CV Overview - Nordgren

Question 1

Define homeostasis.

Answer 1

The process of maintaining constancy within the body in order to maintain life.

Question 2

Where is intracellular, extracellular, and interstitial fluid located?

Answer 2

• Intracellular = within cells
• Extracellular = outside cells
• Interstitial = fluid between cells

Question 3

What is the primary role of the cardiovascular system?

Answer 3

Maintain homeostasis in the interstitial fluid.

(material transport network)

Question 4

How can the cardiovascular system described as a “Series Circuit”?

Answer 4

• Pulmonary
  
  • right side of heart pumps to lungs
• Systemic
  
  • left side of heart pumps to body
• Both RIGHT and LEFT heart must pump an IDENTICAL volume of blood per minute.
  
  • cardiac output

Question 5

How can the cardiovascular system described as a “Parallel Circuit”?

Answer 5

• Pump blood to all ORGANS in PARALLEL
  
  • receive blood of identical composition
  • flow through one organ can be controlled independently of the flow through others
    
    • e.g. blood conditioning (kidney) vs. non-conditioning (brain)

Question 6

What is the equation for Cardiac Output?

Answer 6

• CO = SV x HR
  
  • CO = cardiac output
  • SV = stroke volume
  • HR = heart rate

Question 7

What are the factors that determine the rate of flow?

Answer 7

• Q = ΔP / R
  
  • Q = flow
  • ΔP = pressure difference
  • R = resistance

Question 8

What is the approximate cardiac output for an average human heart?

Answer 8

about 5-6 L/min

Question 9

Whats are the physical factors that determine resistance?

Answer 9

• R = Ln / πr⁴
  
  • Length (L)
  • Viscosity (n)
  • Radius (r)

Question 10

What are two differences between the semilunar and the atrioventricular valves?

Answer 10

• Semilunar
  
  • three cuplike leaflets
  • Pulmonary & Aortic
• Atrioventricular
  
  • have chordae tendinae and papillary muscles to reduce the possibility of valve eversion
  • Tricuspid (R) & Bicuspid (Mitral, L)

Question 11

Where is the Tricuspid Valve located?

Answer 11

Right side between atrium & ventricle

Question 12

Where is the Mitral (Bicuspid) Valve located?

Answer 12

Left side between atrium and ventricle

Question 13

Where is the Pulmonary Valve located?

Answer 13

Right side between ventricle and Pulmonary Artery.

Question 14

Where is the Aortic Valve located?

Answer 14

Left side of heart, between ventricle and aorta

Question 15

What are the five requirements for effective operation of the heart?

Answer 15

1. Rhythmic/synchronized contractions of individual cardiac muscle cells
2. Valves must open fully
3. Valves must not leak
4. Muscle contractions must be forceful
5. Ventricles must fill adequately during diastole

Question 16

What is the main objective of Starling’s Law of the Heart?

Answer 16

• If cardiac filling increases during diastole, the volume ejected during systole also increases.
  
  • Stroke volume (CO) is strongly influenced by cardiac filling during diastole!
  • The heart pumps what it receives.

Question 17

What is the main function for each of the three major types of blood vessels?

Answer 17

• Arteries = pressure reservoir
• Capillaries = site of diffusion
• Veins = volume reservoir

Question 18

What is the composition and purpose of blood?

Answer 18

• Composition
  
  • blood cells (formed elements) + plasma
• Purpose
  
  • carry gases, salts, nutrients, and waste molecules throughout the system