Anatomy Introduction to the cardiovascular system Flashcards
How many layers do all arteries and veins have
3 layers
what are the 3 layers of arteries and veins
- tunica intima
- tunica media
- tunica adventitia
How many layers do capillaries have
1 - tunica intima
describe the structure of the tunica Intima
- Basement membrane
- Endothelium – simple squamous
- Endothelial function – vasoactive/minimizes friction – smooth surface for the blood to flow across
describe the structure of the tunica media
- Circular smooth muscle – mostly made up of smooth muscle
- Collagen and elastic fibres
- Vaso-constriction/dilation
Describe the structure of the tunica adventitia
- Connective tissue elastin and collagen
- Protects, strengthens, anchors
- Vaso vasorum – most blood vessels are thin so can get oxygen by diffusion but in the thick blood vessels the walls are too thick so the vaso vasorum are blood vessels in the blood vessels that take the oxygen to the blood vessel
- This is where autonomic nerve fibres are present here this controls vasco constriction and vaso dilation
what are the 2 types of arteries
elastic/conducting artery
muscular distributing artery
where do the elastic conducting artery originate from
they come out of the heart
where does the muscular distributing artery come from
they are the main named arteries
describe the structure of the elastic conducting arteries
- Large tunica media – made predominantly of smooth muscle not elastic fibres due to volume of blood that they are receiving
- Large amount of elastin
- Own blood supply vasa vasorum
- Aorta – arteries that leave the heart
describe the structure of the muscular distributing artery
- Large tunic media with IEL and EEL – made up of predominantly smooth muscle
- Elastic tissue condensed into two bands there is the internal elastic lamina and external elastic lamina
- Large amount of smooth muscle
- Renal artery
describe the arteriole structure
- Narrow lumen
- Large number of smooth muscle
- Direct blood into capillary beds
Describe the structure of the capillary
- Do not have three layers
- Only have one layer – tunica intima
- Simple endothelial tubes
- Specialised for exchange of nutrients
- Lumen; 7microns or less
- No adventitia or media layers
describe the structure of the veins
- Venules and veins have a larger lumen and thinner walls than corresponding arteries
- Valves – helps blood flow in one direction
- Developed tunica adventitia
- Has a lower pressure than arteries
describe how the musculovenus pump works
- Venous return to the legs is aided by muscular contraction
- Valves keep it flowing in one direction and prevents backflow
- Veins in the lower limb are placed in between muscles so when the skeletal muscles contract is squeezes the vein and helps contract the vein and pushes the blood up towards the heart
How do you differentiate between arteries and veins
- Artieres = away from the heart (most carry oxygenated, except in pulmonary)
- Veins = towards the heart (most carry deoxygenated)
describe the blood flow through the heart
- Deoxygenated blood enters the heart through the superior and inferior vena cava
- Superior – head neck upper limbs
- Inferior – lower limbs abdomen
- Bring it to the right atria
- Right atria goes to the right ventricle, passes through tricuspid valve (3 parts to it)
- From the right ventricle travels through pulmonary valves and goes into the pulmonary trunk
- The pulmonary trunk splits into 2 vessels the left and the right pulmonary arteries – carry deoxygenated blood towards the lungs
- The blood back form the lungs are oxygenated
- Travels into the pulmonary vein (4 of these) they drain in the left atria
- Goes into the left ventricle through the mitral valve
- Passes through the aortic valve into the ascending aorta and then into the arch of the aorta
- Aorta on picture to the right side (your left), pulmonary trunk to the left side (your right)
what are the 3 vessels that lead of the arch of the aorta
1 = brachiocephalic artery - right subclavian artery and right common carotid artery 2 = left common carotid artery 3 = left subclavian artery
what does the brachiocephalic artery split into to
right subclavian artery
right common carotid artery
what does the brachiocephalic artery supply
head, neck, arm on the right hand side
what does the left common carotid artery supply
- head and neck on the left hand side
what did the left subclavian artery supply
- goes under the left clavicle and goes to the left arm
name the veins of the heart
- from the 2 upper limbs your have the right subclavian vein and left subclavian vein
- from the head and neck you have the right internal jugular vein and left internal jugular vein
- where the internal jugular veins and subclavian veins join they produce the brachiocephalic vein
- there is a left brachiocephalic vein and a right brachiocephalic vein
- where the brachiocephalic veins join they form the superior vena cava
what are the two types of veins
deep
superficial
where do the deep veins run
they run with the arteries
where does the superficial vein run
they run in the superficial fascia and drain into the deep vein
what are the superficial veins in the upper limb
- cephalic vein
- basilic vein
- median cubitial vein
describe the veins in the upper arm
- the subclavian vein goes through the clavicle and goes towards the upper limb, when it goes through the armpit it is called axillary artery
- enters the arm and is called the bracial artery
- when it reaches the elbow it splits into two and becomes radial artery and ulnar artery
- it then divides forming the plasma archers and digital braches
what are the deep veins in the upper limb
- follow along the arteries and have the same name
- Subclavian vein
- axillary vein
- brachial vein
- radial vein
- ulnar vein
What are the pulse points in the arm
- Axillary artery – feel a pulse in the armpit
- Branchial pulse- medial to arm
- Radial pulse and ulnar pulse – feel on wrist on either side
describe what the thoracic aorta forms
- Descending aorta in thorax continues into abdomen
- Thoracic aorta forms the intercostal arteries and gives of loads of little vessels called intercostal arteries – in between the ribs supply the thoracic wall
where does the thoracic aorta become the abdominal aorta
T12
describe where the abdominal aorta goes
- 3 unpaired arteries to the gut
- Renal arteries – go to the kidneys
- Then aorta splits goes to either lower limb which are common iliac arteries
- Common iliac arteries
- Gonadal arteries – testes or ovaries
what are the 3 parts of the gut
foregut
midgut
hindgut
what are the parts of the gut defined by
the blood supply
what is the blood supply to the foregut
coeliac trunk - comes out of T12
what is the blood supply of the midgut
superior mesenteric artery
what is the handgut supplied by
inferior mesenteric artery
describe the structure of the common Iliac artery
- Aorta – splits into 2 common iliac arteries
- Common iliac artery (common means splitting)
- Common iliac splits into the internal iliac artery and external iliac artery
- Internal – bladder uterus rectum inside the pelvis
- External – outside the pelvis supplying lower limb
Describe the arteries in the lower limb
- External ilia artery goes into the thigh and then it is called the femoral artery
- Femoral artery is posterior to the knee and this becomes the popliteal artery
- Branches into two anterior tibial and posterior tibial artery
- Veins have the same name – iliac vein, femoral vein, popliteal vein, anterior and poterior tibial vein
what are the superficial arteries in the lower limb
- Great saphenous vein
- Small saphenous vein
What happens to the superficial veins in the lower limb
- Outside muscular compartment don’t have much support to them, they loose there integrity and structure to the wall and the valves are incompetent and don’t work
Describe where the pulse is in the lower limb
- Femoral pulse
- Poplitetal pulse – behind the knee
- Posterior tibila pulse – behind medial malleolus
- Dorsailis pedis pulse – top of foot
describe the hepatic portal circulation
- Deoxygenated blood from the digestive tract passes to the liver before returning to the heart
- Hepatic portal vein – drains the blood from the gut towards the liver, get arterial blood from the abdominal aorta (this contains anything that you have eaten or drank)
- Abdominal aorta -atrial blood towards the gut
- The blood gets sent to the liver and it stores and release glucose when it is needed, clears the blood of drugs and other harmful substances
- From the liver the hepatic vein goes into the inferior vena cava which is then drains into the heart
- Superior mesenteric vein and interior mesenteric vein lead into the hepatic portal vein
describe the lymphatic circulation at different ends of the capillary
- When the blood is in the capillary bed toward the atrial end there is a high hydrostatic pressure and a low osmotic pressure therefore substance are forced out by the hydrostatic pressure
- At the venus end of the capillary bed there is a low hydrostatic pressure and a high osmotic pressure so some fluid moves into the capillary bed, but more blood leaves then renters
How much fluid is reabsorbed into the blood through the capillary
17L
how much fluid is filtered by the capillary every day
20L
What is not reabsorbed into the blood from the capillary
3L
what happens to the 3L that is not absorbed into the blood from the capillary
- lymphatic circulation drains this
- Lymph nodes – contain lymphocytes – filter lymph fluid and mount immune response
- From lymph nodes goes towards larger lymph vessels such as the lymphatic trunk and duct
what is the function of the lymph
- Removal of excess interstitial fluid
- Transport of bacteria and other particles away from tissue
- Transport of antigen-presenting cells for immune response
where is 3/4 of the lymph usually drained
thoracic duct
where is the right hand quadrant of the body usually drained
right lymphatic trunk
what happens when you have your lymph nodes removed due to cancer
get lymphoedema
