Cardiovascular Disease

Question 1

What is the cardiovascular system?

Answer 1

~Responsible for delivering blood to different parts of the body
~organs & tissues
~Heart (muscular pump forces blood around body)
~Closed system of blood vessels

Question 2

What is the vena cava?

Answer 2

~inferior vena cava brings deoxygenated blood from the lower half of the body to the right atrium
~Superior brings deoxygenated blood from to top half of the body to the heart

Question 3

What is the aorta?

Answer 3

Largest artery - connects left ventricle of the heart to all body tissues (except lungs)

Question 4

What is the carotid artery?

Answer 4

In neck - brings blood to brain and head

Question 5

What is a thrombus and what risks factors are associated with it?

Answer 5

~intravascular (within peripheral blood stream) blood clot
Risks include
1 - slow blood flow e.g. hypotension, CHD, long air flights
2- damages the smooth intimal lining of the blood vessels - cholesterol, ketoacidosis, diabetes
3- increased blood coagulation - thrombocytosis

Question 6

What risk factors are associated with blood coagulation?

Answer 6

~some malignant diseases & disorders of blood clotting
~pregnancy - increased blood production
~childbirth
~Oral contraceptives (oestrogen) “The Pill”
~use of tampons & moon cups - blood held in vaginal cavity
~standing for long periods of time e.g. cashiers

Question 7

What is deep vein thrombosis?

Answer 7

~usually occurs in the veins of the lower limb e.g. pelvic & iliac regions
~Pain & swelling - tends to be asymptomatic in deeper veins

Question 8

What is an embolus?

Answer 8

~Mass of any material being carried by the blood
~Most Common - fragment of a thrombus - deep vein thrombus - may cause pulmonary embolism (piece of thrombus carried via blood vessels to lungs)

Question 9

What material can be emboli?

Answer 9

~Pieces of thrombi
~Amniotic fluid emboli
~Tumour fragments - may cause metastases
~Nitrogen bubbles in decompression sickness (bends)
~Fragments of atheromatous plaques
Air emboli - puncture of blood vessel by broken rib, phlebotomy, surgery

Question 10

What is an embolism?

Answer 10

~Travelling embolus lodges and obstructs a blood vessel
~Pulmonary embolism in lungs, blockage of coronary arteries - myocardial infarction, blockage of cerebral artery - cerebral infarction

Question 11

What is infarction?

Answer 11

Tissue death due to interrupted blood supply - may result in amputation

Question 12

What is ischaemia?

Answer 12

Tissue damage due to reduced blood flow - angioplasty to get rid of obstruction

Question 13

What is shock?

Answer 13

~Metabolic needs of a cell are not met due to inadequate blood flow
~Caused by reduction in circulating blood volume, blood pressure, & cardiac output
~Causes hypoxia - inadequate supply of nutrients & accumulation of waste products
~ causes pale skin. weak but rapid pulse, irritability, thirst, irregular heart beat, dizziness, sweating

Question 14

What is hypovolaemic shock?

Answer 14

~Blood volume falls by 15-25% - reduced cardiac output
~caused by severe burning (plasma lost), haemorrhages, emesis & diarrhoea (water & electrolytes lost)

Question 15

What is cardiogenic shock?

Answer 15

~Acute heart disease - damage to muscle can’t maintain adequate cardiac output
~Inadequate blood flow to tissue e.g. myocardial infarction

Question 16

What is septic shock?

Answer 16

~Bacteraemic endotoxin - bacterial endotoxin in blood - massive inflammatory & immune response - powerful mediators released
~Hypotension - widespread vasodilation, depression of myocardial contractibility, poor tissue perfusion. & tissue death
~Multiple organ dysfunction

Question 17

What is neurogenic shock?

Answer 17

~Vasovagal attack-fainting
~Caused by sudden acute pain, severe emotional experience, spinal anaethesia, & spinal chord damage
~Excessive parasympathetic activity or decreased sympathetic activity - reduce heart rate & cardiac output
~Extensive vasodilation - hypotension - reduce blood supply to brain - fainting - short period

Question 18

What is anaphylactic shock?

Answer 18

~Anaphylaxis - severe allergic response e.g. penicillin & peanuts
~Vasodilation - release of mediators e.g. histamine & bradykinin
~Severe bronchoconstriction - respiratory difficulty & hypoxia
~Sudden onset - can cause death

Question 19

What is compensatory shock?

Answer 19

~Blood pressure falls - reflexes stimulated & hormone secretion
~Pressure increased by increased peripheral resistance, increased blood volume, increased cardiac output
~Compensatory mechanisms or medical intervention - perfusion of heart & brain maintained

Question 20

What is uncompensated shock?

Answer 20

~Self perpetuating with deteriorating cardiovascular function
~Hypoxia - cellular metabolism shifts to anaerobic pathways - lactic acid accumulation - progressive acidosis (capillary damage)
~Increased permeability - leaking fluid from vessels - lower blood pressure & tissue perfusion
~Waste products accumulate - vasodilation - hard to control blood pressure
~Organs deprived of oxygen
~Brain including cardiovascular & respiratory centres - starve of oxygen & nutrients
~lead to brain stem damage - death

Question 21

What is atheroma?

Answer 21

~Deposition of lipids (cholesterol) in walls of arteries
~Patchy changes in tunica intima of large & medium sized arteries
~Plaque=cholesterol, other lipids, excess smooth muscle, fat filled monocytes (foam cells) - covered in fibrous cap
~Plaques cause swelling that spread into the lumen of blood vessel
~Ruptures plaques may rupture-expose sub-intimal material to blood in which platelets adhere - may cause thrombosis
~Heart, brain, kidneys, small intestine, & lower limbs

Question 22

Cholesterol in bloodstream-production, composition, use in body, transportation

Answer 22

~Produced in liver & from diet
~Constituent of cells (brain cells & steroid hormones)
~Transported with triglycerides & phospholipids as lipoproteins
~Neutral lipid core (TAG & esterified cholesterol) - surrounded by coat of hydrophilic phospholipids & cholesterol

Question 23

Size of lipoproteins: Big - small

Answer 23

1 Chylomicron (can change shape & breakdown)
2 VLDL
3 IDL
4 LDL
5 HDL

Question 24

Reference ranges for cholesterol

Answer 24

Total cholesterol: <5.5mmol/L
HDL: >1.0mmol/L
LDL: <3mmol/L
Total Cholesterol : HDL: <4
Triglycerides: <2mmol/L

Question 25

What happens in regards to cholesterol after a meal?

Answer 25

~CM enter circulation @ 30 minutes - peak is at 2-4 hours (low VLDL secretion) ~CM conc. falls with time ~VLDL increases as insulin levels decrease ~IDL&LDL

Question 26

What causes atheroma?

Answer 26

~Fatty streaks present in infants - absorbed ~Failure to absorb fatty streaks - lead to atheromatous plaques in later life ~Begin in childhood - present in older people ~Lifestyle - high fat intake, low exercise levels

Question 27

What is atherosclerosis?

Answer 27

The presence of plaques in the circulatory system

Question 28

Risk Factors for atherosclerosis?

Answer 28

~Hereditary ~Obesity ~Gender (common in males, females after menopause - protective effect of oestrogen) ~Diet - high saturated fats & cholesterol ~Older age ~Smoking ~DM ~Excessive emotional stress ~sedentary lifestyle ~Hypertension ~Alcohol

Question 29

Effects of atheroma

Answer 29

~Partial/complete blockage of artery ~Thrombus formation - lead to ischaemia & infarction ~Embolisms

Question 30

What is the occlusion of arteries

Answer 30

~Completely blocks - infarction - tissue degenerates & dies ~Coronary artery - myocardial infarction ~Cerebral artery - cerebral ischaemia - cerebral infarction (stroke)

Question 30

Narrowing of arteries

Answer 30

~Tissue distal to affected artery - ischaemia - receive enough blood for minimum needs but not enough for increased metabolic rate - acute cramp like ischaemic pain ~Angina pectoris - ischaemic pain in heart ~

Question 31

Complications of atheroma

Answer 31

~Infarction & Thrombosis - fibrous cap overlying plaque breaks doen - platelets activated - thrombus forms - blocking artery - may cause emboli to break off - further infarction ~Haemorrhage - plaques calcified - artery becomes brittle, rigis, unresponsive to blood pressure shifts - rupture causing haemorrhage ~Aneurysm - local dialtion of arterial wall due to weakness - may rupture - fatal in aorta ~Hypertension - glaucoma

Question 32

What is hypertension?

Answer 32

~High blood pressure - narrowing of arterioles ~Strain on heart ~Causes include excess sodium intake, cigarettes, alcohol, caffeine, hereditary, old age, stress, saturated fats, obesity

Question 33

What is angina pectoris?

Answer 33

~Pain in chest (radiates to left shoulder & arm) ~Lack of oxygen supply to heart (physical exertion & partial blockages)

Question 34

What are varicose veins?

Answer 34

~ excessive dilation of vessel - valves don't close - backflow - usually in legs ~Veins lose elasticity - enlarged & fibrous tissue replaces tunica media

Question 35

What are the risk factors of varicose veins?

Answer 35

Hereditary, female gender, pregnancy, age (loss of elasticity in older patients - less effective recoil), reduced efficiency of skeletal muscle pump from prolonged standing, sitting

Question 36

What are angiomas?

Answer 36

~Benign tumours of blood vessels (haemangioma) and lymph vessels (lymphangioma) ~Excessive growth of blood vessels in uncharacteristic manner & interspersed with collagen fibres

Question 37

What is oedema?

Answer 37

~excess tissue fluid accumulation - swelling ~Pulmonary oedema - venous congestion in lungs & increased pulmonary vessel permeability - accumulation of fluid in alveoli - less area for gas exchange - dyspnoea (breathlessness), cyanosis (skin at lips, extremities turn blue), foamy sputum ~Causes of pulmonary oedema - cardiac failure, inflammation, irritation of lungs, excessive infusion of IV fluids

Question 38

What is thrombocytopenia?

Answer 38

~Low count (150000-450000 per μl normal) ~ low platelet production, increased platelets in spleen, increased breakdown of platelets ~Bruise easily ~Treat with steroids, transfusions, spleen enlargement or removal

Question 39

What Causes thrombocytopenia?