CV

Question 1

What does plasma contain?

Answer 1

Electrolytes, water, glucose, carbon dioxide, proteins, clothing factors

Question 2

What’s the bloods hematocrit?

Answer 2

0.45

Question 3

What percentage of the blood is cellular?

Answer 3

45%

Question 4

Two functions of heart muscle

Answer 4

Muscular contraction and electrical conduction

Question 5

Why is the resting potential negative?

Answer 5

Controlled by Na/K pump. Sarcolemma only permeable to K+ cells that leave cell. Anions can follow so create a negative environment

Question 6

What happens to the Na+ pump with increased positivity ?

Answer 6

It undergoes a conformational change

Question 7

What part of the cardiac action potential signifies the efflux of Ca2+ ions ?

Answer 7

The plateau

Question 8

What different about cardiac and skeletal muscle action potentials ?

Answer 8

In cardiac muscle cells , the action potential lasts longer and after the action potential the permeability of K+ is less and they only open once Ca2+ channels have closed

Question 9

Where is the mediastinum?

Answer 9

Between the two pleural cavities (right and left lung)

Question 10

Where does the superior mediastinum border?

Answer 10

Horizontal plane from the sternal angle to the lower point of the T4 vertebra

Question 11

What is the brachiocephalic vein formed from?

Answer 11

Subclavian vein and internal jugular vein

Question 12

What is the Azygos vein formed from?

Answer 12

Segmental veins from the thorax and posterior abdominal wall

Question 13

What side of the body does the Azygos vein run ?

Answer 13

Right

Question 14

Where are the phrenic nerves formed from?

Answer 14

Cervical plexus at C 3/4/5

Question 15

What does the phrenic nerve do?

Answer 15

Supplies the diaphragm and sensory innervation to the pleura, pericardium and peritoneum

Question 16

What is the pathway of the right phrenic nerve?

Answer 16

Lies on the ‘big veins’ (SVC, IVC, brachiocephalic) and the right atrium.

Question 17

What is the pathway of the left phrenic nerve?

Answer 17

Crosses the arch of the aorta, runs in front of the root of the lung, on the pericardium and descends to reach the diaphragm.

Question 18

What is the pathway of the right vagus nerve?

Answer 18

Lies on the trachea, crosses behind the root of the lung (unlike the phrenic), branches to form the oesophageal plexus. Passes through the diaphragm via the oesophagus as the posterior gastric nerve.

Question 19

What is the pathway of the left vagus?

Answer 19

Crosses the arch of the aorta and gives off the left laryngeal nerve. It passes BEHIND the root of the lung. Below the root of the lung, the vagus gives off branches forming the oesophageal plexus, passing through the diaphragm and forming the anterior gastric artery.

Question 20

Where does the arch of the aorta commence?

Answer 20

At the level of the sternal angle and ends at the lower border of T4

Question 21

What are the 3 branches of the aortic arch?

Answer 21

Right brachiocephalic trunk (gives off the subclavian artery and right common carotid), left common carotid and left subclavian artery.

Question 22

What nerves cross the arch of the aorta?

Answer 22

Left vagus and Left phrenic

Question 23

Where does the trachea start and finish?

Answer 23

Extends from the lower border of the cricoid cartilage and finishes at the tracheal bifurcation at the level of the T4 vertebra.

Question 24

What muscles is found between the C-shaped cartilage in the trachea?

Answer 24

The trachealis muscle which allows contractions and dilations of the trachea (for sneezing and swallowing)