Physiology Lecture Exam 1 SG

What is blood made of?

liquid CT (fluid CT)

Blood is

continuously regenerative

Arteries carry oxygenated blood

AWAY from the heart to the body

Arterial blood would be

bright red because it is carrying oxygenated blood

Veins carry deoxygenated blood

TOWARDS the heart

Blood carried through veins would be

blue/ dark red because it is deoxygenated

What is the composition of blood?

55% plasma

41% red blood cells (erythrocytes)

4% leukocytes (WBCs) and platelets

Blood functions in

transportation

regulation

protection

How is blood transported?

through veins, capillaries, and arteries

How does blood function in regulation?

Regulates hormones, temperature, pH, and fluid balance

How does blood function in protection?

blood clotting +

contains leukocytes, plasma proteins, and other molecules protecting against microbes.

What is the composition of plasma?

mostly water + plasma proteins and other solutes

Solutes in plasma

proteins- big molecules: albumin (60%), globulins (35%); antibodies or immunoglobulins, + transport proteins, fibrinogens (4%); function in blood clotting, other/ regulatory proteins (1%)

nutrients- water soluble vitamins B1-11

electrolytes- sodium, chloride, potassium, calcium, magnesium

waste products

respiratory gases

Erythrocytes (RBCs)

vast majority of the cells in the blood

hemoglobin, oxyhemoglobin, deoxyhemoglobin, oxygen

What is the life expectancy of RBCs?

120 days

RBCs function to

transport respiratory gases in the blood

Leukocytes (WBCs)

contribute to defending body against pathogens, infection, disease.

Leukocytes are

immune cells

Leukocytosis

high white blood cell count.

normal immune response.

Granulocytes

WBCs with secretory granules in its cytoplasm

What are the 3 granulocytes?

Neutrophils, eosinophils, basophils

Neutrophils

most abundant type of granulocytes.

40-70% of WBCs in humans.

vital for protection against bacterial infection.

Eosinophils

immune cell that fight against parasites.

Basophils

have a low count in blood.

Agranulocytes

account for about 30% of all leukocytes and are produced either in the bone marrow or the lymphatic system.

Lymphocytes

a type of Agranulocyte.

large- natural killer cells

small- divided into B and T lymphocytes

Monocytes

a type of Agranulocyte.

once in tissue can become with macrophages and dendritic.

Thrombocytes

aka platelets.

absolutely essential in the process of blood clotting.

ABO blood group system is determined by

the red blood cell.

Antigen

anything a recipient will recognize as being a foreigner.

Immunoglobulin

aka antibodies.

M, IgM

Blood group Rhesus factor

either dominant (present) or recessive (absent) on the RBC.

Rh-, Rh+.

Chromosome

Rhesus factor is coded by a dominant gene.

A dominant gene is

one that would be expressed if present.

Hemolytic Disease of the Newborn

aka Eryhtroblastosis Fetalis.

Rh- mother, Rh+ father. Fetus Rh+.

Factor incompatibility- blood can mix during birth or at the end of pregnancy.

There are no naturally occurring antibodies to the Rhesus factor in the plasma.

When does the heart begin to develop?

in the third week of gestation; with the formation of two heart tubules.

Where does the heart develop/ form from?

the mesoderm in embryo.

The heart begins to beat on or around day

22

Cardiovascular system consists of

the heart and blood vessels.

Adequate perfusion is

the sufficient delivery of blood to maintain cells’ health.

Ventricules

inferior chambers that pump blood away.

located inferior to atria.

The left ventricle lining is

thicker than the right ventricle.

The interventricular septum

separates the right and left ventricles.

Why is the interventricular septum important?

it separates the ventricles to prevent oxygenated and deoxygenated blood from mixing.

Aorta

receives oxygenated blood pumped from the left ventricle.

What kind of blood will you find in the aorta?

oxygenated

Oxygenated blood is received by the ____ pumped from the ____ ventricle.

aorta, left

The aorta is

the largest blood vessel in the body.

Heart valves

prevent back flow to ensure one way blood flow.

Valves on the left side of the blood

left atrioventricular valve (AV)/ bicuspid valve/ mitral valve.

aortic valve.

Pulmonary artery

carries blood AWAY from heart TO lungs for oxygenation.

Atria

superior chambers that receive blood and send it to ventricles.

Valves on the right side of the heart

right AV valve/ tricuspid valve.

pulmonary valve.

Vena cava/ right atrium

drain deoxygenated blood into right atrium.

Pulmonary circulation

transports blood from the right side of the heart to the alveoli of the lungs for gas exchange, and back to the left side of the heart.

Systematic circulation

transports blood from the left side of the heart to systematic cell of the body for nutrients and gas exchange, and back to the right side of the heart.

What is the first step of blood flow?

Blood enters through the superior/ inferior vena cava from the superior/ inferior parts of the body respectively.

Describe the process of blood flow

Blood enters through the superior/ inferior vena cava from the superior/ inferior parts of the body respectively > enters right atrium > flows through tricuspid/ right AV valve > into right ventricle > leaves right ventricle through pulmonary valve > deoxygenated blood to lungs where gas exchange occurs > pulmonary veins (oxygenated blood) > left atrium > left AV/ bicuspid/ mitral valve > left ventricle > put through aortic valve > into aorta > back to body/ system.

Tendinous cord/ chordae tendineae

holds AV valves in place while heart pumps blood.

Layers of the heart

pericardium, endocardium, myocardium

Heart conduction system

specialized cardiac muscle cells within the heart located internal to the endocardium

What happens in the cardiac circle?

atria contracts first, ventricles will contract from the bottom up

SA node (sinoatrial node)

generates an electrical signal that causes atria to contract.

pacemaker of the heart.

Heart electrical system

SA node generates an electrical stimulus. Atria are activated. Electrical stimulus travels down through conduction pathways and causes ventricles to contract and pump out blood.

AV node (atrioventricular node)

Collects signals from SA node. Serves as a gate that slows electric current before signal is permitted to pass down through to the ventricles.

Bundle of His

a group of fibers that carry electrical impulses from AV node to bundle branches.

Bundle branches

There are 2- left and right.

The bundle of His is divided into these two bundle branches.

Left bundle branch

conducts impulses to left ventricle

Right bundle branch

conducts electrical impulses to right ventricle

Purkinje fibers

Deliver electric signals to ventricles, making them contract.

Components of the heart electrical system

SA node

AV node

Bundle of His

Left and right bundle branches

Purkinje fibers

Heart conduction system

Starts at SA node > action potential distributed through aorta > reaches AV node > action potential delayed at AV node (delay allows ventricles to fill before the contract) > action potential travels through AV bundle to Purkinje fibers (AV node > AV bundle > bundle branches > Purkinje fibers) > action potential spreads through ventricles (ventricles contract simultaneously)

P wave

atrial depolarization (contraction) originating in SA node

QRS complex

ventricular depolarization.

atria also simultaneously repolarizing.

T wave

ventricular depolarization (rest)

EKG segments

two segments between waves correspond to plateau phases of cardiac potentials (NO ELECTRICAL CHARGE)

P-Q segment

atrial cell’s plateau (atria are contracting)

S-T segment

ventricular plateau (ventricles contracting)

Atrial depolarization

P wave

Atrial plateau- muscle cells of atria contract and relax

PQ segment

Atrial depolarization

not visible on EKG

Ventricular depolarization

QRS wave

Ventricular plateau- ventricles contract and relax

ST segment

Ventricular depolarization

T wave

Bradycardia

Persistently low heart rate in adults (normal change in athletes).

Abnormal due to hypothyroidism, electrolyte imbalance, congestive heart failure

Bradycardia heart rate

below 60 beats/ minute

Tachycardia

Persistently high resting heart rate

Caused by heart disease, fever, anxiety

Tachycardia heart rate

over 100 beats/ minutes

Types of blood vessels

arteries

capillaries

veins

Arteries blood flow

Oxygenated blood away from heart > tissues

Do arteries contain a valve?

No. Blood moves by pressure of contraction of heart

Veins blood flow

From body toward the heart

Valves are present in most veins

True

Systematic veins

transport blood low in oxygen

Pulmonary veins

transport blood high in oxygen

Vessels are composed of layers called

tunica

tunica intima/ interna

innermost layer of blood vessel

tunica media

middle layer

thicker, muscular wall

mostly smooth muscle + elastic tissue

Vasucular endothelium

inner cellular lining of blood vessels.

in direct contact with blood.

inside lining of lumen.

allows for smooth blood flow.

increase diameter of artery to increase blood flow.

found in large arteries.

one cell thick- simple endothelium.

Vascular endothelium maintain

vascular homeostasis