Heart physiology

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Class Topics
Title Anat Phys 4/11/07
Objectives

• .

• Heart physiology
• Heart dissection
• Notes blood vessels
• The nice part about being a pessimist is that
  you are constantly being either proven right or
  pleasantly surprised.
• George Will

Sunday, December 6, 2020 1122 AM
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Class Assignments
By When
What

• Heart coloring 4/11/07
• Heart coloring W.S. 4/13/07
• Heart test 4/13/07
• Due this class period
• Due next class period
• Due in the future

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Heart Physiology

• Each beat is stimulated by an area in the right
  atrium near the superior vena cava called the
  Sinoatrial Node (SA Node).
• SA Node is innervated by the autonomic nervous
  system
• Pacemaker of the heart
• Stimulates both atria to contract

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Heart Physiology

• SA Node sends impulse to the AV
  (atrioventricular) Node.
• Located in the interatrial septum
• Holds impulse for a short time (milliseconds) and
  passes electrical impulse to AV Bundle (Bundles
  of His)
• AV Bundles passes impulse to Purkinje fibers
  which stimulates the ventricles to contract

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FromL http//www.personal.dundee.ac.uk/jrelliot/H
TML1/heart.htm
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Cardiac Cycle

• 1st stage
• Atrial Systole
• Atrial contractions
• 2nd stage
• Ventricular Systole
• Ventricular contractions
• lub
• 3rd stage
• Diastole
• Both chambers relax (atria fill with blood)
• dub

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Sound
Electric Activity
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Heart Sounds

• Lub
• AV valves closing (tricuspid and mitral)
• Dub
• Semilunar valves closing

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Lab

• Dissect the pig heart
• look for the following
• atria
• ventricles
• trace the blood flow
• chordae tendinae
• papillary muscles
• valves

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Blood vessels

• Artery
• thick walled, can contract, moves blood away from
  heart
• Arteriole
• smaller lumen than arteries, source of
  vasoconstriction and vasodilation

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Blood vessels

• Capillary
• microscopic size, thin walled - for diffusion,
  osmosis, facilitated diffusion, and active
  transport
• Venule
• small lumen, gain size closer to heart
• Vein - 65 of blood at any time
• thick walled (not as thick as artery), larger
  lumen than artery, internal valves to avoid
  pooling

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From http//www.familydoctor.co.uk/htdocs/varicos
e/varicose_specimen.html
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Capillary bedsFig 13-14

• What purpose do these serve in maintaining
  homeostasis?

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Circulatory Pathways

• Pulmonary circulation
• to lungs and back to heart
• Systemic circulation
• supplying blood to all systems and organs except
  lungs
• All starts with the aorta

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From http//www.people.virginia.edu/dp5m/phys_30
4/figures/19-17a_pulmnrycirc.jpg
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From http//www.people.virginia.edu/dp5m/phys_30
4/figures/19-18_systemcirc.jpg
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Branches of the Aorta

• Ascending aorta
• Coronary arteries
• supply blood to the heart
• blockage can lead to myocardial infarction
• Arch of the Aorta
• Brachiocephalic artery
• left common carotid artery
• Left subclavian artery

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Branches of the Aorta

• Descending Aorta
• intercostal arteries
• celiac artery
• superior mesenteric artery
• suprarenal arteries
• renal arteries
• gonadal arteries
• inferior mesenteric artery
• common iliac arteries

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Celiac Artery

• Branches into
• Gastric artery
• Hepatic artery
• Splenic artery
• Pancreatic artery

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From http//www.personal.psu.edu/ faculty/s/x/sxd
5/Arteries.gif
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Common Iliac Arteries

• Internal iliac artery
• External iliac artery
• Deep femoral artery
• Femoral artery
• Popliteal artery
• Anterior tibial artery
• Posterior tibial artery

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Brachiocephalic

• Right common carotid artery
• External carotid artery - scalp, face, jaw
• internal carotid artery - brain
• Right subclavian artery
• Vertebral artery (branch)
• Axillary artery
• Brachial artery
• Radial artery
• Ulnar artery

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Left Common Carotid and Left Subclavian

• Same branching as right side
• No brachiocephalic

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Systemic Veins

• Superior vena cava drains the body superior to
  the heart
• Inferior vena cava drains the body inferior to
  the heart
• Coronary sinus drains the heart wall (myocardium)

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Superior vena cava

• Right and left brachiocephalic veins
• subclavian veins
• Axillary veins
• Brachial veins
• Ulnar veins
• Radial veins
• jugular veins
• interior jugular vein
• exterior jugular vein

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Inferior vena cava

• Hepatic vein
• Renal veins
• Common Iliac veins
• Gonadal veins (rt enters the CI, but left enters
  the renal vein)
• Internal iliac veins

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Inferior Vena Cava

• External iliac veins
• Femoral veins
• Great saphenous vein - longest in body
• Popliteal
• Posterior tibial vein
• Anterior tibial vein

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Hepatic Portal System

• Blood from the small intestines, large
  intestines, stomach all enter the portal system
• inferior mesenteric vein and superior mesenteric
  vein enter the hepatic portal vein to the liver

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Blood movement

• Trace the blood from the heart to the left arm
  and back to the heart.
• Trace the blood from the heart to the right leg
  and back to the heart.
• Trace the blood from the heart to the small
  intestine and back to the heart.
• Trace the blood from the heart to the left gonad
  (this of course depends upon your gender) and
  back to the heart.

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ACT Math Test Tips

• Each question is worth the same
• Skip the hard ones, answer all the easy ones
• Use your test booklet
• Scratch paper
• organize your work to review answers
• 60 questions, 60 minutes
• Answer all questions
• Guesses have 20 chance of being right

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Math Tests

• Work backwards
• Eliminate answers and plug in those that might
  work
• Be familiar with your calculator
• Dont just assume your calculator is always right
• Think!!!

Sample Problems