B7.2 Flashcards
What is the circulatory system?
A system of blood vessels with pumps and valves to ensure one way flow of blood
What type of blood flows in veins and arteries (both systemic and pulmonary)?
Systemic
Veins -> deoxygenated
Arteries -> oxygenated
Pulmonary
Veins -> oxygenated
Arteries -> deoxygenated
What is double circulation?
For every one lap around the body, blood passes through the heart twice
Where does pulmonary circulation pump the blood?
Right side of heart pumps deoxygenated blood (via arteries) to the lungs where the blood becomes oxygenated and blood is returned to the heart (via veins)
Where does systemic circulation pump the blood?
The left side of the heart receives oxygenated blood and pumps it around the body (from the lungs + via arteries) and picks up CO2 (excess + via veins)
What are the advantages of double circulation?
Traveling through small capillaries in lungs help relieve pressure (allows slower movement and more efficient diffusion )
By going past the heart the pressure can be raised, allowing faster movement and can supply cells with oxygen and glucose faster/more often
Draw and label the structures of the heart (ventricles, atria, muscular wall, septum, one way valves, coronary arteries)
///
What are the bicuspid and tricuspid valves?
Atrioventricular valves
Why do ventricles have thicker muscle walls than the atria?
They need to pump blood out of the heart, so they need to generated a higher pressure
What type of blood does the right side of the heart receive?
It receives deoxygenated blood from the body and pumps it to the lungs
What type of blood does the left side of the blood receive?
The left side receives oxygenated blood from the lungs and pumps it to the body
What does the left ventricle have a thicker muscle wall?
The left ventricle is responsible for pumping the blood throughout the entire body, meaning it needs to generate a higher pressure
The right only needs to pump the blood to the lungs, which are closer
Whatt does the septum do?
The septum separates the two sides of the heart and prevents mixing of oxygenated and deoxygenated blood
What are the function of valves?
The function of the valve is to prevent back flow/ the blood flowing backwards
What are the names and functions of the atrioventricular valves?
The tricuspid (right side) and bicuspid (left side) separate the atria from the ventricles
The valves are pushed open when the atria contract
The valves are pushed up (closed) when the ventricles contract (prevent blood from going back into the atria)
Where can the semilunar valves be found?
They are located at the two arteries the come out of the top of the heart (pulmonary artery and aorta)
Unusual because they are the only arteries that have valves
What is the function of the semilunar valves?
Valves open when ventricles contract and blood is squeezed out of the heart
Valves close when atria contract and blood is stopped from flowing back into the heart
What do the coronary arteries do?
The coronary arteries supplies blood (and therefore oxygen and nutrients+removes waste) to the (cardiac) muscle tissue which makes up the heart
Why are coronary arteries necessary?
They give the muscles oxygen and nutrients and allows the heart to work at it best
The wall of the heart are so thick that oxygen and nutrients cannot easily pass through, hence the need for coronary arteries
Which direction is the blood flowing in veins + arteries?
Vein -> to the heart
Arteries -> away from the heart
Describe the path of blood through the body (emphasis on the contraction of muscles and action of valves)
Deoxygenated blood enters via vena cava into right atrium
Right atrium contracts and blood is pushed pass the tricuspid valve into the right ventricle
Right ventricle contracts and blood is pushed through the semilunar valve and into pulmonary artery (pressure prevents back flow)
Blood travels to the lungs and goes through capillaries (why blood has to slow/low pressure -> capillaries would burst) and past alveoli where gas exchange occurs
Oxygenated blood return to left atrium via pulmonary vein
Left atrium contracts and blood passes through the bicuspid valve into the left ventricle
Ventricle contracts and pushes the blood through the semilunar valve through aorta to the body (required high pressure-> thick muscles)
Name the main blood vessels that go to and from the heart
To-> vena cava, pulmonary vein
Away-> aorta, pulmonary artery
Name the main blood vessels that go to and from lungs
To-> pulmonary artery
Away-> pulmonary vein
Name the main blood vessels that go to and away from kidneys
To->renal artery
Away-> renal vein
What causes coronary heart disease?
Narrowing of the blood vessels to the heart (coronary arteries) reducing blood flow to heart
If blood vessel is blocked -> part of heart might stop and become damaged (heart attack/cardiac arrest)
What do the blood vessels become blocked by causing coronary heart disease? What does this cause in the blood vessels?
Fatty deposits called plaque (formed from cholesterol)
Plaque makes arteries less elastic
Arteries cannot stretch to accommodate blood which is being forced through -> coronary heart disease
Partial blockage -> restricted blood flow and can cause severe chest pains called angina
Full blockage -> cells in the area cannot respire and will die, so it cannot contract and leads to heart attacks
What are risk factors/causes of coronary heart disease?
Male
Older
Smoker (blood vessels become narrower -> increase blood pressure)
Overweight
Inactive
Stressed (increase blood pressure)
Family history of CHD
High cholesterol (produced in liver + obtained through diet/genetics, fatty acid -> cholesterol, reduce cholesterol -> vitamin A C E)
High blood pressure (alcohol, too much salt etc)
High intake of saturated fats (increases cholesterol)
Diabetes
How can coronary heart disease be prevented?
Quit smoking
Diet-> reduce animal fats and eat more fruit+veg (reduces cholesterol) -> weight loss, decrease blood pressure, lower cholesterol and reduce stress
What is pulse rate?
Heart/pulse rate -> how often you heart beats
Measured by ECG or by listen to sound of valves opening using stethoscope
Measured in beats per minute (bpm) -> average resting heart rate 70/75 bpm
Investigate the effects of physical activity on heart rate
- Record pulse at rest for 1 minute
- Do some exercise
- Record pulse rate after exercise every minute until it returns to the resting rate
- Observe that pulse rate increase when you exercise and takes several minutes to return to a resting rate
Effects:
Heart rate increases
Rate and depth of breath increases
Arteries supplying blood to muscles dilate
What are the effects of physical activity on the heart rate?
Increase heart rate mean that enough blood is supplied to the working muscle (oxygen + nutrients -> respiration) and that waste (CO2) can be removed faster
Heart rate stays high after exercise to ensure that all waste product is removed
Repay oxygen debt (from breathing anaerobically) and break down lactic acid
Describe the structure of the arteries
Carry blood at high pressure from ventricles
Carry blood away from the heart
Narrow lumen (empty space in middle)
Strong walls to withstand pressure
Blood moves in pulses with each heartbeat (smooth muscles walls stretch and flex because of elastic fibers)
Describe the structure and function of capillaries
Low pressure blood -> don’t burst
Carry both oxygenated and deoxygenated blood
Very small
Takes nutrients and oxygen to cells and takes waste product (exchange/diffusion)
Thin; permeable, one cell thick wall (good from diffusion)
Describe the structure of veins
Carry blood at low pressure
Thinner walls (doesn’t need to withstand much pressure)
Large lumen-> to not slow the blood even more
Valves in stop black flow of blood (muscles around veins push the blood, pressure pushes blood and opens valve)
How are arteries adapted from their function?
Thick muscular wall with elastic fibers
Withstand the high pressure of blood and maintain the pressure
Narrow lumen
Maintain pressure
How are veins adapted to their function?
Large lumen
Blood pressure low
Valves
Prevents back flow (because blood is under low pressure)
How are capillaries adapted to their function?
Thin walls
One cell thick-> diffusion
Leaky walls
Blood plasma can leak out and form tissue fluid surround the cells
What are the components of blood?
55% plasma
45% red blood cells, white blood cells, platelets
Identify platelets, white blood cells, and red blood cells under a light microscope, on diagrams photomicrographs
Light microscope/diagram
Platelets -> small dot
Red blood cell -> medium dots
White blood cell -> big dot with smaller dots/one big dot inside
Photomircographs
Platelet -> small disc
Red blood cell -> medium disc with small divot
White blood cell -> fluffy looking ball
What is the function of red blood cells (oxygen and haemoglobin)? (+ amount and shape)
5-6million /ml of blood
Shape:
Biconcave -> increase surface area so carry more oxygen
No nucleus -> more space for oxygen
Contains haemoglobin -> oxygen carrying molecule
Function:
Transport oxygen to the body from the lungs (required for aerobic respiration) (oxyhaemoglobin)
What is the function of white blood cells? (+ amount and shape)
5000/ml of blood
Shape:
Larger than red blood cells
Large flexible nucleus
Part of immune system
Different types have different functions and shapes
Function:
Body’s defense
2 types: phagocytes and lymphocytes
Phagocyte:
Monocytes and macrophages (types of phagocyte)
Non-specific response to infection (surround and destroy pathogens (release digestive enzymes) -> phagocytosis)
Has a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
Lymphocyte:
T-cells and B-cells (types of lymphocyte)
Provide a specific immune response to infectious diseases
Produce antibodies to destroy and antitoxins to neutralize toxins released
Recognized by large round nucleus and clear nongranular cytoplasm
What is the function of platelets? (+ amount and shape)
150,000-450,000/ml of blood
Shape:
Fragments of cells (some made in red bone marrow)
Function:
Clot blood to prevent blood loss and infection (scabs)
What is the function of plasma?
Function:
Liquid part of blood
Transports:
Soluble food molecules (glucose, amino acids)
Waste product
Hormones
Antibodies
Enzymes
Etc
What are the components of plasma?
Water
Absorbed in small intestine and colon
Goes to all cells
Excess removed in kidneys
Plasma proteins
fibrinogens -> from liver (blood clotting)
antibodies -> from lymphocytes (kill pathogens)
Stays in blood
Lipids (cholesterol and fatty acids)
Absorbed in ileum (end of small intestine) or from fat reserves in body
Goes to liver (breakdown adipose (for fat) tissue) or to storage (body fat) where it becomes an energy source
Heart depends on fatty acids for energy
Carbohydrates (glucose)
Absorbed in ileum also produced by breakdown of glycogen in liver
Goes to all cells (respiration)
Extra glucose -> glycogen -> in liver
Mineral ions (Na+, Cl-)
Absorbed in ileum and colon
Goes to all cells
Excess are excreted by kidney
Hormones
Secreted into blood from endocrine glands
Goes to all parts of the blood
Will only affect target cells
Broken down by liver and excreted by kidneys
Dissolved gases (CO2)
Waste produce of respiration
Goes to lungs for excretion
Most CO2 is carried as carbonate ions in plasma
