Unit 3 - Structure and anatomy of the heart Flashcards Preview

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Flashcards in Unit 3 - Structure and anatomy of the heart Deck (23)
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1
Q

Outline the movement of blood through the heart

A
  • vena cava into right atrium
  • through tricuspid AV valve
  • right ventricle
  • semi-lunar valves
  • pulmonary artery
  • lungs
  • pulmonary veins
  • mitral value
  • left atrium
  • left ventricle
  • aortic valve
  • aorta
2
Q

What is the heart made out of?

A

Cardiac muscle

3
Q

What is the difference between cardiac muscle and skeletal muscle?

A

Cardiac muscle does not get fatigued and need to rest

4
Q

Why is the heart described as a double pump?

A
  • blood is pumped through the heart twice
  • first time deoxygenated blood is pumped to lungs
  • Second time oxygenated blood is pumped to the body
5
Q

What is the function of the coronary arteries?

A

Supply the heart muscle with oxygen and glucose in order to keep it contracting and relaxing all the time

6
Q

What is the function of pericardial membranes?

A

Help to prevent the heart from over distending with blood

7
Q

Is the wall of the left ventricle thicker than the right?

A

Yes

8
Q

Why is the wall of the right ventricle thinner than the wall of the left ventricle?

A
  • the right side only has to pump blood to the lungs which are close to the heart
  • right side must only overcome resistance of the pulmonary circulation
9
Q

Why is the wall of the left ventricle thicker than the wall of the right ventricle?

A
  • the left side must provide sufficient force to overcome the resistance of the aorta and arterial systems of the whole body
  • left side must move the blood under pressure to all extremities of the body
10
Q

As the atrium fills with blood what happens to atrial pressure?

A

It increases

11
Q

How is cardiac muscle described?

A

Myogenic

12
Q

What does myogenic mean?

A

Heart muscle has its own intrinsic rhythm

13
Q

As ventricular pressure increases, what happens to aortic pressure?

Why?

A

It increases

Blood flows into the aorta at high pressure

14
Q

What is the sino-atrial node? and what is its function?

A

Region of the heart that initiates a wave of excitation that triggers the contraction of the heart

15
Q

What is the sino-atrial node also known as?

A

The pacemaker region

16
Q

What is the atrio-ventricular node? and what is its function?

A

Stimulates the ventricles to contract after a slight delay

17
Q

Why does the atrio-ventricular node impose a slight delay?

A

To ensure atrial contraction is complete

18
Q

What is the bundle of His?

A

Conducting tissue made of purkyne fibres that passes through the septum

19
Q

What are Purkyne fibres?

A

Tissue that conducts the wave of excitation to the apex of the heart

20
Q

What is the function of the septum?

A

Prevents the mixing of oxygenated and deoxygenated blood

21
Q

What is the function of the valves in the heart?

A

Prevent backflow of blood and so ensure efficient movement of blood

22
Q

What is the function of the tendinous cords?

A

Connect papillary muscles to the valves and help to prevent prolapse of the valves

23
Q

Why does hydrostatic pressure of blood drop as blood moves away from the heart?

A
  • divides into smaller vessels
  • vessels have larger total cross sectional area
  • loss of plasma from the capillaries