Nervous and Sensory systems Flashcards
Peripheral nervous system
The peripheral nervous system consists of the nerves that branch out from the brain and spinal cord. These nerves form the communication network between the CNS and the body parts. The peripheral nervous system is further subdivided into the somatic nervous system and the autonomic nervous system.
Somantic nervous system
The somatic nervous system is the voluntary nervous system. Meaning you choose when to activate electrical impulses in this part of the nervous system. This part of the neural pathway controls mainly voluntary muscle movements (skeletal muscles) but also some involuntary muscle responses (reflexes).
The somatic nervous system and autonomic nervous system work in tandem. For example, when you urinate, the autonomic nervous system causes smooth muscle contraction to enable urine to leave the bladder, but some somatic (voluntary) movement is needed to urinate.
Autonomic nervous system
Works automatically (Autonomously). Is a component of the peripheral nervous system that regulates involuntary physiologic processes including heart rate, blood pressure, respiration, digestion, and sexual arousal.
Sympathetic nervous system
(senses danger/stress and causes physiological changes in response)
Best known for its role in responding to dangerous or stressful situations. In these situations, your sympathetic nervous system activates to speed up your heart rate, deliver more blood to areas of your body that need more oxygen or other responses to help your get out of danger.
Parasympathetic nervous system
Responsible for the body’s rest and digestion response when the body is relaxed, resting, or feeding. It basically undoes the work of sympathetic division after a stressful situation. The parasympathetic nervous system decreases respiration and heart rate and increases digestion.
Sensory system
The sensory system is the portion of the nervous system responsible for processing input from the environment.
- Visual - Pertaining to the sense of sight
- Auditory - Pertaining to the sense of hearing
- Somatosensory - Pertaining to the sense of touch
- Olfactory - Pertaining to the sense of smell
- Gustatory - Pertaining to the sense of taste
The Nervous System
Is spread through all areas of the body. It may be divided into the central nervous system (the brain and spinal cord) and the peripheral nervous system (the nerves running to and from the central nervous system. The central nervous system is the processing centre while the peripheral nervous system is the collecting and distribution centre.
Aphasia
Total or partial loss of the ability to use and understand language; usually caused by brain disease, stroke or injury
Apraxia
Inability to execute voluntary movement although muscle function is normal.
Vertigo
Illusion of movement i.e. a sensation as if the external world were revolving around an individual (objective vertigo) or as if the individual were revolving in space (subjective vertigo). This can occur with middle ear infections also.
Congenital Analgia
A rare condition present at birth where a person has no sense of pain. People with this condition can still sense pressure and touch, and sometimes temperature, but not always.
Referred Pain
Refers to pain felt in a region of the body distant to the actual site of injury. For example, an abdominal haemorrhage, such as with spleen/liver injuries in motor vehicle accidents, or with ectopic pregnancy often results in severe pain in the shoulder blade.
Alzheimers Disease
Also know as Alzheimers dementia, is an irreversible brain disorder where the mental capacity deteriorates. Alzheimers causes confusion and memory loss and can lead to an inability to carry out day to day tasks.
Bell’s Palsy
An unexplained episode of facial muscle weakness or paralysis. It begins suddenly and worsens over 48 hours. This condition results from damage to the facial nerve (the 7th cranial nerve). Pain and discomfort usually occur on one side of the face or head. Most people with Bell’s palsy recover fully — with or without treatment.
Brain Cancer
Brain cancers may grow quickly. The cancer cells can invade and destroy the brain tissue.
Brain Tumour
A cancerous or non-cancerous mass or growth of abnormal cells in the brain.
Tumours can start in the brain, or cancer elsewhere in the body can spread to the brain.
Symptoms include new or increasingly strong headaches, blurred vision, loss of balance, confusion and seizures. In some cases, there may be no symptoms.
Treatments include surgery, radiation and chemotherapy.
Epilepsy
A disorder in which nerve cell activity in the brain is disturbed, causing seizures.
Epilepsy may occur as a result of a genetic disorder or an acquired brain injury, such as a trauma or stroke.
During a seizure, a person experiences abnormal behaviour, symptoms and sensations, sometimes including loss of consciousness. There are few symptoms between seizures.
Epilepsy is usually treated by medication and in some cases by surgery, devices or dietary changes.
Guillain-Barre Syndrome
A condition in which the immune system attacks the nerves.
The condition may be triggered by an acute bacterial or viral infection such as campylobacter, a type of bacteria often found in undercooked poultry.
Symptoms start as weakness and tingling in the feet and legs that spread to the upper body. Paralysis can occur.
Special blood treatments (plasma exchange and immunoglobulin therapy) can relieve symptoms. Physiotherapy is required.
Headache
A painful sensation in any part of the head, ranging from sharp to dull, that may occur with other symptoms.
Headaches can have causes that aren’t due to underlying disease. Examples include lack of sleep, an incorrect eyeglass prescription, stress, loud noise exposure or tight head wear.
Migraine
A migraine is a headache that can cause severe throbbing pain or a pulsing sensation, usually on one side of the head. It’s often accompanied by nausea, vomiting, and extreme sensitivity to light and sound.
