Body structure and functions
IntroductionThe human body is a complex system of multiple highly specialized functional units that work together. Cells, tissues, organs and organ systems are included in it’s functional organization
CELLCells are functional units that the human body is made of.
TISSUEA group of cells specialized to make possible a specific function.
Primary tissues include
- Muscular tissue
- Nervous tissue
- Epithelial tissue
- Connective tissue
ORGANOrgans are formed by two or more primary tissue types, which work together to execute the functions of a particular organ.
ORGAN SYSTEMA group of organs that work collectively to execute specific functions of the body.
- The skeletal system provides the basic framework to the body. It includes bones, forming the skeleton, and also ligaments and cartilages.
- The muscular system consists of three main types of muscles. They are smooth, skeletal and cardiac muscles. They co-ordinate both voluntary and involuntary actions of the human body.
- The nervous system is predominantly composed of impulse conducting neurons, and includes the central, peripheral and autonomous nervous systems. It also includes the brain, the spinal cord and all cranial and peripheral nerves.
- The cardiovascular system, includes the heart and blood vessels, and is responsible for the transport of substances across the body as well as for delivering nutrition to the individual cells.
- The respiratory system is concerned with the oxygenation of the blood and removal of carbon-dioxide, which is facilitated via the nasal cavities, pharynx, larynx, trachea, bronchi and lungs.
- The digestive system is concerned with the breakdown of food particles into nutrients and their absorption into circulation. It includes the mouth, pharynx, esophagus, stomach, intestines, liver, gall bladder and pancreas, among others.
- The excretory system is concerned with the removal of waste and toxic metabolites from the body. It includes the kidneys, ureter, bladder and urethra.
- The reproductive system is responsible for the production of progeny and also for regulating the development of sexual characteristics of the individual.
- The endocrine system functions through the secretion of various hormones by the many glands of the body. Hormones regulate all major body functions. The pituitary, pancreas and thyroid are examples of endocrine glands.
