Vascular Anatomy

Question 1

where is the SA node located

Answer 1

located in the intra-atrial wall of the right atrium near vena cava and intravenous tubercle

Question 1

function of the SA node

Answer 1

pacemaker - controls heart rate

Question 2

location of the AV node

Answer 2

caudal right atrium near septum

Question 3

function of the AV node

Answer 3

ensures atrium is completely filled before conducting the signal to the ventricles

Question 4

location of the purkinje fibers

Answer 4

subendocardial layer
(between endocardium and myocytes/myocardium)

Question 5

function of Purkinje fibers

Answer 5

specialized cardiac cells that allow for synchronized contraction

Question 6

fossa ovale

Answer 6

remnant of the foramen ovale during development

located in the right atrium

Question 7

coronary sinus

Answer 7

opening for venous return from coronary circulation; receives deoxygenated blood from coronary veins –> empties into R atrium

located in the right atrium

Question 8

moderator band (septomarginal trabeculae)

Answer 8

allows purkinje fibers to extend to the right lateral heart

located in the right ventricle

Question 9

annulus fibrosus

Answer 9

skeletal component of the heart; provides structural separation between the atrium and ventricles

fibrous rings surrounding all 4 valves to act as an anchor

prevents most connections between atrium and ventricles

Question 10

what is the only thing that can cross from atrium to ventricles

Answer 10

purkinje fibers

Question 11

chordae tendinae

Answer 11

fibrous strands that attach the valves to the papillary muscles of the ventricle wall

prevents valves from inverting into atrium while closing to prevent back flow

Question 12

atrioventricular (AV) valves

Answer 12

separate atrium and ventricle

left side: mitral
right side: tricuspid

Question 13

semilunar (SL) valves

Answer 13

separate ventricles and great vessels

left side: aortic valve
right side: pulmonary valve

Question 14

coronary arteries

Answer 14

first branches off of the aorta; supplies oxygenated blood to the heart

travels in the coronary groove around the heart between atria and ventricles

right C.A.: supplies the right side of the heart

left C.A.: supplies the left side of the heart

Question 15

interventricular subsinuosal groove

Answer 15

groove that the right coronary artery travels in

Question 16

interventricular paraconal groove

Answer 16

groove that branches from the left coronary artery travel in

Question 17

how does sympathetic innervation affect the heart

Answer 17

increases HR, contractility, and conduction velocity

Question 18

what node(s) does the sympathetic nervous system innervate

Answer 18

AV node only

Question 19

sympathetic trunk

Answer 19

dorsal chain of sympathetic ganglia that runs from head to tail alongside the spine

Question 20

cervicothoracic ganglia

Answer 20

“stellate” ganglia

extends nerve fibers down to middle cervical ganglia via ansa subclavia

Question 21

middle cervical ganglia

Answer 21

innervates the heart and lungs

origination point of the vagosympathetic trunk

Question 22

vagosympathetic trunk

Answer 22

combined sympathetic and parasympathetic nerve fibers that run within the same nerve sheath

sympathetic: extends cranially from middle cervical ganglia to innervate the head

parasympathetic: extends caudally from middle cervical ganglia as the vagus nerve

Question 23

how does parasympathetic innervation affect the heart

Answer 23

decrease HR, contractility, and conduction velocity

Question 24

what node(s) does the parasympathetic nervous system innervate

Answer 24

SA and AV node

Question 25

is SNS or PNS the predominant innervation at rest

Answer 25

parasympathetic - keeps HR low

Question 26

vagus nerve

Answer 26

cranial nerve 10
extends to thorax via vagosympathetic trunk until the level of the middle cervical ganglia –> continues caudal as only vagus nerve

branches into dorsal and ventral at the level of the base of the heart

the L and R dorsal & ventral branches merge to form dorsal or ventral vagal trunks

Question 27

species variations in aortic branches

Answer 27

carnivores: 2 branches - L subclavian and brachiocephalic trunk

herbivores: 1 branch - brachiocephalic trunk

Question 28

how do you identify branches off the subclavian

Answer 28

named based off of where they terminate

ex. internal thoracic, superficial cervical, vertebrae, cervical, scapula, intercostal, etc

Question 29

what are the three layers of the vessels

Answer 29

tunica externa
tunica media
tunica intima

Question 30

tunica externa

Answer 30

adventitia; connective tissue surrounding the vessel

contains nerves and vasa vasorum

Question 31

tunica media

Answer 31

smooth muscle

+ elastin in arteries

Question 32

tunica intima

Answer 32

endothelium and basement membrane

Question 33

characteristics of arteries

Answer 33

thick walled
high pressure
no valves

THICK tunica media
wave endothelium

Question 34

characteristics of veins

Answer 34

thin walled
low pressure
valves present

THIN tunica media
smooth endothelium

Question 35

histological layers from inside –> outside of cardiac vessels

Answer 35

1. endothelium
2. sub endothelial CT
3. myocardium
4. subepicardial CT
5. epicardium (mesothelium)

Question 36

cardiomyocyte characteristics

Answer 36

cardiac muscle cells

central nuclei
intercalated discs between cells
branching of individual cells