Cardiovascular System Flashcards
components of cardiovasuclar system (3)
- blood
- heart
- Blood vessels
what is blood?
a connective tissue made of a plasma liquid matrix containg cells (RBC & WBC) and platelets fibres
Functions of blood (7)
MAINTAIN HOMEOSTASIS!!! via….
- Transport of gases, nurients, + waste products to necessary locations
- Transport processed molecules (e.g. Vit D: skin->liver->kidneys->s.intestine->skeletal muscle)
- Transport regulatory monitors (hormones & enzymes)
- Regulate pH + osmosis
- Maintain body temp (warm blood to surface if too warm so heat can be released)
- protection against forgein substances + organisms (WBC and immune system)
- Clot formation
compoents of blood (2)
- Plasma (fluid, dissolved proteins, metabolites)
2. Formed elements (RBC, WBC, platlets)
Plasma
Collid (liquid containing suspended substances that do not settle out of the solution).
composition: 91% water, 9% proteins, gases, ions, nurients, waste products, hormones & enzymes
function: to transport materials around the body
RBC characteristics
bi-concave discs (providing large SA for dissusion of gases and flexible to fit through BVs), circulate in blood via plasma, ~7-8micro m in diameter
structure of RBCs
no nuclei, few organelles
haemoglobin (pigamented quaternary protein made of 4xhaem groups which have a Fe++ at centre allowing O2 to bind to it during transportation),
lipids, ATP, carbonic anhydrase (enzyme)
function of RBCs (4)
- Carry O2 around the body (O2 binds to iron in haemoglobin- 1O2:1haem group- forming oxyhaemoglobin)
- Carry some CO2 around the blood as a wastre product (binds to AA in globin forming carbaminohaemoglobin)
- Carry nitric acid
- help identification of blood type as they are studded with glycoproteins + glyocolipids
Life Cycle of a RBC (6 stages)
- Erythropoietin produced in kidneys
- transportation of erythropoetin via BS to bone marrow
- In bone marrow Erythropeisis (production of RBCs , taking approx. 4 days)
- RBCs circulate body for approx. 120 days
- in Liver + Spleen memrbane becomes weak due to inability of RBC to produce new proteins causing RBC to repture
- Macrophages release lyosomal enzymes which break down RBCs and release haemoglobin
- –> AA from globin are resued / recycled to make proteins
- –>Haem group: iron is released and carried to bone marrow to produce new RBCs, non-iron converted to Bilirubin for removal of bile in liver
which hormone regulates RBC production?
erythropoetin (increase erythropoetin secretion = increased RBCs produced), secretion stimulated by low O2 levels in blood
what is the other name of RBCs?
Erythrocytes
What is the other name for WBCs and % of blood?
Leukocytes
1% of blood vol.
Function of WBCs (2)
- protect body from invading organisms (e.g. bacteria + viruses)
- remove dead cells and debris from the body
Types of WBC (2)
- Granulocytes
2. Agranulocytes
Granulocytes (feactures, location of production, immune reponse, types (3))
- lob-sided multiple muclei
- cytoplasm contains large granules
Produced: bone marrow
NON-SPECIFIC immune reponse
types: esoinphil, basophil, neutrophil
Agranuloctyes (feactures, location of production, immune reponse, types (2))
-1 large nucleus
- cytoplasm w. small granules
Produced: lymphnodes
ACQUIRED immune response (specific & targeted)
types: lymphcyte, moncyte
Platelets (characteristics-3)
- minute fragments of cells
- contains glycoproteins + proteins on surface allowing connections to other molecules
- short life expecdency (5-9days) so must be continually replaced
Function of Platelets
- First defence for damaged blood vessels -> form ‘platelet plugs’ to seal hole in BVs, promote the formation & contraction of clots in large wounds
What do RBCs contain which allow identification of blood grouping?
Antigens -> glycoproteins + glycolipids
What is the purpose of blood grouping & how does it work?
to protect the body and allow the recognition of ‘non-self cells’. If antibodies in plasma don’t match antigens on RBCs then it will cause an immune reponse to ‘destroy’ forgein cells
Types of antigen grouping (2)
- A, B, O grouping
2. Rhesus system of grouping
A B O grouping
A= A antigen + B antibody B= B antigen + A antibody AB= A+B antigens + no antibodies O= no antigens + A+B antibodies
What happens in A+B antigens-antibodies match?
if the antibody in plasma matches the antigen on RBC
(e.g. A+A or B+B) it will agglutinate (antigen and antibody bind) causing an immune response and rejection of RBCs
Compatibility of ABO transfusions
antibodies->antigens A->A or O-> A B->B or O->B A->AB or B->AB or O->AB or AB->AB O->O
Rhesus system of blood grouping in terms of genes
genetic coding of whether a specific glycoprotein is present on RBC. if gene present then Rh+, if gene absent then Rh-. Rh+ is the dominant gene
mismatch of Rh grouping between mum + baby
in first pregancy no issues due to slow pace of mums immune reponse. In second pregancy, Rh- baby will be rejected in mum is Rh+ because blood interaction over placenta will identify baby as a threat to mother
what is haemostasis
the process of blood clotting when appropiate, w/o it when BV is broken there would be continual bleeding + death
What do damage blood vessels expose?
Collagen
what does exposure to collagen stimulate damaged BCs to do? (3)
- Vascular Spasm: contraction of BV to restrict blood flow reducing blood lose and activate nervous sytem response
- Platelet plug formation: accumulation of platelets to act as a temporary seal on BV preventing bleeding
- Coagulation: blood clotting via fibrin following chemical release and prevents bleeding
what is fibrinolysis?
the dissolving of blood clots and repair of connective tissue and creation of epithelium cells to fill torn area
2 types of blood clotting pathways + blood clot formation
- Intristic (chemicals w/in blood - factor IX)
- Extrinstic (chemicals outside blood- Thrombolplastin factor VII complex formed)
both then cause activation of factor X and stimulate the formation of prothrobinase which converts prothrobine to throbin which is converted into fibrin and clotting factors to form blood clot
Functions of the heart (4)
- Generate BP
- Route blood around body
- Ensuring 1-way blood flow
- Regulate blood supply
Layers of heart wall muscle (3)
- Epicardum: serous membrane in outer heart surface
- Myocardium: thick middle layer made of cardiac mucle allowing contraction
- Endocardium: inner layer, simple squamous epithelium tissue over connective tissue
Feactures of Cardiac muscle cells (4)
- Elongated
- Branching
- 1-2 central nuclei
- actin + myosin form myofibrils- allowing muscle contraction
Feactures of L heart (3)
- Left atrium
- Left atrioventricular canal and biscupid valve
- Left ventricle
Fectures of R heart (4)
- Right Atrium
- Right atrioventricular and and tricuspid valve
- Right ventricle
- Pulmonary semi-lunar valve
Veins feeding heart
- L + R pulmony veins (splitting at pulmonary truve)
2. Vena Cava
Arteries branching from heart
- Aorta w. aortic semilunar valve
2. L+R Pulmonary artieries
Pulmonary circulation + side of heart
carries blood heart->lungs so gas exchange can occur
in R-side of heart
Systemic Circulation + side of heart
carries blood heart->body delivering nurients + O2
in L-side of heart
what is the vascular system
a network of arteries and veins carring blood around body
How does contraction occur in the heart?
depolarisation and repolarisation of cardiac mucles result in involunatry cell contraction
CSA of blood vessels=
no. of type of BV x CSA of BV type
relationship between resistence in BVs and BP
inveresly directly proportional- the higher the resistence in a BV = lower BP
movement of blood through BVs (away and towards heart)
aorta-> arteries -> arterioles -> capillaries -> veiniloses -> veins -> vena cava
average Heart rate
HR= approx. 70 bpm (beats per min)
what is cardiac volume and average
amount of blood pumped per minute
approx. 5000ml per min
what is stroke volume and avaerage
amount of blood ejected by heart per contraction
approx. 70ml
Types of artieries in the head + neck (3)
- Carotid (internal + external) serving head + neck
- Vertebral serving branches of subcalvial arteries
- Basilar serving junction of vertebral arteries
