Cardiovascular System Flashcards
What’s the definition of the cardiovascular system
The CV system consists of the heart, blood and blood vessels, arteries, veins and capilliaries
What are the main functions of the CV system?
Transport - carries oxygen, carbon dioxide, nutrients, hormones, salts, enzymes, waste products
Thermoregulation - distributes heat around the body
Homeostasis - maintains a stable internal environment
Explain the steps of how the heart pumps blood around the body
- Blood enters the right atrium.
- It is pumped to the right ventricle.
- The right ventricle pumps it to the lungs.
- In the lungs, blood receives oxygen.
- Oxygen-rich blood returns to the heart through the pulmonary veins.
- Blood enters the left atrium.
- It is pumped to the left ventricle.
- The left ventricle pumps it to the rest of the body through the aorta and a network of blood vessels.
What are characteristics of arteries
Thick, muscular walls, they carry blood under high pressure
Transport oxygenated blood (except pulmonary arteries which take deoxygenated blood to the lungs to become oxygenated)
What are characteristics of capillaries?
One-cell-thick walls. Nutrient and gas exchanges take place in them
What are characteristics of veins
Thin walls, carry blood under low pressure
Transport de-oxygenated blood (except pulmonary veins which move oxygenated blood from lungs to heart)
What 2 systems make up the ANS (autonomic nervous system)?
SNS - sympathetic nervous system
PNS - parasympathetic nervous system
What is the ANS (autonomic nervous system)
It controls involuntary bodily functions like heart rate, digestion, breathing
What is the role and effects of the SNS - sympathetic nervous system
SNS prepares the body for action - fight or flight response
Effects include:
Increasing heart rate and blood pressure
Dilating pupils for better vision
Reduce digestion and urinary activity
Stimulate the release of adrenaline
Redirects blood flow to muscles and away from non-essential organs
What is the role and effects of the PNS - parasympathetic nervous system
Calms the body and conserves energy
Effects include:
Decreases heart rate and blood pressure
Constricts pupils
Stimulates digestion and nutrient absorption
Promotes relaxation and recovery
Facilitates elimination of urine and feaces
What is Coronary Heart Disease (CHD)
It is caused by narrowed coronary arteries due to atheroma (fatty deposits)
Symptoms include angina (chest pain) and heart attack
What is a Stroke (CVA)
Disrupted blood flow to the brain due to clots or vessel damage
Symptoms include confusion, paralysis, slurred speech
What is anaemia
Iron deficiency which reduces haemoglobin levels
Symptoms include fatigue and breathlessness
What is hypertension?
High blood pressure (greater than 140/90 mmHg)
Increases the risks of heart attack, stroke and angina
