In this article we will discuss about the structure and functions of human ear. Structure of Ear: Each ear consists of three portions: (i) External ear, (ii) Middle ear and (iii) Internal ear. 1. External Ear: It comprises a pinna, external auditory meatus (canal) & tympanic membrane. (i) Pinna: The pinna is a projecting elastic cartilage covered with skin. Its [...]
The below mentioned article provides an overview on the Human Brain. Location and Protective Coverings of the Brain: The brain is the anterior most part of the central neural system which is lodged in the cranial cavity (cranium) of the skull. The human brain weighs from 1220 to 1400 grams. The human neural system has about 100 billion neurons, majority [...]
The following points highlight the ten major types of central lymphoid organs. The types are: 1. Thymus 2. Bone Marrow 3. Lymph Nodes 4. Spleen 5. Mucosa Associated Lymphoid Tissue (MALT) 6. Cells of Lymphoreticular System 7. Delayed Type Hypersensitivity T (Tdh Cells) 8. B-Lymphocytes and Plasma Cells 9. Microphages 10. Major Histocompatibility (Complex) (MHC). Thymus: Thymus is a lymphoepitheial [...]