Heartbeat, Electrical Signals, & Blood Vessels Flashcards
If all of the nervous system connections are severed, what happens to the cardiac muscle?
The cardiac muscle will continue to contract spontaneously and independently
What are the 2 systems that act to regulate the heart activity? (2)
- Nerves of the autonomic nervous system
2. Intrinsic conduction system = nodal system
What is the purpose of the intrinsic conduction system specifically?
Sends electrical impulses from the nerves that stimulate the myocardium of the heart chambers → rate and regulation of the heartbeat
List the 2 nodes in the intrinsic conduction system and briefly describe their purposes. (2)
- Sinoatrial node (SA node) → pacemaker of the heart = establishes rhythm and rate of heartbeat
- Atrioventricular node (AV node) → allows the ventricles by pausing them when blood is being pumped into them
What causes the ventricles of the heart to contract?
Purkinje fibers
List the 3 major types of blood vessels.(3)
- Arteries
- Veins
- Capillaries
Define: arteries
Large blood vessels that carry blood away from the heart to all areas of the body
Define: veins
Low pressure collecting system to return deoxygenated blood to the heart
Define: capillaries
Smallest blood vessel in the body
Define: arterioles
Smaller, thinner branches of arteries that carry blood to the capillaries
What is the difference between the carotid artery and the coronary artery? (2)
- Carotid arteries are major arteries that carry blood to the head
- Coronary artery supplies the heart muscle with oxygen
How are veins physically different from arteries? (2)
Walls are thinner and less elastic than arteries
Define: venules
Smallest veins that join to form larger veins
What do the valves for veins do for the blood?
Enables blood to flow only towards the heart and prevents it from flowing away from the heart
What are the 2 largest veins in the body? (2)
- Superior vena cava
2. Inferior vena cava
