Electrical Synapses - Nervous System

 ELECTRICAL SYNAPSES

Most synapses are chemical synapses; however, more recently, electrical synapses (Figure 5.9B) have been discovered in the brain. 


Such synapses also exist be-tween smooth muscle cells, between cardiac cells, and between glial cells. In the region of such a synapse, there are gap junctions  present between adjacent cells. These junctions allow ions to move in both directions and are a route of communication of impulses from one cell to another. As a result of the presence of gap junctions, transmission of impulses is faster than in chemical synapses.

Comments

Post a Comment

Popular posts from this blog

Introduction to Anatomy and Physiology - The Massage Connection

  W  ith the recognition of massage as an alternativeor complementary form of therapy, the demands made of the therapist are increasing. Although mas-sage is more involved with the knowledge and use of physical skills and techniques, the knowledge of anatomy, physiology, and pathology is also necessary for the therapist to effectively use those learned mas-sage skills. The therapist is certainly not required to know the field as thoroughly as medical professionals because diagnosis is not involved; however, the ther-apist should have the knowledge to understand how the body functions and how different parts of the body integrate. With this foundation, a therapist should under-stand how various diseases affect specific functions and how to recognize those conditions in which treatment may be detrimental to the client. Thera-pists should also be able to recognize conditions that may be harmful to his or her well-being. In addition, the therapist must have a thorough knowledge of...
Read more

Microorganisms on the Skin

  Microorganisms on the Skin On the integumentary system would not be complete without considering the invisible layer of microorganisms that inhabit the surface of the skin. This huge colony of organisms is the  “normal mi-crobial flora.”  Similar to residents and tourists in acity, there are resident microorganisms (resident flora) that are regularly found in a specific area at a specific age and transient flora that inhabit the skin for hours, days, or weeks. The resident flora play an important part in maintaining health and normal function. Resident flora prevent harmful bacteria from thriving on the skin by directly inhibiting them or competing with them for nutrients. However, resi-dent bacteria can be infective and harmful if they are introduced in large amounts into the bloodstream, which can occur when the skin is injured or when surgery is performed without adequately cleansing the skin surface before incision. They may also be harmful in individuals whose immu...
Read more

Neuroglia

Image
  NEUROGLIA Neuroglias are the supporting cells. They are five times more abundant than neurons. There are four types of glial cells in the CNS: the  ependymal cells, astro-cytes, microglia,  and  oligodendrocytes  and twotypes in the PNS:  Schwann cells,  or  neurolemmo-cytes, and  satellite cells,  or  ganglionic gliocytes. The ependymal cells line the cavities in the brain and spinal cord and are responsible for producing, circulating, and monitoring the cerebrospinal fluid—the fluid inside and around the CNS that cushions and protects the brain. The astrocytes, as the name suggests, are star-shaped. They are present between the blood capillaries and the brain and spinal cord, monitoring the sub-stances that enter and leave the brain and preventing sudden changes in the environment around the CNS. This is the  blood-brain barrier,  and the astrocytes are responsible for its creation. The astrocytes also help at the time...
Read more