterial infection; head and limbs are affectedTreatment - Benzoyl peroxide shampooZoonotic
30. Sarcoptic Mange - burrowing miteMite has a short life in the environmentSigns: itching, crusted area around the ears, elbows, hocks, inguinal areaTreatment: Mitaban, DipsNot zoonotic
31. Cheyletiella - Walking DandruffAffects dogs, cats and rabbits. Mites feed on the skin scales and can live up to 10 days in the environment.Signs: pruritic skinDx: scotch tape, skin scraping Tx: ivermectin
33. Cuterebriasis - most common in rabbitsBotfly lays the eggs in the soil or feces, the larvae hatch and penetrate the skin, mature to the pupal stage beneath the skin. There will be a small air hole in the skin for the pupal to breath. To remove the pupal, carefully extract it without crushing it or the rabbit will die from the toxin being released.
34. Dermatophytosis - RingwormZoonotic fungus commonly seen in catsSigns: alopecia, scaling, inflamed rash or lumpDx: woods lamp, signs, DTM mediaTx: Antifungal cream or shampoo
35. Lick granulomaCauses are usually boredom or irritation to the area.Signs: the animal will lick the area constantly causing alopecia, inflammation, open