Transcript Other Characteristics Shared by Mammals

MAMMALIAN CHARACTERISTICS
Chapter 30.1
OBJECTIVES:
1. Identify the characteristics of mammals.
2. Describe how mammals maintain a constant
temperature to achieve homeostasis.
3. Compare the respiration in mammals to other
vertebrates.
Hair and Mammary Glands
● two characteristics that distinguish mammals from other
animals
mammary glands: glandular tissue that produce and secrete
milk that nourishes developing young
hair is to mammals as feathers are to birds...
functions of hair
1. insulation
2. camouflage
(bengal tiger blends into the jungle)
3. sensory device (whiskers)
4. waterproofing (sea otter)
5. signaling (white tailed deer)
6. defense (porcupine)
Other Characteristics Shared by Mammals
● mammals are endotherms: produce body heat internally
(high metabolic rates that require large amounts of energy)
feeding and digestion
● energy created through the breakdown of food
● 4 trophic categories based on food source
1. insectivores
2. herbivores
3. carnivores
4. omnivores
● a mammal’s adaptations for finding, capturing, chewing,
swallowing and digesting food influence the mammals
structure and life habits...
● herbivores have a larger cecum and longer digestive tracts
than carnivores
excretion
● kidneys filter urea (end product of cellular metabolism) from
the blood
● kidneys excrete metabolic waste and maintain homeostatic
balance of body fluid (excrete or retain water)
respiration
● high levels of oxygen are required to maintain a high level of
metabolism
● oxygen is taken into the lungs during respiration
● the diaphragm (muscle beneath the lungs) contracts /
flattens - chest cavity enlarges and air enters the lungs (inhale)
- oxygen moves by diffusion into the blood vessels - the
diaphragm relaxes / enlarges - chest cavity gets smaller - air
leaves the lungs (exhale)
circulation
● mammals have a four-chambered heart
● once oxygen is in the blood, vessels carry it to the heart
which pumps it to the rest of the body
● oxygenated (arteries) and
deoxygenated (veins)blood is
kept separate - the delivery of
oxygen and nutrients is more
efficient
brain and senses
● mammals have highly developed brains
cerebrum: responsible for coordinating conscious activities,
memory and the ability to learn
cerebellum: responsible for balance and coordinating
movement
● mammals carry out complex behavior like learning and
remembering - get information about their environment and
retain it
● importance of senses varies between groups of mammals
glands
A group of cells that secrete fluid to be used elsewhere in the
body – helps regulate homeostasis (internal environment)
reproduction
Internal fertilization and development of the embryo takes
place in the uterus , nourished by the placenta
gestation: the amount of time the young stay in the uterus
before they are born – varies between mammals