Mammals 1 Flashcards
What is the sebaceous gland? What does it do?
A gland in the dermis that secretes protective oil around the hair follicle
secrtes an oily mixture (sebum) into hair follicles to keep hair and skin soft and pliable
What is hair composed of?
Keratin
What kinds of features are composed of the same protein as hair?
nails, claws, hooves, whale baleen, and feathers are composed of keratin
The fur coat is also known as what?
Pelage
What are the two hair types that make up the Pelage?
underhair - dense and soft for insulation
guardhair - coarse and longer for protection and colouration
Do all mammals have hair?
Hair is a characteristic of mammals but some have secondarily lost their hair.
ex. whales, naked mole rats
What are 2 purposes for the modifications of some hairs?
defense (quills) or sensory funtions (whiskers)
What are three main characteristics of mammals?
Hairy, Milk-producing, Endothermic vertebrates
What are milk glands?
modified sweat glands
What are vibrissae?
modified hairs for sensing - Whiskers
What kind of hair is human hair?
Bristles similar to lion and horse manes
What is a Rhino horn if it is not a true horn?
Dense, modified hair
What is the process of periodically replacing hair called?
molting
What are sweat glands?
Produce sweat for evaporative cooling and occur over the majority of the body in most mammals
How often does molting occur and what kind of purpose?
Can occur once, twice, or three times a year and switches between summer and winter coats etc.
What are 4 kinds of sweat glands/modified sweat glands?
Sweat glands
Scent glands (pheromones, skunks)
Milk glands
Ear wax (possibly)
What are three purposes for scent glands?
Territorial marking
Attract mates (pheromones - can be inter or intra)
Defense
What is the predominant sense in mammals? What is the exception?
Olfaction
Exception is primates where vision is most important because of an adaptation to arboreal lifestyle and perception of colour for food choice (fruit colour)
What is flemen?
Stallions block nostrils to focus exclusively on pheromone identification
Related to Jacobson’s organ between smell and taste
When do stallions use flemen?
In the presence of mares to detect pheromones
What are 3 types of mammae and where are they on the mammal? Give an example of a mammal that exhibits each type.
Inguinal in the pelvic region - hoofed mammals, whales and porpoises
Pectoral in the forleg/arm region of chest - elephants, bats, primates, manatees, sloths
Both pectoral + inguinal - canids, felines, pigs
What are 6 characteristics of mammals?
1) Hair
2) Integumentary glands (sweat, sebaceous)
3) Endothermic and homeothermic
4) Mandible (lower jaw) = single bone
5) 3 inner ear bones (not one)
6) Diaphragm (negative pressure breathing)