What is the connection between alcohol, other drugs, and HIV?
Start studying Health-Relationships. Learn vocabulary, terms, and more with flashcards, games, and other study tools. According to the definition above, the first recognizable social network site . Self -disclosure is a critical step in the development of close relationships (e.g. beings who enjoy interacting and care about our relationships. Nets allow advertisers or organizations to figure out how to connect you to means presenting information (for example on a Web page) based on what you know about a user.
Astrocytes aren't always beneficial: Microglia are immune cells for the brain. After injury, they migrate to the site of injury to help clear away dead and dying cells. They can also produce small molecules called cytokines that trigger cells of the immune system to respond to the injury site. This clean-up process is likely to play an important role in recovery of function following a spinal injury. Oligodendrocytes are glial cells that produce a fatty substance called myelin which wraps around axons in layers.
Axon fibers insulated by myelin can carry electrical messages also called action potentials at a speed of meters per second, while fibers without myelin can only carry messages at a speed of one meter per second.
Synapses and neurotransmission Messages are passed from neuron to neuron through synapses, small gaps between the cells, with the help of chemicals called neurotransmitters.
To transmit an action potential message across a synapse, neurotransmitter molecules are released from one neuron the "pre-synaptic" neuron across the gap to the next neuron the "post-synaptic" neuron. The process continues until the message reaches its destination.
How the spinal cord works
There are millions and millions of connections between neurons within the spinal cord alone. These connections are made during development, using positive neurotrophic factors and negative inhibitory proteins signals to fine-tune them.
- The Difference Between the Internet and World Wide Web
- Parkinson’s Disease and Caregiving
- An Overview of the Pituitary Gland
Amazingly, a single axon can form synapses with as many as 1, other neurons. There is a logical and physical topographical organization to the anatomy of the central nervous system, which is an elaborate web of closely connected neural pathways.
This ordered relationship means that different segmental levels of the cord control different things, and injury to a particular part of the cord will have an impact on neighboring parts of the body.
Paralysis occurs when communication between the brain and spinal cord fails. This can result from injury to neurons in the brain a strokeor in the spinal cord.
Parkinson’s Disease and Caregiving | Family Caregiver Alliance
Trauma to the spinal cord affects only the areas below the level of injury. However, poliomyelitis a viral infection or Lou Gehrig's disease amyotrophic lateral sclerosis, or ALS can affect neurons in the entire spinal cord.
The information pathways Specialized neurons carry messages from the skin, muscles, joints, and internal organs to the spinal cord about pain, temperature, touch, vibration, and proprioception. These messages are then relayed to the brain along one of two pathways: These pathways are in different locations in the spinal cord, so an injury might not affect them in the same way or to the same degree.
Each segment of the spinal cord receives sensory input from a particular region of the body. Scientists have mapped these areas and determined the "receptive" fields for each level of the spinal cord.
Neighboring fields overlap each other, so the lines on the diagram are approximate. Voluntary and involuntary movement Over one million axons travel through the spinal cord, including the longest axons in the central nervous system.
Neurons in the motor cortex, the region of the brain that controls voluntary movement, send their axons through the corticospinal tract to connect with motor neurons in the spinal cord.
The spinal motor neurons project out of the cord to the correct muscles via the ventral root. These connections control conscious movements, such as writing and running.
Information also flows in the opposite direction resulting in involuntary movement. Sensory neurons provide feedback to the brain via the dorsal root. Some of this sensory information is conveyed directly to lower motor neurons before it reaches the brain, resulting in involuntary, or reflex movements. The remaining sensory information travels back to the cortex. How the spinal cord and muscles work together The spinal cord is divided into five sections: No two injuries are alike.
This diagram illustrates the connections between the major skeletal muscle groups and each level of the spinal cord. A similar organization exists for the spinal control of the internal organs.
GH is essential in early years to maintaining a healthy body composition and for growth in children. In adults, it aids healthy bone and muscle mass and affects fat distribution. LH works with FSH to ensure normal functioning of the ovaries and testes.
Prolactin stimulates breast milk production.
President Clinton impeached
TSH stimulates the thyroid gland to produce hormones. The posterior lobe contains the ends of nerve cells coming from the hypothalamus. The hypothalamus sends hormones directly to the posterior lobe via these nerves, and then the pituitary gland releases them. This hormone prompts the kidneys to increase water absorption in the blood. Oxytocin is involved in a variety of processes, such as contracting the uterus during childbirth and stimulating breast milk production.
Diseases and Disorders of the Pituitary Gland Pituitary tumors are the most common pituitary disorder, and many adults have them. People with PD need to pay close attention to the times they take their medications and note the length of time the medication helps their symptoms and how long the medication effects last before wearing off.
This information helps the physician better determine the amount of medication and the schedule for its use. Side Effects As with all medications, side effects can be a problem. For some, starting Sinemet may cause dizziness or nausea. For other medications, side effects may appear after several years.
Sometimes these hallucinations can be frightening. There is a well-described side effect from dopamine agonists that everyone who starts this class of medication should know about. Agonists and higher doses of Sinemet may cause impulse control behavioral problems. These behaviors vary, but may include: Often reducing or stopping this class of medications stops the behavior.
These behaviors can be so embarrassing for the care recipient and their family that too often the topic is avoided when talking with the doctor. Odd as it may feel, keeping track of unusual impulse behavior to report to the neurologist can provide critical medical management information. Sometimes, in the most advanced stages, a choice has to be made between motor function and cognitive function.
High doses of medications may be required to manage the motor symptoms, but these same doses cause hallucinations or paranoia.
How the spinal cord works - Living with Paralysis - Reeve Foundation
The DBS system consists of leads precisely inserted into a specific brain target, the neurostimulator pacemaker implanted in the chest, and extension wires that connect the leads to the neurostimulator. Though implantation of the system DBS surgery requires a neurosurgical procedure, the treatment itself consists of long-term electrical stimulation.
Advantages of DBS include its ability to reduce the high doses of medications avoiding the systemic side effects of medicationits adjustability stimulation settings are programmed non-invasively using a wireless programmer by the clinician or a patient programmerand its reversibility can turn it on or off. The best candidates who have the most robust response to DBS tend to be younger than 70 years of age, with few center of the body symptoms such as swallowing and balance problems.