2.1: The Skeletal and Muscular Systems Flashcards
Soft, horny covering at the proximal end of the hoof wall
Periople
Type of sweat gland
Apocrine
whiskers
Tactile hair
Skin layer where fat is stored
Hypodermis
Fiber-like protein that gives skin flexibility
Elastin
The visible portion of hair
Hair shaft
Skin layer with collagen
Dermis
What are the 3 parts of a hoof?
wall, sole, frog
gives color to the skin and hair
melanin
What are the 3 phases of hair growth?
Anagen, telogen, catagen
It protects against excessively humid or dry conditions, environmental chemicals, infectious organisms, helps regulate body temperature
Functions of the skin
What are the 2 major layers of the skin?
Epidermis and the dermis
The outermost layer of the skin, the layer you see when you look at a person or an animal, may contain up to five layers
Epidermis
a fibrous protein that provides toughness to the cell and, therefore, to the skin
Keratin
The deepest layer of the epidermis
basal layer
stratum spinosum
spiny layer of the epidermis
stratum granulosum
granular layer of the epidermis
stratum lucidum
clear layer of the epidermis
stratum corneum
outermost horny layer of the epidermis
provides both structural and nutritional support to the epidermis.
Dermis
made of several protein strands braided together, much like a person’s hair
Collagen
a type of collagen that forms a loose net of thin, delicate fibers
Reticular fibers
fibers that stretch like rubber bands, giving the skin flexibility.
Elastin fibers
composed primarily of fat, but it also contains blood and lymphatic vessels, nerves, and connective tissue, stores fat, helps regulate body temperature, and supports the layers above it, both structurally and nutritionally.
hypodermis
the top of the nose in dogs, cats, sheep, and pigs
planum nasale
the top of the nose in horses and cattle
planum nasolabial
a nonliving structure partially composed of keratin
Hair
What 2 parts are hairs made up of?
shaft and root
the free portion that rises above the skin surface
hair shaft
What 3 components are layered over each other to make up the hair shaft?
cuticle, medulla, cortex
single layer of keratinized cells arranged like shingles on the outside of the shaft
cuticle
the core of the shaft, a layer that may not be present in all hairs
medulla
Between the cuticle and the medulla, which makes up the bulk of most hairs and is composed of many keratinized cells packed together
cortex
the portion of the hair beneath the surface of the skin
hair root
If you pluck a hair from your skin, the pale, slightly widened or knoblike area at its end
hair bulb
improve traction during locomotion, can also be used as a weapon for attack or defense, other animals use for gathering food, tearing apart food, or holding food while carrying or eating it
claws
remnants of toes that have progressively become smaller as animals evolved from a four-toed stance to a two-toed stance
Dewclaws
found in primates and are similar to claws but they have only a keratin outer surface and don’t possess a sole
Nails
somewhat less versatile than a claw but serve their specific purpose very well, animals primarily use them to move around, can also be useful as a weapon if the animal kicks with its leg
Hooves
composed of fibers that are intertwined, packed tightly together, and bound into a single unit by keratin, true derivatives of skin, rise from the epidermis and grow throughout life
Horns
different from horns, although they have a similar outward appearance, originates in the dermal layer and is a bony extension of the skull, don’t grow continuously but are shed and regrown every year and tend to appear only in males of the species
Antlers
made of protein and originate from a follicle, used for flight, protect the skin and aid in thermoregulation
Feathers
What the 6 types of feathers?
Contour, semiplume, down, filoplume, bristles, powder down
most visible feathers and include the flight feathers of the wings and tail
Contour feathers
usually found under contour feathers and provide insulation and aid with buoyancy in water birds
Semiplume feathers
soft, fluffy feathers are located close to the skin and function primarily in insulation
Down feathers
barbless feathers that are located on the nape and upper back and play a role in controlling feather movement
Filoplume feathers
may be found around the eyes, nostrils, mouth, or toes and play a role in the sense of touch
Bristles
constantly growing feathers that create a waxy powder that spreads throughout the rest of the plumage to clean it and provide waterproofing
Powder down feathers
process of feather replacement
Molting
keratinized and relatively inelastic skin, made up of the subcutaneous space, dermis, and epidermis
Reptile skin
process of skin shedding in reptiles
Ecdysis
