Cardiovascular System BIO 202 Lab 2

hemolytic disease of newborn

• mother’s antibodies developed through previous exposure to Rh+ blood are transferred through the placenta to the fetus

• treatment = phototherapy (exposure to UV light) to degrade bilirubin

  • exchange transfusion to completely replace infant’s blood

gene

unit of genetic information (segence of DNA nucleotides)

• codes for a specific trait → protein

alleles

• alternative forms of the same gene

• one allele is inherited from mom and other allele from dad

• gene pair = 2 alleles

genotype

the genes (alleles) responsible for a trait

• the genetic code

phenotype

the physical manifestation of the alleles

Which alleles are codominant

A & B

Which allele is recessive?

O

One mate is genotype AO and the other is BO. What are the possible genotypes of their offspring? What are the phenotypes?

• genotypes = AO, AB, BO, OO

• phenoypes = A, AB, B, O

Where is the heart located?

• between the 3rd rib and diaphragm

• posterior to the sternum

• thoracic cavity (mediastinum)

What side does the base of the heart point?

towards the right

What side does the apex of the heart point?

towards the left

What is the heart’s covering that separates it from surroundings?

pericardium (parietal and visceral)

Name the layers of the heart (superficial to deep)

Superficial

• pericardium

  • Fibrous pericardium

    • parietal layer of serous pericardium

    • pericardial cavity

• epicardium (heart wall)

  • visceral pericardium

• myocardium

• endocardium

Deep

myocardium

composed of cardiac muscle (cardiomyocytes)

• thickness proportional to workload (left ventricle thicker than right)

• myocardium vortex = muscle spirals around the heart

loose areolar connective tissue

dense regular connective tissue

dense irregular connective tissue

adipose tissue

myocardium’s fibrous skeleton

• framework of collagenous and elastic fibers

  • concentrated on the left ventricle

3 functions

• structural support

• anchors cardiomyocytes

• electrical insulator

cardiomyocytes

a muscle cell, especially a cell of cardiac or smooth muscle

• uninucleate (1 nucleus)

• blunt, end to end connection

intercalated discs = join individual cells allowing electrical and mechanical connections

• complex of fascia adherens, desmosomes and gap junctions (specialized for direct ionic, electrochemical signal transfers)

endocardium

• endothelial cells ( simple squamous epithelial cells) line up this layer of the heart

• identical to endothelial cells of tunical interna of blood vessels

In what position are both auricles visible?

anteriorly

In what position is the coronary sinus and origins of the pulmonary veins visible?

posteriorly

4 chambers of the heart

• right atrium

• right ventricle

• left atrium

• left ventricle

What structure separates the right and left atriums?

interatrial septum

What structure separates the right and left ventricles?

interventricular septum

Where can pectinate muscles be found?

in right and left atria and auricles

Where can trabeculae carnae be found?

in ventricles

• papillary muscles are a subtype of these

How do atrioventrical valves work when open?

• chordae tendineae are slack

• papillary muscle is relaxed

How do atrioventrical valves work when closed?

• chordae tendineae are taut

• papillary muscle is contracted

During diastole, atrioventricular valves are

passively open

Atrioventricular valves _ with ventricular contraction

close

• this is due to pressure

What holds valves closed with blood?

sinuses

artery

vessel that carries blood away from the heart

vein

vessel that carries blood towards the heart

True or false: Arteries always carry oxygenated blood

False

What structure carries deoxygenated blood away from the heart and to the lungs?

pulmonary arteries

What structure carries oxygenated blood back to the heart?

pulmonary veins

pulmonary circuit

carries blood to and from the lungs

systemic circuit

carries blood to and from all tissues in the body

What is the first step of blood flow through the heart?

blood enters right atrium from superior and inferior venae cavae

What is the second step of blood flow through the heart?

blood in right atrium flows through right AV valve into right ventricle

What is the third step of blood flow through the heart?

contraction of right ventrical forces pulmonary valve open

What is the fourth step of blood flow through the heart?

blood flows through pulmonary valve into pulmonary trunk

What is the fifth step of blood flow through the heart?

blood is distributed by right and left pulmonary arteries to lungs, where is unloads CO2 and loads O2

What is the sixth step of blood flow through the heart?

blood returns from lungs via pulmonary veins to left atrium

What is the seventh step of blood flow through the heart?

blood in left atrium flows through left AV valve into left ventricle

What is the eighth step of blood flow through the heart?

contraction of left ventricle (simultaneous with contraction of right ventricle and opening of pulmonary valve) forces aortic valve open

What is the ninth step of blood flow through the heart?

blood flows through aortic valve into ascending aorta

What is the tenth step of blood flow through the heart?

blood in aorta is distributed to every organ in the body, where it unloads O2 and loads CO2

What is the final step of blood flow through the heart?

blood returns to heart via venae cavae

coronary vessels

• arise from the ascending aorta

• branching patterns varies

• all originate from left and right coronary arteries

• 
  

conduction system

1. SA nodes fires

2. Excitation spreads through the atrial myocardium

3. AV node fires

4. Excitation spreads down AV bundle

5. Purkinje fibers distribute excitation through ventricular myocardium

electrocardiogram (EKG/ECG)

• detects abnormal heart rhythms due to damage to conduction system or electrolyte imbalances

p wave

atrial depolarization, electrical signals moves from SA node to AV node

• right atrium → left atrium

QRS complex

depolarization of R/L ventricles

• happens quickly

T wave

ventricular repolarization

absolute refractory period

beginning of QRS → maximum of T wave

cardiac cycle

• all events concerning blood flow that occur from the beginning of one heartbeat to the beginning of the next

• continues w/o input from CNS (intrinsic)

  • input only increases or decreases the frequency of the cycle

5 major stages of cardiac cycle

1. early diastole (dub sound)

2. atrial systole

3. isovolumentric ventricular contraction (lub sound)

4. ventricular ejection

5. isovolumetric ventricular relaxation

diastole

• semilunar valves close, all of heart relaxed in early stages

• dub sound

• atrial contraction, but much of ventricular filling is passive

• AV valves open

• semilunar valves closed when AV valves open

systole

• Isovolumentric contraction

  • atria relax

  • ventricles contract forcing the AV valves shut

  • lub sound

• isovolumetric = ventricles contract, but do not eject blood

• ventricular ejection

  • occurs when there is enough pressure to force the semilunar valves open

• isovolumetric relaxation

  • no blood enters ventricules, pressure

• AV valves are closed during all of systole

Aortic arch branches

ABCS

• Ascending aorta

• Brachiocephalic trunk - supplied blood to arm, neck, and head

• L. Common Carotid

• L. Subclavian

brachiocephalic vein (left and right)

returns blood from the arm, neck, and head to a great vein

• branches off from superior vena cava

right and left subclavian artery

• have intenral thoracic artery to feed the front of the ribs via the anterior intercostal aa