Integumentary Flashcards
Root Hair Plexus
Arrangement of sensory nerves located at the root of the hair follicle that enables it to sense touch
Sebaceous Gland
Simple holocrine glands that secrete sebum through the hair follicle
Root
Anchor of the hair that attaches it to the connective tissue layer
Secondary Hair
The smaller, yet most numerous hairs in an animal’s undercoat
Shaft
Keratinized, visible portion of hair that extends above the surface of the epithelium
Sinus Hairs
“Tactile hairs”
Sebum
Secretion of the sebaceous gland containing oils and epithelial cells that is released into the hair follicle to lubricate the hair and skin
Velvet Skin
Soft skin on deer antlers that provides a vascular source necessary during the early seasonal growth of the antler, and is often eaten by the buck due to its high nutritive value
Wool-type Hairs
Hair coat composed primarily of secondary hairs seen in sheep
Ungula
“Hoof”
Stratum Germinativum
- “Stratum basale”
- Base layer of the epidermis composed of a single layer of cuboidal cells that divide to replenish the superficial layer of the epidermis
Stratum Granulosum
Granular layer of epidermis located between the stratum germinativum and the stratum lucidum, that contains keratohyaline and lamellated granules that aids in waterproofing skin
Stratum Spinosum
Prickle cell layer of the epidermis that is located between the stratum germinativum and the stratum granulosum, that is weblike and dense with intercellular attachments
Tylotrich Hairs
Hairs that aid in the perception of touch
Ungulate
Hooved animal
Stratum Lucidum
Clear layer of epidermis located beneath the stratum cornerman, that is present in only very thick skin (like paw pads)
Tyrosine Melanin
Pigment that produces brown-black colors in hair
Telogen Effluvium
- “Blowing the coat”
- Overall hair loss that occurs from hair follicles being in a synchronized telegenic phase due to stress, medication, malnutrition, or hormonal changes
Stratum Corneum
- “Horny layer”
2. Most superficial layer of epidermis whose cells are dead remnants of keratinocytes and are anucleated & keratinized
5 Epidermal Layers
- Stratum germinativum/basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
Telogen Phase
Resting phase of hair growth
Tactile Hairs
Hairs sensitive to touch
Tactile Elevations
Small elevations located throughout the epidermal surface that usually contains a tactile hair and is important in the perception of touch
Primary Hairs
Large straight hairs predominant in complex hair follicles
Polled Breeds
Hornless animals from species that normally produce horns, and are specifically bred for this trait
Pigmentation
Degree of coloration that depends on the concentration of melanin (more melanin = darker color)
Pheomelanin
Sulfur-based yellow-brown pigment that produces a reddish color in hair
Papilla
- Nipplelike protuberance
or - Depressions in the death tracts that give rise to new feathers
Pacinian Corpuscle
Tactile nerve endings in the subcutaneous tissue of the skin that sense deep and heavy pressure
Merkel’s Cells
Cells located in small numbers in the epidermal-dermal junction that aid in tactile sensory function
Melanosomes
Granules filled with melanin that are transferred from melanocytes to keratinocytes
Melanocyte
Cell located within the lower epidermis that produces tyrosinase and melanin
Melanin
Sulferous pigment produced by melanocytes in the skin, hair, choroid of the eye, and melanomas
Meissner’s Corpuscles
Oval tactile nerve endings found within the dermal papillae of the epidermis that are sensitive to light tough and often occur in areas with no hair follicles
Medulla
Innermost layer of a hair strand that is made of 2-3 layers of flexible soft keratin
Lanolin
Fat-based secretions of sheep’s sebaceous glands that are often used in lotions and ointments
Langerhans Cells
Macrophages of the epidermis that phagocytize invading microorganisms and serve as antigen-presenting cells
Keratinocytes
- Cells that synthesize keratin
- As they travel away from the basement membrane toward the superficial epithelium, they lose their organelles to make way for keratin. The cells die by the time they reach the surface
Keratinization
Formation of keratin inside epithelial cells of the skin as they mature
Keratin Fibers
Strong strands of fibrous keratin that are insoluble in water
Keratin
Tough waterproof protein that is a major component of the epidermis and makes up scales, beaks, claws, fathers, nails, hair, horns, & hooves
Interdigital Pouch
Pouch of cutaneous tissue found between the toes of cloven-hooved animals that exudes a waxy substance
Integumentary/Integumentary System
Outer covering of the body that consists of skin, nails, hair, hooves, horns, etc.
Inguinal Pouch
- “Mammary pouch”
2. Pouch if cutaneous tissue found within the inguinal area of sheep
Infraorbital Pouch
- “Lacrimal pouch”
2. Pouch of cutaneous tissue found rostral to the medial canthus of the eye in sheep and other ungulates
Implantation Angle
Degree of angulation of a shaft or hair
Horn
Horny keratinized extension of the frontal bone in ruminate ungulates that arises from the corium and varies in shape and size depending on age, sex, & species
Hair follicle
Tubelike invaginations of the epidermis near the arrector pili and sebaceous glands that go through the dermis and into the connective tissue, where the hair is rooted
Hair Bulb
Bulbous portion of the hair follicle in the dermis that provides the material for hair production
Ergots
Horny keratinized growths located behind the fetlocks of horses that are believed to be vestigial remnants of metacarpal and metatarsal pads
Epidermis
Outermost layer of skin that is composed of keratinized stratified squamous epithelium
Epidermal Orifice
Opening of the hair follicle through which the hair emerges
Dermis
Deep connective tissue portion of the skin that contains blood vessels, glands, and hair follicles
Cutaneous Membrane
- “Integument”
2. Composed of dermis and epidermis
Cutaneous Muscles
Thin muscles in the connective tissue beneath the skin that cause the skin to twitch when contracted
Cuticle
Single layer of cells that makes up the outermost lawyer of the hair shaft
Cortex
The layer surrounding the medulla that is composed of hard keratin
Corium
Dermis of the skin
Connective Tissue Papilla
Base of the hair follicle that ultimately provides the material necessary to create hair
Compound Follicles
Follicles through which more than one hair emerges
Claws
Accessory appendages of the integumentary system found mainly in carnivores that are used for grasping prey and self defense
Chestnut
Horny keratinized growths located on the medial forearms and hocks of horses that are believed to be vestigial remnants of carpal and tarsal bones or extra toes
Catagen Phase
Transitional phase between anagen and telogen phases of the hair growth cycle
Arrector Pili Muscle
Smooth muscle that is attached to the base of hair follicles and is responsible for the involuntary ‘hair raising’ response to cold, fear, or aggression
Anagen Phase
Active phase of hair growth
Laminae
Interdigitations between the corium and hoof that serve as attachment sites between the hood and coffin bone
Point
Portion of the frog that points toward the toe of the horse’s hoof
Poll
Top of the head between the bases of the ears
Quarters
Medial and lateral regions of the hoof
Barrel
Trunk of the body formed by the rib cage and abdomen
Brisket
The area at the base of the neck between the front legs that covers the cranial end of the sternum
Withers
The area dorsal to the scapulas
Tailhead
Dorsal part of the base of the tail
White Line
The white (or light-colored) region that marks where the wall and sole of the hood adjoin
Planum Nasolabiale
Topmost plane of the muzzle in horses and cows
Planum Nasale
Topmost plane of the muzzle in cats, dogs, and sheep
Lateral Cartilages
Two large bands of cartilage in the equine hood that aids in venous return in conjunction with the frog and digital cushion
Flank
Lateral surface of the abdomen between the last rib and the hind limbs
Frog
Think triangular pad on the palmar and plantar surfaces of the horse hoof that is part of the “circulatory pump” of the hoof
Heel
Most caudal region of the hoof
Hoof Wall
External cornified portion of the hoof that grows constantly downward from the coronary band to the sole
Central Sulcus
Central depression of the frog in the horse hoof
Angle
Angle of the hoof wall as viewed from a lateral aspect when the foot is flat on the ground
Collateral Sulcus
Deep ridge and n either side of the frog that separates it from the bars in the horse hoof
Coronary Band
Part of the hoof that articulates with the skin
Coronary Corium
Part of the corium that has differentiated to provide nourishment to the hoof at the site of the coronary band
Horn Tubes
Minute lines that transverse the hoof wall vertically from the germinating layer of the coronary band to the sole
Laminitis
- “Founder”
- Inflammation of the laminae that causes extreme pain and heat in the horse hoof (usually the front feet) that can be caused by ingesting large quantities of grain, drug reactions, retained placenta, or trauma