Ch3 The Cardiorespiratory System Flashcards
Cardiovascular System
Composed of the heart, blood and blood vessels hat transport blood from the heart to the tissues of the body
Cardio Respiratory system
A system of the body composed of the cardiovascular and respiratory systems
The Heart
A muscular pump that rhythmically contracts to push the blood throughout the body.
Located in the mediastinum, weighs 300g (10 ounces) size of an adult fist. “Cardiac muscle”
Cardiac muscle contraction
Cardiac muscle fibers are shorter and connected by intercalated discs. Intercalated discs create an electrical connection between cells that allow the heart to contract as one unit.
Structure of heart
Has four chambers, separated right and left. Each side has 1 atria and 1 ventricle. The atria’s sit on top of their respect ventricles.
Sinoatrial (SA) Node
“Pacemaker” a specialized area of cardiac tissue located in the right atrium of the heart which intiates the electrical impulses that determine e heart rate
Atrioventricular (AV) node
A small mass of specialized cardiac muscle fibers located in the wall of the right atrium of the heart hat relieves heartbeat impulses from the Sinoatrial node and directs them to the walls of the ventricles
Function of the heart
Blood high in CO2 from the body gets pumped into right side “pulmonic side” of the heart, atrium-ventricle-pushed into lungs so blood can be oxygenated, the blood than returns into left side of heart via left atrium-left ventricle to be pumped into entire body
Atria
Smaller, superior chambers of the heart that receives blood from veins, acts as “reservoirs” gathers blood
Ventricle
Larger inferior chambers of the heart receives blood from atrium and forces blood into arteries.
Right ventricle has thin walls and pumps under low pressure, pumps blood a short distance to lungs
Left ventricle has thicker walls and pumps under high pressure, it pumps blood out to entire body
Stroke volume (SV)
Is amount of blood pumped out of the heart with each contraction
About: 70 mL
End-diastolic volume (EDV)
Is the amount of blood filled in the ventricle of the heart before contraction
About: 120 mL
End-Systolic volume (ESV)
Is what’s left of blood volume within the ventricle of the heart after contraction
About: 50 mL
Heart Rate (HR)
The rate at which the heart pumps.
Resting heart rate is 70-80 bpm
Cardiac output (Q)
Volume of blood pumped out by the heart PER MINUTE
Function of heart rate and stroke volume
70 bpm X 70 mL = 4,900 mL/min or 4.9 mL/min
Blood
Sustaining fluid that supplies organs and cells with oxygen and nutrients, helps regulate body temp, fight infection, and remove waste products
3 types white, red, platelets
Support mechanism that transports, regulate, and protect
Support mechanisms of blood
Transport: oxygen, nutrients to tissue, waste products from tissue, hormones to organs and tissue, carries heat throughout body
Regulates: body temp and acid balance (PH levels)
Protection: body from excessive bleeding and clotting, contain specialized cells to help fight disease and sickness
Blood vessels
Network of hollow tubes that circulate blood throughout body
3 types: arteries, capillaries, veins
Arteries
Carry blood away from the heart, include aorta and carotid artery, subclavian artery, mesentric arteries, renal artery and iliac artery
Veins
Carry blood back to the heart
Venules
Vessels that collect blood from capillaries
Progressively merge with other venules to form veins
Arterioles
Smaller arteries branched from medium arteries that eventually turn into capillaries
Capillaries
Site of exchange of water and chemicals between blood and tissue,
Also oxygen, nutrients, hormones, and waste products are exchanged between tissue
Respiratory system
“Pulmonary system”
System of organs the lungs and respiratory passageways that collect oxygen from external environment and transports it to the bloodstream as well as remove carbon dioxide CO2 from body and lungs to outside air. Works closely with cardiovascular system
Respiratory pump
Process of moving air in and out of body. Composed of skeletal structures(bones) and soft tissue(muscles) that work together to allow proper respiratory mechanics to occur to help pump blood back to the heart during inspiration.
Inspiration
“Inhalation” process of actively contracting the inspiration muscles ( diaphragm, external intercostals, scalenes, sternocleidomastoid, pectoralis minor) to move air into the body
During inhalation intrathoracic pressure decreases causes a drop in pressure in right atrium to allow better flow back to the heart
Expiration
The process of actively and passively relaxing the inspiration muscles to move air out of he body.
During heavy breathing”actively” relies on expiratory muscles to compress the thoracic cavity and force air out
Conducting airways
Nasal cavity, oral cavity, pharynx, larynx, trachea, right and left pulmonary bronchi, bronchioles, gather air and oxygen to be purified, humidified, warmed or cooled before entering internal body
Respiratory airways
Internal intercostals, abdominals
Collect air from conducting airways
Diffusion
Process of getting oxygen from environment to tissue of the body.
End of bronchioles sit alveoli, which are made up of alveolar sacs - in the sacs are gases, oxygen and carbon dioxide are transported in and out of the blood stream
Maximal oxygen consumption (Vo2max)
Highest rate of oxygen transport and utilization achieved at maximal physical exertion
To measure use YMCA 3 step test, Rockport walk test to get maximal oxygen consumption
