Fitness Theory Chap 6: Cardiorespiratory System Physiology Flashcards
What are the three components of the cardiorespiratory system?
the heart, the lungs, and the blood vessels
Name the three types of blood vessels
arteries, veins, and capillaries
What are the significant functions of the cardiorespiratory system?
- transport oxygen and other nutrients to the cells of the body
- transport carbon dioxide and other by-products away from the cells to the lungs
- regulate body temperature (thermoregulation)
- regulate the levels of fluid in the body cells and blood (important for efficient function)
- exchange oxygen and carbon dioxide at the lungs and at the tissue sites (alveoli and muscle cell)
What causes a heart murmur?
when the valves do not completely close between beats there is a mixing or ‘back flow’ of blood
What is pulmonary circulation?
the circulation of blood between your heart and lungs
process: blood is pumped from the RV through the pulmonary semilunar valve to the lungs by way of pulmonary arteries. In the lungs, exchange of oxygen and carbon dioxide takes place, and the blood, now rich in oxygen, flows back to the LA through the pulmonary veins
What is systemic circulation?
the circulation of blood between the heart and the rest of the body
process: blood that has returned to the LA flows into the LV through the left AV valve, and is then pumped out through the aortic semilunar valve into the aorta. From the aorta, blood continues into the arteries and finally into the capillaries
What are capillaries?
thin-walled blood vessels in active tissue that allow oxygen and carbon dioxide to flow in and out very easily (capillaries surround the alveoli and receive oxygen from the alveoli and deliver it into the red blood cells)
What are arteries?
thick-walled, and carry richly oxygenated blood away from the heart
What are veins?
thin-walled, have one-way valves, and carry poorly oxygenated blood back to the heart
Explain cardiac output (Q)
the amount of blood pumped out by each side of the heart in one minute. Cardiac output is a combination of heart rate (HR) and stroke volume (SV)
Define heart rate (HR)
the number of beats per minute
Define stroke volume (SV)
the volume of blood pumped by the ventricle each beat (average stroke volume for a male is 70-75 ml of blood per beat and females about 65-70 ml/beat)
Define blood pressure
the pressure exerted by blood against the walls of the large arteries in the systemic circulation system
What is the normal blood pressure range?
110-120/70-80 mm Hg
What is systolic pressure?
the pressure in the arteries when the heart is contracting and forcing blood out
What is diastolic pressure?
the pressure in the arteries when the heart is in between beats and filling up with blood
List some factors that affect blood pressure
- narrowing of the arteries (e.g. from plaque or stress)
- increased thickness of the blood (e.g. from dehydration)
- body position (e.g. declined position as when performing a bench press)
- age
- kidney function ( by allowing more or less water to leave the body through urine, the volume of blood and blood pressure can change)
- excessive salt in the diet
What is hypotension?
defined as low blood pressure when ‘systolic’ is less than 100 mm Hg
What is hypertension?
defined as high blood pressure when readings are 140/90 (borderline hypertension) or greater
What is venous pooling?
veins do not have smooth muscle and as a result, cannot assist in maintaining blood pressure or in returning blood to the heart. Therefore, if someone stands for a long period of time or sits down right after exercise, the blood can pool in the veins of the lower body. This can decrease the blood returning to the heart and cause blood pressure to drop
What are the components of the respiratory system?
- nose
- pharynx (throat)
- trachea (wind pipe)
- bronchi (conducting tubes of oxygen)
- lungs and alveoli (sites of exchange of oxygen and carbon dioxide)
Explain pulmonary ventilation
air from the environment moves into the nose and mouth and travels into the pharynx, trachea and bronchi where it is warmed, cleaned and moistened
Explain external respiration
oxygen in the lungs diffuses into the blood and carbon dioxide (a waste product of cell activity) in the blood moves into the lungs where it can be exhaled. The alveoli are the sites of external respiration
What are alveoli?
grape-like clusters of elastic hollow sacs. They represent the last stop for air coming into the lungs before oxygen moves into the blood