Regulation of Reproduction by Dopamine
Nira Ben-Jonathan in Dopamine, 2020
Human oviducts are long narrow tubes whose main role is to transport the egg from the ovary to the uterus, transport sperm from the vagina and cervix in the opposite direction, and provide a supporting environment for fertilization and early zygote development. The oviduct is not attached to the ovary. Rather, its funnel-shaped structure, the infundibulum, is equipped with finger-like projections, called fimbria, which collect the ovulated egg from the vicinity of the ovary. The ampulla, where fertilization normally occurs, is the widest part of the oviducts and is connected through a narrower isthmus to the uterine cavity. In cross section, the oviduct consists of an innermost ciliated and secretory epithelium, surrounded by outer circular and longitudinal muscles. Both ciliary movement and muscular peristalsis aid in egg and sperm transport.
Structure and Function of Human Skin
Marc B. Brown, Adrian C. Williams in The Art and Science of Dermal Formulation Development, 2019
The hair shaft is composed of an inner medulla overlaid with a cortex and then a cuticle. The root sheath has various layers but the outer root sheath is a keratinised layer that is continuous with the epidermis and is therefore of greatest importance with regard to drug diffusion and delivery. The hair follicle can be divided into several regions starting from the skin surface. The infundibulum is the outer part of the hair follicle and extends down to the sebaceous duct. In this area, the hair shaft is not in intimate contact with the skin and can move relatively freely. Due to the loss of epidermal differentiation, the thickness of the stratum corneum decreases deeper in the infundibulum, which results in a lesser barrier to drug diffusion compared to the stratum corneum at the skin surface.
Endocrine system
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha in Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
The pituitary gland lies in the sella turcica of the sphenoid bone (Fig. 10.2). The infundibulum (pituitary stalk) connects the gland to the hypothalamus of the brain, which lies above the optic chiasm and below the third cerebral ventricle and controls pituitary function by hormonal influence. The pituitary is divided functionally and anatomically into anterior and posterior lobes. Production of the two posterior lobe hormones (oxytocin and antidiuretic hormone [ADH]) is influenced by hormones sent down the axons of neurones in the pituitary stalk directly to that part of the gland. The anterior lobe produces seven hormones, and their control is by hormones released by the hypothalamus into the portal venous plexus that runs down the stalk to the anterior lobe, so that systemic blood levels of those hormones are very small indeed.
Recent advances in follicular drug delivery of nanoparticles
Published in Expert Opinion on Drug Delivery, 2020
Alexa Patzelt, Juergen Lademann
The permanent part of the hair follicle combines the infundibulum, the isthmus and the bulge region. The infundibulum is described as the part of the hair follicle between the skin surface and the sebaceous gland, and provides an intact keratinized epidermis in the upper part. In the lower infundibulum, the differentiation pattern changes from epidermal to trichilemmal with reduced barrier function in the region of the outer root sheath [48]. Especially in this region, a close network of capillaries and dendritic cells surrounds the hair follicle. It can be suggested that substances or xenobiotics that are able to pass the follicular barrier in this region can be immediately recognized by the immune system and evacuated by the blood system. In porcine anagen hair follicles, a continuous tight junction barrier was found from the infundibulum down to the upper suprabulbar region. In the infundibulum, the barrier was found in the stratum granulosum. In the isthmus, bulge and suprabulbar region, the tight junction barrier was localized in the outer root sheath. Additional tight junction barriers were observed between Henle’s and Huxley’s layer of the upper suprabulbar region. In the region of the hair bulb, no barrier can be detected [49,50]. The barrier properties of the hair follicle are schematically presented in Figure 3.
Amenorrhoea and reversible infertility due to obstructive hydrocephalus: literature review and case report*
Published in British Journal of Neurosurgery, 2018
Kimberly Hamilton, Bermans Iskandar
Intracranial pathologies that cause endocrine dysfunction consist most commonly of sellar and suprasellar masses, which may result in over- or under-production of hormones. Though uncommon, hydrocephalus has also been documented to cause hormonal abnormalities since the early 1900’s1–3 and manifests predominantly as precocious puberty or primary amenorrhoea (the failure of menarche to occur by age 16 in the presence of normal growth and secondary sexual characteristics).4–8 Less frequently, secondary amenorrhoea (loss of menstrual cycles in a female who has previously experienced menarche in the presence of secondary sexual characteristics)8 may result. The most likely mechanism is compression of the pituitary gland, the infundibulum and/or the hypothalamus by the anterior-inferior border of the third ventricle.
The effect of repeated light-dark shifts on uterine receptivity and early gestation in mice undergoing embryo transfer
Published in Systems Biology in Reproductive Medicine, 2018
Cathy A. Goldstein, Louise M. O’Brien, Ingrid L. Bergin, Thomas L. Saunders
After residing in their assigned light-dark conditions (described below) for 2 weeks, control (normal light-dark condition) and experimental (altered light-dark condition) female mice naturally cycling through estrus were mated in parallel with vasectomized male mice (2 female mice placed with 1 vasectomized male) to produce pseudopregnant females. Vasectomized male mice were maintained on the same light-dark schedule as the female mice they were mated with. Females were checked for copulation plugs on days 1-5 following the introduction of the vasectomized males. Females with copulation plugs received embryo transfer surgery on the day copulation plugs were identified. Embryos were thawed as described [Renard and Babinet 1984], washed through M2 medium, and placed in KSOMaa medium in an incubator until surgical transfer. Female egg recipients were anesthetized with Rompun/Ketamine [Zeller et al. 1998] and Caprofen was used for analgesia. A small incision was made in the skin and body wall and the reproductive tract was exteriorized. The bursa covering the ovary and oviduct was slit and the eggs were placed into the infundibulum of the oviduct in a small volume of sterile media with a transfer pipet and the reproductive tract returned to the peritoneal cavity. The procedure was then repeated on the opposite uterine horn so that 8 embryos were transferred to each uterine horn.
Related Knowledge Centers
- Axon
- Diaphragma Sellae
- Oxytocin
- Third Ventricle
- Vasopressin
- Dura Mater
- Posterior Pituitary
- Hypothalamus
- Magnocellular Neurosecretory Cell
- Neurohypophysial Hormone