Basal bodyA basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). The basal body was named by Theodor Wilhelm Engelmann in 1880. It is formed from a centriole and several additional protein structures, and is, essentially, a modified centriole. The basal body serves as a nucleation site for the growth of the axoneme microtubules.
SpermatozoonA spermatozoon (spərˌmætəˈzoʊ.ən,_ˌspɜrmətə-; also spelled spermatozoön; : spermatozoa; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, that normally develops into an embryo.) Sperm cells contribute approximately half of the nuclear genetic information to the diploid offspring (excluding, in most cases, mitochondrial DNA).
PolysomnographyPolysomnography (PSG), a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Greek πολύς (polus for "many, much", indicating many channels), the Latin somnus ("sleep"), and the Greek γράφειν (graphein, "to write"). Type I polysomnography is a sleep study performed overnight while being continuously monitored by a credentialed technologist.
DynactinDynactin is a 23 subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (Arp1). Dynactin was identified as an activity that allowed purified cytoplasmic dynein to move membrane vesicles along microtubules in vitro. It was shown to be a multiprotein complex and named "dynactin" because of its role in dynein activation. The main features of dynactin were visualized by quick-freeze, deep-etch, rotary shadow electron microscopy.
SnoringSnoring is the vibration of respiratory structures and the resulting sound due to obstructed air movement during breathing while sleeping. The sound may be soft or loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of obstructive sleep apnea (OSA). Research suggests that snoring is one of the factors of sleep deprivation. Snoring is the result of the relaxation of the uvula and soft palate. These tissues can relax enough to partially block the airway, resulting in irregular airflow and vibrations.
SpermatogenesisSpermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes.
