ANA 202 Thorax Flashcards
What forms the thoracic wall anteriorly
sternum and costal cartilages
What forms the thoracic wall posteriorly
thoracic part of the vertebral column
What forms the thoracic wall laterally
The ribs and intercostal spaces
What forms the thoracic wall inferiorly
Diaphragm
What forms the thoracic wall superiorly
suprapleural membrane
The diaphragm separates__from___
Thoracic cavity from abdominal cavity
The thoracic cavity is divided into
mediastinum
the laterally placed pleurae and lungs (right and left)
Thoracic cage includes
•12 thoracic vertebrae
• intervertebral (IV) discs
• 12 pairs of ribs and their costal cartilages
• sternum
Ribs and their cartilages are separated by ____________
intercostal spaces
Typical ribs
3rd- 9th
Atypical ribs
1,2,10-12th
What are the categories of ribs?
True (vertebrocostal) ribs
False (vertebrochondral) ribs
Floating (vertebral, free) ribs
Problems that can occur in people with a 13th rib
Between the clavicle and 1st rib
It compresses the subclavian artery, restricting blood flow to the upper limb, causing numbness
Which are true ribs
1st-7th ribs
Which are false ribs?
8th, 9th, and usually 10th ribs
Which are floating ribs?
11th, 12th, and sometimes 10th ribs
What are true ribs?
They attach directly to the sternum through their own costal cartilages
What are false ribs?
Their cartilages are connected to the cartilage of the rib above them; thus their connection with the sternum is indirect
What are floating ribs?
•Their cartilages are rudimentary
• they do not connect even indirectly with the sternum
• instead they end in the posterior abdominal musculature
Characteristics of a typical rib
include the 3rd-9th ribs
•a curved shaft (body) with 2 ends;
• anterior end
•posterior end
•The anterior end is continuous with its costal cartilage
•The posterior end articulates with the vertebral column and is characterized by;
•a head
•Neck
• tubercle
Describe the head of the posterior end of a typical rib
Posterior end of a typical rib
head
•Is expanded (wedge shape)
•two articular surfaces (superior and inferior) separated by a crest
• The smaller superior surface articulates with the inferior costal facet on the body of the vertebra above, whereas the larger inferior facet articulates with the superior costal facet of its own vertebra
Characteristics of the first rib
broadest
shortest
most sharply curved of the seven true ribs
•has a single facet on its head for articulation with the T1 vertebra only
• has two grooves crossing its superior surface for the subclavian vessels
• the grooves are separated by a scalene tubercle and ridge
Parts of the sternum
- Manubrium
- Body
- Xiphoid Process
What is the joint between the manubrium and sternum?
Manubriosternal joint
The diaphragm work with which cavity for breathing?
Pleural cavity
Describe the shaft of the posterior end of the typical rib
Shaft:
• generally thin and flat with internal and external surfaces
•it bends anterolaterally at the costal angle
•The inferior margin of the internal surface is marked by a distinct costal groove
Describe the neck of the posterior end of the typical rib
•separates the head from the tubercle
Describe the tubercle of the posterior end of the typical rib
• projects posteriorly from the junction of the neck with the shaft
•consists of 2 regions
• articular part (smooth)
• nonarticular part (rough)
Function of the intervertebral disc
•to absorb the stress and shock that is placed on the vertebral column when a person walks, runs, moves, bends, or twists
• prevent the vertebral bodies from grinding against each other
Parts of the intervertebral discs
•annulus fibrosus (which means, roughly, the fibrous ring)
•nucleus pulposus (which means the pulpy interior)
In between the manubrium and body of the sternum lie a slightly projecting called__________
sternal angle (of Louis)
Location of the sternal angle of Louis
located opposite the 2nd pair of costal cartilages at the level of the IV disc between the T4 and T5 vertebrae
Describe the manubrium of the sternum
Manubrium:
•superior part of the sternum
• it lies at the level of the bodies of the T3 and T4 vertebrae
•Its thick superior border is indented by the jugular notch (suprasternal notch)
• On each side of this notch, a clavicular notch articulates with the sternal (medial) end of the clavicle
• Just inferior to this notch, the costal cartilage of the 1st rib fuses with the lateral border of the manubrium
Describe the body of the sternum
body of the sternum(T5- T9 vertebral level)
•is longer, narrower, and thinner than the manubrium
•its lateral borders has costal notches for articulation with the 3rd-6th costal cartilages
Describe the Xiphoid process of the sternum
The xiphoid process (T10 vertebral level)
• is the smallest and most variable part of the sternum
•It is relatively thin and elongated but varies considerably in form. The process is cartilaginous in young people but more or less, ossified in adults older than 40 years
• In elderly people, the xiphoid process may fuse with the sternal body
Causes of chest pain
• chest pain can result from pulmonary disease, it is probably the most important symptom of cardiac disease
•However, chest pain may also occur in intestinal, gallbladder, and musculoskeletal disorders
Describe the fracture of the 1st rib
The 1st rib is rarely fractured. However when broken, structures crossing its superior aspect may be injured, including:
The brachial plexus of nerves
subclavian vessels
Which are the most commonly fractured ribs?
Middle ribs