Anatomy 1: Chapter 2-Thoracic Wall-Test 1 Flashcards
thoracic cage
the framework of the walls of the thorax; formed by the vertebral column behind, the ribs and intercostal spaces on either side and the sternum and costal cartilages in front
mediastinum
the median partition of the thorax cavity ; laterally are the pleurae and lungs
visceral pleura
thin membrane that covers the lungs
parietal pleura
inner surface of the chest wall
pleura cavities
two membranous sacs are formed from the parietal and visceral pleura; each one is on each side of the thorax
sternum
a flat bone that can be divided into three parts: the manubrium, the body and the xiphoid process
manubrium
upper part of the sternum (handle); articulates with the clavicles and the 2nd costal cartilages; lies opposite the T3 and T4
body of sternum
articulates above with the manubrium at the manubriosternal joint and below with the xiphoid process at the xiphisternal joint; attaches at the 2nd to 7th costal cartilage
xiphoid process
a thin plate of cartilage that becomes ossified at its proximal end during adult life; no ribs or costal cartilage attaches to it
sternal angle (Angle of Louis)
formed by the articulation of the manubrium with the body of the sternum, at the 2nd costal cartilage and at T4 and T5
xiphisternal joint
lies opposite the body of sternum at T9
Types of Ribs (3)
12 pairs and are attached posteriorly at the thoracic vertebrae; True: the upper 7 are attached anteriorly to the sternum by costal cartilages, False: 8,9,10 pairs of ribs attached anteriorly to each other and to the 7th rib, floating ribs: 11th and 12th and have no anterior attachment
Typical Rib
long twisted flat bone that has a rounded smooth superior border and a sharp and thin inferior border; the anterior end attaches to corresponding costal cartilage
costal groove
where the inferior border of the rib overhangs and accommodates for the costal vessels and the nerves
head of the rib
has two facets for articulation with the vertebral body and the vertebra
neck of the rib
constricted portion situated between the head and the tubercle
tubercle of the rib
a prominence on the outer surface of the rib at the junction of the neck with the shaft; articulation with the transverse process
atypical rib
the 1st rib is an example and is important because of its close proximity to the lower nerves of the brachial plexus and the main vessels of the arms (subclavian artery and vein)
scalenus anterior muscle
attached at the 1st rib to its upper surface and inner border; anterior to it is the subclavian vein crosses the rib and posterior the subclavian artery and the lower trunk of the brachial plexus
costal cartilage
bars of cartilage that connect the upper seven ribs to the lateral edge of the sternum and the 8,9,10 ribs to the cartilage above; it contributes to the elasticity and mobility of the thoracic walls
manubriosternal joint
joint between the manubrium and the body of the sternum; a small amount of angular movement is possible during respiration
intraarticular ligament
connect the head to the intervertebral disc
thoracic outlet
opening that the chest cavity and the root of the neck communicate through; important vessels and nerves emerge from the thorax here and the esophagus and trachea (1st rib and T1)
external intercostal muscle
forms from the most superficial layer; fibers directed downward and forward; it extends forward and is replaced by the anterior (external) intercostal membrane
internal intercostal muscle
forms the intermediate layer; fibers are downward and backward from the subcostal groove to the upper border of the rib below; muscle is replaced by the posterior (internal) intercostal membrane
innermost intercoastal muscle
forms the deepest layer that crosses more than one intercostal space within the ribs; lined internally by the endothoracic fascia and parietal pleura and externally to the intercostal nerves and vessels
intercostal muscles actions
when they contract the tend to pull the ribs nearer to one another; the tone of these muscles during respiration strengthen the tissues of the intercostal spaces with changes in pressure
Where are the intercostal nerves and blood vessels?
between the middle and innermost layers of muscle; arranged from above downward: intercostal vein, intercostal artery, intercostal nerve (VAN)
intercostal space
space in between ribs; contain a single large posterior intercostal artery (drains backwards) and to smaller anterior intercostal arteries (drains forward)
subcostal nerve
nerve that the anterior ramus of the 12th thoracic nerve lies in the abdoment and runs forward in the abdominal wall
intercostal nerves are located…
in between the parietal pleura and the posterior intercostal membrane
second intercostal nerve
is where the pain that runs to the medial side of the arm in coronary artery disease
suprapleural membrane
attached laterally to the medial border the the first rib and costal cartilage; attached at its apex to the tip of the transverse process of C7; it protects the underlying cervical pleura and resists the chanes in pressure during respiration
endothoracic fascia
a thin layer of loose CT that separates the parietal pleura from the thoracic wall
diaphragm
a thin muscular and tendinous septum that separates the chest cavity above and the abdominal cavity below
sternal part of the diaphragm
arising from the posterior surface of the xiphoid prcess
costal part of the diaphragm
arising from the deep surfaces of the lower six ribs and their costal cartilages
vertebral part of the diaphragm
arising by vertical columns and the arcuate ligaments
right and left dome of the diaphragm shape? and what do they support?
RIGHT: reaches as high as the upper border of the 5th rib; LEFT-may reach lower border of the 5th rib; they support the two lungs
Where does the central tendon lie? and what does it support?
at the level of the xiphisternal joint; it supports the heart
diaphragm action
on contraction the diaphragm pulls don its central tendon and increases the vertical diameter of the thorax
muscle of inspiration of diaphragm
pulls down central tendon and increases diameter of the thorax
muscle of abdominal straining of diaphragm
during a deep breath the diaphragm is unable to rise because air is trapped in the respiratory tract
weight-lifting muscle of diaphragm
the diaphragm assists the muscles of anterior abdominal wall raising the pressure to help support the vertebral column
thoracoabdominal pump
descent of the diaphragm decreases the intrathoracic pressure and increases the intraabdominal pressure, which compresses the blood in the interior vena cava and forces it upward into the right atrium
aortic opening of the diaphragm
anterior to the body at T12; transmits the aorta
esophageal opening of the diaphragm
lies at the level of T10; transmits the esophagus, the right and left vagus nerves, esophageal branch of gastric vessels, and lymphatics
caval opening of the diaphragm
lies at T8 in the central tendon; transmits inferior VC and terminal branches of the right phrenic nerve
internal thoracic artery and internal thoracic vein
supplies the anterior wall of the body from the clavicle to the umnilicus
levator costa muscle: action and nerve supply
action: raises the rib below and is therefore an inspiratory muscle; nerve supply: posterior rami of thoracic spinal nerves
serratus posterior superior muscle: action and nerve supply
arises form the lower cervical and upper thoracic spines; Action: elevates the ribs and is therefore an inspiratory muscle, nerve supply:intercostal nerves
serratus posterior inferior muscle
thin muscle that arises from the ipper lumbar and lower thoracic spines; action: it depresses the ribs and its therefore an expiratory muscle, nerve supply:intercostal nerves
subcostal angle
at the inferior end of the sternum at the 7th costal cartilages
costal margin
ends at the 11th and 12th cartilages
Where is the apex beat normally found?
fifth left intercostal space
Where is the superior angle of the scapula?
lies opposite the T2
where is the spine of the scapula?
T3
Where does the inferior angle of the scapula lie?
T7
where is the apex of the heart?
formed by the left ventricle and found in the fifth intercostal space
where is the superior border of the heart?
point on the 2nd left costal cartilage from the edge of the sternum to a point on the 3rd right costal cartilage
where is the right border of the heart?
formed by the right atrium and extends from the third right costal cartilage from the edge of the sternum downward to a point on the 6th right costal cartilage
where is the left border of the heart?
formed by the left ventricle, extends form the point on the 2nd left costal cartilage from the edge of the sternum to the apex of the heart
where is the inferior border of the heart?
formed by the right ventricle and the apical part of the left ventricle and extends from the 6th right costal cartilage from the sternum to the apex beat
where is the mammary gland found in young adult females? middle aged women?
young: 2nd-6th rib; women: lower boarder of the pectoralis major and enters axilla
