) Describe the composition and function of the cell body. b) How are axons and dendrites alike? In what ways (structurally and functionally) do they differ? • The neuron cell body consists of a spherical nucleus with a conspicuous nucleolus surrounded by cytoplasm. The cell body of some neurons also contains pigment inclusions. It is the focal point for outgrowth of neuron processes during embryonic development. In some neurons, the plasma membrane of the cell body acts as part of the receptive region
functionally related axons, supports the blood brain barrier, provides nutrients, and repairs scar tissue • Microglia- act as part of the immune system, remove waste material and viruses and fungi from the brain • Oligodendrocyte- forms myelin sheath in the central nervous system cells, won’t repair damaged axons, exists in the CNS • Shwaan cells- form myelin sheath outside of the central nervous system and therefore exists in the peripheral nervous system will repair damaged axons. • Radial
when connections are made. The structure of neuron explains how the communication process takes place where the neurons grow appendage is the form of dendrites. Information is sent to a neuron through the axon formation and even as neurons have various dendrites they have one axon. It is the axons that carry information to other neurons, and dendrites receive input from various neurons. Other than the neuron the other type of
The refractory period, which is before the resting potential is rebalanced by the pump, prevents the action potentials from traveling both ways down an axon at one time due to the neurons inability to respond to stimuli as a result of the imbalance of Na+ and K+ ions. This entire process repeats in a sort of chain reaction down the axon of the neuron until the impulse reaches the synapse, which is the gap between two neurons. When the neuron is depolarized, voltage-gated Ca2+ channels are activated
muscles and joints bringing information to the CNS. It is made up of nerves that connect to skin, sensory organs, and skeletal muscles. One sensory neuron, photoreceptors in the eye, sense light. The neural impulses are then transmitted down the axons of the sensory neurons to the brain, where the brain then interprets what that input means. PNS plays a role in regulating blood pressure, thirst, and body temperature. Thermoreceptors in the skin help the body sense temperature. Motor neurons are
• Touch: Our sense of touch is mainly governed by a huge network of free-nerve endings and touch receptors located near or at the surface of the skin. These receptors combined with the free-nerve endings in the skin are known as the somatosensory system. They are activated by a stimulus, which in turn makes the neural membrane more permeable to sodium ions, thus allowing an action potential to occur (given that the charge exceeds the threshold). The impulse may or may not travel to the brain depending
The ability to do literally anything is due to the action potential originating in neuronal cells. It makes it possible for neurons to convey vital information over long distances, such as from pain receptors in the foot to muscle contractions in the leg, causing a reflexive move away from the painful stimulus. Without this kind of rapid communication throughout the nervous system, humans and other organisms would be unable to function. The neurons themselves are small, self-driven circuits, each
sheath has its own specific and characteristic ultrastructure to help it carry out its function efficiently (Morell and Quarles, 1999). Myelin is a modified and extended version of the plasma membrane found in a spherical pattern wrapped around the axon of a neurone. Damage of the myelin sheath can lead to a condition called multiple sclerosis. Multiple sclerosis is a disorder which can result in muscle weakness and walking difficulties amongst things. It is caused by a person’s own immune system
1. In the human body, the spinal cord includes both white matter and gray matter. The grey matter, which consists of neuronal cell bodies and dendrites of neurons, neuroglia and unmyelinated axons, is the major component. The white matter contains myelinated axons that create the nerve tracts. “The nerve tracts of the spinal cord provide a two-way communication system between the brain and body parts outside the nervous system” (Shier, Butler, & Lewis, 2003). As we know, there are 31 pairs of spinal
are the nerves that connect the central nervous system specifically the brain and the spinal cord to the limbs and organs (Guillain-Barre syndrome, pg.1) Precisely, the immune systems response attacks a particular part of peripheral nerves called axon, which are the extensions of nerve cells (neurons) which transmit nerve impulses (Guillain-Barre syndrome, pg.1) this disorder can be the cause of ... ... middle of paper ... ..., from http://www.aafp.org/afp/2004/0515/p2405 Guillain-Barre syndrome
Biology Assignment 1. Tissue types and their properties! Body tissues! The four core types of tissues in the body are; epithelial, connective, muscle and nervous. Each is designed for specific functions. Epithelial Tissues! Epithelial tissues are spread out all over the body. They cover all surfaces and also line body cavities and hollow organs. These tissues are also the major tissue in glands. Epithelial tissues have many functions including secretion, protection, excretion, diffusion, absorption
It was the beginning of February when my grandfather was going in to receive his second knee replacement. Being his second time, we were optimistic that the surgery would go well and that he would recover without any issues. My grandfather made it through surgery and accordingly, had to stay for observation. During this time everything appeared to be normal, and knowing that my grandfather hates to be in hospitals, wouldn’t have said otherwise. When he was finally discharged, we took him home and
When Luke Skywalker's hand was sliced off by Darth Vader in the trilogy Star Wars, he received a new prosthetic hand which was fully functional in use and appearance.Today, this science fiction is becoming reality as an exciting new technology called Biomechatronics is promising revolutionary advances in the field of prosthetics. As the name implies, biomechatronics merges man with machine. It is an interdisciplinary field including biology, neuroscience and physics. Biomechatronic scientists
dendrites and axons (top of Figure 1). Dendrites, along the cell body, receive information in the form of stimuli from sensory receptors or from other nerve cells. The axon is a long, thin cellular extension responsible for transmitting information to other nerve cells, and is filled with a viscous intracellular fluid called the axoplasm. If stimuli received by the dendrites or the cell body is above the cellâs intensity threshold, a nerve impulse is initiated which propagates along the axon. It flows
conversation what is termed as a nerve. A nerve is consists of axons that are right outside the central nervous system. The axons is where contained our central nervous is contained by what is called a tract or pathway. Neurons communicate over long distances by sending signals called nerve impulses through the axons which make up a tract or nerve. Axon usually branch into a whole tree due to the nerve impulses that go down each branch when the axon divides. Then a single neuron sends signals to thousands
Multiple sclerosis, also known as MS, is one of the humankind’s most mysterious diseases. Multiple sclerosis has the ability to affect nearly 3 million people worldwide. This disease tends to be more common in individuals of northern European descent and women are more than twice as likely to develop multiple sclerosis as men are. Of those 3 million people, most of them are between the ages of 20 and 50 years old. Even though multiple sclerosis is a mystery disease, scientists are working to determine
called the dendrite and axon, also called nerve fibers. The dendrites are like tentacles that sprout from the cell and the axon is one long extension of the cell. The dendrites receive signals from other neurons, while the axon sends impulses to other neurons. Axons can extend to more than a meter long. Average sized neurons have hundreds of dendrites; therefore it can receive thousands of signals simultaneously from other neurons. The neuron sends impulses by connection the axon to the dendrites of
neurological diseases are other main causes for the syndrome (5). Axons that carry brain signals leave the larger motor areas on the surface of the brain and direct their signals towards the brain stem. It is here where they converge linking one another to form a tightly packed bundle called the motor tract. The brain stem motor tract is extremely sensitive; thus even the slightest impact of a stroke can lead to destruction of the axon bundles resulting in a total paralysis (1). For a locked-in patient
within the central nervous system are surrounded by a myelin sheath. Myelin insulates the axon and allows electrical impulses to travel faster throughout the body. Oligodendrocytes produce myelin in the central nervous system and can wrap myelin around several axons at a time. Some Schwann cells produce myelin in the peripheral nervous system. Unlike oligodendrocytes, Schwann cells can only wrap around one axon at a time.
myelin sheath that covers the nerve fibers and axon in the (CNS) central nervous system and (SC) spinal cord (Compston & Coles, 2008). According to Goodman and Fuller (2015), the primary clinical manifestation of MS is visual deterioration (double vision, nystagmus, etc.) due to the affected optic nerve associated with demyelination of the cerebral cortex. Furthermore, weakness is due to the diminished impulses secondary to the damaged nerve fibers and axons of the spinal cord, sensory and balance deficits