Respiratory L1 Flashcards
Describe the division of the respiratory system
- Divided into two at levels of vocal cords
- Upper Respiratory Tract (URT): Nasal cavity, paranasal sinuses, pharynx, larynx above vocal cords
- Lower respiratory tract: Larynx below vocal cords, treacha, bronchi, bronchioles
State the role of the thoracic cavity
What are the boundaries of the thoracic cavity?
Protects lung + heart
Point of attachment for upper limbs
Support of back muscles
Attachment of abdominal muscles
Boundaries:
Posterior: Vertebral column (T1-T12)
Anterior: Sternum + costal cartilages
Lateral: Ribs + intercostal spaces
Inferior: Diaphragm
Which opening allows the thoracic cavity to communicate with the root of the a) neck b) abdomen?
Superior thoracic aperture
Inferior thoracic aperture. Diaphragm closes off aperture
How many thoracic vertebrae are there?
Describe the a) Body b) Vertebral Foramen c) Spinous Processes d) Articulation with ribs e) Demi Facets f) Costal Facets on Transverse Process
a) Heart-shaped, medium size. Size of vertebral bodies increase progressively from T1-T12. Because lower thoracic verterbrae bear more weight as you move down to lumbar region
b) Vertebral Foramen is opening through which spinal cord passes. Circular. Smaller
c) Spinous process long + slender, point downwards (inferiorly) and backwards (posteriorly). Spinous processes provide attatchment points for muscles + ligaments of back. Limit hyperextension of spine
d) Articulation of ribs, Achieved through specific facets + demifacets on vertebreae. Defining feature of thoracic
e) Each thoracic vertebrae has two pairs of demifacets (small flat surfaces), located on sides of vertebral body, one pair superior, one paie infeior. Articulate with head of ribs.
f) Located on transverse process (bony projection on side of vertebra). Articulates with tubercle of corresponding rib(rib with same number as vertebra(
Diagram showing the sternum and joints of the thorax
Sternal angle/ Angle of Louis:
- Palpable anatomical landmark located at junction between manabrium (upper sternum) and sternum body. This junction creates a slight ridge that can be felt on surface of chest
- Located at location of 2nd rib
What is the sternal angle and why is it important?
- Clinically useful feature of manubriosternal joint. Palpated easily
- Marks site of articulation of rib II with sternum. Rib I not palpable - lies inferior to clavvicle and embedded in tissues at base of neck
- Therefore, rib II used as reference for counting ribs
Describe the classification of ribs
(ribs categorised based on how they connect to sternum + other structures)
Ribs 1-7 - True ribs - directly connected to sternum through their own costal cartilages
Ribs 8-10 - False ribs - Indirectly connected to sternum. Costal cartilages of 8-10 connect to cartilage of ribs above them
Ribs 11-12 - Floating ribs - No anterior attachment. Free-ending. end free in the abdominal musculature (means their anterior ends are not attached to any other ribs or sternum)
Which ribs are typical?
Which ribs are atypical?
Typical: 3-9
-Head has 2 facets
-Tubercle has facet for articulation with transverse process of numercially corresponding vertebra
-Shaft
-Anterior end of each rib is attached to corresponding costal cartilage
Atypical: 1,2,10,11,12
1st rib:
- Broad + flat
- Tubercle for scalenus anterior muscle on its upper surface
- Grooves for subclavian vein + artery + lower trunk of brachical plexus
2nd rib:
- thinner, longer than 1st
- upper surface roughened for attachment of serratus anterior muscle
10th rib:
Articulation: head has single facet for articulation with corresponding vertebra (no articulation with vertebra above)
12th and 12th:
Shape: Short, slender
Articualtion: Do not articulate anteriorly, they are “floating ribs”
Each head has single fact for articulation with corresponding vertebra
What is the most common type of joint present in the ribs?
Synovial joints
(Synovial joints are supported by ligaments that allows for movement of chest wall during respiration)
a) State two main causes of rib fractures
b) common characteristics
c) complications
d) flail chest
a) direct trauma, crush injuries
b) middle ribs most commmonly fractured because they are less protected than upper ribs and less flexible than lower ribs. Compressive forces, experienced in e.g. car accidents
c) Soft tissue injury: broken rib fragments pose risk to surrounding soft tissue
- lungs, spleen, diapghagm
d) 2 or more fractures occur in two or more adjascent ribs, leads to part of chest all that is no lonnger under control of thoracic muscles. This leads to paradoxical movement
- during inspiration, affacted area moves inward, paradox to normal outward expansion of chest
-during expiration, affacted area moves outward, opposite to normal chest contration
-leads to impraired ribcage expansion, reducing lung efficiency
-leads to reduced oxygen content in blood, causes hypoxemia.
a) What are the spaces between the ribs called?
b) What are the contents of these spaces?
c) What are the layers of these spaces?
d) What are the three layers of muscles in these spaces and which nerves supply them?
What is the neurovascular bundle? Location? Components? Function
a) intercostal spaces
b) muscle, blood vessel, nerves, connective tissue
c) Skin, superficial fascia, intercostal muscles, endothoracic fascia, plerua
d) external intercostal muscles (inspiration), internal intercostal muscles (expiration), innermost intercostal muscles (expiration), INTERCOSTAL NERVES
What is the neurovascular bundle? Location? Components? Function
Found in subcostal groove of each rib
Arrangement: from superior to inferior. Components arranged as Vein, Artery, Nerve (VAN)
- Intercostal vein
-Intercostal artery
-intercostal nerve
Describe a) shape b) function of diaphragm
a) Dome shaped, musculo-tendinous structure
b)
- Separates thoracic cavity from abdominal
- contraction, relxation, alters vol of thoracic cavity and lungs
- PRIMARY MUSCLE OF INSPIRATION AND EXPIRATION
- Help raise intrathoracic/abdmonal pressure (important in defecation)
What are the three attachments of the diaphragm?
All three parts inset into…..
- Sternal part (from xiphoid process)
- Costal part (lower 6 ribs and their costal cartilages)
- Vertebral part (crura + arcuate ligaments)
All three part inset into CENTRAL TENDON. Shaped like three leaves.
For understanding: Clinical significance: attachment provides broad, stable bace where it can generate forces needed for respiration)
Why is the right dome of the diapghram higher than the left?
- Liver position. liver occupies substantial portion of RUQ. pushes right side of diaphragm upwards. left side of diaghragm adjascent to sromach and spleen, smaller, less dense than liver, allowing left dome to sit lower
State 3 openings of the diaphragm
State the location and structures passing through
- Caval aperture (T8)
located in central tendon of diaghram at level of 8th thoracic vertebra.
-inferior vena cava, branches of right phrenic nerve - Oesophageal aperture (T10) located at 10th thoractic vertebra. Formed by fibes of right crus, around eosophagus, lefy of midline
- oesophagus
- right, left vagus nerve (gastric nerves)
-oesophagal branches of left gastirc vessels - Aortic aperture
between right & left crura, bounded by the median arcuate ligament
- Aorta
-Thoracic duct lymphatic
-Azygous and hemiazygous vein
Describe “Referred pain - Diapghagmatic pain”
What is a classic example of referred pain?
- Shoulder + diaphragm share common nerve supply
- Phrenic + supraclavicular nerve share cervical orgins C3,C4
- Kehr’s sign - left shouler pain caused by irritation of phrenic nerve on inferior surface of diapghragm due to bleeding from splenic rupture.
UNDERSTANDING: diaghragm + shoulder share common nerve supply (c3,c4), pain originating in diaphragm can be perceived in shoulder area. REFERRED PAIN
Describe a diaphragmatic hernia
Congenital
Diaphrag does not develop properly
Hole in diaphragm
CAN ALSO BE ACQUIRED
(penetrating injuries, blunt force trauma)
-Liver partially up into chest
- Small intestine, in left chest, pushing heart and lungs to right
-compressed left lung
Diagram showing basic body plan - body cavities
What is the mediastinum?
Central compartment in thoracic cavity
Located between two pleural cavities that house the lungs
Passageway for vital structures
WHAT YOU NEED TO KNOW
Location: Between the lungs
Borders:
1) Anterior - Sternum
2) Posterior - Thoracic Vertebrae
3) Superior: superior thoracic aperture
4) Inferior - diapghram
Describe the pleural cavity
(2 layers)
B) State the functions of pleural fluid
Visceral layer - against organs within the cavity
Parietal layer - against wall of cavity
Pleural fluid - thin layer of fluid in between
B)
- Allows parietal + visceral parts to slide on each other
- Allows movement of lung against chest wall
- Surface tension of pleural fluid keeps lung surface in contact with thoracic wall
What can collect in the pleural cavity
Air - pneumothorax
Fluid - pleural effusion
Blood - heamothorax
Pus - empyema
Describe the structure of the lungs
(APEX, BASE, LOBES, SURFACES, LUNG ROOT AND HILUM, BORDERS
APEX: above 1st rib + into root of neck
BASE - inferior surface of lung, sits on diaphragm
LOBES (2/3) - separated by fissues in lung
SURFACES (3) - respond to area of thorax they face
-Costal - facing intercostal muscles
-Mediastinal (INCLUDES LUNG ROOT + HILUM)- faces mediastinum
-Diaphragmatic - concave surface
Borders (3)
- Anterior
-Inferior
-Posterior
-Posterior
Describe lung lobes and fissures
Right lung (A, C)
3 lobes: superior, middle, inferior
2 fissures: oblique + horizontal
Left lung (B,D)
2 lobes: superior + inferior
1 fissure: oblique
HAS CARDIAC NOTCH
What components enter through the hilum of the lung?
Each lung has
- Main bronchus
-Pulmonary artery
-2 pulmonary veins
BRONCHIAL VESSELS, NERVES, LYMPHATICS
Surface markings of lungs and pleura
Know:
1) where midclavicular line, midaxillary line, paravertebral line
2) PLEURA EXTENDS 2 RIBS LOWER THAN LUNGS AT EACH POINT. This extra space, called the costodiaphragmatic recess, is an important area for the accumulation of fluid or air in conditions like pleural effusion or pneumothorax.
he difference in pleura and lung positions allows room for the lungs to expand during deep inspiration.
Surface marking of lung fissues
- Oblique fissue
-found in both lungs (separates superior + inferior lobes)
posterior - Horizontal fissure
-RIGHT LUNG ONLY
-separates middle lobe from superior lobe
anterior
Surface markings of lobes and fissures
1)Where does the trachea start?
2) Where does it divide? (TRACHEOBRONCHIAL TREE)
3)How does the trachea divide?
1) Starts below cricoid cartilage of larynx
2) Sternal angle
Primay Bronchi (right and left main)
(right: shorter, wider, more vertical)
Secondary (lobar bronchi)
-right 3, left 2)
Tertiary (segmental)
-each supplies a bronchopulmonary segment
-Pulmonary arteries accompany the bronchi, while pulmonary veins lie between adjacent segments.
Segmental bronchi divide into subsegmental bronchi
then bronchioles
terminal bronchioles
respiratory bronchioles
alveolar ducts
alveoli
