The Circulatory System Flashcards
What is the function of the circulatory system (transport system)
Carry nutrients to cells / waste away
Transport hormones/enzymes from cells in one part of body to another
Allow transport of immune cells throughout body
What makes up the circulatory system
Blood vessel
Heart (brain of the system)
Blood
Open circulatory system
Blood carrying oxygen/nutrients is pumped into the body cavities where it baths the cells directly
Low pressure system
Closed circulatory system
Blood carrying oxygen/nutrients is always contained within blood vessels
High pressure system
How many liters of blood does the average person contain ?
70kg contains 5L of blood
In those 5L, 55% is plasma and 45% is formed solid cells
Erythrocytes (RBC)
Transport oxygen and contain hemoglobin (respiratory pigment molecule that increases RBC ability to carry oxygen)
280M hemoglobin found in 1 RBC
Hemoglobin contains a Heme group ( _____ containing pigment that actually binds to oxygen) and a globin (a _______ protein structure)
Hemoglobin contains a Heme group (iron containing pigment that actually binds to oxygen) and a globin (a globular protein structure)
How many iron molecules can attach to 1 hemoglobin molecule
4 iron molecules can attach to 1 haemoglobin molecule
Each iron molecule can carry 1 oxygen molecule
1 hemoglobin molecule can carry how many oxygen molecules?
4 oxygen molecules
Describe the difficulty of the first oxygen molecule binding when no binding sites are occupied by oxygen and how it changes after the first heme group is occupied.
When no binding sites are occupied by oxygen, it is difficult for the first oxygen molecule to bind. However, after the first heme group is occupied, subsequent oxygen binding becomes easier.
Life span of RBC
Is 120 days
Is the blood of elderly people older then the blood of younger people?
No, since blood cells are constantly replenished, so blood age remains relatively consistent regardless of a person’s age.
When the RBC is mature, it does not contain a nucleus. WHY?
To make more space for oxygen-carrying hemoglobin molecules
Where are RBC produced
Red bone marrow
Leukocytes (white blood cells)
Contain a nucleus
Produced in red bone marrow
The life span is 7-10 days
What is the function of leukocytes
kill invading microbes by phagocytosis (eat) . Once the microbe has been engulfed, the leukocyte releases
enzymes that digest the microbe and the leukocyte itself
Platelets
Don’t contain nucleus
Produced in red bone marrow
They aren’t cells, there are fragments of cell that were created when larger cells in the bon marrow broke apart
Function and life span of platelets
Break down easily in blood (life span 7-10 days)
Function in blood clotting = prevent excessive blood loss
Your blood does not clot until a blood vessel is broken, which indicates that the first step is triggered by injury
Formation on blood clot (detailed)
- Blood does not clot until the blood vessel is broken = indicates that the first step is triggered by injury
- Substances are released from the broken blood vessel (chemicals called PF3’s)
- The chemicals (PF3’s) attract platelets to the site
- As the platelets collect, they rupture and release other chemicals called thromboplastin
- Thromboplastin reacts with prothrombin (protein produced by the liver) with the help of Calcium ions which catalyze the reaction
- Thromboplastin + Prothrombin ➡️CA2
Thrombin - Thrombin reacts with fibrinogen (plasma protein) = fibrin
- Fibrin is an insoluble material that forms a mesh of strands around the area of injury
9.This mesh prevents the loss of blood and eventually solidifies to form a clot
Formation of blood clot (simple)
- Blood vessel ruptures and releases chemical called PF3’s
- PF3’s attract platelets to the site
- Platelets release thromboplastin
- Thromboplastin react with Prothrombin to produce Thrombin. This reaction is catalyzed by Calcium ions
- Thrombin reacts with Fibrinogen to produce Fibrin
- Fibrin forms a mesh that prevents blood loss
What are the 4 major blood groups
A, B, AB, O
Each blood group is characterized by the presence/absence of particular protein markers on the walls of RBC
The four blood groups results from different combinations of two protein markers (___and ___)
The four blood groups results from different combinations of two protein markers (A and B)
What are the proteins that stimulate the formation of antibodies
Antigens are proteins that stimulates the formation of antibodies
what are the proteins in blood plasma that react with antigens?
Antibodies (proteins in blood plasma that react with antigens)
People who have Type A blood have the ___ antigen attach to their RBC membrane and have Antibody ___ in plasma
People who have Type A blood have the A antigen attache to their RBC membrane and have Antibody B in plasma
People with Type B blood have the ___ antigens attached to their RBC membrane and have Antibody ___ in plasma
People with Type B blood have the B antigens attached to their RBC membrane and have Antibody A in plasma
People with AB blood have ___ antigens attached to their RBC membrane and have neither Antibody ___ or ___
People with AB blood have AB antigens attached to their RBC membrane and have neither Antibody A or B
People with O blood have ____ antigens attached to their RBC membrane, but have Antibody ___ and ___.
People with O blood have NO antigens attached to their RBC membrane, but have Antibody A and B.
Can only accept blood from O type donor.
How does the body react when different markers (antigens) enter the blood and what is the role of white blood cells in this process?
When markers (antigens) that are different enter the blood, the body identifies them as though they are invading microbes. The body‛s white blood cells will destroy the invading antigens
The transport vessels (3 main types of blood vessels)
Arteries
Veins
Capillaries
Arteries
Carry blood AWAY from the heart
Have thick walls
1. Connective tissue (outer most layer)
2. Smooth muscle(thickest/middle layer)
3. Smooth epithelial cells (1 cell thick, reduce friction from blood, inner layer)
Strong walls make arteries capable of withstanding great __________.
Every time your heart contracts, blood surges from your heart and enters the arteries, forcing the arteries to _______. When the heart relaxes, the arteries _________.
Strong walls make arteries capable of withstanding great pressure
Every time your heart contracts, blood surges from your heart and enters the arteries, forcing the arteries to stretch. When the heart relaxes, the arteries recoil
What is a pulse?
Change in diameter of arteries after heart contacts blood surges through the arteries
Aorta (parts)
- Ascending aorta
- Aortic arch
- Thoracic aorta
- Abdominal aorta
Descending aorta = 3+4
Artery disorders
Atherosclerosis
Carotid Artery Disease
Aneurysms
Raynaud’s Syndrome
Atherosclerosis = fat in arteries
Plaque (fat) blockage in arteries anywhere in body
Build up takes a while
Narrows diameter of artery causing INCREASE in blood pressure
Carotid artery disease
Blockage in carotid artery
Artery in neck (supply blood to brain) becomes clogged and may cause stroke
Atherosclerosis treatments
- Angioplasty (inflated balloon squeezing fat build up) - non permanent
- Stenting ( mesh stent that opens up/expands the artery)
- Endarterectomy ( surgically removing the build up from artery)
Aneurysm
Abnormal bulge in artery wall
If grow and gets big enough, it can burst caused dangerous/fatal bleeding in body
If happens in brain = stroke or even death
Raynauds syndrome
Rare disorder that affects blood vessels (brief episodes of vasoconstriction)
Vasoconstriction = causes decreased blood flow to fingers/toes/nose/lips/ears, mostly fingers only
Arterlioles
Blood moves from arteries to smaller vessels arterioles
Covered with smooth muscle
Nervous system can tell them to contact (vasoconstriction) = less blood flow to tissue
Nervous system can tell them relax (vasodilation) = increases blood flow to tissue
Capillaries
Blood moves from arterioles to capillaries
Gas exchange happens
Directions of blood flow
Heart ➡️ arteries ➡️ arterioles ➡️ capillaries ➡️ venules ➡️ veins ➡️ heart
Venules
Capillaries merge and become larger vessels venules
Venules merge and become larger vessels veins
Veins
Bring blood back to heart
Has same 3 layers as artery just smaller middle layer (smooth muscle)
Valves (veins)
Opens only in one direction/ direct blood to heart
Muscle contraction help bring blood back ( muscle contract = vein diameter less = venous pressure increase = veins to open
Varicose veins
Distorted/twisted veins
Happen cause venous valves don’t work = blood pools
Heart
Has 4 chambers
2 thin wall atria’s
2 thick wall ventricles
Atrium (receiving chambers)
Top 2 chambers of heart
Receive blood from veins
Ventricles (dispatching chambers)
Bottom 2 chambers of heart
Deliver blood to arteries
Thick muscular walls = need to pump the blood to rest of body
The 2 sides of the heart are considered parallel pumps. They are separated by a muscular _______
The 2 sides of the heart are considered parallel pumps. They are separated by a muscular septum
The pump on the right receives oxygen _____ blood from the body
The pump on the left receives oxygen _____ blood from the lungs
The pump on the right receives oxygen poor blood from the body
The pump on the left receives oxygen rich blood from the lungs
Pericardium
Protective membrane surrounding the heart (has liquid = reduces friction when heart beats)
Pulmonary Circuit
Made up of vessels that carry blood to and from the lungs
Systemic Circuit
Made up of vessels tha carry blood to and from the body tissues
Pulmonary arteries
Artery with oxygen poor blood
Pulmonary vein
Vein with oxygen rich blood
Superior/inferior vena cava
Brings back oxygen poor blood from body to heart
Aorta
Artery that transport oxygen rich blood from heart to body
One way blood flow
- Blood gets pumped to atria
- From atria, blood moves to ventricles
- Direction of blood flow is controlled by valves, that separate atria from ventricles and each ventricle from arteries
AV valves
Separate atria from ventricles
Prevents blood from flowing back to atria from ventricles
Tricuspid valve
On right side
3 valves
Bicuspid valve
On left side
2 valves
Chordae tendineae
Thin valves that anchor valves and prevent them from flipping inward to atria
Semilunar valves
Separate ventricles from arteries
Prevents blood that is in arteries to flow back into ventricles
Pulmonary semilunar valve
Entrance of pulmonary artery from right ventricle
Aortic semilunar valve
Entrance of aorta from left ventricle
Flow of blood through heart
- Superior/inferior vena cava
- Right atrium
- Tricuspid valve
- Right ventricle
- Pulmonary semilunar valve
- Pulmonary trunk
- R/L pulmonary arteries
- Lungs
- R/L pulmonary veins
- Left atrium
- Bicuspid valve
- Left ventricle
- Aortic semilunar valve
- Aorta
- Body
Coronary arteries
Arteries that supply blood to heart tissue
Cardiac veins
Transport oxygen poor blood is carried away into right atrium
Coronary artery disease
Fat build up (atherosclerosis) in coronary arteries = not enough oxygen delivered to heart muscle
Cause heart pain due lack of oxygen (angina)
If oxygen starved cells die = myocardial infractions (heart attack)
Coronary artery disease treatment
Coronary angioplasty
Stenting
Coronary artery bypass (blood
Vessel from another body part is removed and bypasses blocked coronary arteries
Systole
Contractions of a heart chamber
Diastole
Relaxation of a heart chamber
Heart sounds
- Atria in state of diastole = fill with blood
- Atria then become systole = push blood into ventricles in state of diastole
- Ventricle enter systole and contract = backside AV valve cusps slam shut = first sound (LUBB)
- Blood enter artery attached to ventricles, some blood will fall down on semilunar valve = slam shut = second sound (DUBB)
Cardiac muscle
striated ( a mix between skeletal and smooth muscle)
Myogenic muscles
Don’t require any nerve stimulation to make them contract
Sinoatrial Node (SA Node)
Located in the right atrium, generates an electrical impulse.
Acts as a natural pacemaker, setting the rhythm of the heart.
Atrial Contraction
The electrical impulse spreads over both atria through atrial conducting fibers.
Atria contract simultaneously, pushing blood into the ventricles.
Atrioventricular Node (AV Node)
The impulse travels to the AV node located at the base of the right atrium.
Bundle of His
From the AV node, the signal moves to the Bundle of His, located in the septum between the ventricles.
Bundle Branches
The signal travels down the septum and up the ventricular walls through left and right bundle branches.
Purkinje Fibers
Bundle branches send out purkinje fibers, long fibers distributed throughout the ventricular muscles.
Ventricular Contraction
Bundle branches and purkinje fibers stimulate the ventricles, causing them to contract.
Contraction forces blood out of the heart to the lungs and the rest of the body.
How heart beats
- Sinoatrial (SA) Node
- Atrial Conducting Fibers
- Atrioventricular (AV) Node
- Bundle of His
- Bundle Branches (right and left)
- Purkinje Fibers
Electrocardiogram (ECG)
Change in voltage produced by electrical signals of heart
Electrocardiograph
Tracing produced by the electrocardiogram
How does a doctor obtain a heart tracing?
Placing electrodes on the skin over the heart and transmitting signals to an instrument that measures electrical changes in the heart muscle.
What does the first part of the heart tracing (1) represent?
Shows the depolarization (contraction) of the atria, accompanying their contraction.
What does the second part of the heart tracing (2 - QRS) represent?
Shows the depolarization (contraction) of the ventricles, accompanying their contraction.
What does the third part of the heart tracing (3 - T wave) represent?
It shows the repolarization (relaxation) of the ventricles.
Arrhythmias
Any change from the normal sequence of the electrical impulse, causing abnormal heart rhythms
Tachycardia
Heart rate exceeding 100 beats/min
Hinders ventricles from filling adequately, leading to insufficient blood pumping
Oxygen deficiency = shortness of breath, dizziness, blackouts, and fainting.
Bradycardia
Less than 60 beats/min
Shortness of breath, dizziness, blackouts, fainting,
Treatments (Arrhythmias, Tachycardia, Bradycardia)
Pacemaker (can take charge of sending the signal)
Defibrillator (corrects arrhythmia‛s )
