Lecture 19- Mammals

What is the class name for mammals?

Mammalia

What are the 3 subclasses of mammals?

Prototheria, Metatheria, Eutheria

What type of mammals are in Subclass Prototheria?

Monotremes (egg-laying mammals, e.g., platypus, echidna)

What type of mammals are in Subclass Metatheria?

Marsupials (pouched mammals, e.g., kangaroos)

What type of mammals are in Subclass Eutheria?

Placentals (e.g., humans, dogs, whales)

What are the three layers of mammalian skin?

Epidermis, Dermis, Hypodermis

What cells in the epidermis produce keratin?

Keratinocytes

What is the outermost layer of the epidermis called?

Stratum corneum (dead, keratinized cells)

What layer gives rise to new skin cells?

Stratum basale

What are the 2 main types of hair in mammals?

Underhair (insulation) and Guard hair (protection, color)

What is the function of vibrissae (whiskers)?

Sensory detection

What are quills?

Modified hairs used for defense

What are 5 functions of mammalian hair?

Insulation, Communication, Sensation, Defense, Camouflage

What controls hair movement for thermoregulation and camouflage?

Arrector pili muscles

What are the 4 types of mammalian skin glands?

Sweat, Sebaceous, Scent, Mammary

What do eccrine sweat glands secrete?

Watery, odorless sweat (mainly for cooling)

Where are eccrine glands typically found?

Hairless areas (e.g., footpads)

What do apocrine glands secrete?

Viscous fluid (may produce odor with skin bacteria)

When do apocrine glands become active?

At sexual maturity

What do sebaceous glands produce?

Sebum (oily substance for waterproofing & lubrication)

What can clogged sebaceous glands cause?

Acne

What is the function of scent glands?

Communication (territory marking, mating, defence)

Where might scent glands be found in animals?

Deer (face), Skunks (anal region), Foxes (tail base)

What is the function of mammary glands?

Milk production for feeding young (lactation)

Do male mammals have mammary glands?

Yes, but they are rudimentary

What structures in the gland produce milk?

Alveoli (in lobules)

What are true horns made of?

Bony core covered by a keratin sheath

Do true horns shed?

No, they grow continuously

What are antlers made of?

Bone (shed annually, covered in velvet during growth)

Are antlers usually found in both sexes?

No, typically only males

What types of teeth/mouth parts match different feeding styles?

• Snipping: incisors

• Piercing/punching: canines

• Grinding/slicing: molars/premolars