Multicellular life

Evolution of multicellular life

Animal tissue types

CampbellFig1.1

CampbellFig 20.2

Animal tissue types

• What is a tissue?

• A cooperative unit of many very similar cells that perform a specific function.

• Examples– Epithelial– Connective– Muscle– Nervous

Epithelial tissue

• Covers and lines the body and its parts

• One surface free, the other bound to basement membrane

• Tissues are named by – Shape of cells– Number of layers of cells

Epithelial tissue

• Simple = single layer

• Stratified = multiple layers

• Squamous = flat (tiles)

• Cuboidal = like dice

• Columnar = like bricks

CampbellFig 20.4

Simple SquamousSimple Cuboidal

Lines the lungsIn the kidney tubules

CampbellFig 20.4

Stratified Squamous Epithelium

Lines the esophagus

CampbellFig 20.4

Ciliated columnar epithelium

Lines the air ways in the respiratory system

CampbellFig 20.4

Connective tissue• Binds other tissues an provides support

matrices

• Few cells in a nonliving matrix

• Three fiber types– Collagen fibers– Elastic fibers– Reticular fibers

• Fibroblasts - cells that produce connective tissue

Loose connective tissue(Areolar)

Holds other tissue in placeA “binding” material

CampbellFig 20.5A

Other Connective tissues

Loose

Adipose

Blood

Fibrous connective

Cartilage

CampbellFig 20.5

Bone

Tendons

Dense connective tissue thatAttaches muscle to bone

Like CampbellFig 30.7

Bone Tissue

• Osteocytes• Haversian canal• Lamelle (matrix)

CampbellFig 20.5D

Bone Development

Muscle tissue• Functions in movement• Bundles of long cells ( muscle fiber= muscle cell)

• Skeletal muscle– Attached to bones by tendons, produces voluntary movement– Striated unbranched

• Smooth muscle– Found in walls of digestive tract, produces involuntary movements– Unstriated, spindle shaped

• Cardiac Muscle– Striated , branched, produces heartbeat

Muscle tissueCampbell 20.6

Smoothmuscle

Skeletalmuscle

Cardiacmuscle

• Responsible for coordinating body activties

• Neurons are nerve cells

• Motor neurons are nerves that activate muscles

• Sensory neurons transmit information

• Composed of cell body and dendrites

• Supported by glial cells

Nervous Tissue

CampbellFig 28.3AModified

Nervous TissueCampbellFig 28.2

Summary