Cardiovascular system II Flashcards
Systemic circulation
Blood from the heart is distributed around
the body before returning to the heart.
Pulmonary circulation
Blood from the heart to the lungs and
back to the heart.
Main role of capillaries
Exchange of
substances between blood and cells / tissues
Arteries & Arterioles
Location
Blood content
Pressure
Valves?
Away from heart
Oxygenated
High pressure
No valves
Veins & venules
Location
Blood content
Pressure
Valves?
Towards the heart
Deoxygenated
Low pressure
Valves
How does the structure of capillaries support their main role?
Capillaries contain only one layer of
cells (the ‘endothelium’).
Inner layer of blood vessels
Tunica intima
Middle layer of blood vessels
Tunica media
Outer layer of blood vessels
Tunica externa
3 functions/ characteristics tunica intima
endothelium (epithelial tissue)
protects the vessel wall & secretes chemicals.
Monitors changes in the blood
2 characteristics Tunica media
Smooth muscle
Controls blood vessel diameter
Tunica externa made from
elastic and collagen fibres
Which muscle type supports the return of venous blood to the heart?
Skeletal muscles
Which transport process supports the capillary exchange of gases?
Diffusion
Which transport process supports the capillary exchange of nutrients?
Facilatated diffusion and active transport
Which transport process supports the capillary exchange of water?
osmosis
Where is most blood found in the body?
64% blood in systemic veins / venules.
* 13% in systemic arteries / arterioles.
What is the hepatic first pass?
Venous blood passes from the
digestive tract, spleen and
pancreas directly to the liver
Portal vein
The vessel that carries the
absorbed substances from the GIT, spleen pancreas to the liver
Which nervous system stimulates vasoconstriction?
Sympathetic nervous
How do vasoconstriction and vasodilation impact blood pressure?
Vasoconstriction - increases blood pressure
Vasodilation - reduces blood pressure
Heart location
The heart rests on the
diaphragm, in the thoracic
near the midline, pointing left.
Apex 5th intercostal space.
Heart key facts
fist-sized muscular
organ
Blood pumps through 60k
miles of blood vessels
12 cm long, 9 cm wide
250 g in females. 300 g in males
Endocardium
Inner lining of the heart
Smooth endothelium
Provides a smooth lining
Myocardium
Cardiac
muscle and
makes up
95% of heart.
PUMP
Pericardium
fibrous pericardium that
attaches to the diaphragm and
an inner serous pericardium
Keeps position and allows free movement
HEart layer than contains cardiac muscle
Myocardium
Auto-rhythmic
Ability to generate its own rhythm
Four chambers of the heart
- Right atrium.
- Right ventricle.
- Left atrium.
- Left ventricle.
Is the right ventricle thicker than the left ventricle?
No, left ventricle is thicker.
Role of ductus arteriosum
Temporary blood vessel during foetal life
shunts blood from
the pulmonary trunk to the aorta.
4 factors that influence heart rate and strength
Hormones
Age
Sex
Body Position
Exercise
Stress
Temperature
How does the sympathetic nervous system influence heart rate and strength?
Increases strength and rate of constriction
Vasoconstriction
How does the parasympathetic nervous system influence heart rate and strength
Vagus nerve
Decreases strength and rate of constriction
Vasodialation
Describe the role of the sinoatrial node
pacemaker of the heart
where is the sinoatrial node?
right atrial wall
Conduction system of the heart
- Sinoatrial node - causes atrial contraction
- Atrioventricular node - replay station
- Atrioventricular bundle (‘Bundle of His’): conduct from atria to ventricles.
- Right and left bundle branches - towards the apex of the heart
- . Purkinje fibres:- vertricular contraction
Which type of respiration does the cardiac muscle require
aerobic respiration
What is the predominant fuel used by the cardiac muscle?
Fatty acids - 50-70%
What can the heart use to produce ATP during exercise?
Lactic acid
What is meant by pulse rate?
Blood pressure wave originating from the heart
Average adult pulse rate
70-90
Cardiac output
Volume of blood being pumped by the heart per minute
Tachycardia
Resting heart rate over 100 bpm
Bradycardia
Resting heart rate under 60 bpm
Systole
The force that drives blood out of
the heart (contraction).
Diastolen
Period of relaxation when the
heart fills with blood
NHS normal range of blood pressure
90/60
–140/90
2 organs have the highest priority for blood
Brain & heart
2 functions of cholesterol
Cell membrane integrity (vital in the brain).
Vitamin D and calcium metabolism.
Sex hormones (e.g., oestrogen, testosterone).
How cholesterol is transported around the body
Hydrophobic transported as lipoproteins.
Function low density liporoteins (LDL)
Carry 75% of cholesterol from liver to cells in the body
Function of high density lipoproteins (HDL)
Remove excess cholesterol from body cells and transport it to the liver
Pathophysiology of atherosclerosis
Narrowing and hardening of arteries
1. Damage to endothelium creates inflammation
2. LDLs deposit on the Tunica Intima, oxidise and attract phoagocytes
3. Macrophages surround
4. Smooth muscle proliferate
5. A plaque is formed
4 causes of atherosclerosis
Hyperglycaemia (e.g., diabetes),
obesity,
hypertension,
smoking,
stress,
sedentary lifestyle,
excessive
alcohol,
trans fats, gut / oral dysbiosis, intestinal permeability.
2 ways atherosclerosis presents
Angina pectoris .
Stroke
4 causes of hypercholesterolemia
Gene defect
* Age-related (risk increases with age).
* Diet (high refined sugars,
trans fats, table salt, etc.).
* Sedentary lifestyle.
* Diabetes mellitus (insulin resistance).
* Obesity.
* Excessive alcohol.
* Smoking.
Angina pectoris
Ischaemic heart disease due to obstruction
or spasm of the coronary arteries.
Pathophysiology of angina pectoris
demands of the myocardium
not being met by its blood supply; e.g., due
to atherosclerosis or vascular spasm.
Stable and unstable Angina pectoris
Stable: Pain is precipitated by physical exercise.
* Unstable: Occurs randomly, even at rest. More
severe and can last longer
2 signs / symptoms of angina pectoris
constricting chest pain
Eases on rest.
Dyspnoea - difficulty breathing
Most common cause of a myocardial infarction
Usually due to blockage of a coronary artery by a thrombus
Describe the pain associated with a myocardial infarction
Severe chest pain
Does not improve on rest.
Overwhelming anxiety / sense of impending doom.
What does myocardial infarction mean?
Heart attack
Infarction - death of a tissue
2 causes of heart failure
- Other cardiovascular
conditions, e.g., coronary heart disease,
hypertension, heart valve diseases. - Insulin resistance → impaired
myocardial glucose utilisation.
Which type of heart failure is associated with pulmonary oedema?
Left sided
Oedema = swelling / accumulation of water
2 allopathic treatments for acute heart failure
GTN sublingually (nitrate medicine under the tongue)
cardiopulmonary resuscitation (CPR)
2 allopathic treatments for chronic heart failure
ACE inhibitors - reduce blood pressure
beta-blockers
2 causes of a stroke
Thrombus / embolus (80%) = ischaemic stroke.
Haemorrhagic stroke — blood vessel damage
Ischaemic - medical problem where there is a lack of blood flow
What is a stroke?
A disruption of blood supply to the brain.
Brain dysfunction lasting more than 24 hours
What is heart failure
Heart is impaired as a pump and fails to supply sufficient blood flow
What is a heart attack
Necrosis (death) of myocardial tissue due to ischaemia.
Usually due to blockage of a coronary artery by a thrombus
What is ischaemia
Medical problem where there is not enough blood flow to a part of the body
3 signs and or symptoms of a stroke
F – Face
A – Arm
S – Speech
T – Time (act fast and call 999)
Typically asymmetrical
Difference between a stroke and transient ischaemic attack
Transient ischaemic attack
Temporary, lasts no longer than 24 hours
Impaired functions improve
Stroke
Lasts more than 24 hours
Acronym for stroke symptoms
Face
Arms
Speech
Time
Brain location where berry aneurysms typically occur
Centre of the cerebrum
What is an Aneurysm
Abnormal local dilations of arteries due to weakness of
the vessel wall
Define hypertension
High blood pressure
Major risk factor in cardio vascular disease
2 primary causes of hypertension
Generally lifestyle and family
history.
Unhealthy lifestyle - Obesity, age, smoking, sedentary, stress, excess alcohol,
1 secondary cause of hypertension
Another disease - eg diabetes
2 complications of hypertension
Cardiovascular disease
cerebrovascular events
Stoke
Kidney disease
cerebrovascular = relating to the blood vessels that supply the brain
Celebrovascular meaning
Relating to the blood vessels that supply the brain
Difference between valve stenosis and valve regurgitation
Valve stenosis - Fibrosis and calcification of valve causing obstruction to blood flow through heart
Valve regurgitation - Inadequate valve closure causing leakage
Artrial fibrillation
Irregular rhythm and force leading to inadequate blood supply
Compare myocardial infarction and cardiac arrest
Medical emergency as the heart has stopped
Mycardial infarction (heart attack) - Necrosis (death) of myocardial tissue due to ischaemia.
Usually due to blockage of a coronary artery by a thrombus.
Endocarditis
An inflammation of the endocardium and valves
What are Osler’s nodes and what are they are sign of
red tender spots
under skin of fingers
Endocarditis
Compare myocarditis and pericarditis
Myocarditis - Inflammation of the myocardium.
Pericarditis - Acute inflammation of the pericardium.
1 viral cause of pericarditis
Flu
rheumatoid arthritis (RA)
2 signs / symptoms of pericarditis
Chest pain
Dyspnoea - difficulty breathing
Dysnopea
difficulty breathing
Describe ‘cardiac tamponade’ - complication of pericarditis
Fluid collects in the
pericardium, putting pressure on the heart, inhibiting it from
filling completely
2 DVT risk factors
Reduced blood flow (immobility,
pressure on vein by tumour,
long-haul flights).
* Varicose veins.
* Changes in blood (dehydration,
polycythaemia, sticky platelets,
oral contraceptive pill).
* Damage to blood vessel wall
How is DVT diagnosed?
Ultrasound
D Dimer test
Compare DVT and Varicose veins
DVT Thrombus formation in the deep
veins of the legs.
Varicose veins - Incompetent valves cause pooling of the venous
blood
chronically dilated superficial veins.
Haemorrhoids
Dilated veins in the anal canal.
2 causes of haemorrhoids
Chronic constipation
Pregnancy
Hypertension
2 signs / symptoms of haemorrhoids
Bright red blood with bowel movements,
protruding haemorrhoids,
anal itching
Reynaud’s syndrome
Intermittent attacks of ischaemia in extremities
1 rheumatological causue of Raynaud’s syndrome
RA
Extreme temperature
3 signs / symptoms of Raynaud’s syndrome
Pallor,
cyanosis,
redness
2 cardiovascular causes of oedema
Heart failure
Renal disease
DVT
ascites
An excessive accumulation of fluid in the peritoneum
2 causes of ascites
Liver cirrhosis
Heart failure
2 signs / symptoms of ascites
Abdominal distension
Nausea and suppressed appetite.
