Blood components and functions

Blood

• Blood is a major connective tissue with cells, matrix, protein fibers, ground substances, and cellular fragments.
• The blood cells are synthesized in bone marrow
• Plasma is the liquid matrix of blood.
• The components of the blood consist of plasma and cells (formed elements).

Functions of Blood

• Blood delivers dissolved gases, nutrients, hormones, and metabolic wastes throughout the body.
• Blood regulates the pH and ion composition of interstitial fluids.
• Prevents fluid loss at injury sites through clotting.
• Defends against toxins and pathogens.
• Stabilizes body temperature.

Regulation of Erythropoiesis

• Erythropoiesis is the formation of red blood cells.
• Red blood cell formation happens in the yolk sac, spleen, and liver, then after birth, in the bone marrow.
• Inability to absorb vitamin B12 from the gastrointestinal tract reduces health red blood cell production, leading to pernicious anemia.
• Normal stem cell division requires vitamin B12; without it, pernicious anemia results.
• Erythropoietin (EPO), a peptide hormone, directly stimulates erythropoiesis.
• Kidneys and the liver release erythropoietin in response to hypoxia.
• Erythropoietin travels to red bone marrow to stimulate stem cells to develop into red blood cells.
• Synthetic EPO increases number of O2-carrying blood cells and increases blood viscosity and cardiac workload.
• Dosages of synthetic EPO must be carefully controlled, as it can thicken the blood and increase the heart's workload.

Recycling of Red Blood Cells (Haeme)

• RBCs have a biconcave shape, do not have a nucleus, and contain hemoglobin pigment, which gives them their red color.
• Macrophages in the liver, spleen, and bone marrow monitor the quality of red blood cells and engulf old ones.
• Each component of a haemoglobin molecule is recycled.
• Globular proteins is disassembled into amino acids for use by other cells.
• Heme units are stripped of iron and turned into biliverdin (green in bruises).
• Biliverdin is turned into bilirubin (orange/yellow of jaundice) and transported to the liver to be excreted as bile.
• Bilirubin is responsible for transferring blood plasma protein to transport ions.
• Brownish color to faecal matter is provided by Bilirubin-derived products
• Urine excretes eliminated Bilirubin-derived products

ABO Blood Types

• Plasma membranes contain surface antigens that identify blood types.
• There are eight blood types altogether.
• Antigens enable the immune system to recognize cells as 'self'.
• Antibodies in the plasma recognize antigens as 'self' or 'foreign'.
• Blood 'type' classification determined by the presence & absence of antigens on red blood cell plasma membranes.
• RBCs have 50+ surface antigens, of which three are important: A, B, and Rh (or D).
• 03 antigens means the resis antigen is absent and the result would be negative

ABO Blood Types - Antigens

• Type A blood has surface antigen A only.
• Type B blood has surface antigen B only.
• Type AB blood has both surface antigen A and B.
• Type O blood has neither surface antigen A nor B.

ABO Blood Types - Antigens (Rh Factors)

• Rh positive indicates the presence of the Rh antigen on the surface of the red blood cell.
• Rh negative indicates the absence of this surface antigen.
• Expect to have rh in antibodies in plasma but both of them do not have rh if person doesnt have Rh in antigen.
• AB+ blood has antigens A, B, and Rh on the red blood cells' surfaces.
• O+ blood is neither A nor B but possesses Rh surface antigens and is the most common blood type.
• Plasma of individuals with Rh-negative blood will only contain Anti-Rh antibodies if they have been sensitized by exposure to Rh-positive RBCs.
• An example is haemolytic disease of the newborn
• There is a chance of developing antibodies in plasma in negative rh person
• There is an increase in response to a stimulus after repeated exposure to sensitisation

ABO Blood Types - Antibodies

• Type A blood contains Anti-B antibodies in the plasma.
• Type B blood contains Anti-A antibodies in the plasma.
• Type AB blood contains neither Anti-A nor Anti-B antibodies in the plasma.
• Type O blood contains both Anti-A and Anti-B antibodies in the plasma.

Cross-Reactions in Transfusions

• RBCs agglutinate (stick together) and haemolyse (rupture) when a plasma antibody meets its surface antigen.
  • It can cause clumping if the same type of antigen and antibodies meet.
• Clumps and fragments of RBCs can then block small blood vessels.
• Compatibility of the donor and recipient is essential.
• The surface antigens on donor RBCs are more important than antibodies in donor plasma.

Testing for Compatibility

• ABO antigen and Rh antigen presence is determined to iidentify the A, B, O antigen group and Rh antigen factor of both donor and recipient
• Two processes are performed separately including determining blood type and performing a cross-match test.
• A cross-match test has to detects the presence of antibodies
• The process includes taking blood drops and adding synthetic antibodies
• A process called 1-FORWARD TYPING and 2-BACKWARD TYPING is performed after cross-matching samples
• A plasma sample gets added to a known type of A B blood cells

Haemolytic Disease of the New Born

• The mother's immune system starts rejecting the baby.
• This does not affect the first baby, but the second baby and mother have antibodies that will now reject the baby
• Arises when an Rh-negative woman is carrying an Rh-positive foetus.
• Fetal and maternal blood mixing at delivery (or antepartum haemorrhage, amniocentesis) leads to the mother recognizing the foetus' Rh antigens as foreign.
• Amniocentesis is a medical procedure used to collect a sample of amniotic fluid from the amniotic sac that surrounds the foetus.
• Mixing of blood causes the mother's immune system to produce anti-Rh antibodies (sensitisation).
• If mother has another Rh-positive fetus her anti-Rh antibodies crosses the placenta and attack fetus' red blood cells
• Connection is done through placenta
• The anti-D antibodies are administered to the mother during and after pregnancy as a quick destruction tool quickly destroy the antibodies if any mixing occurs during deliver
• In which allows the foetus to not have a chance to produce anti-body sentisation

Anatomy of the Thorax

• The Thorax comprises of 12 thoracic vertebrae, sternum & ribs
• It encloses the heart & lungs but also provides some protection for the spleen, liver and kidneys.
• The pectoral girdle is attached to the upper limns by the Thorax

The Sternum

• The sternum is a bony plate that is anterior to the heart and is palpable [subcutaneous] in parts.
• The sternum is made of three regions starting from the top being the manubrium, following downwards through the bone there is the body (gladiolus), and the xiphoid process.
• The bone has a jugular notch and manubriosternal junction/joint called the sternal angle

The Ribs

• Mosts humans have 12 pairs of ribs
• Posteriorly the rib cage articulates with the bodies and transverse processes of the vertebrae
  • Articulations means that ribs is articulate with body
  • And anteriorly it is connected with sternum
• Anteriorly the ribs articulate with their costal cartilage
• Costal cartilages (hyaline cartilage) attach ribs to the sternum
  • Connected with sternum that is made out of hyaline cartilage
• The costochondral joints are classified as primary cartilaginous joints.
  • This means ribs with cost cartilage and costo with sternm articulates/connects.

Rib Anatomy

• Head: portion of rib that articulates with bodies of thoracic vertebrae
• Neck: narrow portion distal to the head
• Tubercle: wider, rough area distal to the neck that articulates with transverse costal facet of vertebra.
• Angle: lateral curve of rib.
• Shaft: long, sloping, blade-like portion of rib
• Costal groove: on the inferior margin of shaft with most parts
• True ribs (Ribs 1-7): each articulates with sternum via costal cartilage
• Individual parts in individual costal cartilage connections to sternum False ribs (Ribs 8-12): connect to costal cartilage of rib above & forms costal margin
• Floating ribs (Ribs 11-12): have no cartilaginous connection to the sternum, no connections to costal cartilages above, no tubercles, and no attachments to transverse processes of vertebra.
  • All ribs are posterior connected to verterbrate:

Costal Cartilage

• Ribs have costal cartilages

Intercostal Muscles

• Diaphragm separates thorax from abdomen

Chest Cavity & Its Contents

• The mediastinum contains the heart, the great vessels (large blood vessels such as the aorta), the trachea, the oesophagus
• Thorax contains right and left pleural cavities: lungs as well as nerves.

Mediastinal Boundaries

• Anteriorly: sternum
• Posteriorly: vertebral column
• Inferiorly: diaphragm
• Superiorly: thoracic inlet

Mediastinal Subdivisions

• Superior & inferior mediastinum lies along the anatomical plane T4 (sternal angle)
• Most important events in this region are arcing of the aorta, ascending aorta curving to form a form or arch of aorta, tracheal bifurcation dividing trachea into right and left main brochii
• Also found is the azygos vein enters SVC connecting aztgos vein drains deoxygenated blood ,from posterior parts of theorac and abdominal
• As well main lyppatic vessel of the body and it cross from right to left of the verterbral column at this plane containing the thoracic duct crosses vertebral column

Anatomy of the Heart

• Central organ of systemic & pulmonary circulations.
• Known to be a hollow, four-chambered fibromuscular pump that has fibrous and muscular components
• Top part of the heart where the base allows the aorta/pulmonary arteries, and veins to be attached facing faces posterio,slightly to right
• Bottom area it has a pointed end of the heart directed downward foward and to the left with and anterior suraces facing the sternum and ribs
• Inferiorly it hassurfaces facing towards the diaphragm.

The Pericardium

• The Pericardium is enclosed to the heart to create
• It allows the heart to beat without friction & to expand while resisting excessive expansion
• It anchored to diaphragm inferiorly, sternum anteriorly & roots of great vessels

Fibrous Pericardium

• Fibrous pericardium outer layer to prevent excessive expansion of the heart that is collagenous and inelastic that unable heart to expand
• Fibrous layer is fused to central tendon of diaphragm & adventitia of great vessels
• Attached by 'ligaments' to sternum (variable) as well that secure the heart within thorax

Pericardial Cavity

• The "space" lies between parietal serous & visceral serous layers that contains a small amount serous fluid (50 ml)
• The normal intrapericardial pressure either (-ve) or zero that forms closed space to compress the heart
• Can result in a cardiac tamponade means medical emergency where fluid build up in the pericarial that leads compression of the heart
• Is a right atrium - decreased venous return - Decreases cardiac output - and causes hypotensionand circulatory collapse Is when bllod pressure stops

Heart Structure

• Three layers: epicardium, myocardium & endocardium
• Epicardium (visceral pericardium)
  • serous membrane that covers heart
  • adipose tissue thick layer in some places
  • coronary blood vessels travel through this layer
• That seperate blood vessels/circulation for heart wall -the blood is travel through epicardium level
• (ii) Myocardium
  • Lay of cardiac muscle exclusive
  • Spirals around heart which produces wringing motion
• Endocardium
  • Smooth inner lining of heart and also forms blood vessels
  • Smoothly covers heart valve surfaces & its continuous with endothelium of blood vessels

Fibrous Skeleton of the Heart

• Contractile muscles need fixed point (fulcrum) around which they contract.
• Is is helps to provide a structual support by fribous skeleton of heart
• That consists of fibro-collagenous connective tissue
• That has and attachment for musculature and help chambers, be structurally & functionally separate and help keep the chambers opens
• It acts Almost stationary when cardiac muscle contracts
• It electrical insulates between atria & ventricles
• Is important in timing & coordination of the heart contractile activity
  • It helps to maintain the timing of the heart beat

Chambers of the Heart

• The heart has total of four chambers

• The hearts right and left atria are at the superior position of the heart to receive blood

• blood is returned coming frok the heart to the small concical punch projecting from upper anterior part of each atria functions as a overflow chamber and reduce artrial pressure by increasing the capacit

• The heart also comtains a right and left ventricle and in the inferior position

• The pump then pumps blood into aorta & pulmonary trunk

Features of the Right Atrium

• The features of the right atrium include musculi pectinati which contracts to help, crista terminalis (sulcus terminalis) is is a ridge that separate smooth and tough areas of the artrium wall limbus fossa ovalis marking fetal structutes and fossa ovalis helps if it doesn't close it will have a hole in a baby with a depression in internal stecum and cusps of tricuspid valve.
• The openings allows to have a superior & inferior vena cavae in addition to coronary sinus

Features of the Left Atrium

• Comprising of 4 pulmonary veins, cusps of bicuspid valve thats mitral valve and roughened auricle to cause extension of artrium

Key features of the ventricles

• Are made of thick muscular chambers that are cardiac muscles
• Helps receives blood from atria via AV openings
• To pump blood into systemic (LV) & pulmonary (RV) circulation

Valves of the Heart

• The valves of the heart functions to have a control of direction of blood flow through heart to allow flow only in one direction
• Help as well to prevent backflow of blood into chambers as well as for

The Two Valves of the Heart

• Control the atrioventricular and semilunar

Atrioventricular (AV) Valves

• Are made with a collagenous tissue lined with endothelium
• That controls flow from atria to ventricles
• Containing valves within the right AV valve.
• Containing heart valves the has three cusps commonly know as tricuspid valve
• Containing heart valves the has two cusps commonly know as with two cusps (mitral or bicuspid valve)

The Atrioventricular Valve

• In which cordae tendinae is attached to valves
• And is functions to prevent AV valves from flipping back into atria.
• Each papillary muscle has 2-3 attachments to heart wall to distribute physical stress, to coordinate timing of electrical contraction & provide redundancy
• It maintains the delay it is important to have this attachment during contaction

The Semi Lunar Valves

• Consisted of heart connective tissue lined with endothelium but it has firbous nodules - experience high blood pressure it is withstand through this nodules
• it is and functions to control the blood flow into aorta & pulmonary trunk
• Containing pulmonary semilunar valve to provide a connection between right ventricle & pulmonary trunk
• And aortic semilunar valve connects between left ventricle & aorta

Blood Flow Through the Chambers

• A normal heart cycle is the in which is performed through following ventricular and the diastoles
• The first process is when the diastolic ventricular undergoes contaction of the relaxes is performed
• Through which there is a drops in pressure inside the ventricles the semilunar valves to be closed before blood flows back to the ventricles out Great veins and finally to get to get the AV valves
• Contration of the Ventricles causes close of the AV valves and with the process, bblood attempts to back up into the atria which causes preasure rises and to opens the the semilunar valves + blood flows into veins at
• At the very end of the cycle all the heart valves opens and passively

Coronary Circulation

• Five percent of the blood pumped by an individual's heart distributes the blood to the tissues in blood vessels
• It flos through the right and left coronary arteries that provide blood flow heart
• In addition to a rate of about 250ml that is required every mintute of abundence to supply 02

Coronary Circulation (Arteries)

• Left coranary artery - This consists of parts the ascending and
  • Left coranary art supplies both artialventriculur
  • Circumfex branches pass through the coronary slcus that Groove the posterior surfaces of the heart to help with the posterior
• supplies both ventricles & anterior 2/3 of the interven
• To the left with supply atrial wall
• ends on posterior aspect of heart

Coronary Circulation, The Right

• This includes a branch of ascending aorta
• Which helps supplies right artium through the sinoatrial that are involved in pacemaker functioning which can be found at th right, lateral, and ventricle

Veinous Drainage

• By an opening of a vein that has a collection of 5-10% to drain all blood through to the Right artium directly
• With the collection of deox then through to
• There us another opening with collection deox and drained to coronary where the sinus is open that includes great, middle & small veins
• Which helps brings deox and drains to the coronary sinus that is open

Agina and Heart Attack

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• And is is known as ischemia condion there there is inadequate blood to supply that causes partial
• There causes obstruction with all anerorbic feementation through the the that that a
• A connon in the chest can often be heard or seen heart with the A long-term condition has known as -in
• An atherome is a fatty clott that occurs downstream due
• a common for by Is with high amount pressy

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And is to heavy through an arm or with a heart failure or arm

• Common causes is when the blood.down To the blockage or heavy pressure or arm or
• Heavy prssure