Introduction Epithelial tissue is one of the four basic types of animal tissues. It is a covering tissue. It forms thin sheets which cover body structures and also line the cavities of all the hollow organs of the body. It is arranged in single or multilayered sheets. It is supported and attached to underlying connective … Read more
Introduction The glands which do not have any duct are called ductless glands or endocrine glands. Literally, the term ‘endocrine’ means internally secreting. Their secretions are called internal secretions or hormones. These are released directly into the blood, which carries them to different parts of the body, and where they coordinate their metabolic activities. They … Read more
S.N Spermatogenesis Oogenesis 1. It occurs in seminiferous tubules of testes. It occurs in ovaries of female. 2. It results in the production of four sperm cells, all of which are functional. It results in the formation of only one large egg cell or ovum and three polar bodies. 3. Mature sperms are very small … Read more
Nerves are the communication lines for transmitting impulses from one part of the body to another. They are elongated, slender, thread-like structures arising from the brain and spinal cord. They vary in length i.e. from 0.1 mm to several metres. In certain cases they may be almost equal to the body length. They are of … Read more
The menstrual cycle is the regular natural change that occurs in the female reproductive system (specifically the uterus and ovaries) that makes pregnancy possible. It refers to the series of events that occur in the ovaries of sexually mature and non-pregnant females and culminate in menses. The menstrual cycle is approximately 28 days long. The cycle is required for the production of oocytes. … Read more
S.N Medullated nerve fibre Non-medullated nerve fibre 1. It is also known as myelinated nerve fibre. It is also known non-myelinated nerve fibre. 2. The nerve fibre with medullary sheath is called medullated fibre. The nerve fibre without medullary sheath is called non-medullated nerve fibre. 3. It is found in white matter of brain … Read more
The organs which enable us to perceive the undergoing changes in the external environment and body’s internal environment and make aware of them are called sense organs. These sense organs are responsible for senses in the human body. They are provided with specialized receptor cells or sensory receptors. A receptor is the part of the … Read more
A hormone(from the Greek participle “ὁρμῶ”, “to set in motion, urge on”) is any member of a class of signaling molecules produced by glands in multi cellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour. A) Properties Regarded as “chemical messengers” of the body. They carry the message from the site of synthesis to the target … Read more
Liver performs a number of functions. Due to its function, it is also called master laboratory of the body. It is an important organ for metabolism in vertebrates. A summary of its important function is as follows: 1) Secretion of bile The liver cells synthesize the constituents of bile from the mixed arterial and venous … Read more
S.N Axons Dendrites 1. They take message away from the cell body. They bring information to the cell body. 2. They have smooth surface. They have rough surface due to dendritic spines. 3. Generally there is one axon per cell. Usually many dendrites per cell. 4. Nissl’s granules are absent . Nissl’s granules are present … Read more