Cells, Organs and Organisms By Stella Angeli and Charles Maseela Background taken from: 3/fig1.jpg

Specialized Tissues Epithelial Tissue:- – Squamous: Forms alveoli of respiratory membrane and endothelium of capillaries. – Columnar: Lines the small intestine. Has unicellular glands called goblet cells scattered throughout its structure that secrete mucus. Picture taken from: Picture taken from:

Specialized Tissues 2 Muscle Tissue:- –Skeletal muscle: Affects skeletal movement such as locomotion and maintaining posture. Reacts to conscious control. –Smooth muscle: Found in the walls of organs. Involuntary movement, not under conscious control. –Cardiac Muscle: Involuntary muscle, found only in the heart. Picture taken from: _labeled.png Picture taken from:

Specialized Tissues 3 –Nervous Tissue:- –Unipolar neurones: sensory neurones that have only a single process or fibre which divides close to the cell body into two main branches (axon and dendrite). –Bipolar neurones: Spindle shaped with a dendrite at one end and an axon at the other (e.g. light- sensitive retina of the eye). –Multipolar neurones: Motor neurones which have numerous cell processes (an axon and many dendrites). Picture taken from: 4ever-n-4whatever.blogspot.com

Organs Specialized tissue comes together to form structures called organs. Each organ is specialized to carry out a specific task, e.g.: –Epithelial tissue comes together to form the lining of the lungs and the endothelial lining of blood vessels in the respiratory system as well as the lining in the intestines of the digestive system. –Muscle tissue comes together to form support for the skeleton and is the basis for movement in the body (voluntary and involuntary). –Nervous tissue comes together to form the central nervous system (the brain and spinal cord) and has a fundamental role in the control of behaviour and bodily processes (voluntary and involuntary). Background image taken from: ments/2411d t-i organs-jpg Picture taken from: Picture taken from:

Organisms Organ systems come together to form organisms with each organ system performing a certain task, vital for the organism’s survival. In humans the various organ systems come together, with each organ system dependant on the others for the organism to survive:- –Digestive system: Absorption of nutrients and excretion of waste. –Skeletal system: Support, lymphocyte production. –Muscular system: Support and movement, production of heat. –Nervous system: Integration, coordination and regulation through electrochemical signals. –Endocrine system: Integration, coordination and regulation through hormones. –Respiratory system: Elimination of CO 2 and absorption of O 2. –Circulatory system: The transporting of needed materials to the cells and the transporting of wastes away from the cells. –Reproductive system: Production of offspring. –Integumentary system: Body covering. –Lymphatic system: Regulate fluids and immunity. –Urinary system: Excretion of nitrogenous waste, and maintain homeostasis of electrolytes. Background image taken from: