Cardiovascular system Flashcards
Circulation of blood through heart
Deoxygenated blood in right atrium (via tricuspid valve) ➞ right ventricle (via pulmonic semi-lunar valve) ➞ pulmonary artery ➞ lungs, picks up oxygen (via capillaries) ➞ pulmonary vein ➞ left atrium (via bicuspid valve) ➞ left ventricle (via aortic semi-lunar valve) ➞ aorta ➞ tissues, loses oxygen in respiration (via capillaries) ➞ inferior/superior vena cava ➞ right atrium.
right side of heart (left hand side on image)
. blood returning from body to heart
. arrives through veins (veINs transport deoxygenated blood IN to heart)
. deoxygenated
. pumped to lungs
Left side of heart (right side on image)
. receiving blood back from lungs
. oxygenated as been to lungs
. pumped to body via arteries ( a = away)
. walls (esp ventricle) lot thicker
Vena Cava
Transports deoxygenated blood from the body to the right Atrium
. superior vena cava- brings blood from above heart
. inferior vena cava- brings blood from below heart
Right Atrium
Top chamber of the heart that holds deoxygenated blood
Tricuspid Valve
Stops the blood flowing back into the right atrium and into right ventricle
Right Ventricle
Bottom chamber that holds deoxygenated blood
Semi-Lunar Valve
Stops the blood flowing back into the right ventricle
Pulmonary Artery
Transports deoxygenated blood from the heart to the lungs
is the only artery to transport deoxygenated blood
Pulmonary Vein
Transports oxygenated blood from the lungs to the heart
only vein to transport oxygenated blood
Left Atrium
Top chamber of the heart that holds oxygenated blood
Bicuspid Valve
Stops the blood flowing back into the left atrium
Left Ventricle
Bottom chamber that holds oxygenated blood
Semi-lunar Valve
Stops the blood flowing back into the left ventricle
Aorta
Transports oxygenated blood to the rest of the body
high blood pressure and is largest artery in body
is very elastic
Septum
A wall that separates the left from the right side of the heart
Coronary Artery
Arteries that supply blood to the heart
Arteries
. Carry blood away from the heart to the tissues of the body
. Have thick muscular walls
. Have elastic walls
. Contain blood under high pressure
. Usually contain oxygenated blood (except pulmonary artery)
. Do not contain valves
veins
. first venules which are thicker then veins
. Carry blood towards the heart from the tissues of the body
. Thin and less muscular walls
. Less elastic walls
. Contain blood under low pressure
. Usually contain deoxygenated blood (except pulmonary vein)
. Contains valves
Arterioles
. connect arteries to capillaries.
. They are similar to arteries but have thinner walls
. they can change diameter to control the blood to the capillaries.
. Venules connect capillaries to veins.
Capillaries
. 1 cell thick and allow the diffusion of gases
. they surround muscles and the alveoli to allow the exchange of oxygen and carbon dioxide
Red blood cells
. The function = to carry oxygen.
. Oxygen is carried by a protein called haemoglobin
. The red blood cells are disc shaped = a large surface area.
. A drop of blood contains millions of red blood cells
Plasma
. Is the transport system that carries the other components of the blood (& carbon dioxide)
. It is a straw-coloured liquid that is 90% water
White blood cells
. White blood cells protect the body by fighting infections.
. White blood cells identify, destroy and remove pathogens such as bacteria or viruses.
. They originate in bone marrow but are stored in the blood
Platelets
. Platelets prevent blood loss.
. If you are cut platelets will gather and stick together plugging the site of the injury stopping blood loss
Functions of the cardiovascular system: Delivering Oxygen and Nutrients
. The cardiovascular system delivers nutrients and oxygen to the tissues of the body.
. During exercise the demand for oxygen increases the blood will deliver this oxygen
Functions of the cardiovascular system; Removing Waste Products (carbon dioxide & Lactate)
. As well as providing oxygen to the working muscles, the cardiovascular system transports waste products to the kidneys and the liver.
. It also returns carbon dioxide to the lungs.
. During exercise lactate and carbon dioxide increases
Functions of the cardiovascular system: Thermoregulation
. The cardiovascular system is responsible for the distribution of heat within your body.
. This maintains your body temperature and ensures you don’t overheat.
. The cardiovascular system uses vasodilation and vasoconstriction to thermoregulate
Functions of the cardiovascular system: Fighting Infection
. White blood cells are produced in the bone marrow and stored in the blood.
. They ingest pathogens and destroy them.
. They also produce antibodies that destroy pathogens
Functions of the cardiovascular system: Clotting of Blood
. Platelets in the blood gather together at a cut and stick together they plug the wound and stop bleeding
Vasoconstriction (nervous control of cardiac cycle- Thermoregulation)
Vasoconstriction narrows the diameter of the blood vessels near the skin.
This reduces the blood flow resulting in an increase in temperature as heat loss is prevented
Vasodilation (nervous control of cardiac cycle- Thermoregulation)
Vasodilation widens the diameter of the blood vessels near the skin
This increases the blood blow resulting in a decrease in temperature as heat is carried to the skin surface
Sinoatrial Node (SAN)
. often called the hearts pacemaker.
. The SAN sends an impulse to the right atrium causing the muscular walls to contract. . The contraction forces blood from the atrium down into the ventricles
Atrioventricular Node (AVN)
. The atrioventricular node (AVN) is located between the atria and the ventricles.
. It acts as a buffer that slows down the signal from the SAN. (otherwise the atria and ventricles would contract at the same time) The slight pause allows the ventricles to fill with blood before contraction
Bundle of His & Purkinje Fibres
. The bundle of his is a specialist muscle cell that transports the impulses from the AVN.
. They are found in the walls of the ventricles.
. The impulse travels down the bundle of his to the purkinje fibres that allow the ventricles to contract causing the blood to be pushed out of the heart
. Both have large SA for this.
heart beat
atrial diastole + atrial systole = 0.5 secs
ventricle diastole + atrial systole = 0.3 secs
At exercise, atrial both speeds up as more blood into the atrium from vessels. (Increase in venous return)
Effects of the sympathetic and parasympathetic nervous system
. During exercise the heart rate increases this is controlled by the sympathetic nervous system that speeds up the heart
. After exercise the heart slows down this is controlled by the parasympathetic nervous system
Responses of the cardiovascular system to a single sport or exercise session: Anticipatory rise in heart rate prior to exercise
. You may feel your heart rate increase prior to a sports match or event due to the release of adrenalin, this is known as an anticipatory rise.
. It is preparing your body for the increased demands that are about to be put on their body
Responses of the cardiovascular system to a single sport or exercise session: Increased heart rate
. Heart rate increases due to the rise in carbon dioxide picked up by the chemoreceptors. . An increase in heart rate is needed due to the increase in demand for oxygen to working muscles. Therefore we increase HR so muscles are not tired.
Responses of the cardiovascular system to a single sport or exercise session: Increased cardiac output
. Cardiac Output = Stroke Volume X Heart Rate
. Stroke volume = amount of blood ejected from the heart per beat
. Heart rate = how many times the heart beats per minute
. Cardiac Output = amount of blood pumped from the heart in one minute
. When we exercise the demand for oxygen increases, therefore heart rate, stroke volume and cardiac output increases (venus return)
Responses of the cardiovascular system to a single sport or exercise session: blood pressure
. controlled by vasomotor
. Blood pressure increases during exercise as more blood is pumped through the blood vessels
. Blood pressure = the pressure of the blood against the walls of your arteries
. Blood pressure has two readings 𝟏𝟐𝟎/ 𝟖𝟎
. Systolic = top number, the pressure on your artery wall when the heart contracts
. Diastolic = bottom number, the pressure on your artery when the heart relaxes
Responses of the cardiovascular system to a single sport or exercise session: Redirection of blood flow ( vascular shunt )
. Blood is redirected where it is needed the most, when exercising the blood is needed for the working muscles the blood vessels will vasodilate to allow this extra blood flow.
. During exercise blood is not needed for the digestive system blood flow is reduced to this area by vasoconstriction
. muscular pump- muscle space decreases, muscles larger (contraction), send blood back to heart via vessels
. respiratory pump- reduced thoracic cavity, reduced pressure in vessels to heart
Adaptations of the cardiovascular system to exercise: Cardiac Hypertrophy
Cardiac hypertrophy is where the walls of the heart get thicker, this increases the strength of its contractions. Stretch further, more blood. Sv increases, hr decreases
Adaptations of the cardiovascular system to exercise: Increase in resting and working stroke volume
Because there is cardiac hypertrophy the heart can pump more blood per beat (stroke volume). More blood = more oxygen can be transported to the working muscles during exercise.
Adaptations of the cardiovascular system to exercise: Decrease in resting heart rate
Because the heart is bigger and can pump more blood per beat, the heart does not have to work as hard which results in a reduced resting heart rate. Higher intensity, further from MAX HR, range
Adaptations of the cardiovascular system to exercise: Reduction in resting blood pressure
. Training reduces blood pressure, this reduces the risk of heart disease and stroke.
. Exercise keeps our blood vessels healthy.
Adaptations of the cardiovascular system to exercise: Decrease heart rate recovery time
Because the heart is bigger, it can not only pump blood at an increased rate during exercise, it does this after exercise = decreases recovery time removing waste products at a faster rate.
Adaptations of the cardiovascular system to exercise: Capillarisation of
skeletal muscle and alveoli
Exercise increases the capillarisation both around the muscle and alveoli= more oxygen and nutrients can be diffused into the blood from the alveoli and into the muscles.
Adaptations of the cardiovascular system to exercise: Increase in blood volume
Training increases blood volume due to capillarisation through training= more oxygen
and nutrients to be delivered around the body.
You can also regulate temperature more efficiently
Additional factors affecting the cardiovascular system: Sudden Arrhythmic Death
Syndrome
. a heart condition that can cause sudden death.
. It is usually caused by an irregular heartbeat (cardiac arrhythmia), structure of heart, impulses (conduction centre) or weak muscular walls)
. There are often no clear symptoms and when people participate in strenuous exercise, even though they appear fit and healthy they can die due to SADS
Additional factors affecting the cardiovascular system: High and low blood pressure
Blood pressure = the pressure blood exerts on the arteries
High blood pressure can be a risk factor for heart disease and stroke
Low blood pressure can be dangerous, symptoms include dizziness, lightheadedness,
nausea and fainting
High blood pressure is called hypertension
Low blood pressure is called hypotension
Additional factors affecting the cardiovascular system: Hyperthermia/Hypothermia
Hypothermia = a drop in core body temperature below 35°C
It can occur when you are exposed to cold or cold and wet conditions for a long period of time
Hyperthermia = an increase in core body temperature
It can lead to heat cramps, heat exhaustion or heat stroke 40 degrees
We usually lose heat through thermoregulation but the body may find this difficult in hot conditions.
nervous control of the cardiac cycle to reduce HR after exercise
. parasympathetic nervous system (signals from chemoreceptors, medulla oblongata)
. sends a message via vagus nerve to the SA node
. SA node reduces firing (number of impulses per min)
. sends a signal to AV node, to bundle of hiss and purkinje fibres (at a slower rate, due to HR lower)
transport of CO2 and O2
. 02 binds to haemoglobin = oxyhaemoglobin in red blood cells
. co2 bicarbonate ions (carbonic acid in plasma i.e lactic acid) , dissolved in plasma (10%), bound to haemoglobin as carbaminohemoglobin
VO2 max
O2 used in 1 min. O2 in and out = O2 volume
