Lateral Congenital Anomalies of the Pharyngeal Apparatus: Part I. Normal Developmental Anatomy (Embryogenesis) for the Surgeon

2011 ◽  
Vol 77 (9) ◽  
pp. 1230-1242 ◽  
Author(s):  
Petros Mirilas
Keyword(s):  
Congenital Anomalies ◽  
Cranial Nerves ◽  
Pharyngeal Arches ◽  
Developmental Anatomy ◽  
Extensive Area ◽  
Spinal Nerves ◽  
Pharyngeal Apparatus ◽  
Aortic Arches ◽  
Apparatus Part ◽  
Derivatives Of

Knowledge of the embryogenesis of the pharyngeal apparatus is the only means of understanding the “architecture” of the neck. The embryonic pharynx (which includes future oral and nasal cavities) is a much more extensive area than the adult pharynx. The main feature of the developing pharynx is a series of arches, internal pouches, and external clefts, which together comprise the pharyngeal apparatus. This structure is associated with other developing splanchna of the neck, e.g., the thyroid and parathyroid glands, tonsils, and thymus. Within each of the pharyngeal arches are the developing aortic arches and, specific for each arch, cranial nerves. The complex relations of the mesenchymal derivatives of arches (muscles, cartilage, bones) with the neurovascular bundles within each arch are presented and explained. The pharyngeal apparatus undergoes dramatic transformations: pouches and clefts disappear without interruption (interruption would produce gills and support the misnomer “branchial apparatus”). In addition, in the lateroventral neck, somites migrate to produce other muscles such as sternocleidomastoid and trapezius innervated by spinal nerves. Lateral congenital anomalies largely rely on persistence of a cleft/and or pouch or communication between the two. Their tracts have a “crooked” course among other entities generated by alterations that take place during embryogenesis.

Lateral Congenital Anomalies of the Pharyngeal Apparatus: Part II. Anatomy of the Abnormal for the Surgeon

2011 ◽  
Vol 77 (9) ◽  
pp. 1243-1256 ◽  
Author(s):  
Petros Mirilas
Keyword(s):  
Congenital Anomalies ◽  
Internal Carotid ◽  
Surgical Anatomy ◽  
External Carotid ◽  
Pharyngeal Arches ◽  
Pharyngeal Apparatus ◽  
Fourth Arch ◽  
Complicated Course ◽  
Arch Structures ◽  
Recurrent Laryngeal Nerves

“Anatomy of the abnormal”—a branch of surgical anatomy—deals with relations of an anomaly to surrounding entities. Here, lateral congenital anomalies of the pharyngeal apparatus are examined; their relations to entities of the neck can be explained embryologically. Location of embryonic pharyngeal arches, clefts, and pouches in the adult is presented and terminology of these anomalies (fistulas, sinuses, cysts) is defined. First “cleft and pouch” anomalies relate with the parotid and facial nerve. Second cleft and pouch anomalies course deeply to second arch structures and superficially to third arch structures. Consequently, they relate with hypoglossal and glossopharyngeal nerves and internal and external carotid arteries. Third cleft and pouch anomalies pass deep to third arch entities and superficial to those of the fourth arch and relate with glossopharyngeal, hypoglossal, superior and recurrent laryngeal nerves, and the internal carotid artery. The complicated course of fourth cleft and pouch anomalies brings them into relationship with glossopharyngeal, hypoglossal, superior and recurrent nerves, internal carotid, aorta, and subclavian arteries. Found superficially are veins (external and anterior jugular, common facial, communicating), nerves (transverse cervical, great auricular, mandibular, cervical branches of facial), and relevant spinal nerves (e.g., accessory). Knowledge of these anatomical relations helps prevent anatomical complications.

A study of the development of the head and pharynx of the larval urodele Hynobius and its bearing on the evolution of the vertebrate head

1959 ◽  
Vol 242 (690) ◽  
pp. 151-204 ◽  
Keyword(s):  
Cranial Nerves ◽  
Blood System ◽  
The Other ◽  
Neural Arch ◽  
Classical View ◽  
Spinal Nerves ◽  
Anatomical Features ◽  
Muscle Nerve ◽  
11Th Segment ◽  
Nasal Capsule

The early development of the head and pharynx of Hynobius nebulosus (11.5 to 32 mm long) and retardatus (27 and 37 mm specimens) was investigated in some detail from transverse serial microtome sections. Analysis included the chondrocranium, jaws and hyobranchial skeleton, ossifications, cranial and anterior spinal nerves, musculature, blood system and other associated anatomical features. The structure of the skeletogenous elements in general agreed with earlier descriptions. However, a rudimentary fenestra lateralis nasi is found in the nasal capsule of H. nebulosus , hitherto not reported, and a complete cartilaginous processus pterygoideus, confluent with the trabecula and inner margin of the lamina orbito-nasalis described by Edgeworth (1923 a ), was not extant in any Hynobius specimen. H. retardatus has a hypoglossal foramen (and nerve) and joins H. nebulosus (Fox 1957), Cryptobranchus japonicus and alleghaniensis as the only living Amphibia to possess this structure. The neural arch homology of the occipital crest is reaffirmed. The columella stilus of the 32 mm H. nebulosus is confluent with the pterygo-quadrate cartilage and because the hyoid and columella have a common blastematous origin in Hypogeophis (Marcus 1910), it is suggested that there was an ancestral cartilaginous continuity between the hyoid and pterygo-quadrate cartilage, similar to the commissura terminales of the branchiale. This feature would further emphasize the branchial segmental homologies of the mandibular cartilage, hyoid and branchiale. The pattern of the cranial nerves is similar to that of other urodele larvae and the arrangement of the profundus and maxillaris nerves supports the view of the descent of urodeles from porolepiforme crossopterygians (Jarvik 1942). There is a segmental series of eleven head-pharynx segments, a complete branchial segment including a levator muscle, nerve, cartilage bar and gill cleft. Each post-hyoid segment is complete except for the absence of branchiale V and VI, and behind the fourth functional gill cleft there are three vestigial blind ones and then the larynx and trachea leading to the lungs. The masseter (2nd segment), digastricus (3rd segment), dilator laryngeus (10th segment) and trapezius (11th segment) are considered to be the homologues of the other six intervening levator gill arch muscles. The arytenoid and tracheal cartilages are considered to be branchial bars of the 10th and 11th segments respectively, and the lungs to have developed from gill pouches of the 11th segment which failed to reach the exterior early in vertebrate evolution. The classical view of the homology of the laryngo-tracheal skeleton with a branchial bar enunciated by Gegenbaur and Wilder independently in 1892 is therefore upheld; disagreement is merely a numerical one. The basic segmental components of the amphibian head and pharynx are modified in ontogeny by omission, distortion or addition, in order to fit the animal for a terrestrial existence.

scholarly journals Experiments in examination of the peripheral distribution of the fibres of the posterior roots of some spinal nerves. Part II

1897 ◽  
Vol 60 (359-367) ◽  
pp. 408-411 ◽  
Keyword(s):  
Cranial Nerves ◽  
Sensory Nerve ◽  
Nerve Roots ◽  
Spinal Nerves

This paper is in continuation of one brought before the Society in 1892, and published in ‘Phil. Trans.,’ B, vol. 184. In that communication the peripheral distribution of the sensory nerve-roots of the sacro-lumbar and the thoracic regions was examined. In the present the examination is extended to the cervical and brachial sensory roots, and to the skin distribution of the cranial nerves.

The cranial nerves

2013 ◽  
Author(s):  
Martin E. Atkinson
Keyword(s):  
Head And Neck ◽  
Cranial Nerves ◽  
Dental Students ◽  
The Body ◽  
Neural Function ◽  
Nerve Supply ◽  
Spinal Nerves ◽  
Complete Detail ◽  
And Function ◽  
The Brain

The cranial nerves are the most important neural structures relevant to dental students and practitioners. The cranial nerves are the nerve supply to all the structures in the head and neck and underpin of the anatomy and function of these regions—the head and neck will not work without them. In a wider context, correct functioning of the cranial nerves is a very good indicator of the health or otherwise of the CNS; it may be necessary to test the function of some, or even all, of the cranial nerves at times to assess neural function. In addition, many of the cranial nerves may be involved in various diseases of the head and neck. As outlined in Chapter 3, 12 pairs of cranial nerves arising from the brain form one major component of the peripheral nervous system, the 31 pairs of spinal nerves forming the other. Each pair of cranial nerves has a name and number. Conventionally, they are numbered using the Roman numerals I to XII. The nerves are numbered from one to 12, according to their origin from the brain; nerves with the lowest numbers arise from the most anterior aspect of the brain (the forebrain) whereas those with highest numbers arise from the lowest part (the medulla). Several aspects of any nerve anywhere in the body are required to d escribe its anatomy and function in complete detail: • Its origins and terminations in the CNS; • Its neuronal components—are they motor, sensory, or autonomic? • Its course to and from its target tissues; • Its distribution to specific areas and structures through specific branches; • Its overall functions and specific functions of its component parts. In addition, if the clinical significance is going to be appreciated, we w ill also need to consider: • The effects of damage or disease on the nerve; • Its important relationships to other structures; • How to test whether the nerve is functioning correctly. Given that there are 12 pairs of nerves, does a competent dentist need to know everything in the two lists about every cranial nerve? The answer, you will be relieved to hear, is ‘no’.

scholarly journals I. On the relation between the structure, function, and distribution of the cranial nerves. Preliminary communication

1888 ◽  
Vol 43 (258-265) ◽  
pp. 382-390 ◽  
Keyword(s):  
Spinal Cord ◽  
Structure Function ◽  
External Surface ◽  
Cranial Nerves ◽  
The Body ◽  
Spinal Nerves ◽  
Internal Surfaces ◽  
Preliminary Communication ◽  
And Function ◽  
Lateral Plates

In a previous paper I have pointed out that the structure, distribution, and function of the spinal nerves, as well as the arrangement of their centres of origin in the spinal cord, all lead to the conclusion that these nerves are divisible into two parts; (1) a somatic part, supplying the external surface of the body and the muscles derived from the muscle plates, and (2) a splanchnic part, supplying the internal surfaces and organs and the muscles derived from the lateral plates of mesoblast. I also pointed out that the cranial nerves were built up on a similar plan and arose from similar centres of origin to the spinal nerves; that they too were divisible into somatic and splanchnic groups of the same type as in the spinal nerves.

Cranial Nerves and Cervical Spinal Nerves

Head and Neck ◽  
2018 ◽  
pp. 363-428
Author(s):  
Enrico Marani ◽  
Ciska Heida
Keyword(s):  
Cranial Nerves ◽  
Spinal Nerves

scholarly journals I. Note on the development of the olfactory nerve and olfactory organ of vertebrates

1879 ◽  
Vol 28 (190-195) ◽  
pp. 324-329
Keyword(s):  
Cranial Nerves ◽  
Olfactory Nerve ◽  
The Body ◽  
The Other ◽  
Olfactory Organ ◽  
Spinal Nerves ◽  
Mode Of Development

In the course of an investigation into the development of the cranial nerves of the chick, certain facts came to light indicating that the olfactory nerve, instead of being, as usually described, a structure differing totally in its mode of origin from all the other nerves in the body, in reality “exactly corresponds in mode of development and in appearance with the other cranial nerves, and with the posterior roots of the spinal nerves.”

scholarly journals Exclusion of Dlx5/6 expression from the distal-most mandibular arches enables BMP-mediated specification of the distal cap

2016 ◽  
Vol 113 (27) ◽  
pp. 7563-7568 ◽  
Author(s):  
Joshua W. Vincentz ◽  
Jose J. Casasnovas ◽  
Ralston M. Barnes ◽  
Jianwen Que ◽  
David E. Clouthier ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Positional Information ◽  
Bmp Signaling ◽  
Homeodomain Proteins ◽  
Pharyngeal Arches ◽  
Local Signaling ◽  
Cranial Neural Crest Cells ◽  
Multiple Signaling ◽  
Derivatives Of ◽  
Drive Reporter Gene Expression

Cranial neural crest cells (crNCCs) migrate from the neural tube to the pharyngeal arches (PAs) of the developing embryo and, subsequently, differentiate into bone and connective tissue to form the mandible. Within the PAs, crNCCs respond to local signaling cues to partition into the proximo-distally oriented subdomains that convey positional information to these developing tissues. Here, we show that the distal-most of these subdomains, the distal cap, is marked by expression of the transcription factor Hand1 (H1) and gives rise to the ectomesenchymal derivatives of the lower incisors. We uncover a H1 enhancer sufficient to drive reporter gene expression within the crNCCs of the distal cap. We show that bone morphogenic protein (BMP) signaling and the transcription factor HAND2 (H2) synergistically regulate H1 distal cap expression. Furthermore, the homeodomain proteins distal-less homeobox 5 (DLX5) and DLX6 reciprocally inhibit BMP/H2-mediated H1 enhancer regulation. These findings provide insights into how multiple signaling pathways direct transcriptional outcomes that pattern the developing jaw.

Brainstem and Cranial Nerves: Overview and Medulla

2021 ◽  
pp. 68-81
Author(s):  
Kelly D. Flemming
Keyword(s):  
Cranial Nerves ◽  
Fiber Types ◽  
Functional Characteristics ◽  
Spinal Nerves

This chapter reviews the anatomy of the brainstem and cranial nerves and important structures at the level of the medulla. The next 3 chapters discuss important structures at the level of the pons, important structures at the level of the midbrain, and pathways that traverse the entire brainstem. The 12 pairs of cranial nerves (numbered I-XII), like spinal nerves, contain sensory or motor fibers or a combination of fiber types. These fibers are classified according to their embryologic origin or common structural and functional characteristics.

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