Download Thursday, February 19, 2015

Monday, February 6, 2017
• Grab a sheet of scrap paper
out of the basket.
• Get out something to write
with.
Bellringer – answer on the scrap paper
1. How are plasma and the formed elements of
blood different?
2. What are the steps of hemostasis?
Are you correct?
1. The formed elements include the RBCs,
WBCs, and platelets, or the cells found in the
blood. The plasma is the liquid portion of
blood that is mostly water.
2. Hemostasis: 1) vascular spasm; 2) platelet
plug formation; 3) coagulation
LEQs
• What is the structure of the heart?
• What path does blood take through the
heart and body?
• What are the differences and similarities
in the functions of the systemic system,
pulmonary system, hepatic portal, and
coronary circulation?
Read pgs. 362-366
1. What are the layers of the heart from outermost to inner-most?
2. What is the difference between atria and
ventricles in terms of location, structure and
function?
3. Starting with the vena cava, what is the path
of blood through the heart? Include the trip
to the lungs, blood vessels & specific valves.
Get out CVS Notes
Cardiovascular System
Notes Part 1
Basics
• Cardiovascular system is composed
of the heart and blood vessels
• Cardio- = heart
• -vascular = refers to the blood
vessels
• Basic path: arteries – arterioles –
capillaries – venules - veins
Pulmonary circuit
•Sends deoxygenated
blood to the lungs to
get O2 and get rid of
CO2
Systemic Circuit
•Sends O2 rich blood
and nutrients all over
body
•Removes wastes
Path of blood
1. O2- poor blood to right atrium
2. Right atrium to right ventricle
3. Right ventricle pumps to lungs
4. Lungs to left atrium
5. Left atrium to left ventricle
6. Left ventricle to body
Structure of heart
• Hollow, cone-shaped, muscular pump
• In thoracic cavity, on top of the
diaphragm
• Size: approx. 14 cm long by 9 cm wide
• Pericardium = covering around heart
• Heart wall = epicardium (outer layer);
myocardium (muscular middle layer);
endocardium (inner layer)
Chambers
• 2 atria on top; thin walls; receive
blood
• 2 ventricles on bottom; thicker walls;
pumps blood out into arteries
• Septum; wall that separates left and
right sides
Valves
•
•
•
•
•
Function: to ensure one-way blood flow
AV (atrioventricular) valves: tricuspid & mitral
Tricuspid: on right, 3 cusps (flaps)
Mitral: on left, a.k.a. bicuspid; only 2 cusps
Pulmonary valve: between right ventricle and
pulmonary artery; 3 cusps
• Aortic valve: at base of aorta and top of left
ventricle; 3 cusps
Blood Supply
• Coronary arteries: 1st 2 branches of
aorta; provide for the capillaries of
the myocardium
• Cardiac veins: remove blood from
myocardial capillaries
• Coronary sinus: empties into right
atrium
Cardiac cycle
• Systole = contraction
• Diastole = relaxation
• Cycle = atrial systole / ventricular
diastole – ventricular systole /
atrial diastole – both relax; equals
a complete heart beat
Beating heart
• https://www.youtube.com/watch?v=p1xEvCzs
vTM
Heart sounds
• Through a stethoscope sounds like “lubb –
dupp”
• Lubb = ventricular contraction; AV valves
closing
• Dupp = ventricular relaxation pulmonary &
aortic valves closing
• Murmur = abnormal heart sounds
Functional Syncytium
• Mass of merging cells that
function as a unit
• Atrial walls and ventricular walls
Cardiac conduction system
• Fibers that initiate and distribute impulses
throughout the myocardium
• Coordinates cardiac cycle
Sinoatrial node (S-A node)
• In right atrium near superior vena cava
• Initiates impulses that spread into
myocardium and cause cardiac contractions
• A.k.a. the pacemaker
The Path
• S-A note  atrial syncytium  junctional
fibers  A-V node  A-V bundle  bundle
branches  Purkinje fibers  ventricular
syncytium
Electrocardiogram (ECG or EKG)
• Recording of electrical changes during cardiac
cycle
• Muscle fibers are polarized between cycles
• P wave = depolarization of ventricles
• T wave = ventricles repolarizing
• P-Q interval = time between beginning of P
wave and beginning of QRS complex; time for
impulse to travel from S-A node through A-V
Regulation of Cardiac Cycle
• cells need more blood during certain times,
like strenuous exercise
• parasympathetic or sympathetic nerve fibers
“tell” the heart to increase heart rate
• Temperature changes can affect HR (colder =
slower HR)
• Ions affect HR (CA+2, K+)
Blood Vessels
• Closed circuit
• Tubes that carry blood from the heart to
the cells and back
• Includes: arteries, arterioles, capillaries,
venules, veins
Arteries & Arterioles
•
•
•
•
•
•
•
•
Carry blood away from the heart
Under high pressure
Arteries are larger
Arterioles are smaller and branched
Contain muscle in the artery wall
Vasoconstriction: contraction of the artery
Vasodilation: increase diameter of the vessel
Aorta = largest-diameter artery
Capillaries
• Smallest-diameter blood vessel
• Connect to arterioles and venules
• Where exchange of gases and nutrients
happens between blood and cells
• Happens by osmosis, diffusion and
filtration
Veins and venules
• Carry blood back to heart
• Veins are larger than venules
• Lower pressure than in arteries and
arterioles
• Less muscle in the wall than arteries
• Many contain valves
Blood pressure
• Force blood exerts against the inner walls of
blood vessels
• Systolic pressure: max pressure during
ventricular contraction
• Diastolic pressure: lower pressure during
ventricular relaxation
• Influenced by stroke volume / cardiac output,
blood volume, peripheral resistance, viscosity
• Normal = 120 / 80 (+/- 20)
Tuesday, February 7, 2017
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•
•
•
Turn in homework (3 questions)
Grab a copy of the Pulse / BP Lab
Get a ruler
Get out several sheets of paper & something
to write with
• READ THROUGH THE ENTIRE PACKET
Set Up Paper
• Put your first & last name in upper right
corner of your paper
• Put the title on the top line & underline it
– BP & Pulse Lab
• Set up for answers; leave space to answer
• Activity 1
– 3. _______ sec
– (question)
– (question)
• Activity 2
–
–
–
–
–
–
–
(question)
(question)
(question)
count 1
count 2
count 3
average
• Activity 3
– apical count _____ beats / min
– radial count _____ pulses / min
– pulse deficit _____ pulses / min
• Activity 4
– First trial: systolic pressure _____ diastolic
pressure _____
– Second trial: systolic pressure _____ diastolic
pressure _____
Activity 5
• Copy Charts 1 & 2
– Use a ruler & make it neat
– leave room to answer 2 questions
• Activity 6
–
–
–
–
–
3. (question)
4. (question)
5. (2 questions)
7. (3 questions)
Effects of Venous Congestion
• color of raised arm:
• color of dependent arm:
• (question)
• Effect of Mechanical Stimulation
– (question)
– (question)
• You will complete the entire lab procedure
tomorrow & Thurs. / Fri. in class.
Lab directions
• Before using, clean off ear pieces
of stethoscope w/ alcohol-soaked
cotton ball; throw cotton ball in
trash
• read & follow all directions
• Ask if you have any questions