Cardiovascular system A/P

what is the cardiovascular system made up of

heart, blood and blood vessels

what is Blood

Liquid connective tissue that transports oxygen and nutrients around the body

what are the Main functions of blood

Transport, regulation, protection

what are the key things that blood transports

O₂, CO₂, nutrients, hormones, and waste

what is the Regulation role of blood

Maintains pH, temperature, fluid and electrolyte balance

what is the Protection role of blood

Prevents blood loss (clotting) and infection (WBCs)

Buffy coat percentage

what are the three components of blood

plasma, buffy coat and red blood cells

what are the Formed elements in blood

RBCs, WBCs, platelets

where is the Site of blood cell production

Bone marrow

what is Plasma

Non-living liquid matrix of blood

what are the Main plasma solutes

Proteins, electrolytes, nutrients, wastes, hormones

what are some Electrolytes in plasma

sodium, potassium, chloride, magnesium, phosphate

what are the Waste products in plasma

Urea, uric acid

what are the three proteins in plasma

albumins, fibrinogen and globulins

what does Albumin do in plasma

Maintain osmotic pressure and blood viscosity; bind drugs

what does Fibrinogen do in plasma

Essential for blood clotting

what do Globulins do in plasma

Transport substances and support immunity

what are Gamma globulins

Antibodies (immunoglobulins)

what is an Antibody

Y-shaped proteins that bind specific antigens

what is an Antigen

Substance that triggers an immune response

what is the difference between an antigen and antibody

antigen= foreign substance such as bacteria or virus, antibody= proteins that bind to antigen and get rid of them

what is the function of an antibody

Bind and agglutinate antigens for immune destruction

what are red blood cells also known as

erythrocyte

what is the primary function of a RBC

Transport oxygen and carbon dioxide

what is the shape of a RBC and why

Biconcave disc increased surface area

does a RBC have a nucleus and why

no, to have maximum space to carry as much oxygen as possible

what is the structure of a haemoglobin

2 alpha subunits and 2 beta subunits

what is a Haem group

Iron-containing site that binds O₂ or CO₂

what is the importance of Iron in haemoglobin

Required for oxygen binding

what is Oxyhaemoglobin

Haemoglobin bound to oxygen

what is Deoxyhaemoglobin

Haemoglobin not bound to oxygen

what is the cause of Cyanosis

Low oxyhaemoglobin, blue colouring on skin

what is the structure of Foetal haemoglobin

2 alpha + 2 gamma subunits

why is foetal haemoglobin have higher oxygen affinity

contain gamma subunits which hold oxygen more tightly than beta chains

Purpose of foetal haemoglobin

Pull oxygen from maternal blood in placenta

what is Erythropoiesis

Production of new red blood cells

what is Erythropoietin

Hormone stimulating RBC production

what triggers the release of Erythropoietin

Low oxygen levels

where is the source of Erythropoietin

Kidneys (and liver)

how are Old RBC removed

Phagocytosis by macrophages in liver and spleen

how is iron recycled in the body

Returned to bone marrow for erythropoiesis

how is Bilirubin formed in the body and how is it removed

Breakdown product of haem → excreted in faeces

what is the function of white blood cells

Immune defence against pathogens

where are WBC located in blood

Buffy coat

when does WBC count change

during increased infection/inflammation and decreased immunosuppression

what is a platelet also known as

thrombocyte

what is the function of a Platelet

Blood clotting

what is blood clotting also known as

haemostasis

what is the structure of a Platelet

Cell fragments without nucleus

where are Platelets recycled

Liver and spleen

what is Haemostasis

Process that prevents blood loss after injury

what is haemostasis also known as

blood clotting

what are the three key steps in haemostasis

vasoconstriction, platelet plug formation and coagulation cascade

Step 1 haemostasis

Vasoconstriction

Vasoconstriction trigger

Vessel injury and pain receptors

Step 2 haemostasis

Platelet plug formation

what is Platelet activation

Platelets stick to exposed collagen

Step 3 haemostasis

Coagulation cascade

what two things form a stable clot mesh

Fibrinogen → fibrin

what does Positive feedback in clotting achieve

Recruits more platelets

what does Negative feedback in haemostasis achieve

Prevents excessive clotting

what are the three steps of clot breakdown in the body

syneresis, fibrinolysis and plasmin

what is Syneresis

Clot retraction pulling wound edges together

what is Fibrinolysis

Breakdown of fibrin clot

what is Plasmin

Enzyme that dissolves fibrin

what are the four blood types

A, B, AB, O

what are Blood group based on

Antigens on RBC surface

what does Type A blood contain

A antigens; anti-B antibodies

what does Type B blood contain

B antigens; anti-A antibodies

what does Type AB blood contain

A and B antigens; no antibodies

what does Type O blood contain

No antigens; anti-A and anti-B antibodies

what does Rh positive contain

D antigen present

what does Rh negative contain

No D antigen; anti-Rh antibodies

what is the Rh transfusion rule

Rh- patients receive only Rh- blood

what blood type can O blood type receive

Can only receive O blood

what can type A blood type receive

Can receive A or O

what can B blood type receive

Can receive B or O

what is AB blood type

Universal recipient

what is O- blood

Universal donor

what can a Transfusion reaction cause

Antibody-antigen agglutination

what is the Risk of wrong blood type being given

Acute haemolytic transfusion reaction (life-threatening)

what is the Vascular system function

Transport blood throughout body

what is the Blood vessel sequence

Arteries, arterioles, capillaries, venules , veins

where does Oxygenated blood exit the heart

Via aorta

where does Deoxygenated blood return

Via vena cava

what is the Tunica intima

Inner endothelial layer of blood vessel

what is the Tunica media

middle layer of blood vessel containing Smooth muscle for vasodilation/constriction

what is the Tunica externa

Outer connective tissue layer on the blood vessel

what is structure of Capillaries

Only one endothelial layer (one cell thick)

what is the role of Arteries

Carry blood away from heart under high pressure

what and where are Elastic arteries

Stretchy; near heart (e.g. aorta)

what are Muscular arteries

Thick smooth muscle; regulate flow

what are Arterioles

Small resistance vessels controlling BP

what are Metarterioles

Connect arterioles to capillary beds

what are the three types of arteries

elastic artery, muscular artery and arterioles

what is the function of Capillaries

Exchange gases, nutrients, waste

what is the Capillary wall made up of

Single endothelial cell layer

what is Fenestrae and its purpose

Tiny pores allowing exchange

what do Venules do

Drain capillaries; low pressure