Chapter 3 - The Cardiorespiratory System Flashcards
The cardiorespiratory system
Composed of the respiratory and cardiovascular system
The cardiovascular system
Blood vessels, blood, and the heart
Arteries
Carry blood away from the heart to the rest of the body
Veins
Return blood to the heart from the rest of the body
Stroke volume
The amount of blood pumped out the heart with each contraction
Cardiac output
Heart rate × stroke volume
Sinoatrial (SA) node
The “pacemaker” of the heart because it initiates the heartbeat
Typical heart rate for an adult
70-80 BPM
Atriums
The right atrium receives blood coming from the body while the left atrium receives the blood (oxygen-rich) that comes from the lungs and the heart.
Ventricles
The right ventricle has thinner walls because it only needs to pump blood a short distance back to the heart and the lungs. The left ventricle, on the other hand, has much thicker walls and is a much higher pressure pump because it is required to push blood to the rest of the body.
The 3 functions of blood
- Protection: The white blood cells help to protect your body against diseases and blood clotting helps with fluid loss.
- Regulation: Blood helps keep a stable body temperature, electrolyte, and water level as well as pH.
- Transportation: The primary function of blood is to transport nutrients and oxygen to the cells of the body. It also takes away CO2 and various wastes from the cells and delivers hormones to specific tissues.
The respiratory pump
The thoracic and abdominal structures that help with the contraction and expansion of the lungs.
Muscles used for inhalation
The Scalene muscles, the pack minor, sternocleidomastoid, and the diaphragm
Muscles used for exhalation
The internal intercostals and the abdominal muscles
Cycle of the respiratory pump (venous return)
Inhalation:
- The thoracic cavity expands new
- The pressure within the pleural cavities drop
- This pulls air to the lungs
- It also brings blood into the IVC and the right atrium from the smaller veins that exist in the abdominal cavity
Exhalation:
- The pressure in the pleural cavities rise
- This forces blood into the right atrium
- This is important especially for heavy exercises
Mediastinum
The space in the chest between the lungs that contains all the internal organs of the chest except the lungs
Atrioventricular (AV) node
A small mass of specialized cardiac muscle fibers, located
in the wall of the right atrium of the heart, that receives heartbeat impulses from the sinoatrial node and directs them to the walls of the ventricles.
Blood vessels
Network of hollow tubes that circulates blood throughout the body.
Capillaries
The smallest blood vessels, and the site of exchange of chemicals and water between the blood and the tissues.
Inspiration (inhalation)
The process of actively contracting the inspiratory muscles to move air into the body.
Expiration (exhalation)
The process of actively or passively relaxing the inspiratory muscles to move air out of the body.
Diffusion
The process of getting oxygen from the environment to the tissues of the body
Maximal oxygen consumption (Vo2max)
The highest rate of oxygen transport and utilization achieved at maximal physical exertion
