4. Nerves of Heart

Question 1

Identify 1 → 4

Answer 1

1. Superior cervical ganglion
2. Vagus nerve (CN X)
3. Phrenic nerve
4. Thoracic (sympathetic) cardiac branches

Question 2

Identify 5 → 8

Answer 2

1. Superior cervical ganglion
2. Vagus nerve (CN X)
3. Phrenic nerve
4. Thoracic (sympathetic) cardiac branches

Question 3

The cardiac muscle of the heart is innervated by the ____ system

Answer 3

autonomic nervous

Question 4

The cardiac muscle of the heart is innervated by the autonomic nervous system.

→ Sympathetic contributions to the cardiac plexus arise from (1)___ that originate largely from the (2) ___ but also send direct (3)____ medially toward the heart.

Answer 4

1. cardiac nerves
2. cervical portions of the sympathetic trunk
3. thoracic cardiac branches (postganglionic sympathetics)

(Your autonomic nervous system is a network of nerves throughout your body that control unconscious processes.)

Question 5

The parasympathetic contributions (preganglionic) travel with ___

Answer 5

the vagus nerve (CN X) (2)

Question 6

Sympathetic contributions to the cardiac plexus arise from cardiac nerves that originate largely from the cervical portions of the sympathetic trunk

The parasympathetic contributions (preganglionic) travel with the vagus nerve (CN X).

→ Together, the parasympathetic and sympathetic branches form a rich (1)___ around the great vessels arising from the (2)___ and around the (3)____.

→ The vagus preganglionics synapse on postganglionics in this plexus.

Answer 6

1. cardiac plexus
2. heart
3. bifurcation of the trachea

Question 7

The role of sympathetic and parasympathetic innervation of the heart

Answer 7

• Sympathetic innervation to the heart increases the heart rate and contractile force
• Parasympathetic innervation decreases the heart rate.