CV ANATOMY Flashcards
What does the CV system consist of?
- Consists of cardio which is the heart (pump) & vascular which are arteries, arterioles, veins, venules & capillaries.
What are the 2 circuits that are attached in series?
- Pulmonary circuit
- Systemic circuit
Where does the pulmonary circuit send blood to?
- Sends deoxygenated blood to the lungs, so that it may become oxygenated
Where does the systemic circuit send blood to & through what?
- Sends blood to the rest of the body through capillary networks
What is the heart surrounded by & where is it located?
- Surrounded by the pericardium
- Located in middle mediastinum
Where is the mediastinum located & where does it extend to?
- Located b/w 2 pleural cavities
- Extends from sternum to vertebral column, from the first rib to the diaphragm & b/w the lungs
What does the pericardium fuse w/ & what does this mean?
- Fuses w/ the central tendon of the diaphragm
- Means that whenever you breathe, your heart goes for a ride
What does the pericardium consist of?
- Parietal pericardium
- Visceral pericardium
What is the parietal pericardium?
- Epithelial lining the actual pericardial cavity
What does the visceral pericardium do?
- Lines the surface of the heart & is actually part of the heart wall
What do both layers of the pericardium secrete & what does this allow?
- Secrete lubricating fluid (i.e. serous fluid)
- Allows heart to move around pericardial cavity in friction-free manner
What does the heart look like?
- Looks like blunted cone, shifted to the left & tilted on side & covered in pericardium
What is the heart roughly the size of & what is it responsible for?
- Roughly the size of a fist
- Responsible for pumping 4-5 L/minute of blood throughout body
What is located at the bottom of the heart & what is it formed by?
- Apex of the heart is located at bottom & forms an “arrow-shape”
- Formed by the tip of the left ventricle
What is located at the top of the heart & what does it give rise to?
- Base of the heart
- Great vessels
What is mostly made up of the right atrium?
- The right border
What is mostly made up of the left musculature of the left ventricle?
- The left border
What surface is attached to the diaphragm?
- Inferior surface
What does the Superior Vena Cava do?
Where does it flow into?
- Major vein that brings systemic blood back from the upper limbs, the head & parts of the thoracic cavity
- Right atrium
What does the Inferior Vena Cava do?
Where does it flow into?
- Returns blood from the rest of the thorax, the abdomen & lower limbs
- Right atrium
What can you see on the anterior surface of the heart?
- Arch of the aorta
Where does the aorta arise from & what does it give off?
Where does it quickly dive behind?
- Arises from the base of the heart
- Gives off 3 major branches that will feed the upper limbs & the head
- Dives behind the heart into the abdominal cavity & services the lower limbs
Why isn’t the aorta seen?
- Its location is behind the heart
What structure comes off the right ventricle?
- Pulmonary trunk
Where are the sternum & vertebrae location?
- Sternum is out front
- Vertebrae is out back
What is the mediastinum locked in b/w?
- B/w 2 bony structures & the heart is locked b/w them
What is performed when someone’s heart has stopped?
What do you apply pressure to?
How does the heart fill up w/ blood again?
- Applied cardiac compressions
- Sternum bc the person’s heart is located there- apply pressure & squeeze the blood out of it
- When you release pressure
What can the mediastinum be broken down into?
- M.A.P.S.
- Middle mediastinum
- Anterior mediastinum
- Posterior mediastinum
- Superior mediastinum
What is the sternal angle?
- Junction of the manubrium
Where is the body of the sternum found?
- At level of 5th vertebrae
What are the sternebrae?
- 4 segments that fuse into the body of the sternum
What is the mediastinum bordered by?
- Sternal angle & 4 sternebrae located anteriorly
- First rib located superiorly
- 4 vertebrae (T5-T8) located posteriorly
- Diaphragm located inferiorly
What structures are located in the middle mediastinum? (M-4)
- The heart (pericardium)
- Ascending aorta
- Pulmonary trunk
- Phrenic nerves (2 nerves that are innervating the skeletal muscle of the diaphragm)- bc they came from C3, C4- spinal levels that keep us alive
What is the anterior mediastinum right by?
What structures are located in the anterior mediastinum?
A-1
- Uppermost region, right by sternal angle
- Tiny space & the thymus gland is located here- part of the immune cells where T-cells go to get educated, so they can fight viruses & bacteria
What is the thymus gland very large in?
What happens when you get older?
- In infants (as big as baby lung)- bc immune system is still developing
- It atrophies, replaced by fat tissue & gets smaller & smaller
What is the posterior mediastinum immediately anterior to?
What structures are located in the posterior mediastinum (P-5)?
- Behind the middle region & anterior to T5-T8
- Descending aorta → blood back from the left ventricle all the way down to the lower extremities & abdominal cavities
- Esophagus → pathway for food b/w the oral cavity & the stomach
- Lymph nodes → areas that drain fluid from the tissue & where immune cells say- “hey, I have been affected by something, should I amount a response to it?”- found in trachea & esophagus as well
- Vagus nerve → arises from cranial nerves in skull & has to get through mediastinum & passes down w/ other structures such as the esophagus- to get into the abdominal cavity
- Thoracic duct → separate set of vessels- called lymphatics- drain excess fluid from the tissues & return it back to circulation
What is the superior mediastinum found b/w?
What structures are located in the superior mediastinum? (S-3)
- Sternal angle & first rib
- Arch of aorta
- Esophagus passing by
- Trachea-stops- bifurcates & sends 2 bronchi into each of the lungs
How many chambers does the heart have?
- 4
- 2 atria & 2 ventricles
What is the most striking feature of the heart?
What does it form most of?
How can you tell how it sits in the chest cavity?
- right ventricle
- Anterior surface
- When you find the right ventricle & have it facing you
What feature does the right atrium have?
What is its purpose?
- Ear-like appendage called an auricle that is hanging off the atrium
- Allows any extra blood if returning from body during exercise
- Get a lot of venous return & it needs to sit somewhere, so auricle expands to accomodate
What structures drain in the right atrium?
- SVC
- IVC
- Coronary sinus
- Anterior cardiac veins
What forms the apex of the heart?
- Left ventricle
Where does the ascending aorta come off?
- Left ventricle behind pulmonary trunk & arches over the top
What direction does the aortic arch go?
What direction does the descending thoracic aorta go?
- Posteriorly
- Inferiorly
Where does the PT carry blood to?
-To the lungs (anterior to the aorta) for oxygenation & waste removal
What do the pulmonary veins do?
- Return deoxygenated blood to the heart & from the lungs & drain into the left atrium
What is the texture of the heart?
- Not smooth on surface- indentations/grooves (known as sulci)
What are the grooves on the heart called?
- Sulci
What do the inside grooves supply?
- Vessels that supply the muscles of the heart-coronary circulation
Describe the location of the coronary sulcus & what it contains.
- Goes around the top
- Left & right
- Located: b/w the atria & ventricles on both sides of the heart (“crown”)
- Contains: circumflex artery, great cardiac vein/coronary sinus, right coronary artery
Describe the location of the interventricular sulcus & what it contains.
- Located b/w the right & left ventricles
- Anterior & posterior
- Anterior: LAD (left anterior descending coronary artery), great cardiac vein
- Posterior: middle cardiac vein, posterior interventricular artery
In which sulcus do the main coronary vessels lie & why?
- Interventricular sulcus
- To protect them (against things like friction- don’t want the BV sticking out)
• as heart contracts & relaxes
• how you find in lab → see that there is fat that is running along BV as well
How many types of grooves on the heart are there?
What are they called?
- 2 types (2 of each type)
• Coronary sulcus
• Interventricular sulcus
Where does the left coronary artery come off?
What lies in front of it?
What artery does it branch into?
- Ascending aorta
- Pulmonary trunk
- Circumflex
What does the circumflex artery branch off of?
Which sulcus does it lie in?
What artery does it branch into?
- Left coronary artery
- Coronary
- LAD (left anterior descending interventricular artery)
Which sulcus does the LAD lie in?
What does it supply?
What is it often involved in?
- Interventricular
- Left & right ventricles
- Complications
What does the right coronary artery branch off of?
What does it go through?
What 2 arteries does it branch into?
- Ascending aorta
- Coronary sulcus located b/w the right atrium & left ventricle
- Marginal artery → supplied anteriorly
- Posterior interventricular artery → supplies posterior sections of right & left ventricles
What is formed b/w the left & right coronary arteries?
What does it occur b/w?
- Anastomoses
- Coronary sulci
What is an anastomosis?
- Connection or opening b/w 2 things that are normally diverging or branching
What happens if the anastomoses are not as developed?
- If we had fast blockage in 1 of coronary arteries (e.g. LAD), this anastomoses b/w right & left coronary arteries may not be enough
- Equates to heart attack
- If occurs slowly, then anastomoses may work
What would happen if the LAD interventricular artery was fully obstructed?
- May have a heart attack, myocardial infarction
i. ) limits the amount of blood flowing through region & thus, if tissue cannot get oxygen & nutrients, will die
ii. ) LAD heart attack- known as “widow-maker”
iii. ) feeds most of LV- supplies most of the body
iv. ) lumen gets smaller & smaller (atherosclerotic plaque)- as you get older
In the anterior view, what is one of the major coronary veins?
- Great cardiac vein- travels in interventricular sulcus where the LAD artery lies as well
- Branches around coronary sulcus where it joins w/ circumflex artery
- Drains into coronary sinus
- Comes up from bottom
What is at the end of the great cardiac vein?
- An enlargement known as “coronary sinus”- drains most of the coronary veins
- Small cardiac vein, anterior cardiac vein, middle cardiac vein
Where does the great cardiac vein travel?
What does part of the vessel lack?
- Travels all the way to back of coronary sulcus- area of vessel that LACKS smooth muscle cells
• don’t have smooth muscle cells- do not have muscles to alter diameter of vessel → so, in coronary sinus, it expands, but diameter not dependent on smooth muscle cells
What is the pericardium & what does it consist of?
- Thin, fibrous sac that protects the heart (outside surface of the heart)
- Consists of…
• Fibrous pericardium → very tough connective tissue
• Serous pericardium → parietal pericardium (thinner) & visceral pericardium (thinner)
What is the fibrous pericardium?
- Outermost layer
- Dense, irregular connective tissue
- Protects & anchors the heart
• when we move around, it is connected to the diaphragm, so heart doesn’t just float
What does the parietal layer of the serous pericardium do?
- Secretes serous fluid
- Lines the cavity
What does the visceral layer of serous pericardium do?
- Secretes serous fluid
- Heart wall- referred to as part of the heart wall, epicardium
What is the serous pericardium?
- Space b/w the parietal & visceral layer of the pericardium → pericardial cavity
- Secretion of serous fluid & allows for friction-less movement of the heart in the pericardial sac (sliding)
In a car accident, the steering wheel pierces the chest. What happens if there is bleeding into the pericardial cavity?
- Build-up of blood in the space will not allow heart to fully expand & contract
- Heart not able to fully fill w/ blood & release into body
- Cardiac tamponade
