Fig.1.
(A-D)Macroscopic aspects of the respiratory system organs of Rhea americana with 27 days of development of the nasal cavity (nc) in cross section, larynx (la), trachea (t) and lung (lu) respectively. Bar = 1cm.
Fig.2.
Nasal cavity of Rhea americana during foetal development at different ages. (A-F) The nasal cavity at 11, 13, 15, 21, 27 and 30 days respectively. (A) The oral cavity is in communication with nasal cavity the (OC-NC); nasal meatus (NM). HE, Bar = 200μm. (B) Middle nasal concha (MC) in the form of parchment and early in the histogenesis of hyaline cartilage (HC), epithelium (EP), nasal meatus (NM). HE, Bar = 100μm. (C) Nasal rostral concha (RC) in a “C”, nasal septum (NS). HE, Bar = 200μm. (D) Note the middle nasal concha (MC) further developed, nasal meatus (NM), submucosa consists of loose mesenchyme (m), intramembranous ossification (IO) clear. HE, Bar = 200μm. (E) The epithelium of the middle nasal concha region displays reorganization, becoming pseudostratified (EP) showing groups of cilia (ci) and formation of intraepithelial glands (G), mesenchyme (m), blood vessels (bv). HE, Bar = 50μm. (F) In the region of the rostral concha, the epithelium (EP) has a stratified keratinized surface (k) and column of cells (col). HE, Bar = 20μm.
Fig.3.
The larynx of Rhea americana foetuses at different ages of development. (A-D) Larynx at 18, 21, 30 and 31 days respectively. (A) Note the cubic epithelium (EP) and mesenchymal (m). HE, Bar = 20μm. (B) Arytenoid cartilages (AC) and cricoid cartilage (CC), lumen (L). HE, Bar = 200μm. (C) Lumen (L) is irregular due to the formation of intraepithelial glands (G), arytenoid cartilage (AC), cricoid cartilage (CC), muscular tunica (mt). HE, Bar = 200μm. (D) The pseudostratified epithelium (EP) with of cilia (ci), intraepithelial glands (G), lumen (L), blood vessels (bv). HE, Bar = 20μm.
Fig.4.
The trachea of embryos and Rhea americana foetuses at different ages of development. (A-F) Trachea at 9, 15, 18, 21, 27 and 31 days respectively. (A) Epithelium (EP), mesenchyme (m), lumen (L). HE, Bar = 50μm. (B) Mesenchymal differentiation (md) characteristic in the histogenesis of hyaline cartilage, epithelium (EP), lumen (L). HE, Bar = 50μm. (C) Stratified epithelium (EP), progression of mesenchymal differentiation (md), lumen (L). HE, Bar = 100μm. (D) Hyaline cartilage (HC), epithelium (EP), lumen (L), blood vessel (bv). HE, Bar = 50μm. (E) Pseudostratified epithelium (EP) with cilia (ci), blood vessels (bv). HE, Bar = 20μm. (F) Formation of intraepithelial mucous glands (G), pseudostratified epithelium (EP) with cilia (ci), lumen (L), submucosa (sm). HE, Bar = 20μm.
Fig.5.
Rhea americana foetuses syrinx at different ages of development. (A-B) Syrinx at 18 days. (C-D) With 27 and 30 days respectively. (A) Note the thin layer of longitudinal muscle (LM), bronchiosyringeal cartilage (BC), tracheosyringeal cartilage (TC), pessulus cartilaginous (p). HE, Bar = 200μm. (B) Stratified epithelium (EP) with cilia (ci), mesenchyme (m). HE, Bar = 20μm. (C) Epithelium becomes pseudostratified (EP), ciliated (ci), pessulus (p), loose mesenchyme (m). HE, Bar = 100μm. (D) Longitudinal muscles are more evident (LM), bronchiosyringeal cartilage (BC), tracheosyringeal cartilage (TC), tympanic membrane (TM), pessulus (p). HE, Bar = 2mm.
Fig.6.
Bronchi of Rhea americana foetuses at different ages of development. (A-D) With 18, 21, 27 and 31 days respectively. (A) Stratified epithelium (EP), lamina propria consists of loose mesenchyme (m), hyaline cartilage forms the bronchial ring (HC). HE, Bar = 20μm. (B) Isolated cilia (ci), loose mesenchyme (m), blood vessels (bv), hyaline cartilage (HC). HE, Bar = 50μm. (C) The pseudostratified epithelium (EP) with ciliated cells (ci), mesenchyme (m), hyaline cartilage (HC). HE, Bar = 50μm. (D) Cilia are evident (ci), pseudostratified epithelium (EP) mesenchyme (m). HE, Bar = 20μm.
Fig.7.
Embryo lung and Rhea americana foetuses at different ages of development. (A-F) Lung at 9, 12, 15, 18, 27 and 31 days respectively. (A) Branching of the main bronchus (MB) into the mesenchyme (m). HE, Bar = 200μm. (B) Secondary bronchi (SB), mesenchyme (m), blood vessel (bv). HE, Bar = 100μm. (C) Secondary bronchi originating parabronchi (SB-PB), with a large number of blood vessels (bv). HE, Bar = 200μm. (D) Parabronchi (PB) with a simple cubic epithelium (EP) and blood vessels (bv) close to parabronchi. HE, Bar = 50μm. (E) Is observed parabronchi (PB) with numerous air and blood vessels (bv) and smooth muscle (sm). HE, Bar = 100μm. (F) Parabronchial surface (PB) indicating the atria (a) with simple squamous epithelium and increased number of blood vessels associated with capillary air (ca), and blood capillaries (bc). HE, Bar = 50μm.
Fig.8.
Scanning electron microscopy (SEM) of fragments of the respiratory organs of developing foetuses of Rhea americana. (A) Region of the rostral nasal cavity of a 15-day-old foetus, showing the mucosa with a layer of cuboidal cells. Bar = 3μm. (B) Rostral region of the nasal cavity of a 30-day foetus with keratinized surface and cells sloughing off (cs). Bar = 100μm. (C) A 27-day foetal larynx with numerous eyelashes and goblet cells (GC). Bar = 30μm. (D) Trachea (t) of a 21-day-old foetus; note the cartilaginous tube syntopy with the oesophagus (e). Bar = 300μm. (E) Trachea epithelium with goblet cells and multiple eyelashes (GC) of a 30-day-old foetus. Bar = 10μm. (F) Bronchiosyringeal region of a 21-day-old foetus showing cilia groups (ci). Bar = 10μm. (G) A 21-day foetal syrinx longitudinal section showing the trachiosyringeal regions (RT), bronchiosyringeal (RB) and pessulus (p). Bar = 200μm. (H) A 15-day foetal lung showing the parabronchi (PB) and blood vessel (bv). Bar = 30μm. (I) A 27-day foetal lung with the main bronchus (BP), secondary bronchi (BS), and parabronchial surface comprising numerous atria. Bar = 300μm.