Thorax and cardiovascular system Flashcards
What is the function of the thorax?
- protection
- support
- conduit
- breathing
- pumping blood
What encircles the thoracic contents and provides a stable thorax cage?
sternum
ribs (12)
thoracic vertebrae (12)
What does the thorax protect?
visceral structures of the thorax and offers some protection for the abdominal viscera, including the liver, gallbladder, stomach. spleen, and the adrenal glands on both kidneys
What does the thoracic skeleton form?
the osteocartilaginous thoracic cage
What does the thoracic skeleton inlcude?
12 pairs of ribs and costal cartilages
12 thoracic vertebrae and IV discs
sternum
What forms the anterior continuation of the ribs, providing a flexible attachment at their articulation with the sternum?
costal cartilage
What is separated by the intercostal spaces?
ribs and their cartilages
What can be found in the intercostal spaces?
intercostal muscle, vessels, and nerves
What is inflammation of the costal cartilage called?
costochondritis
What are the curved, flat bones that form most of the thoracic cage, are light in weight but highly resilient?
the ribs
Each rib has a spongy interior containing what?
bone marrow
What does the bone marrow in each rib form?
blood cells (hematopoietic tissue)
What are the three classes of ribs?
true (vertebrosternal) ribs
false (vertebrochondral) ribs
floating (free) ribs
Which ribs are attached directly to the sternum anteriorly through their own costal cartilages?
true ribs
Which ribs are considered true ribs?
ribs 1-7
Which ribs have cartilages on their anterior ends that are joined to the cartilage of the rib just superior to them; thus, there connection with the sternum is indirect?
false ribs
Which ribs are considered false ribs?
ribs 8-10
Which ribs have rudimentary cartilages on their anterior ends that do not connect even indirectly with the sternum; instead, they end in the posterior abdominal musculature?
floating ribs
Which ribs are considered floating ribs?
ribs 11 and 12; sometimes the 10th
When a few ribs in a row are broken or out of place, what can it cause?
flail chest
Which ribs are considered “typical ribs”?
ribs 3-9
Typical ribs have what parts?
-head of rib
-facet that articulates with body of numerically corresponding vertebrae
-facet that articulates with superior vertebrae
-neck of the rib
-tubercle of the rib
-body of the rib
-costal groove
What protects the intercostal nerve and vessels?
costal groove
Which ribs are considered atypical?
ribs 1, 2, and 10-12
Which rib is the shortest?
1st rib
Which ribs are short and have no neck or tubercles?
ribs 11 and 12
What prolongs the ribs anteriorly and contribute to the elasticity of the thoracic wall?
costal cartilage
What is the flat, vertically elongated bone that forms the middle of the anterior part of the thoracic cage?
sternum
What are the different parts of the sternum?
manubrium
body
xiphoid process
What is the name of the superior part of the sternum?
manubrium
What levels of the vertebral bodies can you find the manubrium?
T3 and T4
The manubrium and body of the sternum lie in slightly different planes, forming a projecting ______
sternal angle
The sternal angle is located opposite to the second pair of costal cartilages at the level of the IV disc between which vertebrae?
T4 and T5
What level can you find the body of the sternum?
T5-T9
What is longer, narrower, and thinner than the manubrium & its width varies because of the scalloping of its lateral borders by the costal notches?
body of the sternum
What level can you find the xiphoid process?
T10
What is the smallest and most variable part of the sternum; it is relatively thin and elongated; it is cartilaginous in young people but more or less ossified in adults older than 40?
xiphoid process
What level can you find the xiphisternal joint?
T9
What is the xiphisternal joint a midline marker for?
- superior level of the liver
- central tendon of the diaphragm
- inferior border of the heart
The thoracic cage provides muscular support, attachment, weight support for what?
upper limb (pectoral girdle)
What provides the anchoring attachment of many of the muscles that move and maintain the position of the upper limbs relative to the trunk?
thorax
What provides for a superior and inferior thoracic aperture and a central mediastinum?
thorax
What does the superior thoracic aperture convey?
- large vessels
- important nerves
- thoracic lymphatic duct
- trachea
- esophagus between the neck and thorax
What is another name for the superior thoracic aperture?
the anatomical thoracic inlet
What does the inferior thoracic aperture convey?
- IVC
- aorta
- esophagus
- nerves
- thoracic lymphatic duct between the thorax and abdominal cavity
What is another name for the inferior thoracic aperture?
the anatomical thoracic outlet
What is the mediastinum divided into?
- superior mediastinum
- inferior mediastinum
What is the midline compartment that lies above an imaginary horizontal transverse thoracic plane that passes through the manubrium of the sternum (sternal angle) and the IV discs between T4 and T5?
superior mediastinum
What is the midline compartment below an imaginary horizontal transverse thoracic plane that is further subdivided into an anterior, middle, and posterior mediastinum?
inferior mediastinum
What is contained in the superior mediastinum?
- SVC
- brachiocephalic veins
- arch of the aorta
- thoracic duct
- trachea
- esophagus
- thymus
- vagus nerves
- left recurrent laryngeal nerve
- phrenic nerves
What is contained in the anterior mediastinum?
- remnants of the thymus
- lymph nodes
- fat
- connective tissue
What is contained in the middle mediastinum?
- heart
- roots of the great vessels
- arch of the azygos vein
- main bronchi
Where is the middle mediastinum located?
boundaries of which correspond to the pericardial sac
What is contained in the posterior mediastinum?
- esophagus
- thoracic aorta
- azygos and hemiazygos veins
- thoracic duct
- vagus nerves
- sympathetic trunks
- splanchnic nerves
Where is the posterior mediastinum located?
posterior to the pericardium
What is the functionary component of the breast?
mammary gland
What is the function of the mammary gland?
synthesizes, secretes, and delivers milk to the newborn
What do the lobules within mammary glands produce?
milk
What transports the milk into openings in the nipples?
lactiferous ducts
What is the structural support for the pectoral muscles and the mammary glands primarily provided by?
the upper 8 ribs along with their attachment to the lateral part of the sternum by way of costal cartilages
What is considered a modified sweat gland consisting of 15-25 lobes?
the breast
What is the pigmented skin surrounding the nipple?
areola
What attaches the breast to underlying muscle?
suspensory ligaments
lobules within the lobes of the breast contain what that produce milk?
glandular alveoli
Milk is passed into ________ and then into the ______ that open to the outside at the nipple?
lactiferous ducts, lactiferous sinuses
Glandular structure is underdeveloped in who?
non-nursing women
The arterial supply of the breast is derived from what vessels?
- medial mammary branches of perforating branches and anterior intercostal branches of the internal thoracic artery (originating from subclavian artery)
- mammary branches of lateral thoracic and thoraco-acromial arteries (branches of the axillary artery)
-posterior intercostal arteries (branches of the thoracic aorta)
The venous drainage of the breast is mainly to what?
axillary vein but there is some to the internal thoracic vein
Most lymph of the breast drains to what?
axillary lymph nodes
Most of the lymph of the breast first drains to what lymph nodes?
pectoral nodes
Some of the lymph from the lateral quadrants of the breast drains into which lymph nodes?
central nodes
Lymph from the medial breast quadrants drain to what?
parasternal lymph nodes or to the opposite breast
Lymph from the inferior breast quadrants may pass deeply to what?
abdominal lymph nodes (inferior phrenic nodes)
Breast lymph from the axillary nodes drains to what?
infraclavicular and supraclavicular nodes and then to the subclavian lymphatic trunk
Breast lymph from the parasternal nodes enters what?
bronchomediastinal trunks, which ultimately drain into the thoracic or right lymphatic duct
What does the thoracic duct drain?
the chest
What are the principal muscles of inspiration?
external intercostals and diaphragm
What are the active breach muscles of expiration?
internal intercostals and abdominals
What muscles help elevate the ribs in inspiration?
external intercostals
What muscles pull the ribs down in expiration?
internal intercostals
What is the vital organ responsible for circulating blood throughout the body by contraction of its muscular wall?
heart
What does the heart effectively function as?
a 2 pump system with one side devoted to circulating oxygen-poor blood, and the other circulating oxygen-rich blood
What are the 3 layers of the heart from superficial to deep?
- epicardium
- myocardium
- endocardium
What is the thin external layer of the heart formed by the visceral layer of serous pericardium?
epicardium
What is the thick middle layer of the heart composed of cardiac muscle?
myocardium
What is the thin internal layer of the heart or lining membrane that also covers its valves?
endocardium
What is the motor system of the heart?
myocardium
What does the trabeculae carnae do?
prevents blood from being stuck to the wall of the heart
Where is the trabeculae carnae found?
only in the ventricles of the heart
What is the “plumbing” system of the heart?
chambers and valves
What receives nutrient-rich but O2-poor blood from systemic circulation?
right atrium
What pumps to the pulmonary circulation (pulmonary trunk)?
right ventricle
What receives nutrient-poor and O2-rich blood from pulmonary circulation?
left atrium
What pumps to systemic circulation (aorta)?
left ventricle
Which side of the heart will have the higher pressure?
left
What forms the right border of the heart and receives venous blood from the SVC, IVC and coronary sinus?
right atrium
Where are the pectinate muscles located?
right and left atrium
Where does the coronary sinus drain into?
right atrium
At what level is the opening of the SVC into the right atrium?
3rd costal cartilage
At what level is the opening of the IVC into the right atrium?
5th costal cartilage
What is the name of the thumbprint-sized depression in the right atrium and what is it the remnant of?
fossa ovalis
remnant of the foramen ovali
What forms most of the base of the heart and forms the superior part of the left border of the heart and overlaps the pulmonary trunk?
left atrium
How many veins enter the posterior wall of the left atrium?
4 pulmonary veins
What parts of your heart are at a higher risk for developing blood clots and why?
the left and right atrium because there is lower pressure that causes the blood not to move as much
What forms the largest part of the anterior surface of the heart, a small part of the diaphragmatic surface, and almost the entire inferior border of the heart?
right ventricle
Superiorly, the right ventricle tapers into what?
an arterial cone, the conus arteriosus, which leads into the pulmonary trunk
The inflow part of the right ventricle receives blood from what?
right atrium through the right AV (tricuspid) orifice (located at the level of the 4th and 5th intercostal spaces)
What connects the interventricular septum to the anterior wall of the right ventricle and carries the right branch of the atrioventricular bundle of the heart’s conduction system to the anterior papillary muscle?
septomarginal trabecula (moderator band)
What forms the apex of the heart, nearly all of its left surface and border, and most of the diaphragmatic surface?
left ventricle
What performs more work, the left or right ventricle?
left ventricle
What are the characteristics of the trabeculae carneae in the left ventricle?
finer and more numerous than those in the right ventricle
What is the size comparison between the anterior and posterior papillary muscles in the left and right ventricle?
they are larger in the left ventricle than those in the right ventricle
What is the most important chamber of the heart?
left ventricle
What valve is associated with the left ventricle?
mitral (bicuspid) valve
How many papillary muscles are in the left and right ventricle?
2 in the left ventricle
3 in the right ventricle
What are the two valves on the right side of the heart?
right AV valve (tricuspid)
right semilunar valve to pulmonary circulation
What are the two valves on the left side of the heart?
left AV valve (bicuspid/mitral)
left semilunar valve (aortic) to systemic circulation