Slides- Biology II (40) Animal form and function

Physiology

Biological function; how organisms work

Tissues

Cells of similar form/function

Organs

Functional units of the body

Organ Systems

Coordinated organs

There are only 4 major tissue types:

Epithelial, connective, muscular, and nervous

Epithelial Tissue

• Closely packed cells lining surfaces

• Cover the outside of the body and line organs and cavities within the body

• Physical barrier against injury, infection, dehydration

• Active interface with environment

Connective Tissues

Bind and support other tissues of the body

6 Major types of Connective tissue:

• Loose connective tissue

• Cartilage

• Fibrous connective tissue

• Adipose tissue

• Bone

• Blood

Loose connective tissue

Bind epithelium; rich in collagen & elastin

Cartilage

Collagen fibers in protein-carbohydrate matrix; secreted by chondrocytes

Fibrous connective tissue

Dense collagen fibers; tendons & ligaments

Adipose tissue

Fat for storage, cushioning, & insulation

Bone

Osteoblasts secrete collagen matrix that becomes mineralized

Blood

Liquid matrix

Nervous tissue

Convert external stimuli to electronic impulses, conduct impulses

Neurons

Have long extensions (axons) that connect to other cells

Glia

Associated cells that protect and nourish neurons

Muscle tissue

Contractile cells with actin and myosin filaments; most abundant, uses most energy

Types of Muscle Tissue:

• Skeletal

• Smooth

• Cardiac

Skeletal Muscle Tissue

Voluntary movements; striated

Smooth Muscle Tissue

Involuntary movements; not striated

Cardiac Muscle Tissue

Involuntary heartbeats; striated

Which systems coordinate the actions of organ systems?

The nervous & endocrine systems

Nervous System

• Sends point-to-point messages, short duration

• Axons carry electrical impulses lasting milliseconds

Endocrine System

• Broadcast message, tissues respond, longer duration

• Hormones have effects on tissues with receptors

• Slow-acting (second to get around body) and long lasting (up to hours)

Nervous system different function:

for immediate responses, coordinating movement

Endocrine system different function:

for regulation of growth and development, involuntary processes