Vocal Motor Disorders *
Rolland S. Parker in Concussive Brain Trauma, 2016
Speech production is the product of a complex laryngeal apparatus that includes the muscles of the vocal folds, various cartilages, ligaments, and the mouth and throat. The structures of the laryngeal and other vocal apparatus, as well as their neural control, differ significantly from those used for the trunk, limbs, and the respiratory apparatus. They evolved through aeons from the bilateral spaces and cartilages, forming the gill arches of primitive fish, rather than the transaxial segments that form the limbs, ribs, and muscles utilized for movement (Black, 1970, pp. 240–242; Butler & Hodos, 1996, pp. 156, 256–258; Kent, 1978, pp. 146–158, 165, 361, 376). The five branchial nerves that evolved from the gill arches of primitive fish (V, VII, IX, X, XI) are both sensory and motor nerves. Detailed text and diagrams of the human branchial (pharyngeal) arches and their muscular and neural derivatives are found in Williams (1995, pp. 274–287). Thus, structures and neural control of vocalization are located around the body axis rather than as part of the axial and bilateral structures (spinal segments).
De Fabrica Humani Corporis—Fascia as the Fabric of the Body
David Lesondak, Angeli Maun Akey in Fascia, Function, and Medical Applications, 2020
Blood vessels, often as neurovascular bundles, play a role in the shaping of the body. In the development of the embryo, strands of connective tissue surrounding a vascular structure may function as a restraining structure, providing resistance and biomechanical constraint to growth with flexure, or “flexion growth”, if you will, as consequence. This may be observed in developing limbs or in the formation of pharyngeal arches.13 The widespread presence of capillaries throughout the body also reinforces the idea of fascia in a broader sense as the matrix in which all organs are woven and embedded. Blood and fascia take the shape of the body, one might say, and literally create the web in which everything is both connected and separated.
Answers
Samar Razaq in Difficult Cases in Primary Care, 2021
Abnormal development of the third and fourth pharyngeal arches during embryonic development results in DiGeorge’s syndrome. The majority of cases are caused by chromosomal deletion at 22q11, although other chromosomal abnormalities have also been implicated. It results in immunodeficiency (due to inadequate thymic development), congenital heart defects, hypocalcaemia (due to underactive parathyroids) and abnormal facies. An extra copy of chromosome 18 results in Edwards’s syndrome, in which there may be a wide variety of congenital defects and mental retardation. Trisomy 21 is commonly known as Down’s syndrome.
The carotid body and associated tumors: updated review with clinical/surgical significance
Published in British Journal of Neurosurgery, 2019
Nasir Butt, Woong Kee Baek, Stefan Lachkar, Joe Iwanaga, Asma Mian, Christa Blaak, Sameer Shah, Christoph Griessenauer, R. Shane Tubbs, Marios Loukas
Each carotid body has a fibrous capsule and is lobulated by a septum. Within each lobule are collections of type I or chief cells, which are enveloped by type II or sustentacular cells. Between the type II cells and endothelium are non-myelinated nerve fibers, neurolemmocytes, fibrocytes, and collagen fibers.11 Chief cells of the carotid body are also known as amine precursor uptake and decarboxylation (APUD) cells and are components of the neuroendocrine system. These groups of cells are associated with the sympathetic nervous system and can take up amine precursors, while sustentacular cells of the carotid body are associated with the parasympathetic nervous system and have chemoreceptor activity. The carotid body itself is an embryological derivative of the third pharyngeal arch.4 During the embryogenesis, neuroblasts migrate along the glossopharyngeal nerve to form the carotid body.4
Anatomical structure, and expression of CCL4 and CCL13-like during the development of maxillary barbel in Paramisgurnus dabryanus
Published in Organogenesis, 2019
Kianann Tan, Ruijing Geng, Zhiqiang Wang, Han Liu, Weimin Wang
Through light microscopy (Fig. 4) and scanning electron microscopy (Fig. 5), we observed that a pair of maxillary barbels developed first, followed by the development of a pair of mandibular barbels. The maxillary barbels were first visible at 24 hpf as lateral protrusions on the head located posteriorly to the eye and anteriorly to the midbrain-hindbrain boundary. Maxillary and mandibular barbel protrusions at the first pharyngeal arch became apparent at 24 hpf. Maxillary barbel buds were positioned on the above processes. Throughout the embryonic development, maxillary barbels migrated anteriorly together with the mouth, but retained their position at the margin of the upper jaw. Once their position was fixed, maxillary barbels underwent elongation process starting from 56 hpf. Through the scanning electron microscopy observation, scattered taste buds could be seen on the surface of barbels.
Inner ear malformations and neurological involvement: a review
Published in Hearing, Balance and Communication, 2021
Davide Brotto, Roberto Bovo, Alessandro Martini
Oculo-auriculo-vertebral spectrum is characterized by first and second pharyngeal arch anomalies leading to a facial asymmetry [29] but the inner ear and the nervous system may be involved with different kinds of abnormalities. In addition, cerebral abnormalities are reported to be more frequent in patients with more severe clinical features [30]. The observed anomalies are diffuse cerebral hypoplasia, dilated ventricular system, midline anomalies such as corpus callosum dysgenesis or lipoma, absence of septum pellucidum and hypothalamic hamartoma, white matter abnormalities, microcephaly, and obstructive hydrocephalus due to the aqueduct of Sylvius stenosis [31], Chiari I anomaly, encephaloceles [32], tegmental cap dysplasia, cerebellar dysplasia and non-specific white matter signal abnormalities [13]. Also, anomalies of the II, III, V, VII and VIII cranial nerves, such as hypoplasia, fusion or neuroma have been reported [12]. In our experience, the patients presented in 46% of cases concomitant IEMs and brain anomalies, in 40% IEMs and cranial nerves anomalies and 34% presented concomitant IEMs, brain and cranial nerves anomalies frequently homolateral to the facial and auricular involvement [12].
Related Knowledge Centers
- Embryonic Development
- Fish Gill
- Germ Layer
- Mesoderm
- Neural Crest
- Pharynx
- Skull
- Animal Embryonic Development
- Aortic Arches
- Facial Skeleton