Cardiovascular Overview -
- Distribution of O2 and Nutrients
-Delivers oxygen (O2) and
essential nutrients, such as glucose, amino
acids, and fatty acids, to cells throughout
the body. Oxygen is crucial for cellular
respiration, the process by which cells
produce energy. Nutrients are necessary
for various cellular functions, including
growth, repair, and energy production.
The circulatory system achieves this
distribution through the bloodstream,
facilitated by the pumping action of the
heart and the branching network of blood
vessels (arteries, capillaries, and veins).
- Transportation of CO2 and Metabolic
Waste Products
- Transports metabolic waste
products, such as carbon dioxide (CO2),
away from cells. Cells produce CO2 as a
byproduct of cellular respiration. Other
metabolic waste products, such as urea
and lactic acid, are also carried away by
the bloodstream. Said waste products are
then eliminated from the body through
processes like breathing, urination, and sweating.
- Distribution of Water, Electrolytes, and Hormones
- The circulatory system maintains fluid balance within the body by distributing
water and electrolytes (ions like sodium, potassium, and chloride) to cells and
tissues.
- Hormones, which are chemical messengers produced by various glands, are also
transported through the bloodstream to target organs and tissues. Hormones
regulate a wide range of physiological processes, including metabolism, growth,
reproduction, and stress response.
- Thermoregulation
- The body's ability to maintain a stable internal temperature. When the body
becomes too hot, blood vessels near the skin surface dilate (vasodilation), allowing more
blood to flow closer to the skin's surface. This helps dissipate heat from the body through
radiation and convection.
-When the body is cold, blood vessels near the skin surface constrict
(vasoconstriction), reducing blood flow to the skin and conserving heat.
, - Blood circulation helps distribute heat generated by metabolic processes
throughout the body.
- Immune System Infrastructure
- The immune system defends the body against pathogens (e.g., bacteria, viruses,
and fungi) and foreign substances.
- White blood cells, or leukocytes, are carried by the bloodstream to sites of
infection or inflammation, where they help identify and neutralize pathogens.
- The lymphatic system (closely associated with the circulatory system), plays a
key role in immune function by transporting lymph fluid containing immune cells
and pathogens to lymph
nodes, where they are
filtered and destroyed.
, Cardiac Cycle
•The heart as a pump works in a cycle (heartbeat):
–first relaxing and filling with blood and then contracting and ejecting blood
•Basically four major events
1. Atrial systole
- After SA node firing
and P-wave; blood is ejected into
ventricles
2. Ventricular systole
- Initiated by ventricular
depolarization (QRS);
- blood is ejected from
ventricles; ventricles do
not empty completely
3. Atrial diastole
–when atria relax and refill
4. Ventricular diastole
- Period when the ventricles relax
and refill (T-wave to QRS)
Duration of cardiac cycle
-The total duration of the
cardiac cycle, including systole and
diastole, is the reciprocal of the heart
rate.
-For example, if heart rate is 72 beats/min, the duration of the cardiac cycle is 1 min/72
beats, about 0.0139 minutes per beat, or 0.833 seconds per beat.
Definitions
•End-diastolic volume – Volume of blood in ventricles at the end of each diastole.
•End-systolic volume - Volume remaining in each ventricle after each systole.
•Stroke volume - Volume ejected from one ventricle in one heartbeat
- Distribution of O2 and Nutrients
-Delivers oxygen (O2) and
essential nutrients, such as glucose, amino
acids, and fatty acids, to cells throughout
the body. Oxygen is crucial for cellular
respiration, the process by which cells
produce energy. Nutrients are necessary
for various cellular functions, including
growth, repair, and energy production.
The circulatory system achieves this
distribution through the bloodstream,
facilitated by the pumping action of the
heart and the branching network of blood
vessels (arteries, capillaries, and veins).
- Transportation of CO2 and Metabolic
Waste Products
- Transports metabolic waste
products, such as carbon dioxide (CO2),
away from cells. Cells produce CO2 as a
byproduct of cellular respiration. Other
metabolic waste products, such as urea
and lactic acid, are also carried away by
the bloodstream. Said waste products are
then eliminated from the body through
processes like breathing, urination, and sweating.
- Distribution of Water, Electrolytes, and Hormones
- The circulatory system maintains fluid balance within the body by distributing
water and electrolytes (ions like sodium, potassium, and chloride) to cells and
tissues.
- Hormones, which are chemical messengers produced by various glands, are also
transported through the bloodstream to target organs and tissues. Hormones
regulate a wide range of physiological processes, including metabolism, growth,
reproduction, and stress response.
- Thermoregulation
- The body's ability to maintain a stable internal temperature. When the body
becomes too hot, blood vessels near the skin surface dilate (vasodilation), allowing more
blood to flow closer to the skin's surface. This helps dissipate heat from the body through
radiation and convection.
-When the body is cold, blood vessels near the skin surface constrict
(vasoconstriction), reducing blood flow to the skin and conserving heat.
, - Blood circulation helps distribute heat generated by metabolic processes
throughout the body.
- Immune System Infrastructure
- The immune system defends the body against pathogens (e.g., bacteria, viruses,
and fungi) and foreign substances.
- White blood cells, or leukocytes, are carried by the bloodstream to sites of
infection or inflammation, where they help identify and neutralize pathogens.
- The lymphatic system (closely associated with the circulatory system), plays a
key role in immune function by transporting lymph fluid containing immune cells
and pathogens to lymph
nodes, where they are
filtered and destroyed.
, Cardiac Cycle
•The heart as a pump works in a cycle (heartbeat):
–first relaxing and filling with blood and then contracting and ejecting blood
•Basically four major events
1. Atrial systole
- After SA node firing
and P-wave; blood is ejected into
ventricles
2. Ventricular systole
- Initiated by ventricular
depolarization (QRS);
- blood is ejected from
ventricles; ventricles do
not empty completely
3. Atrial diastole
–when atria relax and refill
4. Ventricular diastole
- Period when the ventricles relax
and refill (T-wave to QRS)
Duration of cardiac cycle
-The total duration of the
cardiac cycle, including systole and
diastole, is the reciprocal of the heart
rate.
-For example, if heart rate is 72 beats/min, the duration of the cardiac cycle is 1 min/72
beats, about 0.0139 minutes per beat, or 0.833 seconds per beat.
Definitions
•End-diastolic volume – Volume of blood in ventricles at the end of each diastole.
•End-systolic volume - Volume remaining in each ventricle after each systole.
•Stroke volume - Volume ejected from one ventricle in one heartbeat
