What does increased automaticity mean?
The automaticity in the sinoatrial node increases during physical exercise. The increased automaticity is a normal reaction since the cardiac output must increase during exercise. This is an example of normal (physiological) increase in automaticity.
What neurological conditions cause headaches?
Headache disorders, characterised by recurrent headache, are the most common disorders of the nervous system. Due to their prevalence, they are responsible for almost three quarters of all neurological-related disability. Primary headache disorders include migraine, tension-type headache and cluster headache.
What causes automaticity?
Automaticity is the property of cardiac cells to generate spontaneous action potentials. Spontaneous activity is the result of diastolic depolarization caused by a net inward current during phase 4 of the action potential, which progressively brings the membrane potential to threshold.
What is early Afterdepolarization?
Abstract. Early afterdepolarizations (EADs) are secondary voltage depolarizations during the repolarizing phase of the action potential, which can cause lethal cardiac arrhythmias.
What factors can cause enhanced automaticity?
Enhanced automaticity can also occur in the AV node, under conditions of acute myocardial infarction, digitalis toxicity, isoprenaline administration, and recent cardiac surgery.
What disease can cause headaches?
Conditions that might cause nonprimary chronic daily headaches include:
- Inflammation or other problems with the blood vessels in and around the brain, including stroke.
- Infections, such as meningitis.
- Intracranial pressure that’s either too high or too low.
- Brain tumor.
- Traumatic brain injury.
What does a hypertension headache feel like?
Hypertension headaches A hypertension headache will usually occur on both sides of your head and is typically worse with any activity. It often has a pulsating quality. You may also experience changes in vision, numbness or tingling, nosebleeds, chest pain, or shortness of breath.
Where are ectopic foci located?
SA node
Ectopic foci are abnormal pacemaker sites within the heart (outside of the SA node) that display automaticity. Their pacemaker activity, however, is normally suppressed (overdrive suppression) by the higher rate of the SA node. They can occur within the atria or ventricles.
What is ERP heart?
In electrocardiography, during a cardiac cycle, once an action potential is initiated, there is a period of time that a new action potential cannot be initiated. This is termed the effective refractory period (ERP) of the tissue.
What is triggered automaticity?
au·to·ma·ti·ci·ty. (awtō-mă-tisi-tē) A property of myocardial cells by which they intrinsically depolarize and initiate an action potential.
What causes a secondary headache in the head?
A secondary headache is a symptom of a disease that can activate the pain-sensitive nerves of the head. Any number of conditions — varying greatly in severity — may cause secondary headaches. Possible causes of secondary headaches include: Acute sinusitis (sinus infection) Arterial tears (carotid or vertebral dissections)
What causes headaches according to the Mayo Clinic?
Some primary headaches can be triggered by lifestyle factors, including: 1 Alcohol, particularly red wine 2 Certain foods, such as processed meats that contain nitrates 3 Changes in sleep or lack of sleep 4 Poor posture 5 Skipped meals 6 Stress More
Why do I keep getting headaches and migraines?
Types and causes of headaches. Many of those triggers for tension headaches—especially stress, hunger, fatigue, and lack of sleep—can also set off a migraine headache. But nailing down causes of headaches in the migraine category is a little trickier; the headaches may stem from many factors, or combinations of factors.
What causes a recurrence of a chronic headache?
The Overuse of Medication Ironically, taking medication for chronic headaches can actually cause the recurrence of them. This type of headache is known as a rebound headache and is most often caused by taking certain medications daily to relieve headaches and then stopping them abruptly.