An action potential is a rapid, brief sequence of changes in the membrane potential that occurs after excitation.The size and duration of an action potential vary and depend on the nature of the tissue. For example, in nerves, it is no more than a few milliseconds, while in cardiac muscle, it is 200 to 300 milliseconds.
Category Archives: general studies
Understanding the Nernst Equation: Derivation and Key Application
The membrane potential at which net passive flux of that particular ion becomes zero is called the Nernst equilibrium potential for that ion. This equation considers only a single permeable ion in isolation.
Resting Cell Membrane-Explained
The compositions of ECF and ICF differ markedly in ionic concentrations. For example, Sodium ions are more abundant in ECF, and potassium ions are more abundant in ICF. Anions like Chloride are diffusible, but many anions are non-diffusible, e.g., proteins, phosphates.
Apoptosis -Explained
Apoptosis is programmed cell death. It is a well-coordinated and planned cell death procedure. It is a natural process that is under genetic control.
Apoptosis is different from necrosis.
Apoptosis is derived from the Greek word meaning the falling of leaves from trees or petals. Apo is a prefix meaning “away from,” and ptosis means “falling.”
Physiology: Understanding How Body Functions
Physiology is the study of the functions of living organisms. It is divided into many branches.
Physiology is derived from a Greek word with a Latin equivalent, Physiologia, meaning “natural knowledge”. Physiology is the branch of science that deals with the functions of the body and how these functions occur and are controlled. It also describes which organs initiate and maintain these functions.
Thymus-Explained
The thymus is a small (5 mm x 5mm) gland, a central or primary lymphoid organ. It has two lobes that are connected by a fibrous isthmus.
It is situated in the superior mediastinum and extends upward to the root of the neck and downward to the anterior mediastinum.
Understanding Cystometry: A Comprehensive Guide
A cystometrogram plots the volume of urine passed from the bladder against intravesical pressure.
Understanding the Spleen: Structure and Function Explained
Spleen performs multiple functions, although it is not essential for survival ,it is vital for healthy life. Dysfunctions of spleen will produce serious problems.
Understanding the Limbic System: Key Functions and Components
1. The limbic lobe and the related subcortical nuclei.
The limbic lobe includes the cingulate gyrus, isthmus, hippocampal gyrus, and uncus.
2. The related subcortical nuclei are the hypothalamus, amygdala, septal nuclei, portion of the basal ganglion,paraolfactory area, and anteriorthalamic nucleus.
The hypothalamus is located in the middle of all these structures and plays a vital role in the limbic system.
Functions and Structure of the Uterus Explained
The uterus is a hollow muscular organ situated in the female pelvis. It is a pear-shaped (Pyriform) organ that lies between the urinary bladder in front and the rectum behind. The uterus is usually anteflexed and anteverted.
The size of the uterus in an adult female is 3 inches x 2 inches x 1 inch (7.5 cm long x 5 cm wide x 2.5 cm thick. The weight of the adult nulliparous uterus ranges from 50 to 80 g.
The uterus develops from the fused vertical part of the two Müllerian ducts.
