Cardiovascular system

18,19,20

Cardiovascular system

provides transportation for blood cells and dissolved materials ─ heart, blood vessels, and blood

Cardiovascular system functions?

Transports O2 and nutrients 2. Transports CO2 and cellular waste 3. Transports hormones 4. Defends body against pathogens 5. Regulates body fluids and pH 6. Regulates body temperature

Blood

is the liquid connective tissue of cardiovascular system

Blood plasma

is liquid matrix that carries cells and dissolved materials ─ 55% of total volume ─ H2O, proteins, nutrients, ions, gases

Formed elements

are the blood cells ─ 45% of total volume ─ erythrocytes, leukocytes, and platelets

What is blood plasma composed of?

Blood plasma is primarily composed of water (92%) and protein (7%) ─ most plasma proteins made in liver

Albumin

is protein that maintains osmotic pressure and draw water out of tissues ─ most abundant plasma protein

Globulins

transport materials in blood and form part of immune response ─ alpha, beta, and gamma

Lipoproteins

are globulin proteins that transport lipids in blood ─ HDL transports lipids to liver ─ LDL transports lipids to organs

Fibrinogen

is plasma protein involved in blood clotting

Bilirubin

is yellow pigment formed during breakdown of red blood cells

Erythrocytes (RBCs)

are discoid, anucleated cells that transports O2 and some CO2 ─ involved in bicarbonate buffering

Hemoglobin

is protein found in RBCs

Heme

is iron pigment that binds to O

Globin

is protein unit

How is O2 saturation measured?

% of hemoglobin that is saturated with oxygen ─ 95-100% of O2 is bound to hemoglobin

Antigen

is molecule capable of stimulating an immune response

Antibody

is a Y-shaped protein produced by immune system to bind specific antigen ─ directly neutralizes antigen ─ tags antigen for removal

How many antigens is an antibody specific for?

An antibody is specific for one antigen

A antigen and/or B antigen

on surface of red blood cells ─ determines ABO type ─ may have one, both, or neither

anti-A

Targets cells with A antigen, within blood plasma

anti-B

targets cells with B antigen, within blood plasma

What are ABO and Rh systems used for?

ABO and Rh systems are both used to type an individual’s blood (e.g. A+, B-)

Review Blood chart

Leukocytes (WBCs)

are blood cells that protect the body from disease ─ retain nucleus and organelles

Granular leukocytes

contain abundant, visible granules within the cytoplasm ─ neutrophils, eosinophils, basophils

Agranular leukocytes

lack visible granules within the cytoplasm ─ monocytes and lymphocytes

Neutrophils

phagocytize bacteria ─50-70% of WBCs - granular leukocytes

Eosinophils - granular leukocytes

neutralize parasitic worms and mediate allergic responses ─ 2-5% of WBCs

Basophils- granular leukocytes

promote inflammation and opposes blood clotting ─ 0-1% of WBCs

Lymphocytes - agranular leukocytes

are blood cells that differentiate in lymphoid tissue ─ 20-30% of WBCs

NK cells - agranular leukocytes

provide rapid response to cells that do not express “self” proteins

B cells - agranular leukocytes

target specific pathogens by producing antibodies

T cells - agranular leukocytes

activate immune response and physically attack diseased cells

Monocytes - agranular leukocytes

are large blood cells with indented or horseshoe-shaped nuclei ─ 2-8% of WBCs

Macrophages - agranular leukocytes

are monocytes that have moved from blood into body tissues ─ phagocytize pathogens ─ present antigens to immune cells ─ attract leukocytes to site of infection

Platelets

are cell fragments that play role in blood clotting ─ secrete growth factors to repair tissue

Megakaryocytes

are bone marrow cells that produces platelets

RBC count

is estimate of total number of RBCs in blood

Hematocrit

measures the % of blood that is RBCs

Hemoglobin

measures the amount of hemoglobin in the blood

Hemoglobin A1c

is average blood glucose concentration over 2-3 months

WBC count

is estimate of total number of WBCs in blood

WBC differential

measures the % for each type of WBC

Platelet count

is estimate of total number of platelets in blood

Heart

is muscular organ that pumps blood ─ pinecone-shape and size of fist

right/left sides of the heart

right side pumps to lungs. left side pumps to body

Mediastinum

is central compartment between lungs that contains the heart

Location?

Two-third of heart lies to the left of the midsternal line ─ apex points towards left hip

Pericardium

is tough, two-layered membrane that surrounds the heart

Fibrous pericardium

is tough, outer layer of dense CT that protects heart

Serous pericardium

is delicate, inner layer of CT that covers heart surface ─ parietal and visceral layers

Pericardial cavity

is space between parietal and visceral layers ─ filled with lubricating serous fluid

Auricles

are thin-walled extensions of atria on superior heart

Coronary sulcus

is groove between the atria and ventricles

Anterior interventricular sulcus

is anterior groove between ventricles

Posterior interventricular sulcus

is posterior groove between ventricles

Epicardium

is outermost layer of heart (i.e. visceral layer of serous pericardium)

Myocardium

is thick, middle layer of cardiac muscle cells ─ lots of blood vessels and nervous fibers ─ left side is thicker than right side

Endocardium

is innermost layer that lines heart chambers and heart valves

Right atrium

receives deoxygenated blood from the body ─ contains pectinate muscles ─ pumps blood to right ventricle

Left atrium

receives oxygenated blood from the lungs ─ pumps blood to left ventricle

Interatrial septum

is wall of tissue that separates the right and left atria

Right ventricle

pumps deoxygenated blood to lungs and back to heart

Left ventricle

pumps oxygenated blood to body tissues and back to heart

Interventricular septum

is wall of tissue that separates right and left ventricles

Trabeculae carneae

are ridges of muscle inside right and left ventricles

Tricuspid valve

is a heart valve between right atria and right ventricle

Mitral (bicuspid) valve

is a heart valve between left atria and left ventricle

Chordae tendineae

are fibrous bands of CT that connect valves to papillary muscles

Pulmonary valve

is a heart valve between right ventricle and pulmonary trunk

Aortic valve

is a heart valve between left ventricle and the aorta

How do heart valves flow?

Heart valves ensure flow in one direction ─ open and close due to pressure changes

systole

is phase when ventricles contract

diastole

is phase when ventricles relax

Arteries

carry blood away from heart

Veins

carry blood towards heart

Superior vena cava (SVC)

returns blood from above heart to right atrium

Inferior vena cava (IVC)

returns blood from below heart to right atrium

Pulmonary trunk

receives deoxygenated blood from right ventricle

Pulmonary arteries

carry deoxygenated blood from pulmonary trunk to lungs

Pulmonary veins

carry oxygenated blood from lungs to left atrium

Aorta

receives oxygenated blood from left ventricle and carries it to body

Contractile cells

are myocardial cells that contract to pump blood ─ 99 percent of cardiac cells

Conducting cells

are myocardial cells that initiate and propagate action potentials ─ 1 percent of cardiac cells

Intercalated discs

links myocardial cells together to synchronize contractions ─ gap junctions allow passage of ions

Cardiac skeleton

is dense CT structure found inside the heart ─ forms and anchors heart valves ─ provides structure and support ─ isolates atria from ventricles

Sinoatrial node

is mass of conducting cells in the superior right atrium ─ intrinsic rate of ~100 bpm ─ acts as pacemaker for heart ─ establishes sinus rhyth

How do Electrical signals spread?

across atria ─ insolated from ventricles

Atrioventricular node

is mass of conducting cells in interatrial septum ─ delays impulse from SA node ─ intrinsic rate of 40-60 bpm

functional rhythm

occurs when the AV node sets heart rate

Atrioventricular bundle

routes signal into interventricular septum

Right and left bundle branches

carries signal to apex of heart

Purkinje fibers

spread signal from apex to contractile cells in ventricles ─ rapidly excites ventricles

Cardiac conduction system

allows for bottom up contraction

Electrocardiography (ECG)

is recording of electrical activity of heart ─ tracing follows conduction system

Arteries

carry blood away from the heart and have thicker walls (higher pressure)

Veins

carry blood towards the heart and have thinner walls (lower pressure)

─ may have valve to prevent backflow

Capillaries

are where exchange between blood and tissue cells occurs

─ connects artery and vein