Circulatory System Flashcards
What vessel takes blood from the left side of the heart ?
Aorta
Which vessel takes blood into the left side of the heart?
Pulmonary vein
Where does the blood from the aorta go?
It’s oxygenated so is pumped to capillaries of head and forelimbs, abdominal organs and hind limbs.
Which vessel carries deoxygenated blood back to right side of heart?
Superior vena cava
Which vessel carries deoxygenated blood from lower organs of the body?
Inferior vena cava
How many times does the blood circulate through the heart?
Twice ( double circulatory system)
Right side of circulatory system oxygenated or deoxygenated ?
Deoxygenated
Left side of circulatory system oxygenated or deoxygenated ?
Oxygenated blood
What does the pulmonary circuit do?
Carries blood to lungs to be oxygenated and return to heart
What does the systemic circuit do?
Takes blood around the body and returns deoxygenated blood back to heart.
What’s in blood?
RBC, WBC, waste ,platelets, hormones, plasma, co2, O2, nutrients.
What is blood?
Tissue, transport system, maintains stability of interstitial fluid,distributes heat
List the characteristics of RBC?
Numerous 1/3 haemoglobin Biconcave discs (increased SA) Squeeze through capillaries No organelles
What happens when when there is a high conc of O2 (eg alveoli)?
Haemoglobin combines with oxygen to form oxyhemoglobin.
What happens when blood reaches tissues with a low O2 conc?
O2 from the oxyhemoglobin dissociates and O2 released into tissues via diffusion (high to low conc)
Where are RBC produced?
In bone marrow (2.4 million per second)
What is released when blood O2 levels are low?
Erythropoietin
What is erythropoietin?
Protein hormone released by kidney. When released in blood it binds with receptors in bone marrow. Stimulates production of RBC
What destroys our worn out RBC?
Macrophages in spleen and liver
What is the function of leucocytes (WCC)?
Fight disease
What are granulocytes?
They are a type of leucocyte that contain granules within the cytoplasm .
Where are granulocytes produced?
Bone marrow
What are the 3 types of granulocytes?
Neutrophils 50-70%
Basophils 2-4%
Eosinophils 0.5-1%
List the three mechanisms of phagocytosis?
Sticks to it
Cytoplasmic arms around it
Lysosomes inside kill and digest it
Where are neutrophils produced?
Bone marrow
What do neutrophils do?
Fight infection- migrate to point if infection- absorb bacteria by phagocytosis.
Dissolve dead tissue/ turns to liquid called pus
What is an eosinophil and what do they do?
Combat parasitic infection
Impact on allergies and asthma
What do eosinophils contain?
Histamine protein
What are basophils and what do they do?
Less common granulocytes Cause inflammatory reaction They are large cytoplasmic granules/ obscure nucleus Contain heparin Contain histamine also
What are agranulocytes?
Leucocyte with little or no granules
Produced by lymph nodes (spleen and thymus)
What are the 2 types of agranulocytes ?
Lymphocytes
Monocytes
List the function of lymphocytes?
Provide specific immune response
Recognise foreign antigens
Produce antibodies
Where do B cells mature?
Bone marrow
What’re are T cells produced?
Thymus gland
How to monocytes fight infection?
Migrate into connective tissue and become macrophages- don’t produce pus
What are macrophages?
Key cells of immune response
Provide non specific immediate response to infection
Name the 3 blood vessels?
Artery
Vein
Capillary
Name the 3 layers of tissue in the walls of an artery?
Squamous epithelial cells(lining)
Elastic fibres and smooth muscle(middle)
Fibrous layer
What joins the arteries to the capillaries?
Arterioles
List the properties of capillaries ?
1 cell thick Numerous Small in diameter Semi permeable Huge surface area.
How does water flow between the capillary and the tissue fluid?
Osmosis - pressure in the venule end is lower than osmotic pressure exerted by plasma proteins in the capillary so water move back into the capillary.
Where does blood go after passing through the capillary bed?
Returns to heart- venules connect to veins
List the properties of veins?
Less elastic than arteries
Larger lumen reduce resistance to flow
Semi luner valves- prevent back flow
