What do glial cells do?

Primarily, glial cells provide support and protection to the neurons (nerve cells), maintain homeostasis, cleaning up debris, and forming myelin. They essentially work to care for the neurons and the environment they are in.

What is source sink mismatch?

determined source–sink mismatch occurs when a relatively. thin bundle of fibers expands to a broader region of tissue.

Do astrocytes have gap junctions?

Astrocytes in the CNS form a highly interconnected network via gap junctions or hemichannels. Each connexin hemichannel consists of six protein subunits termed connexins, which belong to a protein family encoded by 20–21 genes in mammals (Scott et al., 2012).

Are connexins proteins?

Connexins are a family of at least 15 proteins that form intercellular membrane channels of gap junctions and allow diffusional movement of ions, metabolites, and potential signaling molecules. These structural molecules play important roles in bi-directional communication between the oocyte and granulosa cells.

What is the difference between an axon and a dendrite?

Dendrites receive electrochemical impulses from other neurons, and carry them inwards and towards the soma, while axons carry the impulses away from the soma. 2. Dendrites are short and heavily branched in appearance, while axons are much longer.

What is the relationship between neurons and glial cells?

Glial (Neuroglial) cells do not conduct nerve impulses, but, instead, support, nourish, and protect the neurons. Glial cells are far more numerous than neurons and, unlike neurons, are capable of mitosis.

Where are connexins found?

The connexin subunit proteins that make up connexons are synthesized on the membranes of the cells endoplasmic reticulum. These subunits are then oligomerized, or combined with other smaller parts, into connexons in the golgi apparatus. The connexons are then delivered to their proper location on the plasma membrane.

What is the difference between the sinoatrial and atrioventricular nodes?

The sinoatrial node (SAN) and the atrioventricular node (AVN) are specialized tissues in the heart: the SAN is specialized for pacemaking (it is the pacemaker of the heart), whereas the AVN is specialized for slow conduction of the action potential (to introduce a delay between atrial and ventricular activation during the cardiac cycle).

Is connexin dysregulation responsible for atrioventricular (AV) node dysfunction?

Finally, it is argued that connexin dysregulation may be responsible for AV node dysfunction. The atrioventricular (AV) node is the “gatekeeper” between the atria and the ventricles and is located at the AV junction on the right side of the heart ( Figure 1 A).

What is the principal connexin in the working atrial and ventricular myocardium?

The principal connexin in the working atrial and ventricular myocardium is the medium-conductance Cx43.

What is the function of the sinoatrial node?

The sinoatrial node, also referred to as the pacemaker of the heart, coordinates heart contractions. Located in the upper wall of the right atrium, it generates nerve impulses that travel throughout the heart wall causing both atria to contract.