A spermatozoon is a highly specialized, free swimming, actively motile cell which measures about 60 µm in length. The spermatozoon is made up of three parts. They are: a head, a neck and a tail or principal piece. Head is piriform in shape and measures 4 µm in length. It is derived from the nucleus, … Read more
It is seen that a part of the distal convoluted tubule (at the junction of its straight and convoluted parts) lies close to the vascular pole of the renal corpuscles that is between the afferent and efferent arterioles. The muscle cells in the wall of the afferent arterioles are modified in this region. They are … Read more
Outside the brain and spinal cord there are aggregations of cell bodies of neurons called ganglia. There are two main types of ganglia. They are sensory and autonomic ganglia. A) Sensory ganglia These ganglia are present on the dorsal nerve roots of spinal nerves, where they are called dorsal nerve root ganglia or spinal ganglia. … Read more
• The term was coined by an American physiologist Walter Cannon in 1932 AD. • It is defined as the tendency of biological systems to maintain a state of equilibrium. • The body’s self-regulation of hormones and acid-base levels, the composition of body fluids and body temperatures are examples of it. • Thus, the processes … Read more
It is the largest gland of our body. It weighs between 1 to 2.3 kg which is situated in the upper right part of the abdominal cavity just below the diaphragm. It’s upper and anterior surfaces are smooth and lie in close association to the posterior surface of diaphragm. Similarly, its posterior surface is irregular … Read more
Human teeth are thecodont, diphyodont and heterodont. They are borne by the premaxillae of upper jaw and mandibles of lower jaw. They are found embedded in jaw sockets which we call thecodont. Human have two sets of teeth. The milk teeth also known as deciduous dentitions appear first and are progressively replaced by the permanent … Read more
Breathing is a physical process of taking or inhaling the fresh air in and expelling CO2 out. It is accomplished through changes in the volume and air pressure of the thoracic cavity. It is accomplished by the movement of ribs, internal and external intercostal muscles between each pair of ribs, diaphragm and abdominal muscles. Breathing … Read more
Human heart is a roughly triangular structure and a muscular organ. It is situated in the thoracic cavity between the two lungs. One third of its part lies on the right side and two third on the left side. An average human heart weighs about 300-350 grams which is about 12 cm long and 9 … Read more
The central nervous system consists of two parts. They are – a)Brain and b)Spinal cord A)Brain It is highly specialized delicate organ of the human body. It weighs about 1.3-1.5kg depending on the gender (in case of human). It is protected by a bony brain case or cranium. It is composed of soft nervous tissues … Read more
Introduction to heart sound With each heart-beat, the detectable heart sounds are produced. These sounds represent the auscultatory events of the cardiac cycle. Heart sounds can be amplified and recorded by placing an electronically amplified microphone on the chest. The recording of such sounds is called a phonocardiogram. There are four heart sounds associated with … Read more