Thorax - other

Question 1

what is different about the first thoracic vertebra? 10th and 11th/12th?

Answer 1

the first vertebra has a full costal facet on the top for complete articulation with its own ribs head
10th rib lacks an inferior demifacet because the 11th an 12th are floating ribs , it also has a single whole facet for 10th rib (doesnt articulate w above for some reason)
the 11th and 12th vertebra has no costal facet on the transverse process and have just one on each side of a superior costal facet , these are whole and only aritculate with their own rib (not the one above)

Question 2

what are the true and false ribs

Answer 2

1-7 are true (meet with sternum)
8-12 are false
8-10 meet with cartilage and 11 and 12 are floating ribs.

Question 3

what do the transverse processes articulate with

Answer 3

tubercles of the corresponding ribs (present for t1-t10)

Question 4

what is distinct about ribs 1, 10, 11 and 12?

Answer 4

Rib 1 has two large grooves with a scalene tubercle in the middle. the grooves are for the subclavian vein (anterior) and subclavian artery (posterior). The head of the rib articulates just w its vertebra so it has only one articular surface on it. It also has its regular tubercle that meets with the transverse process (typical)

Rib 10 has a single facet for articulation with its own vertebra

Ribs 11 and 12 have no tubercles OR necks and just 1 facet on heads. both are short, little curvature, and point anteriorly.

Question 5

what are the muscles of the thoracic wall

Answer 5

external intercostal, internal intercostal, innermost intercostal, internal thoracis, and subcostales

Question 6

what is the function of pectoralis major and minor?

Answer 6

major - adduction at GH joint, flexion at GH joint, medial rotation

minor - depresses tip of shoulder, protracts scapula

Question 7

external intercostal muscle function

Answer 7

active during inspiration- supports intercostal space, moves ribs superiorly

Question 8

internal intercostal muscle function

Answer 8

active during expiration - supports intercostal space and moves ribs inferiorly

Question 9

innermost intercostal muscle function

Answer 9

acts with internal intercostal muscles

Question 10

transversus thoracis function

Answer 10

depresses costal cartilages

Question 11

serratus anterior function

Answer 11

protraction and rotation of scapula, keeps opposed to thoracic wall

Question 12

where does the inferior vena cava pass through diaphram?

Answer 12

-the inferior vena cava passes through the central tendon around T8 vertebra level

Question 13

what passes through diaphram?

Answer 13

inferior vena cava, esophagus and vagus nerve, azygous and hemiazygous veins

Question 14

what is the diaphram function/action?

Answer 14

when the diaphram contracts it depresses and when it relaxes, it is elevated. so inspiration involves contraction of the diaphram , it depresses and more space for lungs to fill up. when expiration, relaxation of diaphram it elevates and less space as air moves out.

Question 15

what are the features of the right lung

Answer 15

• larger
• has three lobes and two fissures. the fissures separate the lobes and they can move freely on each other. fissure are formed by invaginations of visceral pleura. right lung has:
  1. the oblique fissure separates inferior lobe with the superior and middle lobe
  2. the horizontal fissure separates superior and middle lobes.

Question 16

what are the three openings of the diaphram?

Answer 16

aortic hiatus - aorta, thoracic duct , hemi and azygous veins pass (dorsal)

oesophageal hiatus - esophagus and vagus nerve

caval foramen - central tendon region. inferior vena cava (aka caudal vena cava)

Question 17

what are the features of the left lung

Answer 17

smaller
two lobes separated by an oblique fissure.
inferior of medial surface of left lung is notched because of the hearts projection into the left pleural cavity.
-from the anterior border of the lower part of the superior lobe, a tongue like extension - LINGULA OF LEFT LUNG projects over the heart bulge.

Question 18

what is the hilum?

Answer 18

it is a ‘comma shaped’ space through which structures (pulmonary artery, pulmonary veins, bronchus).
it is the entranceway on mediastinal surfac eof lungs and is covered with mediastinal pleura projecting onto the lung
-part of the root of the lung which is the tubular collection of sturcutres that attach lung to mediastinum structures.

Question 19

what is the trachea and bronchus?

Answer 19

trachea from C6 to T4-T5 where it bifurcates into right an left main bronchus
right bronchus is wider and goes more vertically through hilum than left main bronchus. inhaled bodies go into right more

Question 20

what is the carina

Answer 20

the lowest tracheal c shaped ring has a hook shaped structure called the carina which projects backwards in midline between the origins of the two main bronchi.

Question 21

what do bronchus become

Answer 21

each bronchus goes into lobar bronchi - each supplying a lobe. these divide into segmental bronchi (tertiary). many divisions to bronchioles which further multiply and supply the respiratory surface.

Question 22

what are the contents of the mediastinum?

Answer 22

thymus gland, pedicardial sac, heart, trachea, major arteries and veins. also thoracic duct, esophagus, parts of nervous system as they pass through

Question 23

what is the boundary of the middle mediastinum?

Answer 23

the fibrous pericardium , separate from serous (which has parietal and visceral)
base is attached to central tendon of the diaphram
attached to sternum posterior side by sternopericardial ligaments

Question 24

what are the apex, base, anterior surface, inferior margin, right and left pulmonary surfaces of the heart?

Answer 24

base ; quadrilateral shape, it is facing the posterior and consists of a small part of the right atrium, as well as the proximal parts of the great veins - superior and inferior vena cava and pulmonary veins. esophagus is right behind

apex ; forward, down and left from base, is the apex which is the inferolateral part of the left ventricle

anterior ; mostly right ventricle with some of right atrium on the right, some left ventricle on left.

inferior ; or diaphragmatic side - left ventricle, small part of right ventricle, separated by the posterior interventricular groove.

left pulmonary surface ; left ventricle and part of left atrium

right pulmonary surface; right atrium

-coronary sinus separates the base of the heart from the rest.

Question 25

what are the margins of the heart?

Answer 25

right and left margins - same as left and right pulmonary surfaces
inferior margin - sharp edge between anterior and diaphragmatic surfaces formed by right ventricle amd a small part of the left ventricle near apex
obtuse margin - separates anterior and left pulmonary surfaces, extends from left auricle to cardiac apex.

Question 26

what is the coronary sulcus and what does it contain?

Answer 26

it circles the heart and separates atria from ventricles. contains right coronary artery, small cardiac vein, coronary sinus, and the circumflex branch of the left coronary artery

Question 27

what are the interventricular sulci and what do they contain

Answer 27

anterior and posterior interventricular sulci separate the two ventricles.
-anterior contains anterior interventricular artery and great cardiac vein
posterior- on diaphragmatic surface and has posterior interventricular artery and middle cardiac vein

Question 28

what is the coronary sinus

Answer 28

large vessel formed from the collection of veins that supply the heart, which delivers the deoxygenated blood to the right atrium

Question 29

what separates the right ventricle/atrium?

Answer 29

tricuspid valve of the right antrioventricular orifice

Question 30

what separates the continuous spaces of the right atrium

Answer 30

an external groove indicates the separation of the two continuous spaces of the right atrium (which is internal) the external groove is SULCUS TERMINALIS CORDIS

-internally the division is called crista terminalis, its a ridge

Question 31

what are the two parts of the right atrium

Answer 31

the sinus of the venae cavae is the posterior part, it has smooth thin walls and both vena cavae empty into it. the anterior part to the crista is atrium proper, it includes the right auricle. walls are covered in ridges - musculi pectinati

Question 32

what is the fossa ovalis

Answer 32

a depression in the interatrial septum , remnant of foramen ovale

Question 33

what is the conus arteriosus?

Answer 33

aka infundibulum. outflow tract of right ventricle which leads to the pulmonary trunk

Question 34

what are the irregular shaped structures in ventricles?

Answer 34

trabeculae carnae
some have one end attached to wall and the ohte rend is a point for tendon like chords (chordae tendinae). these are papillary muscles

Question 35

what are chordae tendinae and what do they attach to

Answer 35

attach to papillary muscles . they connect to cusps of the tricuspid valve/mitral valves

Question 36

what is the septomarginal trabecula?

Answer 36

moderator band. forms a birdge between lower part of interventricular septum and he base of the anterior papillary muscle. carries part of cardiac conduction system - the right bundle of the atrioventricular bundle, to the anterior wall of the right ventricle

Question 37

what happens in the heart during diastole and systole

Answer 37

diastole- blood flows from the atrium into the ventricle. semilunar valves are shut
systole - ventricles contract and the two AV valves are shut (FIRST SOUND; lub )

Question 38

what are semilunar valves?

Answer 38

valves between right and left ventricles and pulmonary trunk/aorta respectively.
-stops blood from going back into the ventricles during diastole (SECOND HEART SOUND; dub)