Resp Anatomy Flashcards
What are the three surfaces of the lungs?
Diaphragmic, costal, mediastinal
What is the carina?
Sensitive area between primary L/R bronchus for coughing reflex and bronchus obstruction
Which bronchus is longer and steeper?
Left longer and steeper angle so more likely to get things stuck in it, right shorter and smaller angle
How many bronchopulmonary segments does each lung have and where are they concentrated and why?
Left - 8-9
Right - 10
More in the inferior lobe as larger shape and forced lower for better perfusion
How does infection affect the functional bronchopulmonary units?
Infection doesn’t spread between units because each is separated by CT so still function even if one affected
Outline the innervation of the lung?
GVA - sensory to stretch/pressure in mucosa, chemosensitive in respiratory tree
Para - Vagus which bronchoconstricts and vasodilates and mucosal control
Symp - T1-5 ganglion - vasoconstricts (endocrine controls bronchodilation)
Outline pleural innervation?
Visceral - GVA only detect stretch
Parietal - symp only detecting pressure, pain, temp with phrenic innervating mediastinal parietal nerves with referred pain to shoulder
What part of the respiratory tree is the acinus? (4)
Terminal branch, resp bronchioles, alveolar ducts, sacs
Histology of trachea and bronchi?
Conductive tubes so pseudostratified columnar epithelium with goblet cells and cilia
Histology of bronchioles and alveoli
starts to transition from resp to cuboidal to simple squamous with thicker sm to adjust lumen size
Cells of the alveolar ducts and sacs? (3)
- Type 1 pneumocyte - squamous with large SA for gas exchange covering 95% areolar surface and fused to basement membrane
- Type 2 pneumocyte - cubodial covering 5% of alveolar lining. Synthesis and secretion of surfactant to reduce alveolar fluid accumulation
- Alveolar macrophages - dust cells which patrol alveoli and are easily observed once they ingest something
What is the first stage of development of the lungs?
Embryonic week 4-7
-tertiary bronchi develop from secondary bronchi which develop from primary. Pulm arteries follow bronchi to remove O2 and visceral pleura adheres to lung
What is the second stage of development of the lungs?
Pseudoglandular week 6-17
- final number of bronchopulmonary segments formed, tertiary bronchioles develop, still have thick wall and dense mesenchyme
What is the third stage of development of the lungs?
Canalicular week 16-28
- terminal to resp bronchioles, alveolar ducts and primitive alveoli. Walls start to thin and epithelium starts to differentiate into type 1 and 2 pneumocytes. Formation of capillary beds and increased diameter of bronchi
What is the fourth stage of development of the lungs?
Saccular week 28-36
- further differentiation and increase in primitive alveoli. Type 1 and 2 develop still and surfactant lowers surface tension so easier to breathe. Diffusion distances reduces so increased gas exchange and at 36 weeks, have ability to breathe and transpire (early term before 37 weeks so lung development compromised)
What is the fifth stage of development of the lungs?
Alveolar week 36 - 22 years old
- Alveolarization and septation and multiplication of alveoli including the thinning of airspace walls and formation and differentiation on craniocaudal fashion. Subphases - 1st from 36w to 2/3 yo is fast, from 2/3yo until adult is slow, set at 18/22 years old, terminal bronchiole enlargement is final
What is the sixth stage of development of the lungs?
Microvascular maturation birth until 3-21 years old
- fusion of capillary networks of interalveolar septa from double to single layer to reduce distance to optimize cap to airspace
Developmental errors of lungs? (3)
- Tracheoesophageal fistula with or without atresia (narrowing) of trachea/oesophagus
- Congenital diaphragmatic hernia with incomplete fusion of septum transversum and pleuroperitoneal folds
- Asymmetric branching abnormalities - unilateral agenesis, aplasia (bronchi but no lung tissue) or hypoplasia (lung tissue but no alveoli)
Preterm birth errors?
Surfactant
- production from weeks 24-34 to hold open smaller airways by reducing surface tension resulting in equalised air flow to sacs.
Lack of surfactant means you cannot retain air once inflated as wall will stick together when oved and stretched which can tear/damage and not retain air
What are the preterm birth considerations? (5)
- surfactant needs to be produced
- lungs need minimal diffusion distance
- diaphragm need to be able to do the work of breathing
- thorax needs to be rigid enough to resist diaphragm
- respiration interventions alone aren’t enough, look at other systems
where are ribs and sternum derived from?
Ribs - somites
Sternum - somatopleure
Tidal respiration, active or passive?
Inspiration - active where the diaphragm. intercostals and scalene muscles make the longer and wider so boyles law states inverse volume to pressure
Expiration - passive due to tension created once muscles stop so recoil moves air out
What are the two joints of the posterior costal joints?
- Costovertebral - synovial joints between ribs and vertebral bodies
- Costotransverse - synovial joints found on transverse facet - true ribs have cup shaped facet, false ribs have plane shaped facet, floating ribs have no joint as they arent attached to transverse process
What are the 3 anterior costal and sternal joints?
- Synchondroses - cartilaginous immoveable joints at 1st sternocostal (forming fulcrum) and xiphisternal joint
- Symphysis - cartilaginous moveable making sternal angle more obtuse with deep inspiration lifting up sternum
- Synovial - sternocostal joints (2-7) which are mobile but highly constrained
What are the 3 movements of the chest wall?
- Bucket handle - true ribs elevate with synovial joints
- Pump handle - rib 1 lifts manudibrum and carries sternum forward
- Callipers - false ribs act on costal margi and widen laterally so A shape is broader
What happens to structures running through diaphragm when it contracts?
T8 - IVC widens slightly so increased blood flow and venous return
T10 - Oesophagus going through muscular component reinforces the cardiac sphincter of stomach
T12 - Aorta has no effects as diaphragm ends before this so no affected function
What are the three intercostal muscles?
- External intercostals - going down and in (V shape) situated posteriourly fr inspiration
- Internal intercostals - going down and out (A) shape and further broken into parasternal for inspiration and interosseous for expiration
- Innermost intercostals - more internal than nerve, artery and veins and active during inspiration and expiration
What are the 5 muscles used in deeper respiration?
1/2. Scalene and sternocleidomastoid - lift first rib up or prevent depression of first rib due to force of diaphragm
3. Serratus posterior - lifts superior ribs and depresses lower ribs
4. Ouadratus lumborum - holds rib 12 down when breathing in
5. Postural muscles - maximum lung volume dependent on posture so scapular muscles (trap, rhomboids, lats) and vertebral muscles (erector spinae groups)
What happens during forced expiration and why do we have to be careful?
Abdominal wall muscles pushes out to increase abdominal pressure so organs push up on diaphragm to help breathe out, but increased abdominal pressure means pelvic floor muscles must be active or the increased pressure will make you urinate or defecate.
Why do COPD patients have a barrelled chest?
Usually muscles act on the lightest end of muscle so the pectoral girdle muscles of the arm and lighter than the pec minor and major. Ribs move up towards arms to get more air into lungs which is seen in COPD patients because they need to get more air into lungs
What are the two concepts of pleural anatomy and pneumothorax?
- Lungs are stuck to chest wall which creates tension force attempting to pull lungs from the body wall, and always negative pressure which becomes more negative during inspiration
- Pleura lined with serous secreting mesothelium allowing movement so shape can change but not volume.
Outline where the pleural recesses are and what rib level they extend to?
Cupula at top above first rib
Lungs - costomediastinal from rib 2-4, then 4-6 L deviates then 6-8 to midaxillary line. Costodiaphragmatic from midaxillary rib 8 to rib 10 posteriorly
Pleura - follows same pattern but midaxillary, pleura extends to rib 10 and then to rib 12 posteriorly
Clinical implications of lung/pleural recess spaces? (2)
- chest tube in costdiaphragmatic region goes in 9th intercostal space between rib 9-10 as lungs extend to rib 8 midaxillary and pleura extends to rib 10
- Pericardiocenteses to sample pericardinal fluid through left infrasternal angle to avoid pleura
Which muscles form the frenulum and what is the importance of them?
genioglossus muscles form the fremulum (midline under tounge) which have openings from submandibular ducts which release saliva when muscles push it out
Nerve supply to the mouth? Maxillary and mandibular control where from, where to?
- Maxillary - trigeminal CN.V2 GSA
- all radiate from pterygopalatine fossa
- roof of mouth from naso/palatine n.
- upper teeth, gums, vestibule from ant/post superior alveolar n. - Mandibular - CN.V3 from foramen ovale supplying all muscles of mastication
- lower teeth/gums from inferior alveolar n.
- lower vestibule from buccal n.
- ant 2/3 tongue and floor from lingual
- post 1/3 tongue from CN.IX glossopharyngeal (GVA)
What initiates the gag reflex?
GVA somatics around from of tongue turn into visceral somatics around back of tongue
How is tongue innervated by the first 4 arches and which nerves?
1st arch - GSA from lingual nerve CN.V3 taste anterior 2/3
2nd arch - SVA from chorda tympani CN.VII
3. GVA from glossopharyngeal CN.IX taste post 1/3
4. SVE to platoglossus from vagal CN.X
Extrinsic muscles from occipital somites CN.XII
What forms the hard palate?
Palatine processes of maxillary bones and palatine bone
Which nerve senses taste from soft palate?
CN.VII SVA from greater petrosal nerve
What are the 5 muscles of the palate and which nerve innervated them?
1-4 innervated by vagus CN.X:SVE
1. Muscula uvulae - stiffens uvula
2. Palatoglossus - lowers palate and brings up tongue
3. Palatopharyngeus - lifts pharynx
4. levator palati - raises palate
5. Tensor palati muscles stiffen the palate but does not move it, innervated by CN.V3
What 2 bony components divide nasal cavity in half?
Ethmoid and vomer
Which paranasal sinuses open into which meatuses?
Frontal - middle
Ethmoid air cells-middle/sup
Sphenoid sinus - Sphenoethmoid recess
Maxillary - middle
nasolacrimal - inferior
Why do people get tooth pain when they have a cold/flu?
Nerves cannot discriminate between pain so if maxillary sinus is full, nerves that sense tissue around it are same nerves supplying teeth leading to referred pain
Nerves of GSA and GVA to nose?
- GSA
- nasal cavity from CN.V1 opthalmic and CN.V2 maxillary - GVA
- pharynx from glossopharyngeal
- Larynx from vagus
- tongue sensation from lingual n. CN.V3
Parasympathetic control of nose and palate, mouth and tongue?
Nose and palate - Greater petrosal from CN.VII with postsynaptic ganglion in sphenopalatine ganglion
Mouth and tongue - Chorda tympani CN.VII with submandibular postsynaptic ganglion
