[Anatomy] Thoracic Wall And Lungs

Front 1

what is the thoracic skeleton composed of?

Back 1

12 thoracic vertebrae and associated discs, 12 pairs of ribs, costal cartilages, sternum

Front 2

what are the functions of the thoracic skeleton?

Back 2

protect viscera within the thoracic cavity, provide framework for attachment of muscles of respiration

Front 3

what are the parts of the thoracic vertebrae?

Back 3

vertebral body, transverse processes, costal facets

Front 4

what part of the vertebrae articulates with the ribs? what kind of joint is this?

Back 4

costal facet, synovial

Front 5

what are the features of a typical rib? describe.

Back 5

head, tubercle, body (costal groove, rib). head: 2 facets for articulation with vertebral bodies. tubercule: articulates with transverse process of a vertebra. body: costal groove on inferior border (VAN), angle has highest curvature (commonly fractured)

Front 6

describe the atypical ribs

Back 6

1st rib: flat, short, tightly curved; superior surface of body has 2 shallow grooves for subclavian artery and vein; 11th/12th: rudimentary

Front 7

the head of rib 5 articulates with _____ vertebra; the tubercule articulates with _______ vertebra

Back 7

T5 and T4; T5

Hint 7

the head of a typical rib articulates with the superior costal facet of the thoracic vertebra of the same number,the inferior costal facet of the vertebra above, and the intervertebral disc between the two vertebrae; the costal tubercle articulates with the transverse process of the vertebra of the same number

Front 8

costal cartilages

Back 8

Hyaline cartilage; Contribute to the elasticity of the thoracic wall; Connect to body of rib (little movement possible at these joints); Connect to sternum via sternocostal joints (most are synovial)

Front 9

costal margin

Back 9

formed by medial borders of costal cartilages 7-10

Front 10

rib classification

Back 10

True ribs (1-7) attach to sternum via their own costal cartilages; False ribs (8-10) attach to the sternum via the costal cartilages of the ribs above (do not have their own cartilage); Floating ribs (11-12) have no attachment to the sternum

Front 11

sternum

Back 11

manumbrium, body, xiphoid process

Front 12

manubrium

Back 12

Jugular (suprasternal) notch on the superior border; Articulates with the clavicles at the sternoclavicular joints; Articulates with 1st and 2nd costal cartilages; Articulates with the sternal body

Front 13

sternal angle

Back 13

Palpable landmark at level of T4/T5 intervertebral disc, or 2nd costal cartilage; junction of sternal body and manubrium

Front 14

sternal body

Back 14

articulates with costal cartilages 2-7

Front 15

xiphoid process

Back 15

Palpable landmark, at T10 vertebral level; Ossifies and unites with body of sternum ~ 40 years of age; The xiphisternal joint marks the inferior limit of the thoracic cavity and the inferior border of the heart.

Front 16

median sternotomy

Back 16

splitting the sternum to allow for surgical access to underlying organs/structures (e.g., during coronary bypass surgery).

Front 17

intercostal muscles

Back 17

between ribs; innervated by intercostal nerves; stabilize intercostal spaces during respiration; external, internal, innermost

Front 18

external intercostal muscles

Back 18

fiber direction: hands in pockets; incomplete anteriorly, aponeurosis (membrane) extends to sternum

Front 19

innermost intercostal muscles

Back 19

fibers parallel to internal intercostals

Front 20

internal intercostal muscles

Back 20

fiber direction: right angle to external intercostal; incomplete posteriorly, aponeurosis (membrane) extends to vertebrae

Front 21

intercostal neurovascular bundle

Back 21

intercostal vein, artery, nerve (sup to inf), course between internal and innermost intercostal muscles along the costal groove

Front 22

intercostal nerves

Back 22

ventral rami of thoracic spinal nerves T1-T11, motor innervation to muscles of the thoracic wall and sensory innervation to the skin

Front 23

subcostal nerve

Back 23

ventral ramus of T12, emerges inferior to the 12th rib

Front 24

collateral branches

Back 24

(of intercostal nerves), travel along superior edge of the rib below

Front 25

dermatome

Back 25

area of skin supplied by a single spinal nerve; overlap in dermatome territories of adjacent spinal nerves

Front 26

what creates the segmental arrangement of dermatomes in the torso?

Back 26

terminal branches of intercostal nerves along with sensory branches from corresponding posterior rami

Front 27

intercostal nerve block

Back 27

Anesthetic injected into the intercostal spaces close to nerves and near skin area to be anesthetized; May require multiple injections at adjacent levels to compensate for overlapping cutaneous innervation

Front 28

intercostal arteries

Back 28

thoracic aorta, posterior intercostal arteries, internal thoracic arteries, anterior intercostal arteries

Front 29

primary blood supply of the thoracic wall

Back 29

via the thoracic aorta and the internal thoracic arteries (branches of the subclavian artery)

Front 30

posterior intercostal arteries

Back 30

majority arise from the aorta; Course with an intercostal nerve and vein; anastomose with anterior intercostal arteries to form a cycle

Front 31

anterior intercostal arteries

Back 31

arise from internal thoracic arteries ; Usually two per intercostal space; One anastomoses with the collateral branch of the posterior intercostal artery, other anastomoses with the posterior intercostal a. and courses with an intercostal n. and v.

Front 32

intercostal veins

Back 32

drain into azygos system of veins posteriorly and internal thoracic veins anteriorly; internal thoracic veins drain into the brachiocephalic veins then to SVC

Front 33

azygos system

Back 33

hemiazygos vein, accessory hemiazygos vein --> azygos vein --> SVC

Front 34

thoracic cavity

Back 34

region enclosed by thoracic wall

Front 35

pleura

Back 35

serous sacs investing the lungs; visceral and parietal pleura

Front 36

visceral pleura

Back 36

lines the surfaces of the lung; it is closely adherent to the lungs and extends into lung fissures; no sensory (pain/temp/touch) innervation

Front 37

parietal pleura

Back 37

lines the walls of the thoracic cavity, continuous with visceral pleura, sensitive to pain/temp/touch due to innervation by adjacent intercostals nerves and phrenic nerves

Front 38

pleuritis / pleurisy

Back 38

inflammation of the pleura leading to adhesion of visceral and parietal layers, resulting in acute pain associated with elevated activity

Front 39

pleural cavity

Back 39

potential space between the visceral and parietal pleurae; right and left pleural cavities are separate from one another; normally contains thin layer of serious fluid a a lubricant facilitating movement of the lungs during respiration

Front 40

hydrothorax / pneumothorax / hemothorax

Back 40

accumulation of fluid / air / blood in pleural cavity

Front 41

costodiaphragmatic recesses

Back 41

inferolateral recesses within the pleural cavities; decrease with inspiration, reappear with expiration

Front 42

thoracocentesis

Back 42

procedure to drain excess fluid form pleural cavity; needle inserted into costodiaphragmatic recess, at the midaxillary line between ribs 9 and 10

Front 43

characteristics of the lungs

Back 43

elastic (shrink to 1/3 of size if thoracic wall breached), pink (darkens with exposure to air particles)

Front 44

parts of the lung

Back 44

root, apex, base

Front 45

root of the lung

Back 45

collection of structures entering/exiting the lung; pulmonary vessels and bronchi

Front 46

apex of lung

Back 46

superior portion extending into the base of the neck

Front 47

base of lung

Back 47

concave inferior portion adjacent to diaphragm

Front 48

right lung

Back 48

3 lobes (superior, middle, inferior), oblique fissure separating middle/inferior, horizontal separating superior/middle

Front 49

left lung

Back 49

2 lobes (superior, inferior), oblique fissure separates the 2 lobes; cardiac notch

Front 50

cardiac notch

Back 50

left lung; superior lobe on anterior margin

Front 51

trachea

Back 51

inferior to the larynx, bifurcates at T4/T5, palpable at suprasternal notch due to cartilaginous rings (hyaline, C-shaped, incomplete posteriorly), smooth muscle on posterior side

Front 52

carina

Back 52

ridge of cartilage at the bifurcation of the trachea into right and left main bronchi (T4/T5)

Front 53

right and left main bronchi

Back 53

extrapulmonary, supported by C-shaped rings of cartilage

Front 54

right main bronchus

Back 54

wider, shorter, more vertical, aspirated foreign objects more likely to be here

Front 55

lobar bronchi

Back 55

divided from each main bronchus, intrapulmonary; right lung: 3 (sup/mid/inf), left lung: 2 (sup/inf)

Front 56

segmental bronchi

Back 56

divided from segmental bronchi, corresponding to specific bronchopulmonary segment

Front 57

bronchopulmonary segments

Back 57

10 per lung; area of lung supplied by a segmental bronchus and a segmental branch of the pulmonary artery; Separated from adjacent segments by connective tissue septa (can be surgically resected); Tributaries of the pulmonary veins lie in the connective tissue between adjacent segments (intersegmental)

Front 58

pulmonary trunk

Back 58

exits right ventricle of heart, divides into right and left pulmonary arteries which then enter the lungs

Front 59

pumonary arteries

Back 59

carry oxygen poor blood from the heart to the lungs for oxygenation, each divides into lobar and segmental marteries

Front 60

lobar and segmental arteries

Back 60

divide from pulmonary artery, paired with and running parallel with the bronchi

Front 61

pulmonary veins

Back 61

two on each side; carry oxygen rich blood form lungs to left atrium of the heart; lie in intersegmental connective tissue separating bronchopulmonary segments, do not course with arteries and bronchi

Front 62

bronchial arteries

Back 62

carry oxygen rich blood to the tissues of the lung itself; branches off the thoracic aorta

Front 63

bronchial veins

Back 63

return oxygen poor blood from the tissues of the lung to the azygos system or intercostal veins

Front 64

lymphatic drainage of lungs

Back 64

superficial lymphatic plexus drains into bronchopulmonary nodes; deep lymphatic plexus into pulmonary lymph nodes; pulmonary -> bronchopulmonary -> tracheobronchial -> tracheal; lymphatic plexus of left and right lungs communicate

Front 65

innervationof the lungs

Back 65

via pulmonary plexuses with contributions from vacus nerve (CN X) and sympathetic splanchnic nerves

Front 66

vagus nerve

Back 66

parasympathetic; achieves bronchoconstriction; preganglionic cell bodies in brain, preganglionic fibers constitute vagus nerves, postganglionic cell bodies in wall of target organ (lung); postganglionic fibers in wall of target organ (very short)

Front 67

sympathetic innervation in lungs

Back 67

bronchodilation; preganglionic CB in lateral horn of thoracic spinal cord; preganglionic fibers from ventral root -> spinal nerve -> white ramus communicans -> sympathetic trunk; postganglionic CB in upper thoracic paravertebral (chain) ganglia, postganglionic fibers (pulmonary nerves) travel from paravertebral ganglia to cardiac plexus in mediastinum

Front 68

diaphragm

Back 68

separates thoracic and abdominal cavities; skeletal muscle surrounding C-shaped central tendon; 2 domes (right higher than left), heart in pericardium lies on central tendon

Front 69

attachments of diaphragm

Back 69

all peripheral; xiphoid process, costal margin, ribs 11-12, lumbar vertebrae (via right and left crura)

Front 70

diaphragm openings

Back 70

caval opening (T8): through central tendon for inferior vena cava; esophageal hiatus (T10) for esophagus and vagus nerves; aortic hiatus (T12): for aorta, thoracic duct, azygos vein

Front 71

sensory innervation of diaphragm

Back 71

primarily phrenic nerves; periiopherally, innervation via intercostal nerves

Front 72

motor innervation of diaphragm

Back 72

phrenic nerves cause contractions

Front 73

phrenic nerve

Back 73

ventral rami of C3, C4, C5; course superficially through the mediastinum, anterior to the root of the lungs, and continuing onto the superficial aspect of the pericardium to its final target, the diaphragm; Provide motor innervation to diaphragm
and sensory innervation to diaphragm and the parietal pericardium and pleura

Front 74

lesion of a phrenic nerve (to diaphragm)

Back 74

paralyzes corresponding half of the diaphragm; x-ray during inspiration will show a depressed (active side) and raised (paralyzed side) of the diaphragm

Front 75

diaphragm during respiration

Back 75

primary muscle of inspiration: contracts, domes descend and flatten, increasing vertical dimension of the thoracic cavity; relaxes during expiration, allowing domes to rise

Front 76

inspiration

Back 76

Contraction of the diaphragm causes the abdominal contents to be forced down, increasing vertical dimension of the thorax; Contraction of muscles that elevate the ribs (e.g., external intercostals) expands the thoracic cavity transversely ("bucket handle") and anteroposteriorly (“pump handle”); During forceful inspiration, the pectoral muscles may be recruited

Front 77

expiration

Back 77

thoracic cavity reduces in size due to relaxation of diaphragm and elastic recoil of lungs; During forceful expiration, abdominal muscles (e.g. external and internal obliques, rectus abdominis) are recruited to compress abdominal viscera upward, expelling air from the lungs