Animal Form and Function Overview

Animal Form and Function

• Anatomy is the biological form of an organism.
• Physiology is the biological function(s) an organism performs.
• Form and function are closely related.
• Size and shape affect how an animal interacts with its environment.
• The black-tailed jackrabbit lives in hot climates.

Diverse Forms, Common Challenges

• Black-tailed and white-tailed jackrabbits are closely related animals.
• Jackrabbits' size and shape affect their survival in different climates.
• The black-tailed jackrabbit inhabits hot climates.

Divergent and Convergent Evolution

• Divergent evolution occurs when two species diverge from a common ancestor.
• Convergent evolution leads to unrelated species developing similar structures with the same function.
• An example of convergent evolution includes birds, bats, and butterflies.

Exchange with the Environment

• Nutrients, waste products, and gases must pass through cell membranes.
• Exchange rate is proportional to a cell's surface area.
• The amount of exchange material is proportional to a cell's volume.
• Surface area increases faster than volume as an animal grows.
• Single-celled organisms in water have sufficient surface area for exchange.
• Multicellular organisms with thin body walls (e.g., a hydra) facilitate diffusion of materials.
• Larger, complex bodies enable animals to maintain stable internal environments.

Tissues

• Animals are composed of cells organized into tissues.
• Tissues consist of structurally and functionally similar cells and their intercellular material.
• Histology is the study of tissue types and functions.

Tissue Classification

• Tissues can be categorized based on their origin (ectodermal, endodermal, mesodermal).
• Tissues can also be classified based on cell composition (epithelial, endothelial, connective).
• Tissues can also be categorized based on organ systems (e.g., nervous tissue).

Epithelial Tissue

• This tissue covers the body's exterior and lines organs and cavities.
• Epithelial cells are closely joined.
• Epithelial cells can be cuboidal, columnar, or squamous.
• The arrangement of epithelial cells can be simple (single layer), stratified (multiple layers), or pseudostratified (a single layer with varying cell lengths).

Connective Tissue

• This tissue binds and supports other tissues.
• The matrix of connective tissue contains fibers in a liquid, jelly-like, or solid form.
• Types of connective tissue include loose connective tissue, fibrous connective tissue, adipose tissue, blood, bone, and cartilage.
• Blood is composed of blood cells and cell fragments in plasma.
• Bone forms the skeleton.

Muscle Tissue

• Responsible for body movement.
• Muscle cells contain actin and myosin filaments.
• Types of muscle tissue include skeletal (voluntary), smooth (involuntary), and cardiac (heart contraction).

Nervous Tissue

• Receives, processes, and transmits information (responds to stimuli).
• Nervous tissue contains neurons (nerve cells) and glial cells (support).
• Neurons transmit nerve impulses.
• Glial cells support nerve cells.

Organ Systems in Mammals

• Endocrine system coordinates body functions through hormones.
• Nervous system coordinates body functions through electrical signals.
• Musculoskeletal system supports and moves the body.
• Cardiovascular system transports substances throughout the body.
• Respiratory system facilitates gas exchange.
• Urinary system filters blood and eliminates wastes.
• Gastrointestinal system breaks down and absorbs nutrients.
• Reproductive system produces offspring.
• Immune system protects against pathogens.
• Integumentary system protects the body.