Blood Vessels, Blood and Clotting Flashcards
What chamber does the aorta originate from?
Left Ventricle
What chamber does the pulmonary vein drain into?
Left atrium
What chamber does the pulmonary artery originate from?
Right ventricle
What chamber does the Vena Cava drain into?
Right Atrium
Where can the radial artery be palpated?
Lateral aspect of the forearm, close to the wrist.
Where can you palpate the brachial artery?
Antecubital fossa
Where can you palpate the femoral artery?
Medial anterior thigh, inferiorly to the inguinal ligament
Where can you palpate the dorsalis pedis artery?
Dorsal surface of the foot, between the first and second metatarsal
Where can you palpate the popliteal artery?
Posterior aspect of the knee
Where can you palpate the carotid artery?
Either side of the neck, lateral to the cricoid cartilage
Where can you palpate the posterior tibial artery?
Posterior and inferior to the medial malleolus
Name the arteries that branch of the aortic arch, from first to last
Brachiocephalic trunk, left common carotid, left subclavian.
What two arteries branch off the brachiocephalic trunk?
Right common carotid and right subclavian.
What two arteries branch off the aorta immediately superior to it’s anastamosis with the heart?
Right and left coronary artery
Name the branches of the RCA
Sinu-atrial nodal, right marginal, posterior intraventricular
Name the branches of the LCA
Anterior intraventricular (LAD), left circumflex
What arteries branch off the abdominal aorta at l3 l4?
Left and right common ileac arteries
What spinal level does the abdominal aorta begin?
T12
At what spinal level does the inferior Vena Cava perforate the diaphragm?
T8
What 3 main veins drain into the portal vein?
Superior mesenteric, gastric and splenic veins
What does the inferior mesenteric artery supply?
Distal third of the transverse colon, the descending colon and sigmoid colon, and the superior portion of the rectum
What does the superior mesenteric artery supply?
Proximal 2/3 of transverse colon, ascending colon, jejunum, ileum, appendix, caecum, hepatic flexure.
What vertebral level do the common ileac arteries branch off the abdominal aorta?
L4
What vertebral level do the renal arteries branch off the abdominal aorta?
L1-L2
Name the 3 branches of the celiac artery
Left gastric, splenic and common hepatic
Which veins make up the azygos system?
Azygos, hemiazygos, accessory hemiazygos, left superior intercostal
What vertebral level does the azygos vein arise?
T12
What two veins does the azygos vein originate from?
Right ascending lumbar vein and the right subcostal vein
What two veins does the azygos system join?
IVC and SVC
Where does the left gonadal vein drain into?
Left renal vein
Where does the right gonadal vein drain into?
IVC
What general area do the carotid arteries supply?
Head and neck
What general area do the subclavian arteries supply?
Upper limbs
The external and internal carotid separate at what vertebral level?
The carotid sinus at C4-5
What is the connective tissue layer of blood vessels called?
Tunica adventitia
What is the tunica media made of?
Smooth muscle
The tunica intima is the innermost layer of blood vessels, what does it consist of?
Single layer epithelium, basement membrane and elastic fibres.
What are the three types of capillary?
Continuous, fenestrated and sinusoidal
What does a fenestrated capillary look like?
Small gaps in epithelium but a continuous basement membrane.
What function do sinusoidal capillaries have?
Allow larger structures (like red and white blood cells) to pass through them.
Where is the cephalic vein?
Lateral aspect of the upper limb
What is the percentage of plasma in the blood?
55%
The large molecules in plasma are mainly what?
Proteins
Where are albumin and fibrinogen produced?
Liver
Name a major role of albumin?
Maintaining the balance of fluids in the vessels
Name a role of fibrinogen
Blood clotting
Describe the shape of erythrocytes and why it is important
Biconcave discs, have a large surface area to volume ratio which maximises gas exchange
What is the lifespan of a red blood cell?
120 days
Name the 5 types of leucocytes
Neutrophils, Basophils, Eosinophils, Lymphocytes and Monocytes
Neutrophils respond to tissue damage. They are increased in what type of infection?
Bacterial
Basophils release what two molecules to promote inflammation?
Histamine and Heparin
What type of leucocytes are elevated most in viral infections?
Lymphocytes
What is the structure of platelets and why is this important?
Small discoid shaped cell fragments when unactivated, however, when activated, the proteins on its surface allow it to change shape and extend “tentacle-like” projections that help the platelets stick together
Once platelets are adhered to the break in the vessel, forming a temporary clot, they secrete proteins from their granules to promote what?
Vasoconstriction and further clotting
In simple terms, what is the clotting cascade?
A series of enzyme catalysed reactions that lead to the production of fibrin.
What are the elastic arteries?
Aorta and its branches
What vessels make up the largest portion of the circulatory system?
Systemic veins and venules
What are the three layers of a blood vessel?
Tunica intima, tunica media and tunica adventitia
What does the tunica intima consist of?
Endothelium, subendothelium (connective tissue) and internal elastic lamina (only arteries, not veins)
Which layer of a blood vessel regulates diameter and how?
Tunica media, made up of smooth muscle cells that are can vasoconstrict and dilate.
What are the layers of the tunica media?
Smooth muscle cell layer and external elastic lamina
Which layer is made up of connective tissue?
Tunica adventitia
What is the purpose of muscular arteries?
They have a thicker tunica media, more smooth muscle so they can regulate blood flow to organs as required.
If someone refers to the “reservoir of blood”, which vessels are they talking about?
Veins and venules
Which vessels have a thinner tunica adventitia?
Arteries
What layers make up capillaries?
One cell thick layer of endothelial cells, basement membrane and collagen fibrils
What is a pericyte?
A contractile cells found sparsely in capillaries
What type of capillaries are found in the liver and spleen?
Sinusoidal
What are the three types of capillaries?
Continuous, fenestrated and sinusoidal
What type of capillaries are found in the gastrointestinal tract and endocrine glands?
Fenestrated
What are the three types of flow within a vessel?
Lamina, turbulent and pulsatile
Why can turbulent flow be harmful?
It can irritate the vessel walls, exposing the RBC to collagen causing the blood to clot.
What three types of transport happen across endothelial cells?
Transcellular, active and pinocytosis
What is the MAP in the right atrium?
Almost 0
What is the dicrotic notch?
A blip in the pressure profile chart of arterial pressure where the aortic valve closes
How would you work out pulse pressure?
Systolic - diastolic BP
What is the equation for MAP?
MAP= DiastolicBP - 1/3PP
How much time, when we are at rest, does the heart spend in systole?
1/3
What percentage of blood is in the venous system at any one time?
70%
Describe the cellular response to shear stress on endothelial cells in the blood vessels
Endothelial cells sense shear stress -> produce nitric oxide -> NO diffuses into smooth muscle -> activates guanylyl cyclase -> synthesises cGMP -> smooth muscle relaxation
Which factors are affected by Vitamin K deficiency?
II, VII, IX and X
What drug causes Vitamin K deficiency and how?
Warfarin, blocks the activation of vitamin K by it’s enzyme
What genetic condition causes collagen synthesis disorder?
Ehlers-Danlos
What process does Von Willibrand’s disease affect?
Platelet aggregation and adhesion
Endothelial damage exposes blood to what substances?
Tissue factors and collagen
What arachidonic acid metabolite is formed by platelets?
Thromboxane A2
What molecule performs the opposite function to thromboxane A2?
Prostacyclin
Why are vWF and GPII/III important?
They form crosslink bridges between platelets to help aggregate them together
What is a sinister cause of thrombocytopenia?
Acute Myeloid Leukaemia
What is the initial factor of the intrinsic pathway?
XII
What is the initial factor in the extrinsic pathway?
VII
What is the initial factor in the common pathway?
XIII
What blood test is used to assess the intrinsic pathway?
APTT
What enzyme digests fibrin?
Plasmin
Prothrombin is what factor?
II
Fibrinogen is what factor?
I
What ion is involved in the clotting cascade?
Calcium
What are the steps of haemostasis?
- vasoconstriction
- primary (temporary platelet plug)
- secondary (coagulation)
- fibrinolysis
- repair
Thromboxane A2 triggers what processes after a vessel injury?
Vasoconstriction and platelet aggregation
What molecules form in between platelets?
Fibrinogen
What is the precursor to fibrin?
Fibrinogen
Fibrin and thrombin are what type of molecules?
Proteins
What is needed to activate fibrinogen?
Thrombin
What is the inactive form of thrombin?
Prothrombin
What factor is needed to stabilize fibrin?
XIII
The intrinsic pathway depends on factors that are found where?
In the blood
Which pathway in the coagulation cascade has more steps?
Intrinsic
What factor is tissue factor?
III
What pathway is tissue factor involved in?
Extrinsic
The intrinsic pathway includes what factors?
VIII, IX, XI, XII. (8,9,11,12)
What makes up the prothrombinase complex?
Factor X & V, calcium and platelet.
