INTEGUMENTARY SYSTEM

CH 8

WOD

IMPETIGO

INTEGEMENTARY ROOTS

• Cerumen: EARWAX - cerulytic

• Cornu/o : HORN – cornu/ectomy

• Dermat/o; Derm/o – SKIN – dermat/it is

• Hidr/o; Sudor – SWEAT - Hidropoiesis

• Trich/o; Pil/o: HAIR – trich/o/rrhexis; pil/o/erection

• Kerat/o – HORNY TISSUE/ CORNEA – Keratin, keratits

• Onych/o – NAIL/CLAW: onchyectomy

• Prurit/o – ITCH – Prurit/us

• Pyo – PUS - pyoderma

• Squam/o – SCALES – Squamous

• Seb/o – SEBUM - Seborrhea

Seborrhea

SKIN

• SKIN – largest organ of the body

• HAS ACCESSORY ORGANS: ________, _____________, ______________, _________

FUNCTION

• Barrier against invasion of microorganisms

• Protects underlying structures from injury

• Prevents the body from drying out

• Maintains and regulates body temp

• Receptor for senses: touch, heat, cold, pressure, pain

• Disposes of waste products

MAINTAIN TEMPERATURE

• Balance of heat production and heat loss

• Heat production: ________________

• Heat Loss: ____________, ___________, ___________, _____________________

• Miscellaneous heat loss: mm, resp. tract, digestive and urinary tract

Differences: Epidermis, apocrine glands (seal outer surface, phermones)compound hair

SKIN ANATOMY

• From Deep to superficial– ________________________________(GERMS)– ________________________________(SPIN)– _______________________________(GRANNY)– ________________________________(LUCY)– _______________________________(CORAZY)

Stratum germinativum

SKIN ANATOMY

• 1) Stratum germinativum – basal layer– _______________________________– cells are pushed to outer layer until they die and are sloughed off– continuous process– Melanin

• 2) Stratum spinosum – spinous layer; cells in this layer are – ______________________________________– thick in areas that are susceptible to wear and tear

• 3) Stratum granulosum – granular layer– ___________ in the cytoplasm of cells are visible; – cells are beginning to die; not present in all

areas (esp in hairy skin); – _________________ begins here (cells are packed with protein)

SKIN ANATOMY

• 4) Stratum lucidum – clear layer; – cells are closely packed and clear– _____________________ (esp in hairy skin)– it is found in areas of wear and tear

• 5) Stratum corneum – horny layer– cells are __________, _____________, ________________– cells are overlapping, dry, scales (keeps the bugs away)– Keratinization: give horns, hooves, beaks, and hair their

___________ (protein _______________)– dead cells are continuously sloughed and replaced

from _______________________________

SKIN THICKNESS• VARIATIONS

-thickest in areas of wear and tear (footpads, forehead, dorsal neck, dorsal thorax, rump, base of tail)

-Pachyderms: elephant, rhinoceros, hippopotamus

-thin skinned areas: pinna of the ear, axillary, inguinal, scrotal, periorbital, and perianal regions

SKIN COLOR

• DETERMINED VIA ______________– skin pigment produced by melanocytes in the form of granules

-melanocytes are located in_____________________, however the granules aren’t visible in the cell’s

cytoplasm until stratum granulosum- amount of melanin granules determines color of skin-help to protect against damaging effects of the sun

• ALBINISM – congenital defect of melanin development-normal pigmentation is not present-hair, skin, eyes-lack protection against sunlight

• BLOOD SUPPLY can affect skin color in _____________

• CYANOSIS occurs when oxygen supply is reduced in nonpigmented skin

• Chameleon!!

HAIR- FUR - short, fine hair• 3 TYPES OF HAIR:

– PRIMARY (#1)– “GUARD” hair, top coat• stiff, but with a smooth appearance• water runs off the coat of the animal without

chilling the animal– SECONDARY (#2)– “WOOL” hair,

• Undercoat• soft, shorter, thin, wavy

– TACTILE• thicker and longer than primary hair• found around the face• grow from hypodermis or superficial muscle layer• Each hair is innervated, allowing them to be touch

Receptors• EX: cat whiskers (vibrissa – any large tactile hair)

HAIR-Hair develops from the papilla, which is located inside the hair follicle. -Follicle sits at a 30-60 degree angle to the skin-Hair shaft is what is visible

-ARRECTOR PILLI – bundles of involuntary muscle that are attached to hair follicles-hair stiffens when the muscle contracts-plays a part in the fight or flight response

-HACKLES – hair along the neck and back that is raised when an animal needs to increase its size during a fight

HAIR

- 2 ARRANGEMENTS FOR HAIR GROWTH:

SIMPLE – primary hairs grow from separate follicles (cows, horses)

COMPOUND – 2-5 primary hairs grow from each follicle (dogs, cats) and are surrounded by clusters of secondary hairs; all are growing

from a common pore

-THERMAL REGULATION is affected by HAIR COLOR-light colored coats are cooler in hot, sunny climates

-AGOUTI – individual hairs have several bands of light and dark pigments with black tips

-SHEDDING – process of losing hair-peaks every spring and fall-affected by photoperiod, temperature, nutrition, hormones, genetics, health

GLANDSSWEAT GLANDS (sudor, hidro = sweat; sweat glands =

sudoriferous glands. Inability to sweat = anhidrosis-cool the body-dogs and cats sweat very little amounts that is usually masked by

the hair coat; horses should be able to sweat in much larger amounts

- panting, slobbering, and smearing saliva on their coats helps to dissipate the heat

SWEAT GLANDS CONTINUED-APOCRINE GLANDS – found throughout the body

-secrete strong-smelling substance into follicles

- often line the external ear canal and over-secretion can lead to otitis externa

-ECCRINE GLANDS – coiled structure whose duct emerges on the skin surface

-produce watery sweat-found only n the footpads and between the nostrils in the dog

GLANDS

SEBACEOUS GLANDS – secrete SEBUM (fatty lubricant matter) which lubricates the skin and hair, waterproofs the coat, gives the coat a glossy sheen, spreads sweat, slows bacterial growth, and acts as a territory marker

-absent on foot pads and nose

seborrhea = an excessive

discharge from the sebaceous

glands resulting in abnormally

oily skin

-CIRCUMORAL GLANDS – on lips of cats, marks territory

-HORN GLANDS – produce a strong odor that makes female goats attracted to male goats during breeding season. Located caudomedially to the horns

-ANAL SACS – pouches at 4/5 and 7/8 o’clock. Foul smelling secretion that is expressed during defecation and serves as a territory marker

SEBACEOUSGLANDS

CERUMINOUS GLANDS

- cerumen = earwax

–modified sweat glands

-located in the external ear canal

-secrete earwax

NAILS, CLAWS, HOOVES-modified epidermal structures of the distal phalanges

-used for protection, scratching, digging, or defense in battle

-dermis contains nerves and blood vessels

-all have a WALL, SOLE, and PAD, but with variations

-WALL = hoof or claw-SOLE = underside of hoof or claw

-flaky in small animals-abundant surface area in horses

-PAD = finger tip-small animals have

individual digit pads, metacarpal and metatarsal pads, and a carpal pad

-horses have a FROG that pads the hoof and acts as a

shock absorber with the bulbs

DEWCLAWS

-serve no practical purpose

(are often removed in dogs)

-usually found on front legs in small animals, but can also be found on hindleg

-dogs can be “double dewclawed” – required in Great Pyrenees

-look like miniature hooves in ruminants

CHESTNUTS, ERGOTSCHESTNUTS

-vestigial carpal and tarsal pads-flattened, oval masses of horn in the horse-found on the medial surface of the legs just proximal to

the carpus and at the distal end of the tarsusERGOT

-small mass of horn in a patch of hair on the palmar/plantar aspect of the horse’s fetlock

-vestigial metacarpal/metatarsal pads

HORNS AND ANTLERS

-HORN = permanent structure of keratinized epithelium that grows continuously after birth and originates from the frontal bone

-never branched and are never shed-Hornless breeds of species that can have horns are called POLLED-Shape of horn is determined by breed, sex, age-male horns are usually larger-cow horns are located in temporal position, sheep and goats are in a parietal position-goat horns grow caudally-sheep horns are curled

-ANTLERS-found on male deer and reindeer, and caribou (both male and female)-also grow from the skull, but are made of bone instead of keratin-shed and regrown every year, becoming more complicated in structure-Each year the horns are initially covered in VELVET which is soft hairy skin that produces the antler. The velvet is rubbed off as the skin dies and the bony process is exposed. Once the antler is exposed it begins to lose blood supply and is eventually shed.