transport in humans
Circulatory system is responsible
If we did not have transport systems it will be difficult for everything to reach to where they need to get to
Circulatory system
System
A group of organisms working together to perform a particular function
organs in them
Heart
Bicuspid and tricuspid can also be called AV valves
Atrium and ventricle valves
There are coronary arteries and coronary veins
A - give the very heart the very blood it pumps
myogenic
Only muscle that works 24/7 (ebile 25/8)
Acts as a pump
Parts
Septum
Blocks the blood so that it never combines
Thrombosis
Fancy word for clot
It will block the coronary artery
If that happens, that area will not get oxygen.
The muscle will die with time
Monitor your heart health
Can monitor the heart beat rate
Done by ECT
Electrocardiography
Listen to valves opening and closing
Reading pulse
Blood
Tissue
Blood vessels
Double and single circulation
Double
The blood goes through the heart twice for every single circulation through the body
Arteries are away the heart; veins are to the heart
Between heart and lungs
Pulmonary circuit
Between heart and body
Systemic circulation
Higher pressure because of the aorta
Single
Of a fish
Rules
Direction
Quality of blood
Arteries carry oxygenated blood
Veins carry deoxygenated blood
Exception is the pulmonary vessels
Left side is deoxygenated blood
Right side is oxygenated
Pressure
Can be affected by distance
Arteries
High
Aorta
Highest
Pulmonary artery
Less high
Veins
Less or lower pressure
Can push blood up against gravity with the help of the muscles
Vena cava especially
Blood vessels
Role to transport blood around the body [R pump]
3 types d
Artery
Thick outer wall
Thick layer of muscles and elastic fibres
Prescence of the thick muscle wall in artery
Withstand the pressure of the blood as a result of the surge
Not an ordinary flow caused by contractions of the heart (cardiac muscles)
Abilities to contract and relax
Prescence of elastic fibres
This allows for recoiling of the vessel after the blood has gone through
Capillary
Can penetrate through organs
Get close to the cells to transport quicker
Vein
Tissue fluid
When plasma is exuded from the space surrounding the cells, as soon as it touches the inside of the cell immediately it is called tissue fluid
Tissues should never be dry around them
Terms of composition
It is similar, the substances are same but the red blood cells are left in capillary
Tissue fluid enters capillary to be brought back and continues
Drains into lymphatic system
Lymph fluid
The tissue fluid that goes back and the excess enters the lymphatic vessel and forms lymph fluid
Lymph comes in handy because inside it contains lymphocytes
They have blind ends while capillaries have open ends for blood to flow through
Capillary bed
Nutrients diffuse glucose, amino acids, O2 into the cell
Waste material (CO2, urea,) from cell to capillary
They have pores
Plasma exuded
Plasma is the liquid portion of the blood
Prefix ex- means
Removed because of high pressure from the arteriole
Blood
Classified as a tissue
Liquid part 55%
Cells are suspended in It
Cells do not dissolve in the plasma
Simple soluble are found here
Glucose, amino acids, gases
Water 92%
Dissolved substances 8%
Foods
Salts
Hormones
Protein
Waste products
Cellular part 45%
Red blood cells
Erythrocytes (collectively)
Haemoglobin has affinity to O2
A strong attraction to O2 ensuring that O2 is carried around well
Contains iron
Lack of nucleus causing bi-concave shape
Live to about 4 months
White blood cells
Leukocytes
With a large nucleus that occupies most of the cell
They defend against diseases
Destroys unknown cells and bacteria, it kills the germ and not the disease
A germ causes a disease
All bacteria and other microbes that cause diseases are called pathogens
Phagocytes
It can change in anyway
Lobed nucleus
Larger than leukocytes
Carries out a process called phagocytosis
Grows pseudopodia
Pseudo means falls
Podia - feet
Close the pathogen inside the cell
Hydrolytic enzymes then destroy the pathogen inside the vacuole and diffuses into the space
Lymphocytes
t-cells
b-cells
Destroy the pathogens by producing antibodies
Antibodies are classified as a chemical/protein which destroy pathogens
Platelets
Cell fragments
Role of blood clotting
Converting fibrinogen into fibrin blood proteins
Capillary action
Goes up the x
Cohesive forces
Adhesion and that
| Chapter 9 |
|
Circulatory systems
A system of blood vessels with a pump and valves to ensure one-way flow of blood
Main transport system of all mammals
Network of tubes
Veins and arteries
A pump
Heart
Blood flowing in the correct directions
Help from valves
Oxygenating the blood
Oxygenated blood
Blood containing a lot of oxygen
Left-hand side of the heart
Came from the lungs
Picked up from capillaries surrounding alveoli
Deoxygenated blood
Blood containing only a little oxygen
Oxygenated blood sent around the body
Cells take some oxygen
Deoxygenated blood brought back to the heart to become oxygenated
Double and single circuit systems
Double - a system in which blood passes through the heart twice on one complete circuit of the body
Single - a system in which blood passes through the heart only once on one complete circuit of the body
Double is mainly in mammals, birds and reptiles
Single is mainly in fish
Double has more advantages than single
Double
Low blood pressure delivered to the heart then raised again before sending to the rest of the body
Loses pressure when going through the body
Single
Low blood pressure continues around the fishes body
Blood travels slowly
Cells need oxygen delivered to them quickly as possible for respiration. The quicker the better. Proving double is better
The heart
An organ about the size of your fist that pumps blood through your body
|
|
Pumps blood around body
The cardiac muscles contract and relax regularly throughout life
Atria
Atrium for one
Upper heart chambers
Ventricles
Lower heart chambers
Septum
Separates left and right side of heart
Blood flows into atria
Left
Receives blood from pulmonary veins
Right
Receives blood from venae cavae
Vena cava for one
Blood flows out ventricles and flows in from the atria
Muscle walls contract and large force squeezes inwards and blood pushes far outwards
Left
Pumps into aorta
Largest artery
Blood towards the body
Right
Pumps blood into pulmonary artery
Taken to lungs
Valves
A piece of muscle that opens and closes to prevent backflow of blood
Atrioventricular valves
Between atria and ventricles
Tricuspid valve
Mitral valve
Semilunar valves
Between ventricles and arteries
Name is based on shape
Have a half-moon shape
Aortic valve
Pulmonary valve
Difference in muscle wall thickness
Atria
Simply receive blood then send to the ventricles
Ventricles
Pump blood around body out of the heart
Thicker, more muscular walls
Right
To the lungs
Close by
Less thick
Lower pressure
Left
To rest of the body
Thickest part of the heart
High pressure required
Coronary arteries
Vessels that deliver oxygenated blood to the heart muscle
Muscles in the heart are very thick
Making it hard for nutrients and oxygen diffuse into the muscle quick enough
They need a constant supply of nutrients and oxygen
To undergo respiration
Energy is released through the muscles contracting
Coronary arteries supply what the heart needs
Coronary arteries can get blocked
For some cases, cholesterol deposits build up in the walls of these blood vessels
Makes the artery wall stiffer and lumen narrower
Makes blood flow more difficult
Blood clots can form
When blocked, cardiac muscles can't receive oxygen
They cannot respire aerobically
Cannot obtain energy
Stop beating
This is called Coronary Heart Disease (CHD)
Common cause of illness and death
Preventing CHD
Most common causes of death
Stop smoking
Increases chances
Can cause other unpleasant and dangerous health problems
Increase formation of plaque in blood vessels
Taking care over your diet
Most diets are high in saturated fats which increase cholesterol
Meat is higher in saturated fats than plant-based foods
Substitute animal oils with plant oils
Fast food uses animal oils so eat occasionally
Regular exercise
Very beneficial in general for the whole body
Keeps you fit
Prevents excessive weight gain
Decreases blood pressure
Feel-good effect
Clears mind from worrying thoughts
Causes release of chemicals that increase feelings of well-being
Heartbeat
Rhythmic contraction and relaxation of heart muscles
|
|
Most people have 60 to 75 beats per minute when resting
When you hear a heart beating it is called a "lub-dub"
This is made from the opening and closing of valves
A way to measure
Pulse rate
Expansion and relaxation of an artery by pushing blood through it every minute
Your pulse rate is your heart rate
Pulses found wherever an artery is close enough to the skin
Insides of your wrist
Sides of your neck
Phones and smartwatches with that ability
ECG
Short for electrocardiograph
Electrodes are stuck onto a person's body
Electrical activity in the heart is recorded and presented as a graph
How the heart beats
Muscles in the heart contract and relax
Become smaller when contracting
Become larger when relaxing
The atrioventricular valves
Valve on left is called bicuspid
Valve on right is called tricuspid
Contraction of the different chambers in the heart
Atria contract
Increase pressure of the blood in the atria
Blood pushed down
Valves open line swinging doors to allow blood flow
Ventricle contract
Valves are pushed close
Tendons attached stop them from swinging up too far
Valves stop in a 'closed' positions
Blood vessels
Channels that carry blood throughout your body that form a closed loop that begins and ends at your heart
There are three main ones
Arteries
Away from the heart
Divide into capillaries
Veins
Capillaries join back together and eventually become veins
Blood towards the heart
Have valves
Keep blood flowing in the correct direction
Has to combat gravity in a human
Capillaries
Capillaries deliver blood containing oxygen and nutrients to close-by cells (gets to all of them)
Arteries
A thick-walled vessel that takes high-pressure blood away from the heart
Flows out the heart
Comes out in a high pressure
Blood forced out the heart by the ventricles
The need to be strong
Withstand high pressure
Does not flow smoothly through
Pulses through
Pressure is high and reduces when the ventricles relax
Have elastic tissue
To help with stretch and recoil
Makes the flow of blood smoother
You can feel arteries stretching through your pulse on wrist and neck
Capillaries
A tiny vessel with walls only one cell thick, that takes blood close to body cells
Very small and penetrate to every part of the body
No cell is very far away from a capillary
They take nutrients, oxygen and other materials to all cells in the body
They also take away waste products from cells
Walls are one-cell thick
Veins
A thin-walled vessel that takes high-pressure blood away from the heart
Much lower pressure than in arteries
Blood moves slower and smoother
Veins don't need thick, strong walls
If they did they would have a narrow space for blood to flow through
This would slow the blood even more
Veins have a wider lumen so the blood does not slow so much it cannot reach the heart anymore
Have valves
Stop blood flowing backwards
Naming blood vessels
Each organ, except the lungs, are supplied with blood
Arteries are away the heart; veins are to the heart
Liver has two blood vessels supplying it blood
Hepatic artery
Oxygenated blood
Hepatic portal vein
Brings blood from digestive system so that the liver can process the food which has been absorbed
Hepatic vein
Sends deoxygenated blood to heart
Blood
A specialised body fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products
It is a tissue
Contains cells
Liquid part is called plasma
Most of the cellular part are red blood cells
A smaller number is white blood cells
Small cell fragments in the blood are platelets
Formed in the bone marrow
Red blood cells
Biconcave blood cells with no nucleus, which transport oxygen
Red in colour because of haemoglobin
A red pigment found in red blood cells, which can combine reversibly with oxygen; it is a protein
Haemoglobin is a protein
Contains iron
Carries oxygen
Oxyhaemoglobin
Combination of oxygen and haemoglobin
Combines where oxygen concentration is high
Happens in capillaries close to the alveoli
Releases oxygen where oxygen is low
Happens when capillaries are close to cells
The unusualness of red blood cells
No nucleus
More space for millions of molecules of haemoglobin
Shape
Biconcave discs
Flat disc that has been pinched in
Increases surface area
Speeds up rate of oxygen diffusion in and out the cell
Small size
Enables it to squeeze through the tiniest capillaries
Oxygen can be taken very close to every cell in the body
White blood cells
Blood cells with a nucleus which help to defend against pathogens
Easier to recognise because they have a nucleus
Often quite large
Can move around
Squeeze out through walls of blood capillaries to where they are needed
Fight pathogens
Disease-causing microorganisms
Clear up an dead body cells
Some destroy pathogens by engulfing them and digesting them
Phagocytosis
Phagocytes
Lobed nucleus
Other produce molecules called antibodies
Fix onto pathogens and destroy them
Lymphocytes
Large, round nucleus that almost fills the cell
Platelets
Tiny cell fragments present in blood, which help with clotting
No nucleus
Made in bone marrow
Involved in blood clotting
Stop pathogens from entering the body through cuts in skin
Provides a barriers against entry of bacteria
Prevents blood loss
Plasma has fibrinogen
A soluble protein
When a blood vessel breaks
Plates released make the fibrinogen change into an insoluble protein called fibrin
Forms fibres
Pile onto each other to form a mesh-like structure to seal the wound
Blood gets trapped in the mesh
Platelets stick together to form clumps
Fibres trapped in red blood cells clump together to form a blood clot
Plasma
Liquid part of blood
Mostly water
Many things are dissolved into it
Glucose, amino acids, mineral ions, etc.
Transports hormones and waste products
Component | Source | Destination | Notes |
Water | Absorbed in small intestine and colon | All cells | Excess is removed by kidneys |
Proteins [fibrinogen and antibodies] | Fibrinogen from liver Antibodies from lymphocytes | Remain in blood | Helps with clotting Antibodies kill invading pathogens |
Lipids [cholesterol and fatty acids] | Absorbed in ileum From fat reserves in the body | To the liver for breakdown To respiring cells as energy source | Breakdown of fat yields energy High concentration increases risk of heart problems |
Carbohydrates [glucose] | Absorbed in ileum Breakdown of glycogen in liver | Energy release by respiration | Excess glucose converted to glycogen |
Excretory substances [urea] | Produced by amino acids deamination from liver | To kidneys | Removed and dissolved with water from urine |
Mineral ions | Absorbed in ileum | To all cells | Excess excreted by kidneys |
Hormones | Secreted into blood | To all parts of the body | Only affect target cells |
Dissolved gases | Released from process of respiration | To the lungs | Most carried is hydrogen carbonate ions  |