Anatomy Thorax study guide

which ribs are false ribs?

8, 9, 10, 11

costochondral joint

-a synchondrosis joint (immobile) -located at the body of a rib with costal cartilage -connects ribs to the sternum

sternoclavicular joint

-a synovial joint (moving) -located at the clavicle head attaching to sternum -assists with stabilizing the thoracic wall

interchondral joint

-a synovial joint (moving) -located between costal cartilages of ribs 6-9 -connects the false ribs to costal cartilage of true ribs

phrenic nerve

-arises from C3-C5 -runs on lateral sides of pericardium, with the pericardiacophrenic arteries -supplies sensory to diaphragm, pericardium and mediastinal parietal pleura, motor to diaphragm

subcostal nerve

-arises from T12 -courses along inferior border of 12th rib, just below the diaphragm -supplies sensory and motor to 12th intercostal space

intercostal nerve

-arises from T3-T11 ventral rami -courses along costal groove of respective ribs -sensory to parietal pleura & skin adjacent to ribs, motor to intercostal muscles

vagus nerve

-arises from brain -passes posterior to lung hilum in the posterior mediastinum -supplies parasympathetic to pleural plexus and cardiac plexus (lungs & heart)

left recurrent laryngeal nerve

-arises from cranial nerve X (vagus) -branches off from vagus at the aortic arch, wraps around aortic arch medially before heading to larynx -supplies motor to muscles of larynx (except cricothyroid) and sensory to mucosa up to vocal folds

sympathetic fibers

-arises from sympathetic chain -branch from the sympathetic chain to form plexus around the heart and lungs -supplies sympathetic innervation to pleural and cardiac plexus

first rib

-atypical -single facet head since it only articulates with T1 -very wide -has a tubercle for scalene muscles -grooves for subclavian artery and vein

second rib

-atypical -has 2 facets at head for T1 and T2 -has a tubercle for scalene muscle -has tuberosity for serratus muscle

sternocostal joint

-is a synovial joint (moving) -located at the costal cartilage of 2nd through 7th ribs to sternum (not mobile for rib 1) -allows for bucket handle motion during respiration (w/ costovertebral) -glides ribs, moves the rib superolaterally, increases transverse diameter

costovertebral joint

-is a synovial joint (moving) -located where head of rib articulates with vertebrae -allows for bucket handle motion during respiration (w/ sternocostal) -glides ribs 1-10, moves the rib superolaterally, increases transverse diameter

levatores costarum

-n: dorsal rami -f: assist in rib elevation during inspiration -located in deep back muscles

external intercostal muscles

-n: intercostal -f: forced inspiration (weak) -located in the intercostal spaces, fibers run anterior-caudally, becomes a membrane at anterior

innermost intercostal muscle

-n: intercostal -f: forced expiration (weak) -located in intercostal spaces, fibers run posterior-caudally, becomes a membrane at posterior. deep to the neurovascular bundle

subcostalis muscle

-n: intercostal n -f: forced expiration -located in deep thoracic wall, crosses ribs 1-2

internal intercostal muscles

-n: intercostal n -f: forced expiration (weak) -located in intercostal spaces, fibers run posterior-caudally, become a membrane at posterior. superficial to neurovascular bundle

transversus thoracis

-n: intercostal n. -f: forced expiration -located in deep thoracic wall, fibers run from sternum superiorly onto ribs

diaphragm

-n: phrenic nerve -f: inspiration (major respiratory muscle) -located at the inferior boundary of the thoracic cavity, inserts on the central tendon

costotransverse

-synovial joint (moving) (rotates ribs 1-7, glides ribs 8-10) -located at the tubercle on the rib neck with transverse process of same # vertebrae -allows for the pump handle motion of respiration, moves the sternum anterosuperior, increases the anterior-posterior diameter of the ribcage

sympathetic innervation of lungs

-via sympathetic trunk -bronchodilation -vasoconstriction (including pulmonary arteries)

sympathetic innervation of heart

-via sympathetic trunk/chain -increases HR vasodilates coronaries

parasympathetic innervation of lungs

-via vagus nerve -bronchoconstriction -vasodilation (including pulmonary arteries)

parasympathetic innervation of heart

-via vagus nerve -decreases HR -vasoconstricts coronaries

which ribs are atypical ribs?

1, 2, 10, 11, 12

typical ribs

ribs 3-9 -have a wedged head w/ 2 articulation sites -neck has a tubercle for articulation with transverse process of vertebrae -shaft has a costal groove where the neurovascular bundle travels

which 2 vertebrae would rib 5 articulate with?

superior costal facet of vertebrae 5 and inferior costal facet of vertebrae 4

what landmark aligns with the sternal notch/jugular notch?

the T2 vertebrae / first rib

what landmark aligns with the sternal angle? (where manubrium and body meet)

T4 vertebrae, 2nd rib, aortic arch, and carina