How do things get around the body? Flashcards
1
Q
What is the Cardiovascular System?
A
- Transports fluids, nutrients, waste products, gases, and hormones throughout the body.
- Exchange materials between blood, cells and extracellular fluid.
2
Q
What is the role and what does the cardiovascular system consist of?
A
- Plays a role in the immune response, blood pressure and the regulation of body temperature.
- Consists of the heart, blood vessels, capillary beds and blood.
3
Q
What are the functions of the heart?
A
- Generating blood pressure – moves blood through vessels.
- Routing blood: separates pulmonary and systemic circulations.
- Ensuring one-way blood flow.
- Regulating blood supply.
- Changes to match need.
4
Q
Describe the location of the heart
A
-Size of a closed fist
-Shape
o Apex: Blunt rounded point of cone
o Base: Flat part at opposite of end of cone
-Located in thoracic cavity in mediastinum
5
Q
What is the Fibrous & Serous Pericardium?
A
- Fibrous pericardium: tough fibrous outer layer, prevents over distention; acts as anchor.
- Serous pericardium: thin, transparent, inner layer, simple squamous epithelium.
6
Q
Describe the Parietal & Visceral Pericardium
A
- Parietal pericardium: lines the fibrous outer layer.
- Visceral pericardium: covers heart surface.
- The two are continuous and have a pericardial cavity between them filled with pericardial fluid.
7
Q
Describe the three layers of tissue in the heart
A
- Epicardium: Serous membrane; smooth outer surface of heart.
- Myocardium: Middle layer composed of cardiac muscle cells – contractility.
- Endocardium: Smooth inner surface of heart chambers.
8
Q
What is the Pectinate muscles & Trabeculae Carnae?
A
- Pectinate muscles: muscular ridges in auricles and right atrial wall.
- Trabeculae carnae: muscular ridges and columns on inside walls of ventricles.
9
Q
What are the chambers of the heart?
A
- Atrium (L & R)
2. Ventricle (L, I & R)
10
Q
What is the left and right atrium?
A
- Right atrium: three major openings to receive blood returning from the body.
- Left atrium: four openings that receive blood from pulmonary veins.
11
Q
What is the left, right, atrioventricular and inter-ventricular ventricles?
A
- Atrioventricular canals: openings between atria and respective ventricles.
- Right ventricle: opens to pulmonary trunk.
- Left ventricle: opens to aorta – very muscular wall.
- Interventricular septum: between the two ventricles.
12
Q
What are the great vessels going into the heart and out of the heart?
A
-Blood into the heart:
o Into Right Atrium – superior and inferior vena cava
o Into Left Atrium – left and right pulmonary veins
-Blood out of the heart:
o Out of right ventricle – pulmonary trunk
o Out of left ventricle - aorta
13
Q
What is the Atrioventricular Valves?
A
- Each valve has leaf-like cusps that are attached to cone shaped papillary muscles by tendons (chordae tendineae).
- Right has three cusps (tricuspid).
- Left has two cusps (bicuspid, mitral).
- When valve is open, blood flows from A → V.
- When it is closed, blood exits ventricle.
14
Q
What is the Semilunar Valves?
A
- Each cusp is shaped like a cup.
- When cusps are filled, valve is closed – stop backflow.
- When cusps are empty, valve is open – blood exits heart.
15
Q
Describe the Arteries
A
- Elastic, Muscular, Arterioles
- Take blood away from the heart
- Contain blood under pressure
16
Q
Describe the Veins
A
- Large, medium, small, venules
- Take blood to the heart
- Thinner walls than arteries, contain less elastic tissue less smooth muscle
- Valves to prevent backflow
17
Q
What is the function of the Capillaries and describe them
A
Functions: The site of exchange with tissues (interstitial fluid)
- Capillary beds – extensive networks for exchange.
- Wall consists of endothelial cells (simple squamous epithelium), basement membrane and a delicate layer of C.T.
- Substances move through capillaries by diffusion
18
Q
What is the Tunica Intima, Externa & Media in the arteries and veins?
A
- Tunica intima: Endothelium
- Tunica media: smooth muscle cells arranged circularly around the blood vessel.
- Tunica externa (adventitia): connective tissue
19
Q
What is Vasoconstriction & Vasodilation?
A
- Vasoconstriction: smooth muscles contract, decrease in blood flow.
- Vasodilation: smooth muscles relax, increase in blood flow.
20
Q
What is the function of blood?
A
- Transport: gases, nutrients, waste products, processed molecules, hormones, enzymes
- Regulation of pH and osmosis (normal pH 7.4)
- Maintenance of body temperature
- Protection against foreign substances
- Clot formation
21
Q
Describe red blood cells
A
- No nucleus & bi-concave shape to increase SA and thus oxygen carrying capacity.
- Oxygen from lungs to body cells: 98.5% attached to haemoglobin protein 1.5% dissolved in plasma.
22
Q
Why do we need a cardiovascular system in terms of transport?
A
- Humans are multicellular
- Cells around the body all need a constant supply of oxygen and nutrients, and constant removal of waste products.
- We need a circulating fluid for transportation.
- Exchange materials between blood, cells and extracellular fluid (interstitial fluid).
- Blood and blood vessels.
- Capillaries - exchange
23
Q
Why do we need a cardiovascular system in terms of a pump?
A
- Generating blood pressure – moves blood through vessels.
- Routing blood: separates pulmonary and systemic circulations.
24
Q
Describe the process of gas exchange in the pulmonary circulation
A
- Deoxygenated blood enters right atrium and flows into right ventricle.
- Exits heart through Pulmonary trunk.
- Pulmonary trunk divides into left and right pulmonary arteries.
- Blood travels to right and left lung – gas exchange.
- Oxygenated blood travels in left or right pulmonary veins and enter the left atrium.
25
Describe the process of gas exchange in the systemic circulation
6. Capillary exchange in the body/cells.
7. Oxygenated blood enters left atrium. Blood flows into left ventricle.
8. Left ventricle contracts and pushes blood out of heart through aorta.
9. Aorta branches into Ascending aorta, Aortic arch, Descending aorta.
10. Blood is delivered to all cells and tissues in the body for gas/nutrient/fluid exchange.
11. Blood travels back to heart and re-enters right atrium through vena cava.
26
What does the contraction of the heart do?
-Contraction of heart produces the pressure
o Blood moves through circulatory system from areas of higher to lower pressure
o Cardiac cycle – Repetitive contraction (systole) and relaxation (diastole) of heart chambers – moves blood through the heart and body.
27
What is blood proportional to?
-Blood flow is proportional to metabolic needs of tissues.
o Brain, kidneys, liver, exercising skeletal muscle – very high.
o Can change: Cardiac output = Heart rate x Stroke Volume.
28
In terms of the Nervous System what does the heart do?
- Maintains blood pressure and thus blood flow. Re-routing blood flow. E.G. Increase BP with exercise.
- Re-route blood flow away from skin and viscera towards brain and cardiac muscle in response to blood loss / injury.
29
In terms of hormonal control what happens to the heart?
-Epinephrine (adrenaline) from adrenal gland – increase HR and SV, vasoconstriction in response to stress.
30
What is an action potential?
-A rapid change in membrane potential. Acts as an electrical signal / impulse.
31
What does the heart generate on its own?
-The heart can generate its own action potentials.
32
In the conducting zone what happens?
- Auto-rhythmicity – repetitive contractions.
- Sinoatrial node (SA) – pacemaker.
- Atrioventricular node (AV).
- Action potentials spread through the conducting system of the heart to all cardiac muscle cells – as a result the cardiac muscle cells contract. Blood is ‘pumped’.
33
What is lipid and water soluble?
- Lipid soluble - diffuse through plasma membrane of endothelial cells (O2, CO2, steroid hormones, fatty acids).
- Water soluble - diffuse through intercellular spaces or through fenestrations of capillaries. Glucose, amino acids.
34
What is capillary exchange?
-Capillary exchange: the movement of substances into and out of capillaries. How cells receive what they need to survive and eliminate waste products.
35
What have large & small spaces between cells
- Large spaces between endothelial cells – proteins and whole cells can pass e.g. liver or spleen.
- Very small spaces between cells – very few molecules can pass – e.g. blood brain barrier.
36
What affects the movement of fluid from the capillaries?
-Capillary permeability, Blood pressure, and osmotic pressure affect movement of fluid from capillaries.
37
What is the most important means of exchange?
-Most important means of exchange: diffusion. Oxygen, hormones, nutrients diffuse from a high concentration in the capillary to low concentration in the interstitial fluid.
38
What does transport in and out of cells require?
A pressure gradient
39
In terms of the lymphatic system what happens to the fluid?
- Fluid moves out of capillaries into interstitial (intercellular) space and most returns to capillaries.
- The fluid which remains in tissues is picked up by the lymphatic system then eventually returned to venous circulation.
40
What is the Edema?
-Edema (oedema): swelling caused by excess fluid accumulation in body tissues (interstitial space).
41
What are the causes of Edema?
-Problems with capillaries, Heart failure, Kidney disease, Liver problems, Pregnancy, Problems with lymphatic system, Standing or walking a lot in hot weather, Eating too much salt.
42
What happens if capillaries become leaky?
-If capillaries become ‘leaky’ blood proteins can leak into the interstitial fluid. This increases the osmotic pressure (osmolarity) outside the capillary. More fluid moves from the capillaries into the interstitial fluid.
