Examination of a prokaryotic cell reveals various component structures. Some of the structures are naturally common to almost all prokaryotes, but some structures are present in certain species. Structures found external to the bacterial cell wall aid in protection, attachment, motility, or conjugation. Figure shows a typical prokaryotic cell. The prime features of a prokaryotic

A slowly progressive and degenerative disease affecting the nervous system is termed Parkinson’s disease (named after its pioneer, James Parkinson in 1817). Parkinson’s disease results from an insufficiency of dopamine in the brain, and is thus categorised as a movement disorder. According to the WHO, a chronic progressive neurodegenerative disorder of insidious onset, characterised by

Glaucoma is defined as a progressive optic neuropathy causing damage to optic nerves that result in visual field defects. The disorder is progressive in nature and is usually associated with increase in intraocular pressure (normal intraocular pressure ranges from 1020mmHg). Therefore, management of glaucoma aims at decreasing the raised intraocular pressure which can be achieved

Myasthenia Gravis (MG) is an autoimmune disorder, in which antibodies are produced at neuromuscular junction (NMJ) against the NM receptors, so, it results in decrease in the number of NM receptors. Patients with myasthenia gravis show severe muscular weakness. The degree and intensity may vary at different times. Patients with thymoma show an increased risk of development

Neurohumoral transmission involves the following four steps (figure) Step 1: Initiation of an Action Potential and Axonal Conduction During resting conditions, the membrane potential inside a typical axon is −70mV with respect to exterior of axon. A high concentration of K+ and low levels of Na+ and Cl– (K+ 140mM, Na+ 10- 15mM ) within the cell cause this difference in

Autonomic Nervous System has the following functions : Reflex Activities : The ANS is involved in complex reflex activities that depend on sensory input to the CNS and on motor output. Reflex actions are rapid and are coordinated subconsciously in the brain, i.e., below the level of the cerebrum. Deals with Excitation and Stressed Conditions

The differences between sympathetic and parasympathetic nervous system according to their origin, character and effect on respective organs are listed in table. Sympathetic Parasympathetic Origin From all thoracic and upper 3 lumbar segments. From cranial 3, 7, 9, 10 and sacral 2, 3, 4 segments. Character Short preganglionic and long post-ganglionic fibres. Long preganglionic and

The preganglionic fibres of the parasympathetic nervous system arise from the cell bodies of the CNS. The preganglionic fibres originate from the nuclei of the third, seventh, ninth and tenth cranial nerves (CN III, VII, IX, and X), and, the fourth sacral segments (S2 to S4) of the spinal cord. The parasympathetic nervous system has

The preganglionic fibres of the sympathetic nervous system arise from the cell bodies spanning from the Thoracic (T1) to the Lumbar (L2) part of the spinal cord. The Sympathetic Nervous System is made up of the following parts: Sympathetic Trunks : These represent a pair of long cords located on either side of the vertebral column. They extend from

These receptors possess a subunit along with enzymatic property or bind a JAK (Janus Kinase) enzyme on activation. The outer face of plasma membrane carry binding site for agonist and the inner face has catalytic site (figure). A single transmembrane stretch of peptide chain interconnects these two domains. The two primary subgroups of these receptors