Unit 4 Flashcards
Anatomy
internal and external structures of the body
Physiology
the function of these structures
Define the cardiovascular system
This system is the main transport system of the body, carrying oxygen, carbon dioxide, amino acids, glucose and digested fats, hormones, antibodies and urea.
What is the cardiovascular system made up of
• The Heart
• Arteries and veins
• Blood and blood cells
Cardiovascular
The heart is a muscular pump which forces blood around the body through a system of blood vessels, arteries, veins and capillaries.
Blood carries dissolved oxygen around the body cells and at the same time removes the waste products of respiration (breathing): carbon dioxide and water.
Blood also distributes heat around the body and hormones, nutrients, salts enzymes and urea,
Heart circulation
The circulation to and from the lungs is known as the PULMONARY CIRCULATION
The circulation around the body is called the SYSTEMATIC CIRCULATION
Arteries are blood vessels that leave the heart and veins take blood towards the heart.
The four components of the blood
Platelets
White blood cells
Red blood cells
Plasma
Plasma
90% water. Transports dissolved substances
Glucose
Nutrient needed for energy
Amino acids
Nutrient needed to make proteins
Vitamins
Nutrients needed for essential processes
Minerals
Nutrients needed for essential processes
Albumin
Blood protein needed to maintain fluid levels
Fibrinogen
Blood protein involved in clotting
Antibodies
Proteins made by the immune system
Lipoproteins
Proteins that carry fats/cholesterol
Carbon dioxide
A poisonous waste gas
Urea
A poisonous waste product from protein
Electrolytes
For example, sodium, needed to help maintain correct concentration of the blood
RBC or Erythrocytes
Carry oxygen and some carbon dioxide
WBC or Leucocytes
consist of many types- Helps destroy bacteria
Neutrophils
B-type cells produce antibodies
Lymphocytes
Consists of two types of cells-T and B cells. They combine forces to create a complex interaction to regulate immunity
T cells destroy viruses cells and cancer cells
B cells produce and release anti bodies
Monocyte
Removes dead cells and bacteria
Defend against discase bacterial infection
Platelets
Triggers blood clotting
Granulocytes
includes neutrophils, eosinophils, basophils
Combat infection by rapidly increasing in numbers
Engulf and destroy foreign substances then they die
Right atrium
Two large veins deliver oxygen-poor blood to your right atrium.
The superior vena cava
carries blood from your upper body.
The inferior vena cava
brings blood from the lower body.
The function of the heart chambers
Right atrium: Two large veins deliver oxygen-poor blood to your right atrium. The superior vena cava carries blood from your upper body.
The inferior vena cava brings blood from the lower body.
Then the right atrium pumps the blood to your right ventricle.
Right ventricle: The lower right chamber pumps the oxygen-poor blood to your lungs through the pulmonary artery. The lungs reload blood with oxygen.
Left atrium: After the lungs fill blood with oxygen
pulmonary veins carry the blood to the left atrium. This upper chamber pumps the blood to your left ventricle.
Left ventricle: The left ventricle is slightly larger than the right. It pumps oxygen-rich blood to the rest of your body.
Function of the heart valves, arteries, capillaries and veins
Tricuspid valve: Door between your right atrium and right ventricle.
Mitral valve: Door between your left atrium and left ventricle.
Semilunar (SL) valves open when blood flows out of your ventricles. They include:
Aortic valve: Opens when blood flows out of your left ventricle to your aorta (artery that carries oxygen-rich blood to your body).
Pulmonary valve: Opens when blood flows from your right ventricle to your pulmonary arteries (the only arteries that carry oxygen-poor blood to your lungs).
Your heart pumps blood through three types of blood vessels:
Arteries carry oxygen-rich blood from your heart to your body’s tissues. The exception is your pulmonary arteries, which go to your lungs.
Veins carry oxygen-poor blood back to your heart.
Capillaries are small blood vessels where your body exchanges oxygen-rich and oxygen-poor blood.
Your heart receives nutrients through a network of coronary arteries. These arteries run along your heart’s surface. They serve the heart itself.
Heat valves
Your heart valves are like doors between your heart chambers. They open and close to allow blood to flow through. The atrioventricular (AV) valves open between your upper and lower heart chambers.
Heart chambers
Your heart is divided into four chambers. You have two chambers on the top (atrium, plural atria) and two on the bottom (ventricles), one on each side of the heart.
Systole
Contracting
Diastole
Relaxing
Cardiac cycle
has 3 stages: Atrial and Ventricular diastole (chambers are relaxed and filling with blood) Atrial systole (atria contract and remaining blood is pushed into ventricles) Ventricular systole (ventricles contract and push blood out through aorta and pulmonary artery)
The flow of blood in the heart
Blood from the lung which is oxygenated returns to the heart via the pulmonary vein and enters the left atrium
Blood passes through the bicuspid (mitral) valve into the left ventricle
Blood is forced out of the blood to the rest of the aorta and carries the oxygenated blood to the rest of the body
Deoxygenated blood returns from the body to the right artrium through the superior/ inferior vena cava
Blood is the squeezed through the tricuspid valve into the right ventricle
Blood is forced through the pulmonary artery which carries the deoxygenated blood to the lungs
Cardiac cycle pt2
co-ordinated flow of blood through the heart is called the cardiac cycle and takes place on average 70 times a minute. The part of the cycte when the ventricles are contracting is known as systole; when they are relaxing and the atria are filling it is called diastole.
Purkinje fibres
Purkinje fibres (also known as Purkyne) are very fine specialised cardiac muscles fibres that rapidly transmit impulses from atrioventricular node to the ventricles
Location and role of the sinoatrial(SA) node
• also known as the sinus node, is the key structure responsible for the generation of a regular heartbeat The SA node is situated in the upper wall of the right atrium of the heart
• It is known as the peacemaker and responsible for setting the rhythm of the heart beat
• It ensures both atria contract simultaneously
• An electrocardiogram (ECG) trace shows the spread of the electrical signal generated by the node as it travels through the atria
Location and role of the atrioventricular (AV) node of the heart
• AV node is at the bottom of the RA
• Responsible for delaying the electrical impulses it receives from the SA
• This delay allows time for the blood to empty out of the atria into the ventricles
A Normal ECG Trace
ECG trace tells what is happening in the heart and a normal ECG shows 5 waves named PQRST
- The waves represent the electrical activity of the heart
- The different sections represent different activities within the heart
Electrocardiogram (ECG): P waves
Electrical reading from atrial contraction/sytole. Its when the left and right atria contract at the same time
Electrocardiogram (ECG): QRS waves
Electrical reading from the contraction of the left and right ventricles
Ventricular contraction
Represents the current as the action potential travels through the interventricular septum
Electrocardiogram (ECG): T waves
Represents the relaxation of the ventricles
Veins
carry’s blood towards the heart. Thinner wall, large lumen,Blood flow is a low pressure so it contains valves to help the blood not flow backwards.(usually deoxygenated blood, except for the pulmonary vein). Branch into smaller vessels called venuels
Capillaries
the smallest blood vessel, connects arteries and veins. Allows diffusion of gasses (o2 and co2) and nutrients and water from blood into the body cells, Single cell thick, lumen is Very small, only allows blood to pass through one cell at a time. Blood flow is at a low pressure.Walls are made of semi-permeable membrane to allow transport of gases and nutrients into and out of the blood. Located between arteries and veins. No valves
Arteries
carry’s blood away from the heart. Thick muscular wall, small lumen, Thick muscular walls to withstand blood flowing at high pressure as it leaves the heart; the largest artery is the aorta.
They have no valves. Branch into smaller vessels called arterioles
(usually oxygenated blood, except for the pulmonary artery)
Lumen
the space within the tubes, tracts, cavities, and cells of the body. Air, blood, fluids, food, and other substances move through the lumen, enabling the function of organ systems. Some of the largest lumina in the human body are located in the arteries and intestines
Arterioles
They connect to capillaries. They transport blood to the capillary beds. They are smaller than arteries but bigger than capillaries
Venules
Connect to capillaries. Transport blood away from the capillary beds. They are smaller than veins and bigger than capillaries
What is cardiovascular disease
Cardiovascular disease (CVD) is a general term for conditions affecting the heart or blood vessels.
Associated with a build-up of fatty deposits inside the arteries (atherosclerosis) and associated with damage to arteries in organs.
Leads to increased risk of blood clots.
It is the main cause of death and disability in the
UK, but it can often largely be prevented by leading a healthy lifestyle
Coronary heart disease
Occurs when the flow of oxygen-rich blood to the heart muscle is blocked or reduced thereby puts an increased strain on the heart. This can lead to
Angina - chest pain caused by restricted blood flow to the heart muscle
Heart attacks - where the blood flow to the heart muscle is suddenly blocked
Heart failure - where the heart is unable to pump blood around the body properly
Strokes and TIA
A stroke is where the blood supply to part of the brain is cut off, which can cause brain damage and possibly death.💀
TIA- Transient Ischaemic Attack (mini stroke)
Peripheral arterial disease
Peripheral arterial disease occurs when there’s a blockage in the arteries to the limbs, usually the legs. This can cause:
dull or cramping leg pain, which is worse when walking and gets better with rest hair loss on the legs and feet numbness or weakness in the legs
persistent ulcers (open sores) on the feet and legs
