Blood Vessels and Heart Flashcards
What is the function of arteries?
Carry blood away from the heart [not a function : high pressure, thick walls, narrow lumen]
What is the function of the veins?
Carry blood to the heart [not function : low pressure, thin walls and wide lumen. Valves present]
What is the function of capillaries?
They exchange materials [eg, glucose and oxygen] between the blood and body cells. [not a function : join arteries and veins. They have very thin walls for glucose and oxygen to diffuse through. The capillary wall is one cell think [endothelium]
What is the inner layer of the capillaries, veins and arteries?
The endothelium
What is the middle layer of the capillaries, arteries and veins?
Muscle and elastic fibres
What is the outer layer of the capillaries, veins and arteries?
Non- elastic collagen fibres
What is the lumen?
The centre of the blood vessel through which blood flows
Place the blood vessels in order of lumen size starting with the widest
Vein, artery, capillary
Place the blood vessels in order of wall thickness starting with the thickest wall
Artery, Vein, Capillary
Place the blood vessels in order of position starting from the heart / Blood flow through a capillary
Artery, [arteriole], Capillary, [Venule], Vein
Which blood vessels have valves? Give their function
Veins. They stop the back flow of blood
What are the two different types of circulation in the body?
Double circulation. Two circuits are : Pulmonary Circuit and Systemic Circuit
What is the pulmonary circuit?
It’s a circuit where blood flows between the heart and lungs
What is the systemic circuit
Circuit in the body where blood flows between the heart and the rest of the body
What is the purpose of the double circulation in the human body?
To keep the oxygenated and deoxygenated blood separate
How is a closed circulation system more efficient than an open?
It is more efficient - it pumps blood around body faster which allows nutrients and oxygen to be distributed faster
Allows the flow of blood to different organs to be increased or decreased - if an animal is running, more blood can be supplied to the leg muscles
In what animal would you find a single circulation?
A worm
What is a portal blood system?
It starts and ends at capillaries
Give an example of a portal blood system?
Hepatic portal vein which carries blood from capillaries in the stomach and intestines to capillaries in the liver
Name the blood vessel that carries blood from the lungs
Pulmonary vein
Name the blood vessel that carries blood to the lungs
Pulmonary artery
Name the blood vessel that carries blood from the kidneys
The renal vein
Name the blood vessel that carries blood to the kidneys?
Renal artery
Name the blood vessel that carries blood from the liver
Hepatic vein
Name the two blood vessels that carry blood to the liver
Hepatic artery and hepatic portal vein
Where does the hepatic portal vein carry blood from and to?
From the stomach/intestines to the liver
What is a pulse?
The expansion and contraction of the wall of an artery due to blood pumping from the heart. It is the same as the rate of the heart beat
What is blood pressure?
It is the force of blood against the walls of arteries
Where is the heart located?
The heart is located in the thoracic cavity, between the lungs slightly to the left
What is the heart made of
Cardiac muscle -an involuntary [not consciously controlled, cannot deliberately control] muscle that does not fatigue
What surrounds the heart?
The pericardium, a double membrane. It contains fluid that reduces friction between the lungs and heart when the heart beats
What protects the heart?
The ribcage
Name the blood vessel that carries blood from the body?
Vena cava
Name the blood vessel that carries blood to the body
Aorta
What separates the left and right side of the heart? What is its function?
Septum. It separates oxygenated and deoxygenated blood so they do not mix.
Name the valve found between the upper and lower chamber of the left of the heart?
Bicuspid valve. It stops blood flowing back from the left ventricle to the left atrium
Why are the walls of the atria thinner than those of the ventricles?
The atria only have to pump blood a short distance to the ventricles. The ventricles have to pump blood to the lungs and the rest of the body
Why is the wall of the left ventricle thicker than the wall of the right ventricle?
The LV has to pump blood all the way around the body while the RV only has to pump blood to the lungs
What does the coronary artery do?
Oxygenated blood is supplied to the heart muscle itself by the coronary artery
Where do you find the coronary artery?
It originates in the aorta near the semilunar valve
What does the coronary vein do?
Deoxygenated blood is drained from the heart in the coronary vein. It returns blood directly to the right atrium
A diet high in cholesterol may lead to what?
It may cause blockage of the arteries, causing a heart attack
What occurs in an open circulatory system? And give examples
Blood does not always flow inside blood vessels. The blood vessels are open-ended. Blood makes direct contact with tissue cells eg, insects and snails
What occurs in a closed circulatory system?
Blood flows only within vessels. Exchange of substances occurs through thin walls of vessels. Substances enter into tissue fluid then into cells.
What is the advantage of a closed circulatory system?
More efficient
What is the cardiac cycle?
The sequence of events that occurs when a heart beats
What is a systole?
It refers to the period of contraction by heart muscles. The chambers empty
What is diastole?
Refers to the period of relaxation by heart muscle. The chambers fill.
The cardiac cycle has three stages, what are they?
Atrial systole
Ventricular systole
Diastole
What is the atrial systole?
The SA node transmits electrical impulses throughout the atria. The atria contract and the cuspid valves open. Blood is pushed down into the ventricles. The blood can’t flow back into the vena cava or pulmonary vein because of the valves on the veins stoping the backflips of blood.
What is the ventricular systole
The AV node passes electrical impulses to the ventricles. The ventricles contract and the semi-lunar valves one. Blood is pushed up the aorta and pulmonary artery. The blood can’t go back into the atria because of the cuspid valves forced shut [“lub”]
What is the diastole?
The atria and ventricles relax. Blood flows into the atria and the semi-lunar valves in the arteries close as blood pushes against them [“dup” sound]
Name two tissues present in the walls of arteries and veins and state their functions
Epithelial - protects wall
Connective - gives support
What transports blood out of the heart?
Coronary vein
Name a structure found in cells in which co2 is produced
Mitochondria [respiration]
Give a feature of capillary which allows rapid uptake of co2?
Thin wall
Why are co2 levels higher in venous blood?
Venous blood collects co2 from respiration/ arterial blood is cleared of co2 in lungs
Name a blood vessel that has an exception to venous blood always containing co2
Pulmonary vein - blood is cleared of co2 in lungs
Pulmonary artery - brings Co2 rich blood to lungs
Briefly outline the role of co2 in the control of human breathing
Medulla oblongata - detects co2 levels
More co2 = faster breathing
Less co2 = slower breathing
How is o2 transported?
Red blood cells - haemoglobin
What controls the heartbeat?
The pacemaker
Smoking on circulatory system
Nicotine - increases heart rate and raises blood pressure
Carbon monoxide - reduces amount of oxygen carried by blood = lower energy production
Diet on circulatory system
Fat - high in chloestoral = blockage of arteries
High salt intake = high blood pressure
Why is a double circulation more efficient than a single circulation?
Double circulation allows oxygenated and deoxygenated blood to be separate and ensures that blood pressure is high enough to reach all parts of the body whereas
Single circulation blood is pumps from their hearts, around the body and back to the heart again and can only produce low pressure blood which restricts metabolism
What makes the wrist a suitable part of the body to detect pulse
Artery near surface
What is the control of the experiment on pulse rate and what is the purpose?
Resting rate and used as a comparison
How might you measure recovery time in the experiment on pulse rate
Count your pulse per minute immediately after exercise and measure how long did it take to go back to normal [to recover]
How does blood travel through blood vessels
Arteries - transport oxygenated blood to a arterioles which in turn transport to capillaries. Capillaries are thin blood vessels that allow the exchange between blood and tissues.
When oxygen is transported to body’s tissues by capillaries, another network in body carries blood back to the heart.
Venules pick up now deoxygenated blood and transfer to veins which carry it to the heart
Circulation of blood how travels throughout body
Oxygenated blood from lungs goes to left side of the heart by pulmonary vein and out the heart by the aorta to body tissues
Deoxygenated blood from body tissues go into the right side of the heart through the vena cava and goes to the lungs by the pulmonary artery. In the lungs, the co2 is cleared from blood and cycle continues
Difference between blood and lymph
Blood - in blood vessels has red blood cells and platelets lower conc of lymphocytes lower conc of digested fats Lymph - in lymph vessels has no red blood cells or platelets high conc of lymphocytes high conc of digested fats
Difference between lymph vessels and capillaries
Lymph vessel - less numerous dead ended has valves Capillaries - very numerous open ended no valves
Difference between tissue fluid and plasma
Tissue fluid - surrounds body cells
has nutrients, hormones and waste
no white blood cells, red blood cells or platelets
Plasma - in blood vessels
has nutrients, hormones and waste
Has white blood cells, red blood cells and platelets
Where did you locate the bicuspid valve/tricuspid valve
Bicuspid - Between the left ventricle and atrium
Tricuspid - Between the right ventricle and atrium
Where exactly did you find the semilunar valves?
At the base of the aorta or pulmonary artery
When you investigated the effect of exercise on human pulse, what did you first establish?
Resting rate
How did you measure pulse rate or breathing rate
Feel pulse on wrist and count heart beats per minute. Repeat and find an average
Name the cavity of the body which the heart and lungs are located
Thoracic
How does the heart muscle differ from other muscles in the body
It is involuntary - does not fatigue
Diagram for two women one overweight and one very fit athlete
Time
Pulse rate
Exam papers pg 46
Diagram transverse and longitudinal section through human vein
Pg 53 of exam papers
Which vein carries very little carbon dioxide?
Pulmonary vein
Which vein brings blood into to the right atrium?
Vena cava
Which vein has capillaries at both ends?
Hepatic portal vein
Briefly describe how blood is moved through veins
Skeletal muscle - contracting and valves prevent back flow
If a transverse section of an artery and vein were viewed under a microscope, state one way in which it could be differed/distinguished
Narrow lumen of artery
Name a major blood vessel that returns the blood in B to the heart
Vena Cava
Describe the steps that you followed in order to identify and display the inner structures of the heart
1 - place heart on dissection board and identify front of heart [more rounded and has coronary artery on left side of heart, left side is thicker]
2 - get scalpel and cut ventricles
3 - locate bicuspid and tricuspid valves and identify thickness of ventricles
4 -cut atria and identify thinness
5. Locate septum
6. Cut aorta and pulmonary artery to locate semi-lunar valves
What did you do in order to expose a semi lunar valve while dissecting a heart
Cut base of aorta and pulmonary artery using scalpel
A persons fingers may turn white when exposed to low temperatures for a period of time
Less blood in fingers - minimise heat loss
Which of the circuits [systemic and circulatory] involves the pumping of blood by the left ventricle
Systemic circuit
Comment on the effect of diet on the circulatory system
High salt intake - high blood pressure which leads to a heart attack
Comment on the effect of exercise on the circulatory system
Heart becomes stronger and more efficient
What is the role of the SA and AV modes in the heart?
Causes contraction of heart muscle
Give the precise locations of both the SA and AV nodes in the heart
SA - wall of right atrium
AV - near tricuspid valve
Name the main gas transported in pulmonary vein and how is this gas transported
Oxygen
How transported - Haemoglobin
Explain why pulse rate or breathing rate increases with exercise
More energy is used up when exercising, there for more oxygen a required as more carbon dioxide is being produced
