Lecture 21. Circulatory System II Flashcards
What consist of the conducting system of the heart
- SA ( sinuatrial ) node
- AV atrioventricular node
- atrioventricular bundle ( bundle of His)
Where is the SA node located
right atrium wall, near the superior vena cava
Where is the AV node located
right side of the interatrial septum, close to the opening of the coronary sinus
Describe the path of the bundle of His
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
What regulates the conducting system of the heart
parasympathetic fibers ( vagus nerve) sympathetic fibers ( T1-T4) - vasomotor fibers
Why are there more sympathetic cardiac nerves than those coming from the parasympathetic division ( vagus nerve) when supplying to the heart
needed to constrict blood vessels of the heart
What does the aorta divide into
right and left coronary artery
What does the right coronary artery divide/branch into, and what does it supply
posterior interventricular artery that supplies both the left and right ventricles
What does the left coronary artery divide/ branch into and what does it supply
- circumflex artery (along the coronary sulcus)
2. anterior inter-ventricular artery ( anterior inter ventricular groove)
What does the right coronary artery supply?
right ventricle, right atrium and right border
What does the left coronary artery supply?
both ventricles, left ventricle in particular and left atrium
What are the 3 major cardiac veins that drain the heart
- great cardiac vein
- middle cardiac vein
- smaller cardiac vein
Where does the middle cardiac vein sit
posterior interventricular groove
Where does the great cardiac vein sit
anterior inter-ventricular groove
What is the coronary sinus, where does it drain to?
It is the combination of the great, middle and smaller cardiac vein, that drains to the right atrium
What are the 3 major branches that arise from the aorta
- left common carotid : supplies left half of the head and neck
- left subclavian carotid: supplies left end of the upper limbs
- 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
What are the 2 terminal branches of the left or right carotid
external and internal carotid, where the internal carotid branches further in the cranium whereas the external carotid branches outside of the cranium
What are the branches of the external carotid artery
- lingual artery: supplies the tongue
- facial artery: supplies superficial part of the face ( ie. does not supply nasal or oral cavities)
- superficial temporal artery:
- occipital branch: part of the scalp that covers the occipital bone
- maxillary artery : supplies deep part of the face
Describe the vertebral artery
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
What is the function of the basilar artery
supplies brain stem
What does the posterior cerebral arteries supply
occipital bone
What are the branches of the internal carotid
- opthlamic artery
- middle cerebral artery
- anterior cerebral artery
What is the function of the opthlamic artery
supplies the orbital cavity
What is the function of the middle cerebral artery
largest cerebral artery, supplies all the lobes (parietal, temporal, occipital)
What is the function of the anterior cerebral artery
supplies frontal lobe
What is the anterior communicating
connecting structure between the anterior and middle cerebral artery allows siphoning/shunting of blood from the anterior and middle cerebral or vice versa
What is posterior communicating
connection between the internal carotid and the posterior cerebral
What connects the venous blood of the brain (mostly)
dural sinuses
Is the great cerebral vein a sinus? What does it collect
Not a sinus. it collects deep veins of the brain
What does the dural sinuses collect
superficial veins of the brain
Map the pathway from the great cerebral vein to the internal jugular vein
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]
What forms the brachiocephalic vein
jugular vein and subclavain vein
What forms the superior vena cava
both left and right of the brachiocephalic vein
