Chapter 40: Animal Form and Function Flashcards
Main types of animal tissue
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial Tissue
Covers outside of the body and lines the organs and cavities within the body
It contains cells that are closely joined
The shape of epithelial cells may be:
- Cuboidal
- Columnar
- Squamous
The arrangement of epithelial cells may be:
- Simple- single cell layer
- Stratified- multiple tiers of cells
- Pseudostratified- a single layer of cells of varying length
Cuboidal epithelium
Simple columnar epithelium
Simple squamous epithelium
Pseudostratified columnar epithelium
Stratified squamous epithelium
Polarity of epithelia
Connective tissue
Binds and supports other organs and tissues
Contains sparsely packed cells scattered throughout an extracellular matrix consisting of fibers in a liquid, jellylike, or solid foundation
Three types of connective tissue fiber, all made of protein:
- Collagenous fibers- provide strength and flexibility
- Reticular fibers- join connective tissue to adjacent tissues
- Elastic fibers- stretch and snap back to their original length
Types of connective tissue
In vertebrates, the fibers and foundation combine to form six major types of connective tissue:
- Loose connective tissue- most widespread connective tissue; binds epithelia to underlying tissues and holds organs in place
- Fibrous connective tissue- composes tendons and ligaments
- Bone
- Adipose tissue
- Blood
- Cartilage
Muscle tissue
Muscle cells consist of filaments of the proteins actin and myosin which together enable muscles to contract
It is divided into three types:
- Skeletal muscle- aka striated muscle, is responsible for voluntary movement
- Smooth muscle- responsible for involuntary body activities
- Cardiac muscle- responsible for contraction of the heart
Nervous tissue
Composed of neurons and various types of glia- cells that help nourish, insulate, and replenish neurons; can also modulate neuron function
Thermoregulation
Process by which animals maintain an internal temperature within a tolerable range
Endotherms- generate heat by metabolism
- Birds and mammals
Ectotherms- gain heat from external sources
- Generally need to consume less food than endotherms
- Most invertebrates, fish, amphibians, and nonavian reptiles
Thermoregulatory adaptations
- Insulation- skin, feathers, fur, and blubber reduce heat flow
- Evaporative heat loss- sweating, bathing, panting
- Behavioral responses- huddling to reduce heat loss
- Adjusting metabolic heat production- thermogenesis
- Circulatory adaptations- vasodilation, vasoconstriction, and countercurrent exchange- transfer of heat between fluids that are flowing in opposite directions
Thermogenesis
The adjustment of metabolic heat production to maintain body temperature
- Increased by muscle activity such as moving or shivering
- Some ectotherms produce “antifreeze” compounds to prevent ice formation in their cells
- Some seek warmer environments to increase their body temperature in response to certain infections
Controlled by the hypothalamus
