Lecture 21. Circulatory System II

Question 1

What consist of the conducting system of the heart

Answer 1

1. SA ( sinuatrial ) node
2. AV atrioventricular node
3. atrioventricular bundle ( bundle of His)

Question 2

Where is the SA node located

Answer 2

right atrium wall, near the superior vena cava

Question 3

Where is the AV node located

Answer 3

right side of the interatrial septum, close to the opening of the coronary sinus

Question 4

Describe the path of the bundle of His

Answer 4

starts from the AV node which enters the interventricular septum that divides left and right giving rise to the Purkinje fibers that distribute to the right and left ventricular walls

Question 5

What regulates the conducting system of the heart

Answer 5

parasympathetic fibers ( vagus nerve) 
sympathetic fibers ( T1-T4) - vasomotor fibers

Question 6

Why are there more sympathetic cardiac nerves than those coming from the parasympathetic division ( vagus nerve) when supplying to the heart

Answer 6

needed to constrict blood vessels of the heart

Question 7

What does the aorta divide into

Answer 7

right and left coronary artery

Question 8

What does the right coronary artery divide/branch into, and what does it supply

Answer 8

posterior interventricular artery that supplies both the left and right ventricles

Question 9

What does the left coronary artery divide/ branch into and what does it supply

Answer 9

1. circumflex artery (along the coronary sulcus)

2. anterior inter-ventricular artery ( anterior inter ventricular groove)

Question 10

What does the right coronary artery supply?

Answer 10

right ventricle, right atrium and right border

Question 11

What does the left coronary artery supply?

Answer 11

both ventricles, left ventricle in particular and left atrium

Question 12

What are the 3 major cardiac veins that drain the heart

Answer 12

1. great cardiac vein
2. middle cardiac vein
3. smaller cardiac vein

Question 13

Where does the middle cardiac vein sit

Answer 13

posterior interventricular groove

Question 14

Where does the great cardiac vein sit

Answer 14

anterior inter-ventricular groove

Question 15

What is the coronary sinus, where does it drain to?

Answer 15

It is the combination of the great, middle and smaller cardiac vein, that drains to the right atrium

Question 16

What are the 3 major branches that arise from the aorta

Answer 16

1. left common carotid : supplies left half of the head and neck
2. left subclavian carotid: supplies left end of the upper limbs
3. brachiocephalic trunk: contains the right common carotid artery and right subclavian artery, that supplies the right side of the head and neck and the right upper limb respectively

Question 17

What are the 2 terminal branches of the left or right carotid

Answer 17

external and internal carotid, where the internal carotid branches further in the cranium whereas the external carotid branches outside of the cranium

Question 18

What are the branches of the external carotid artery

Answer 18

1. lingual artery: supplies the tongue
2. facial artery: supplies superficial part of the face ( ie. does not supply nasal or oral cavities)
3. superficial temporal artery:
4. occipital branch: part of the scalp that covers the occipital bone
5. maxillary artery : supplies deep part of the face

Question 19

Describe the vertebral artery

Answer 19

a branch of the subclavian artery, it supplies brain by entering through the transverse foramina of the cervical vertebrae, supplies the spinal cord. the left and right vertebral arteries to form the basilar artery which then divides to form the posterior cerebral artery

Question 20

What is the function of the basilar artery

Answer 20

supplies brain stem

Question 21

What does the posterior cerebral arteries supply

Answer 21

occipital bone

Question 22

What are the branches of the internal carotid

Answer 22

1. opthlamic artery
2. middle cerebral artery
3. anterior cerebral artery

Question 23

What is the function of the opthlamic artery

Answer 23

supplies the orbital cavity

Question 24

What is the function of the middle cerebral artery

Answer 24

largest cerebral artery, supplies all the lobes (parietal, temporal, occipital)

Question 25

What is the function of the anterior cerebral artery

Answer 25

supplies frontal lobe

Question 26

What is the anterior communicating

Answer 26

connecting structure between the anterior and middle cerebral artery allows siphoning/shunting of blood from the anterior and middle cerebral or vice versa

Question 27

What is posterior communicating

Answer 27

connection between the internal carotid and the posterior cerebral

Question 28

What connects the venous blood of the brain (mostly)

Answer 28

dural sinuses

Question 29

Is the great cerebral vein a sinus? What does it collect

Answer 29

Not a sinus. it collects deep veins of the brain

Question 30

What does the dural sinuses collect

Answer 30

superficial veins of the brain

Question 31

Map the pathway from the great cerebral vein to the internal jugular vein

Answer 31

great cerebral vein-> straight sinus ( + superior sagittal sinus) -> transverse sinus [can be left or right, this is a paired sinus] -> sigmoid sinus [passes through the mastoid process]-> internal jugular sinus [after it passes the jugular foramen, also receives the superficial veins : facial]

Question 32

What forms the brachiocephalic vein

Answer 32

jugular vein and subclavain vein

Question 33

What forms the superior vena cava

Answer 33

both left and right of the brachiocephalic vein