the study of the biological form of an organism
the study of the biological functions an organism performs
size and shape affect what?
the way an animal interacts with its environment
Many different animal body plans have evolved and are determined by the?
The ability to perform certain actions depends on an animal’s
shape, size, and environment
evolutionary convergence reflects what?
reflects different species’ adaptations to a similar environmental challenge
physical laws do what?
Physical laws impose constraints on animal size and shape
how do multicellular organisms facilitate diffusion of materials
- Multicellular organisms with a sac body plan have body walls that are only two cells thick, facilitating diffusion of materials
- More complex organisms have highly folded internal surfaces for exchanging materials
In vertebrates, the space between cells is filled with interstitial fluid, which allows for the movement of material into and out of cells
how do animals maintain a stable internal environment?
A complex body plan helps an animal in a variable environment to maintain a relatively stable internal environment
- Most animals are composed of specialized cells organized into tissues that have different functions
- Tissues make up organs, which together make up organ systems
what are the four tissue classifications?
- Different tissues have different structures that are suited to their functions
- Tissues are classified into four main categories: epithelial, connective, muscle, and nervous
what is epithelial tissue?
- Epithelial tissue covers the 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 (like dice), columnar (like bricks on end), or squamous (like floor tiles)
- The arrangement of epithelial cells may be simple (single cell layer), stratified (multiple tiers of cells), or pseudostratified (a single layer of cells of varying length)
what are the 3 shapes of epithelial cells?
what is connective tissue?
- Connective tissue mainly binds and supports other tissues
- It contains sparsely packed cells scattered throughout an extracellular matrix
- The matrix consists of fibers in a liquid, jellylike, or solid foundation
what are the three types of connective tissue?
- collagenous fibers
- elastic fibers
- reticular fibers
connective tissue contains what two types of cells?
- Fibroblasts that secrete the protein of extracellular fibers (produce the proteins)
- Macrophages that are involved in the immune system
what are the 6 types of connective tissue?
- Loose connective tissue binds epithelia to underlying tissues and holds organs in place
- Cartilage is a strong and flexible support material
- Fibrous connective tissue is found in tendons, which attach muscles to bones, and ligaments, which connect bones at joints
- tissue stores fat for insulation and fuel
- is composed of blood cells and cell fragments in blood plasma
- is mineralized and forms the skeleton
what does muscle tissue consist of?
- Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals
- It is divided in the vertebrate body into three types:
- –skeletal muscle, or striated muscle, is responsible for voluntary movement
- –smooth muscle is responsible for involuntary body activities
- –cardiac muscle is responsible for contraction of the heart
- Nervous tissue senses stimuli and transmits signals throughout the animal
- Nervous tissue contains:
- – neurons, or nerve cells, that transmit nerve impulses
- –glial cells , or glia, that help nourish, insulate, and replenish neurons
what two systems are responsible for control and coordination
Control and coordination within a body depend on the endocrine system and the nervous system
what does the endocrine system do
- The endocrine system transmits chemical signals called hormones to receptive cells throughout the body via blood
- A hormone may affect one or more regions throughout the body
- Hormones are relatively slow acting, but can have long-lasting effects
the nervous system
- The nervous system transmits information between specific locations
- The information conveyed depends on a signal’s pathway, not the type of signal
- Nerve signal transmission is very fast
- Nerve impulses can be received by neurons, muscle cells, and endocrine cells