ANHB2212 Lecture Notes - Lecture 13: Endoderm, Anal Canal, Gas Exchange
28 May 2018
School
Course
Professor
L13 Lungs and Pleura
Outcomes
Lungs – General features
Serous membranes of the lungs
Pleura
Epithelium – Terms and Concepts
Lungs
• Fissures, Lobes
• Air passages
• Pulmonary artery
• Bronchopulmonary segments
Bronchi
Root and Hilum
Tissue histology
Lungs – General Features
• 6th Cervical vertebra/ 1st Rib fits apex in the neck
• Apex is covered by fibrous membrane
o Suprapleural membrane
o Sibson’s fascia
o Seal between the neck and the thorax
• Base of the lungs rest on the diaphragm
• Has costal surface
o In contact with the ribs of thoracic wall
• Mediastinal surface/ Medial surface
o Faces the mediastinum
o M.s is in contant with the mediastinum
o Separated by pleura
Serous membranes of the lungs (Pleura?)
• Lateral plate mesoderm → Coelomic Cavity →
Pleural cavity → Pleura (the serous membrane?) →
Visceral, Parietal
o Ie Pleura originate from coelmic cavity
• The lining: Simple Squamous Epithelium +
Supporting Connective Tissue
o Epithelial lining = Mesothelium
• Pleura are double layered continuous sacs
o Parietal and Visceral
• Pleural cavity has watery fluid that facilitate
expansion and contraction of organs
• Theres a part not covered by pleural cavity
o Its covered by mediastinum @ the medial
side
o Where pulmonary artery/veins enter/leave
the lungs → hilum of the left lung
Pleura
• Suprapleural membrane/ Sibsons fascia
o Fibrous sheet that is attached to the 1st rib
and the 6th cervical vertebra
o Seals between the neck and the thorax
• Visceral pleura
• Parietal pleura
o Costal part of parietal pleura
o Diaphragmatic part of parietal pleura
o Mediastinal part of parietal pleura
o Cervical part of parietal pleura
Pleura
• V/P have different sensations to pain
• Visceral pleura (sticked to the lungs)
o Has sensations of visceral type
o No conscious perception, vague
o E.g ischemic, pressure
o Pain receptors/ Nerves from the lungs
• Parietal pleura (sticked to body walls)
o Supplied by Intercostal nerves
o has somatic sensations (localized, sensitive
pain)
o conscious perception
o “arising from the site of damage”
• has costodiaphgramatic recesses
p6
Epithelium – Terms and Concepts
• Ectoderm forms the
o Skin (epidermis)
o Epithelium of mouth cavity
o Epithelium of anal canal
o Stratified Squamous Epithelium
• Endoderm forms the
o Lining of digestive tube
o Glands (Liver, Pancreas, Salivary Gland)
o Respiratory system
• Mesoderm forms the
o Lining of heart (Endothelium =
Endocardium)
o Lining of blood vessels (Endothelium)
o Lining of serous cavities (Mesothelium)
Lungs – Fissures, Lobes
• Oblique
o Begins posterior, reaches anterior
• Horizontal – Right lung
• Right lung = upper, middle, lower
• Left lung = upper, lingula, lower
Lungs – Air passages
• Primary air passage
o Right and Left bronchi
• Secondary air passage
o 1 to each lobe (3R) (3L)
• Tertiary air passages
o to segments
• Trachea → R/L bronchi → Lobes → lose hyaline
cartilage → Bronchioles → Segments → Alveoli
Lungs – Pulmonary artery
• Deoxygenated blood → RA → Tricuspid valve →
RV → Pulmonary valve → Pulmonary artery →
Right lung / Left lung
• Each pulmonary artery is accompanied by
bronchioles/bronchus
• Returning veins do not accompany
bronchioles/bronchus
• Capillaries (from the arteries) surround alveolar
bunch
o Gas exchange occurs here
Lungs – Bronchopulmonary segments
• Pulmonary arteries → become capillaries
• Bronchi → become arterioles
• Branches (Bronchus + Pulmonary Artery) divide into
10 segments in each lung
o 3,2,5
• macroscopically: thin fibrous partitions
• veins run between segments
Document Summary
Lungs: fissures, lobes, air passages, pulmonary artery, bronchopulmonary segments. 6th cervical vertebra/ 1st rib fits apex in the neck: apex is covered by fibrous membrane, suprapleural membrane, sibson"s fascia, seal between the neck and the thorax, base of the lungs rest on the diaphragm, has costal surface. In contact with the ribs of thoracic wall: mediastinal surface/ medial surface, faces the mediastinum, m. s is in contant with the mediastinum, separated by pleura. Serous membranes of the lungs (pleura?: lateral plate mesoderm coelomic cavity . Ie pleura originate from coelmic cavity: pain receptors/ nerves from the lungs, parietal pleura (sticked to body walls, supplied by intercostal nerves, has somatic sensations (localized, sensitive pain) conscious perception. Arising from the site of damage has costodiaphgramatic recesses p6. Endocardium: lining of blood vessels (endothelium, lining of serous cavities (mesothelium) Lungs fissures, lobes: oblique, begins posterior, reaches anterior, horizontal right lung, right lung = upper, middle, lower, left lung = upper, lingula, lower.
