A specialized group of cardiac muscle cells in the right atrium that normally control the rate of the heart beat.
A collection of specialized cardiac muscle fibers found at the junction of the right atrium and the vena cava; the heart's natural pacemaker, generating the electrical discharges that stimulate the beating and pumping of the heart.
a compact mass of cardiac muscle fibers (cells) that are specialized for conduction & located in the right atrium beneath the opening of the superior vena cava; also called the sinuatrial node or pacemaker
The natural pacemaker of the heart; also called the sinus node. The SA node is a group of specialized cells in the top of the right atrium which produces the electrical impulses that travel down to eventually reach the ventricular muscle, causing the heart to contract.
(sigh´ no ay´ tree al) • The pacemaker of the mammalian heart.
A specialized cluster of cells in the heart that initiates the heart beat. Known as the heart's natural pacemaker.
Called the natural pacemaker of the heart. A small bundle of special muscle fibers within the right atrium of the heart that send out electrical impulses at regular intervals to cause contraction of the heart.
(SA) The heart's rhythmic center. It is a tiny patch of tissue in the heart's back wall near the top of its right atrium that is the center of the "cardiac conduction system". It functions as the heart's own internal pacemaker and is central to the complex "nervous system" of the heart.
a specialized bit of heart tissue that controls the heartbeat
The sinoatrial node (SA node) is called the "pacemaker" of the heart. It is a microscopic area of cardiac muscle located in the heart. Is is connected to the autonomic nervous system and acts to speed up or slow down the heart rate when necessary.
(sin'-o-A-tree-awl nod) ( SA node) A cluster of specialized cardiac muscle cells in the wall of the right atrium that initiate each cardiac cycle. Also called the sinuatrial node, or pacemaker.
The normal "pacemaker" for the heart is an area of specialized cells in the atrium called the sinoatrial or "SA" node. These cells automatically send out an electrical impulse to the rest of the heart telling it to contract.
The heart "pacemaker" a group of modified cardiac muscle cells wich defines the rate of contraction of all other cardiac muscle by virtue of a faster contractile rhythm. Located near the entrance of the superoir vena cava.
The heartâ€(tm)s natural pacemaker located in the right atrium. Electrical impulses originate here and travel through the heart, causing it to beat.
A small mass of tissue located in the Atria that serves as the initial focus of activation during a normal Cardiac Cycle.
A region of modiÞed muscle cells in the right atrium that sends timed impulses to the heart's other muscle cells, causing them to contract; the heart's pacemaker. PICTURE
The small area in the right atrium that starts the electrical impulse that is transmitted through the heart, causing it to beat. The SA node is often called the natural pacemaker of the heart. See larger view
A group of cells located in the right atrium that sends out electrical signals which make the heart pump. The SA node is the heart's natural pacemaker. These signals travel from the SA node, through the atrioventricular (AV) node, and then to the rest of the heart. The SA node also responds to the need for a faster heart rate. If a person is exercising or excited, the body will require greater blood circulation. A healthy SA node responds to these changes in the body and increases the heart rate accordingly.
The natural pacemaker of the heart; situated in the wall of the right atrium.
The pea-sized cluster of special-duty cells at the right atrium that generates the tiny jolts of electricity that ripple through the heart muscle to initiate each cardiac cycle
The normal pacemaker tissue that generates electrical impulses traveling to and causing atria and ventricles to contract
A group of cells located high and posterior in the right atrium at the point where the superior vena cava joins the atrial tissue mass which acts as the natural pacemaker in the healthy heart. The healthy sinoatrial node initiates 60 to 100 beats per minute at rest. Abbreviated SA node.
the region of the heart that produces an electrical signal that causes the heart to contract
Specialized heart muscle that serves as an pacemaker for the heart. The sinoatrial node sends one electrical signal telling the atrium to contract and another signal to the AV node for relay to the ventricles.
The sinoatrial node (abbreviated SA node or SAN, also called the sinus node) is the impulse generating (pacemaker) tissue located in the right atrium of the heart. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava. These cells are modified cardiac myocytes.