Hair Of Mammals

Front 1

What is an arrector pili muscle?

Back 1

It is attached to each hair follicle. when it contracts it pulls the hair upright.

Front 2

What stimulus may cause the arrector pili muscle to contract?

Back 2

Fear or cold causing hair to stand up on the back of a cat or dog or gooseflesh of humans.

Front 3

What are 2 categorizes of hair growth patterns?

Back 3

Angora or definitive.

Front 4

What does an angora growth pattern refer too?

Back 4

Refers to continuous growth which results in long flowing hair that may or may not be shed. Ex. heads of humans, manes & tails of horses or lions.

Front 5

What does a definitive growth pattern refer too?

Back 5

Refers to hairs that attain a particular length & shed & replaced periodically.

Front 6

What is the coat of hair or fur coat of mammals referred to as?

Back 6

Pelage

Front 7

What does pelage mostly consists of?

Back 7

Underhair and guard hair.

Front 8

What is underhair?

Back 8

short, fine, and very soft hair that traps warm air.

Front 9

What is guard hair?

Back 9

Long and coarse hair that protects the underhair against wear and often provides protective coloration.

Front 10

3 types of guard hair are:

Back 10

Spines, Bristles, Awns

Front 11

Describe Spines and provide examples.

Back 11

Stiff, enlarged guard hairs that undergo definitive growth. Echidnas, porcupines, hedgehogs have them as a function of protection.

Front 12

Describe Bristles and provide examples.

Back 12

Firm, long hair that undergo angora growth. Hairs of manes and mostly function for communication by accenting facial expressions or body postures.

Front 13

Describe Awns and provide examples.

Back 13

Undergo definitive growth and are the most common kind of guard hairs.

Front 14

Name the 3 types of underhair.

Back 14

Wool, fur & velli.

Front 15

Describe wool.

Back 15

Long, soft and ususally curly.

Front 16

Describe fur.

Back 16

Closely spaced, fine, short hairs which are the most common kind of underhair.

Front 17

Describe velli.

Back 17

Very short, very fine hairs that are sometimes referred to as fuzz. Occurs on many newborn mammals.

Front 18

What is the main function of the pelage?

Back 18

For insulation, by dissipation of heat from the skin surface to the environment and absorption of heat from the environment is retarted by it.

Front 19

What other than pelage provides insulation for mammals?

Back 19

subcutaneous layer or hypodermis that consists of loose connective tissue & adipose tissue - which provides insulation.

Front 20

Name some mammals that have relatively large amounts of adipose tissue and what is it referred to as?

Back 20

Whales and Sea Lions. Blubber.

Front 21

What does adipose tissue consist of and for what purpose?

Back 21

Consists of cells that are specialized to store fat which is a form of stored chemical energy.

Front 22

Shedding of the pelage is referred to as? Why is this necessary? In most species how often does this occur.

Back 22

Molting; because hair becomes damaged as a result of daily activites and sunlight bleaches the color. 2 x a year.

Front 23

Some mammals molt 1 time a year. Name 2 examples and when do they molt.

Back 23

Seals and Foxes (other than artic foxes). Molting occurs in the summer.

Front 24

A few mammals molt 3 times a year. Name an example and when the molts occur. What else is unusual about this molting?

Back 24

Snowshoe hares. Molts occur in spring, early autumn and later autumn. Each molt undergoes a color change from winter white, dark brown/brownish gray, to gray.

Front 25

Name the 2 categories of pigments that occur in mammalian hair.

Back 25

Pheomelanin (shades of red & yellow)

Eumelanin (shades of brown & black)

Front 26

Some mammals have agouti fur what does this mean and describe it's appearance.

Back 26

Color-banded fur. The part nearest the skin is gray, followed by a yellow band and the distal part is black or brown.

Front 27

The permanent absence of any pigment results from a genetic mutation called what?

Back 27

Albinism; which results in mammals having white fur and red eyes.

Front 28

The genetic mutation opposite of albinism resulting in an all or nearly all black body parts is called what? Give an example of a mammal with this.

Back 28

Melanism. Eastern fox squirrel of SE AL - has a black face except for the nose & ears.

Front 29

What is countershading?

Back 29

When the ventral portion of the body is more lightly colored than the rest of the body.

Front 30

What is the purpose of countershading?

Back 30

They look white or like the sky to animals viewing them from below and dark or like the ground to animals seeing them from above. When viewed from the side they are less conspicuous.

Front 31

What is aposematic coloration and give an example.

Back 31

Warning coloration that makes them conspicuous & unmistakeable to predators. Skunks are an example.

Front 32

What is Cryptic coloration and give an example.

Back 32

When the pelage coloration or pattern matches the general background coloration of their habitat. White-tailed deer fawns (spots on brown fur looks like sun shine through trees).

Front 33

What is disruptive coloration and give an example.

Back 33

Stripes or other markings & colors that at close range stand out, but at a distance make them blend in. Zebras, when in a herd it is difficult to pick out individuals and it may make them appear taller.

Front 34

What are vibrissae, what type of growth do they undergo and where are they located? CN and purpose.

Back 34

Long, stiff, sensory hairs attached near the mouth. Undergo definitive growth. Whiskers. Function for obstacle detection in nocturnal species.