a pacemaker that initiated each contraction of a heart beat
"Autorhythmic cells: cardiac or smooth muscle fibers that are self-excitable; act as the heart's pacemaker and conduct the pacing impulse through the conduction system of the heart; self-excitable neurons in central nervous system,as in the inspiratory area of the brain stem." -Principles of Anotomy and physiology, TORTORA, DERRICKSON, 11th edition, Wiley & sons, Inc. (c) 2006 by bio. Sci. textbooks, Inc. and Bryan Derrickson
working on my circadian rhythmicity
The heart is the only organ containing cardiac muscle
medulla oblongata, in the brain stem.
Christopher John McCabe has written: 'Genetic aspects of rhythmicity in Drosophila melanogaster'
- rhythmicity : capability of rhythmic self-excitation therefore no need for external control -conductivity: conduction of action potential along specialised muscle cells. -excitability: ability of muscle fibers to get exited . -contractility; ability of cardiac muscle to contract . It also has a long refractory period meaning it cant tetanus
Kenneth Clarke Fisher has written: 'Heart rhythmicity of embryo fish. 1. The effect of temperature on te hear rate of trout embryos'
there is a specific group of cells found in the medula (part of the brain stem) which regulate the rhythm of breathing, hence the name (of this cellular formation) the Medulary Rhythmicity Center.
Respiration occurs in the hindbrain portion of the brain. The hindbrain is made up of the cerebellum, pons, and the medulla oblongata; these three work together to regulate vital functions such as heart rate and breathing.
Autorhythmicity is the tendency for the sinoatrial node of the heart to have a low threshold for depolarization leading to the heart contracting on a regular basis, i.e. in a regular rhythm, without external stimulus from the nervous system.
No individual invented dance, as music and movement date from the earliest modern humans.The significance of dance is related to language, custom, and ritual, and any sort of regular rhythmic sound seems to trigger a sympathetic activity in the human brain and body. Dance may have developed concurrently with sign language as a form of communication.According to an article in Scientific American in 2008, "dance is a fundamental form of human expression that is intertwined with language and music. It is viewed as a marriage of the representational capacity of language and the rhythmicity of music, allowing people to tell stories with their bodies while synchronizing their bodies."Dancing is an ancient art form that cannot be credited to one inventor. The earliest civilizations used dance for rituals and as a form of communication.
The heart is an involuntary muscle.Involuntary muscles are smooth muscles that are not directly controllable at will. Voluntary muscles are controllable like those found in your arms, legs, hands, etc.