Lo1 Flashcards
(44 cards)
1
Q
White blood cells
A
Leucocytes: 1%
2
Q
Red blood cells
A
Erythrocytes: 45%
3
Q
Platelets
A
Thrombocytes: 1%
4
Q
Plasma
A
Water, protein, glucose, amino acid, salts, co2 and urea: 55%
5
Q
What do erythrocytes do?
A
- Carry oxygen and carbon dioxide to and from organs
- have a flexible disc shape: large surface area to volume ratio: maximum movement of O2 into RB cells
- no nucleus: maximum space for storage of O2: packed with haemaglobin
6
Q
What do leukocytes do?
A
- destroy bacteria
- 3 types of leucocytes: neutrophils, lymphocytes, monocytes
- neutrophils: most common: attach to blood vessel wall to block path of germs invading through cut infection areas: medium size
-lymphocytes: small size: produce antibodies: make memory cells: remember previous infections - monocytes: phagocytosis: any dead cell in the body: large size: allows them to digest large foreign particles
7
Q
What do Thrombocytes do?
A
-20% of diameter of RBC
-prevent bleeding
- contain protein allowing them to stick to breaks in blood vessel wall, and stick to each other.
8
Q
Myogenic
A
Doesn’t need nerve stimulation
9
Q
Right side of the heart
A
Carries deoxygenated blood
10
Q
Left side of the heart
A
Carries oxygenated blood
11
Q
2 chambers
A
Atria: left atrium and right atrium: thin walled
Ventricles: left ventricle and right ventricle: thick wall
12
Q
Valves
A
Tricuspid, bicuspid, semi lunar valves
13
Q
Vein and artery
A
Visiting and awy
14
Q
Right atrium
A
Superior vena cava: arms and head
Inferior vena cava: lower body and legs
15
Q
Right ventricle
A
Pulmonary artery and pulmonary semi lunar valves
16
Q
Left side
A
Pulmonary veins: return oxygenated blood from lungs to left atrium
Aorta: aortic semi lunar valve
Branching from aorta: coronary arteries: supply oxygen to heart
17
Q
Double pump
A
Atria contract and fill up at the same time.
They push the blood down into ventricles through the tricuspid an bicuspid valves.
Once ventricles are full: they contract from bottom- up: force blood against tricuspid and bicuspid valve: force them shut.
Blood leaves through the semi lunar valves into pulmonary arteries and aorta.
When blood leaves the ventricles: semi lunar valves shut
18
Q
Heartbeat is measured with a stethoscope
A
“Lub-dub”
Lub: tricuspid valves shut
Dub: semi lunar valves shut
19
Q
Heart contract and relax
A
Contract: systole
Relax: diastole
20
Q
Heart contract
A
Systole: ventricles contract: atrioventricular valves shut: semi lunar valves open
21
Q
Heart relax
A
Diastole: atria and ventricles relax: atrioventricular valves open, semi lunar valves shut: ventricle fills with blood
22
Q
Sino-atrial (SA) and atrioventricular (AV) nodes
A
Heart’s pumping triggered by electrical control.
* SA node passes wave of electrical current through atria = atrial systole.
* Fibrous tissue spans between the atria and ventricles to stop the current passing through…BUT…
* …the atrioventricular (AV) valve does allow it through. It’s at the top of the wall separating the ventricles.
23
Q
Sino-atrial (SA) node – the heart’s primary pacemaker located in right atrium
A
- Ensures both atria contract simultaneously
- Passes ‘impulse’ to atrioventricular (AV) node
24
Q
Atrioventricular (AV) node – the heart’s secondary pacemaker.
A
- When SA node send electrical impulse, it goes to the AV node first * While the SA node sets the rhythm of your pulse, the AV node sets
the rhythm contractions. - The AV node is located at the bottom right atrium of the heart.
- AV is responsible for delaying the transmission of electrical impulses it receives from the SA node.
25
Purkyne fibres
Carry electrical current down the middle of the ventricles to the base or apex of the heart
26
Electrocardiogram (ECG)
A simple and useful test which records the rhythm and electrical activity of the heart.
27
What the ECG trace tells us about what is happening in the heart
* Waves represent the electrical activity of the heart
* Different sections represent different activities within the heart:
* P wave – at the beginning. Shows atrial contraction
* QRS – ventricular contraction (systole)
* T – final wave before cycle repeats. Shows relaxations of ventricular muscles (diastole)
28
ECG
* If waves are disordered/out of rhythm, it shows which part of the heart is wrong
* Shows if heart rate is too slow
* Shows if heart rate is too fast
* Shows if heart rate is irregular
* Indicates abnormal heart conditions (heart attack/heart valve conditions)
29
What is lymph fluid?
*A colourless fluid made in the body.
*It surrounds all body tissues.
*It travels through the lymphatic system
30
What is the lymphatic system?
The lymphatic system helps protect us from infection and disease.
It is part of the body’s immune system. Lymph fluid passes through lymph nodes.
31
Lymph fluid
Capillaries enable materials to pass in and out of cells.
*When the heart contracts and increases the pressure in the capillaries (hydrostatic pressure), the water in plasma is pushed out of the cells. When this happens, the plasma carries with it oxygen from the oxyhaemoglobin in the red cells.
*Blood cells as well as blood proteins (e.g. albumin) can't pass through the basement membrane so they get left behind in the cell.
*Tissue fluid needs to go back to the circulatory system to stop our bodies from swelling as we would have too much tissue fluid building up (this condition is known as 'oedema' which can be fatal!)
*Most tissue fluid goes back to the capillaries via osmosis (movement of water through semi-permeable membrane from low concentrated area to high concentrated area).
*When plasma is forced out by hydrostatic pressure, more water surrounds the tissues which creates an imbalance, so water is drawn back into the capillaries via osmosis due to albumin in the capillaries (osmotic pressure).
*When water returns to capillaries, it also carries dissolved carbon dioxide and other waste.
32
Purposes of lymphatic system
*Swellings (lymph nodes) store and develop lymphocytes which check for pathogens in the lymph that returns.
*When fighting infection, the nodes in our neck, armpits and groin can swell.
32
Coronary heart disease
*Affects arteries that supply the heart with nutrients and oxygen.
*Causes – mainly lifestyle. Also age, gender and genes.
*Healthy artery – normal wall with inner surface called endothelium (smooth layer helping uninterrupted blood flow).
*Cigarette components that enter the blood via then lungs affect this, as well as high blood pressure.
*Once the endothelium is damaged, artery wall easily ‘invaded’ by fat/cholesterol-carrying lipoproteins LDL (deposit their fats into artery wall.
*White blood cells target these deposits, but die or get trapped with mineral deposits leads to gunge (atheroma) which gradually inflates the wall.
Lumen gets smaller
*This could lead to angina (cells after the obstruction don’t get enough oxygen resulting in pain on exertion.
*If atheroma completely blocks lumen, no oxygen and nutrients can reach the cells beyond so that part of the heart is damaged.
32
What can go wrong with the heart?
Coronary heart disease
Hypertension
32
Hypertension
High blood pressure
33
Hypertension biological explanation
Blood pressure is recorded with two numbers. The systolic pressure
(higher number) is the force at which your heart pumps blood around
your body.
The diastolic pressure (lower number) is the resistance to the blood
flow in the blood vessels.
They're both measured in millimetres of mercury (mmHg). High
blood pressure damages the blood vessels.
33
Hypertension Symptoms and effects:
As a general guide, ideal blood pressure is considered to be between
90/60mmHg and 120/80mmHg. High blood pressure is considered to
be 140/90 mmHg or higher.
Hypertension rarely has noticeable symptoms.
34
Causes of hypertension
Factors that can increase the risk of high blood pressure include:
- Age - the risk of developing high blood pressure increases as you
get older
- A family history of high blood pressure
- A high salt intake
- Lack of exercise
-Being overweight or obese
-Smoking and regularly drinking large amounts of alcohol
Conditions that can cause high blood pressure include:
- Kidney disease
- Diabetes
- Hormone problems such as an under- or overactive thyroid.
35
Monitoring, treatment and care needs for hypotonia:
- Blood pressure will need to be monitored - readings will need to be
taken regularly.
- Impact on lifestyle: Changes in diet - a balanced diet with low fat and
salt; take regular exercise; reduce alcohol intake; stop smoking; get
- enough sleep (at least 6 hours a night); reduce stress.
- Medication: Doctors may recommend taking one or more medicines
to keep blood pressure under control. These usually need to be
taken once a day. Common blood pressure medications include ACE
inhibitors, which lower blood pressure, and beta-blockers, which slow
the heart rate.
- Impacts: Hypertension can lead to an increased risk of coronary heart
disease, strokes and kidney disease.
36
Symptoms and effects of coronary heart disease:
- Angina: Symptoms of angina can include breathlessness, nausea,
dizziness, and chest pain, a feeling of tightness in the chest that may
spread to the arms, neck and jaw.
- Heart attack (myocardial infarction): Light headedness, feeling weak,
sweating, shortness of breath and chest pain that can radiate from the
chest to the jaw, neck, arms and back can all be signs of a heart attack.
37
Biological explanation for coronary heart disease:
- Walls of the arteries become blocked with fatty deposits, a process
called atherosclerosis.
- When arteries become completely blocked it can cause a heart attack,
which can permanently damage the heart muscle and if not treated
straight away can be fatal.
38
Cause of coronary heart disease;
Coronary heart disease is caused by a build-up of fatty deposits on
the walls of the arteries around the heart. Risk of this developing is
significantly increased by lifestyle factors such as smoking, lack of
regular exercise and obesity, or if a person has a high cholesterol level,
high blood pressure or diabetes.
Age, genes and gender can also influence the likelihood of developing
heart disease.
39
Monitoring, treatment and care needs for coronary heart disease
- Blood tests can check the levels of certain fats, cholesterol, sugar and
proteins in the blood.
- An electrocardiogram (ECG) measures the electrical activity of the
heart and can show any damage to the heart muscles or signs of
coronary heart disease.
- Lifestyle changes - as for hypertension (see above).
- Medication:
*Nitrates relax the coronary arteries and allow more blood to reach
the heart; these can be used to treat or prevent angina.
* Cholesterol-lowering medicines, such as statins.
* Antiplatelet medicines, such as aspirin or clopidogrel, and
anticoagulant medicines make the blood less likely to form clots.
They also reduce the risk of having a heart attack.
* ACE inhibitors lower blood pressure and are used if someone has
had a heart attack.
- Surgical procedures:
* Angioplasty passes a tiny deflated balloon into a narrow artery and
then inflates it, pushing the artery open; sometimes a stent or mesh
tube is inserted to treat narrow arteries.
* A coronary artery bypass graft is surgery to bypass the narrow
coronary arteries to improve the flow of blood to the heart.
* Coronary heart disease can't be cured but treatment can help
manage the symptoms and reduce the chances of problems such as
heart attacks.
* PIES impact on being able to complete daily living tasks, and
emotional and social impacts.
40
Structure of vessels
Arteries – carry blood from heart to rest of body at high pressure
- Thick smooth muscle layer: contract pushing blood along
- Have very thick walls: small lumen
- Have no valves (except for the pulmonary artery)
Vein-
Have thin walls
Carry blood towards your heart
Carry deoxygenated blood
Has a thin layer of muscle tissue inside: large lumen
Contain valves to keep blood flowing
Capillaries-
Have a very thin wall
Carry blood between veins and arteries
Carry both oxygenated and deoxygenated blood
Don't have muscle tissue
Don't have valves
