Thoracic Wall Flashcards
how many pairs of ribs are there?
12 pairs
what is the joint type of the ribs with the vertebral column? (posterior)
synovial joint
how are the ribs attached anteriorly? and what to?
costal cartilage, attached to the sternum
how many true ribs? sternum attachment?
7 superior ribs. Directly attached to the sternum
how many false ribs? sternum attachment?
3 ribs below true ribs. attached to sternum INDIRECTLY, their cartilage attaches to the cartilage of the rib cage above
how many floating ribs? sternum attachment?
inferior 2 ribs. DO NOT ATTACH to sternum, they end within muscles of the posterior abdominal wall
which ribs are TYPICAL?
ribs 3-9
how many landmarks do typical ribs have? what are they?
6- head, tubercle, neck, angle, shaft, intercostal groove
head of typical rib?
2 articular facets for articulation with the body of corresponding vertebra above
tubercle of typical rib?
1 articular facet articulates with transverse process of corresponding vertebrae
neck of typical rib?
located between head and tubercle
angle of typical rib?
region where shaft of rib makes a sharp bend
shaft of typical rib?
thin, flat, curved part, attaches anteriorly to costal cartilage
intercostal groove of typical rib?
located near inferior border of rib, on internal surface. provides protection to intercostal nerves and vessels.
what ribs are ATYPICAL?
1, 2, 10, 11, 12
why is the FIRST RIB atypical? (4 points)
wide, short, flat.
head possesses ONE ARTICULAR FACET.
SCALENE TUBERCLE on superior surface forms attachment point for anterior scalene muscle.
2 grooves anterior and posterior to scalene tubercle marking site where subclavian vessels cross the rib
why is the SECOND RIB atypical?
similar to first rib but possesses a ROUGH TUBEROSITY on its superior surface for the anterior scalene muscle
why is the TENTH RIB atypical?
head possesses only ONE ARTICULAR FACET for articulation with the body of its corresponding vertebra
why are the ELEVENTH and TWELFTH ribs atypical?
HEAD possesses only ONE ARTICULAR FACET for articulation with body of corresponding verterba. SHORT NECK.
NO TUBERCLE
how many vertebrae in the vertebral column?
33 vertebrae
how many regions of vertebral column? name them
5 regions- cervical, thoracic, lumbar, sacrum, coccyx
4 main functions of vertebral column?
protection of spinal cord, supports weight of body above pelvis, forms central axis of the body, has role in posture and movement
all verterbae consist of a …. and an ……. (which is anterior/posterior/lateral?)
vertebral body is anterior, vertebral arch is posterior and lateral
what do the vertebral body and arch give? what do these enclose?
the VERTEBRAL FORAMEN, enclose the spinal cord inside the vertebral canal
vertebral arch has how many bony prominences? name them
5- pedicles, lamina, transverse processes, articular processes, spinous processes
what are the pedicles of the vertebral arch?
2 PEDICLES, left and right.
point POSTERIORLY, meeting the flatter laminae
what are the lamina of the vertebal arch?
bone between the transverse and spinal processes
what are the transverse processes of the vertebral arch?
extend LATERALLY AND POSTERIORLY away from the pedicles.
in thoracic vertebrae they articulate with ribs
what are the articular processes of the vertebral arch?
at the JUNCTION OF THE LAMINA AND THE PEDICLES. superior and inferior processes arise. articulate with articular processes of vertebrae above and below
what are the spinous processes of the vertebral arch?
POSTERIOR AND INFERIOR bone projection. site of attachment for muscles and ligaments
how many cervical vertebrae are there?
7 CERVICAL
how many thoracic vertebrae are there?
12 THORACIC
how many lumbar vertebrae are there?
5 LUMBAR
how many vertebrae in sacrum and coccyx?
sacrum is 5 FUSED VERTEBRAE
coccyx is 1 BONE
distinguishing features of the THORACIC VERTEBRAE? 4 main points
MEDIUM sized. increase in size as move downwards.
2 DEMI FACETS on each side of vertebral body which articulate with head of respective rib and inferior rib.
COSTAL FACET on the TRANSVERSE PROCESSES for articulation with rib
SPINOUS PROCESSES are LONG and slanted inferiorly and anteriorly = increased protection to spinal cord
CIRCULAR FORAMEN
HEART SHAPED BODY
costovertebral joints are the joints between…
… the ribs and the vertebrae
costovertebral joints include which 2 sites?
between the head of the rib and the vertebral body, and between the rib tubercle and the transverse process of the vertebrae
how many costovertebral joints are there between a typical rib and a vertebrae?
3 costovertebral joints
what is the sternum and where does it lie?
flat bone, lies anteriorly in middle of chest
the important landmarks of the sternum? (5)
manubrium, body, jugular notch, sternal angle, xiphoid process (xiphisterum)
what is the manubrium of the sternum?
most SUPERIOR portion.
TRAPEZOID in shape
lateral edges there is a FACET for articulation with costal cartilage of 1st RIB, and a DEMIFACET for 2nd RIB
INFERIORLY articulates with body of sternum
what is the body of the sternum?
FLAT, ELONGATED largest part. articulates with manubrium and xiphoid process.
laterally ARTICULAR FACETS for costal cartilages of RIBS 3-6.
DEMIFACETS for 2nd and 7th ribs
what is the jugular notch of the sternum?
easily palpated, lies at T2 vertebral level. either side are FOSSAE which articular the medial ends of the clavicles, forming sternoclavicular joints
what is the sternal angle of the sternum?
where the manubrium articulates with body.
level T4 vetebra.
felt as a transverse ridge on anterior aspect, used as level of 2nd costal cartilage
what is the xiphoid process of the sternum? or xiphisternum?
cartilaginous in young adults, ossifies with age. denotes position of central tendon of diaphragm and inferior border of heart.
T10 level
what does the sternum articulate and where?
with the clavicle
and with upper 7 ribs
what is the sternoclavicular joint classed as functionally and structurally?
functionally synovial, structurally saddle
what are the 2nd to 7th sternocostal joints classed as?
synovial
what type of joint is it between 1st rib and mandibrum of sternum?
synchondris (where hyaline cartilage is the connective medium)
what are the accessory muscles of the thoracic wall? (5)
pect major, pec minor, serratus anterior, sternocleidomastoid, scalenes
when are the accessory muscles of thoracic wall used?
when ventilation is forces eg during exercise, or in respiratory disorder
what other muscles other than accessory are used during forced ventilation?
the abdominal muscles, used only during EXPIRATORY phase
the origin and insertion of sternocleidomastoid?
originates at manubrium of sternum and clavicle.
attaches onto mastoid process of temporal bone of skull
the origin and insertion of the scalenes?
arise from transverse processes of C4-6
attach onto first or second ribs
the origin and insertion of pectoralis major?
originates from clavicular head, sternum and upper 6 costal cartilages
inserts onto bicipital groove of humerus
the origin and insertion of pectoralis minor?
originates from 3rd to 5th ribs
inserts into coracoid process of scapula
the origin and insertion of serratus anterior?
originates from external surface of upper 8 ribs
inserts onto anterior surface of medial border of scapula
sternocleidomastoid muscle use in ventilation?
elevates manubrium and medial end of clavicle = forced inspiration
use of scalene muscles in ventilation?
when contracted they fix the upper ribs making contraction of external intercostals more effective
role of pec major in ventilation?
increases anterior posterior diameter of the thorax
role of pec minor in ventilation?
helps move 3-5th ribs up and out
use of serratus anterior in ventilation?
stabilizes the scapula
how many layers of intercostal muscles are there?
3- external, internal and innermost
what lines the innermost intercostals?
endothoracic fascia
what distinguishes the intercostal muscles?
the direction of their fibres
how many pairs of external intercostals are there?
11 pairs
where does external intercostals extend between?
from tubercle to costochondral junction
external intercostal fibres run in what direction?
antero-inferior direction
what do the external intercostals do?
elevate the ribs
origin and insertion of external intercostals?
originate at lower border of ribs
insert into superior border of rib below
where do internal intercostal muscles extend between?
between sternum and angle of the rib
what direction do internal intercostals run?
postero-inferior direction from rib above to rib below
role of internal intercostals?
depress the ribs
origin and insertion of internal intercostals?
original from lateral edge of costal groove.
insert into superior surface of rib below
where are the innermost intercostal muscles found?
lateral aspect of ribcage
what is the anterior layer of innermost intercostals formed of?
transversus thoracis
what is the posterior layer of innermost intercostals formed of?
subcostal muscles
role of innermost intercostals in ventilation?
weakly depress the ribs
where do the innermost intercostal muscles attach?
attach to the inferior surface of the ribs
neurovascular structures of the thoracic wall run within the intercostal spaces between which layers?
between the internal and innermost intercostals
where do the neurovascular structures lie in the intercostal space?
in the upper aspect, partially protected by the costal groove
order of the neurovascular structures of thoracic wall?
VAN- superior intercostal VEIN, ARTERY, inferior NERVE
what forms the intercostal nerves?
the ventral rami of T1-T11,
and the subcostal nerve from T12
what branches are given off each intercostal nerve? (5)
rami communicantes, collateral, lateral cutaneous, anterior cutaneous, muscular
what is the role of the rami communicantes branch of the intercostal nerve?
connects the nerve to the sympathetic chain
what is the role of the collateral branch of the intercostal nerve?
arises at angle of rib, along superior border of rib below, supplies intercostal muscles and parietal pleura
what is the role of the lateral cutaneous branch of the intercostal nerve?
arises near midaxillary line, pierces internal and external intercostals, supplies skin on lateral aspect of thorax and abdomen
what is the role of the anterior cutaneous branch of the intercostal nerve?
pierces muscles at side of sternum, supplies skin on anterior aspect of thorax and abdomen
what is the role of the muscular branch of the intercostal nerve?
supplies the intercostal muscles
what does the superior part of T1 contribute to?
brachial plexus
how many arteries supply intercostal space?
1 posterior intercostal artery and 2 anterior intercostal arteries
where do the posterior intercostal arteries arise?
in the superior 2 spaces, it arises from the superior thoracic branch of the costocervical trunk
in the remaining spaces, it arises from the thoracic aorta
where do the anterior intercostal arteries arise?
the upper 6 spaces arise from the internal thoracic artery, remaining vessels arise from musculophrenic artery terminating branch of the internal thoracic artery
where do the intercostal veins empty?
into the azygous system of veins
what happens to the posterior and anterior intercostal veins?
they anastomose (cross connect)
where do the anterior intercostal veins empty?
into the musculophrenic veins
