THE CARDIORESPIRATORY SYSTEM

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THE CARDIORESPIRATORY SYSTEM

• Chapter 9

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Cardiorespiratory System

• What are the functions of the cardiorespiratory
  system?
• Transport O2 to tissues and removal of waste
• Transport of nutrients to tissues
• Regulation of body temperature

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Cardiorespiratory System

• What are the components of the cardiorespiratory
  system?
• Cardio-
• Heart a pump between external and internal
  respiration
• Blood Vessels transportation
• Respiratory
• Lungs gas exchange

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Cardiovascular System

• Heart
• Blood vessels

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THE HEART
PULMONARY CIRCUIT
SYSTEMIC CIRCUIT
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THE HEART

• Four chambers
• Right atria - blood from systemic system to...
• Right ventricle - blood to pulmonary system and
  then to...
• Left atria - blood from pulmonary system to...
• Left ventricle - blood to systemic system and
  then to...
• Right atria (and repeat)

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Cardiovascular System

• Pulmonary circuit
• Which side of the heart is part of the systemic
  circuit?
• What is the oxygen content of the blood (high or
  low)?
• Which chamber of the heart does the blood return
  into?

• Systemic circuit
• Which side of the heart is part of the systemic
  circuit?
• What is the oxygen content of the blood (high or
  low)?
• Which chamber of the heart does the blood return
  into?

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BLOOD FLOW THROUGH THE HEART

• Blue section shows blood flow through the right
  side of the heart
• Red section shows blood flow through the left
  side of the heart

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MYOCARDIUM or Cardiac Muscle

• What is the myocardium?
• Why is the left ventricle the most powerful and
  largest of the chambers?
• Note
• Thickness varies directly with stress placed on
  chamber walls.
• With vigorous exercise, the left ventricle size
  increases.

Right Left Wall Wall
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MYOCARDIUM Cardiac Muscle

• Intercalated disks
• What are they?
• What is their function?

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CONTROL OF THE HEART - INTRINSIC
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CONTROL OF THE HEART - INTRINSIC

• What part of the heart is referred to as the
  pacemaker of the heart?
• What is the function of the A-V node?
• What is an electrocardiogram?

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Electrocardiogram (ECG or EKG)

• Terms
• Depolarization stimulation of the myocardium
• Repolarization recovery of the myocardium from
  stimulation

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CONTROL OF THE HEART - ECG
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Assignment Questions from Chapter 9

• What are the functions of the cardiorespiratory
  system?
• What are the components of the cardiorespiratory
  system?
• Which side of the heart is part of the systemic
  circuit?
• What is the oxygen content of the blood (high or
  low)?
• Where does the blood flow to at the end of the
  systemic circuit?
• Which side of the heart is part of the pulmonary
  circuit?
• What is the oxygen content of the blood (high or
  low)?
• Where does the blood flow to at the end of the
  pulmonary circuit?
• What is the myocardium?
• Why is the left ventricle the most powerful and
  largest of the chambers?
• What are intercalated disks?
• What is the function of intercalated disks?
• What part of the heart is referred to as the
  pacemaker of the heart?
• What is the function of the A-V node?
• What is an electrocardiogram?

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CONTROL OF THE HEART - EXTRINSIC

• Medulla control center
• Neural input to medulla
• Higher brain centers
• Baroreceptors (blood vessels)
• Stretch receptors (heart)
• Chemoreceptors (blood vessels)
• Mechanoreceptors (muscles/joints)
• The medulla can alter speed of contraction (heart
  rate) and/or force of contraction (stroke volume)

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CONTROL OF THE HEART - EXTRINSIC
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CONTROL OF THE HEART - EXTRINSIC

• Parasympathetic Nervous System acts through the
  vagus nerve.
• What affect does the vagus have on heart rate?
• What affect does the Sympathetic Nervous System
  have on heart rate?
• What affect do the hormones epinephrine and
  norepinephrine have on heart rate?

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HEART FUNCTION

• When the energy needs of the body increase, what
  happens to the heart rate?
• How else can the heart supply more blood to the
  body?

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HEART FUNCTION - Heart Rate

• Heart Rate
• Definition?
• What is a typical resting heart rate?

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HEART FUNCTION - Cardiac Cycle
w Cardiac Cycle Events that occur between two
consecutive heartbeats (systole to systole)
w What is Systole?
w What is Diastole?
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HEART FUNCTION - Cardiac Cycle
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HEART FUNCTION - Heart Rate

• Why does heart rate increase during exercise?
• How is heart rate increased?

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HEART FUNCTION Stroke Volume

• What is stroke volume?
• What happens to stroke volume during exercise?
• How is stroke volume increased?

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HEART FUNCTION - Cardiac Output (Q)

• What is cardiac output?
• Cardiac Output Heart Rate x Stroke Volume
• Example HR of 72 beats/minute x SV of 70 mL/beat
• the beat(s) cancel out

• Therefore, Q equals 72 x 70 or 5,040 mL/min or
  5.040 L/min

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HEART FUNCTION - Cardiac Output (Q)

• How is cardiac output increased during exercise?
• What might cause cardiac output (or blood flow)
  to decrease during exercise?

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HEART FUNCTION

• Heart Rate
• 50-75 beats per minute
• Stroke Volume (SV)
• 60-100 milliliters per beat (ml/beat)
• Cardiac Output (Q)
• 4500-5000 milliliters per minute
• 4.5-5 liters per minute (L/min)

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a-v O2 Difference

• Oxygen Extraction at Rest
• Arteries
• 20 ml or oxygen in every 100 ml of arterial blood
• Veins
• 15 ml/100 ml of blood.
• How much oxygen did the muscles use?
• This amount is call the a-vO2 difference.

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THE VASCULAR SYSTEM (Circulation)
w Arteries
w Arterioles
w Capillaries
w Venules
w Veins
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THE VASCULAR SYSTEM - Arteries

• How do arteries differ from other blood vessels?
• Thick and Elastic
• Pulse

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THE VASCULAR SYSTEM - Arterioles

• Unique?
• Smooth muscle sphincters
• Function?
• Blood distribution
• Vasodilation
• Vasoconstriction

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THE VASCULAR SYSTEM - Capillaries

• What makes them unique?
• Thin
• Internal respiration or gas exchange

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THE VASCULAR SYSTEM - Veins

• Unique?
• One-way valves
• Muscle pump
• Venous return

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Muscle Pump
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Muscle Pump
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BLOOD PRESSURE

• Systolic is the pressure in the __________ when
  the heart is __________.
• Diastolic is the pressure in the __________ when
  the heart is __________.
• What is a normal resting blood pressure?
• What happens to systolic blood pressure during
  exercise? Why?
• Why is high blood pressure at resting unhealthy?

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BLOOD PRESSURE
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BLOOD PRESSURE
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THE BLOOD
w What are some of the functions of the blood?
w Transportation gas, nutrients, and wastes
w Regulates temperature
w Buffers and balances acid base
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THE BLOOD BLOOD VOLUME
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THE BLOOD FORMED ELEMENTS

• Red blood cells.
• What do they do?
• White blood cells.
• What do they do?
• Platelets.
• What do they do?

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THE BLOOD - Hematocrit

• What is Hematrocrit?
• Ratio of formed elements (mostly RBC) to the
  total blood volume
• What is a typical value?
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