Animal Structure and Function

Chapter 40

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Tissues

•      Epithelial - covers outside of body; lines organs and cavities

•      Connective - binds & supports other tissues

•      Muscle - contract when stimulated by nerve impulses

 

Epithelial Tissue

•      Classified as simple (single layer of cells) or stratified (multiple layers of cells)

•      Attached to basement membrane - dense mat of extracellular matrix

•      Provide barrier protecting against mechanical injury, invasion by microorganisms and fluid loss

•      Some absorb or secrete solutions (mucous)

 

Connective Tissue

•      Loose - binds epithelia to underlying tissue; holds organs in place - most widespread

•      Adipose - stores fat

•      Fibrous - joins muscle to bone (tendons) and bones to each other (ligaments)

•      Cartilage - flexible support

•      Bone - support

•      Blood - variety of functions

 

Nervous Tissue

•      Senses stimuli and transmits signal from one part of animal to another

•      Functional unit is neuron (nerve cell)

•      Dendrites transmit impulse from tips

•      Axons transmit impulse toward another neuron

 

Muscle Tissue

•      Composed of fibers containing proteins of actin and myosin

•      Contract when stimulated by nerve cell

•      Skeletal (striated) muscle - aids voluntary movements

•      Cardiac - striated and branched - heart

•      Smooth - lacks striations - responsible for involuntary movements (e.g., stomach)

 

Organs & Organ Systems

•      Composed of several types of tissues

•      Suspended by mesentaries - sheets of connective tissue

•      In mammals, most occur in thoracic and abdominal cavities

•      Carry out major body functions

 

Body Plans

•      Physical support on land depends on both body proportions and posture

•      Body shape and size affect interactions with environment

 

Metabolic Rate

•      Total amount of energy used per unit time

•      Basal metabolic rate - endothermic (“warm blooded” organism at rest

•      Standard metabolic rate - ectothermic (“cold-blooded) organism at rest

•      Rate inversely related to body size among similar animals

 

Homeostatis

•      Regulation of internal environment - “steady state” - internal fluctuations less than environment

•      interstitial fluid - internal environment of vertebrates

•      Depends on positive and negative feedback circuits

 

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