Anatomy

The study of animal form and function is integrated by the common set of problems that all animals must solve. These include how to extract oxygen from the environment, how to nourish themselves, how to excrete waste products, and how to move. Knowledge of a structure provides insight into what it does and how it works. Conversely, knowing the function of a structure provides insight about its construction. Anatomy is the study of the structure of an organism. Physiology is the study of the functions an organism performs. Introduction

Animals are multicellular organisms with their specialized cells grouped into tissues. Tissues are groups of cell with a common structure and function. Tissues are classified into four main categories: epithelial tissue, connective tissue, nervous tissue, and muscle tissue. In most animals, combinations of various tissues make up functional units called organs, and groups of organs that work together form organ systems. For example, the human digestive system consists of a stomach, small intestine, large intestine, and several other organs, each a composite of different tissues. Introduction

All systems must be coordinated for the animal to survive. For instance, nutrients absorbed from the digestive tract are distributed throughout the body by the circulatory system. The heart that pumps blood through the circulatory system depends on nutrients absorbed by the digestive tract and also on oxygen obtained from the air or water by the respiratory system. There are two types of circulatory systems : open circulatory systems and closed circulatory systems. Both have blood, a set of blood vessels and a heart.

A)- Open circulatory system In insects, other arthropods blood bathes organs directly in an open circulatory system and blood is called hemolymph. The heart pumps the hemolymph into sinuses surrounding the organs, hemolymph does not transport O2 and CO2 B)- Closed circulatory In humans and other vertebrates and often called the cardiovascular system. The heart consists of two atria and two ventricles. Arteries, veins, and capillaries are the three main kinds of blood vessels. Blood transports oxygen and carbon dioxide The circulatory system

lungs are restricted to chest. The circulatory system transports gases between the lungs and the rest of the body. Lungs of mammals have a spongy texture. A system of branching ducts conveys air to the lungs. Respiratory system

The mammals, digestive system consists of the alimentary canal and various accessory glands that secrete digestive juices into the canal through ducts. The accessory glands include the salivary glands, the pancreas, the liver, and the gallbladder. Digestive system

 Asexual reproduction involves the formation of individuals whose genes all come from one parent.  There is no fusion of sperm and egg.  Sexual reproduction is the formation of offspring by the fusion of haploid gametes.  Ovum: female gamete - usually large and nonmotile.  Sperm: male gamete - usually small and motile.  Most insects have separate sexes with complex reproductive systems.  In many species the female reproductive system includes a spermatheca, for storing sperms. Reproductive system

Central N.S. Peripheral N.S. (CNS) composed of Brain & Spinal cord is responsible for integration (PNS) composed of peripheral nerves Nervous system

Structure of Brain

The Summary