Fifth Through Eighth Weeks of Stages Fetal Development /Weeks five through eight of gestation are characterized by the development of the major organ systems, including the circulatory, nervous, lymphatic, and gastrointestinal systems. During this time, the embryo is extremely susceptible Read More …
Category: Anatomy A – Z
Fourth Week of Development of Embryo
Fourth Week of Development of Embryo (the embryonic disc) will grow from about 2 to about 6 mm. The processes of the third week (neural tube formation, development of blood circulation) continue in the fourth week. At the same time, Read More …
Third Week of Development – Anatomy, Types, Functions
Third Week of Development/The third week is concerned with establishing left and right handedness, the craniocaudal axis, as well as the conversion of the bilaminar disc into a trilaminar embryo. Additionally, there is further specialization of the extraembryonic structures that Read More …
Trophoblast Development – Anatomy, Mechanism
Trophoblast Development/Week 2 is often referred to as the week of twos. It’s the week when the embryoblast, extraembryonic mesoderm and trophoblast each separate into two distinct . Trophoblast Development Trophoblasts are the outer layer of cells that provide nutrients to the embryo and form part Read More …
Female Reproductive System
Oogenesis is the maturation of the female gametes through meiotic division. Key Points Oogenesis starts with the process of developing oogonia via the transformation of primordial follicles into primary oocytes, a process called oocytogenesis. Oocytogenesis is complete either before or Read More …
Female Reproductive System – Anatomy, Organ, Functions
The female reproductive system is made up of the internal and external sex organs that function in the reproduction of new offspring. In humans, the female reproductive system is immature at birth and develops to maturity at puberty to be able to produce gametes and to carry a fetus to full term. Read More …
Male Sexual Response Cycle – Anatomy, Structure, Functions
The Male sexual response cycle is a four-stage model of physiological responses to sexual stimulation, which, in order of their occurrence, are the excitement, plateau, orgasmic, and resolution phases. This physiological response model was first formulated by William H. Masters and Virginia E. Johnson, in their 1966 book Human Sexual Read More …
Male Reproductive System – Anatomy, Mechanism, Functions
The male reproductive system consists of the internal structures: the testes, epididymis, vas deferens, prostate, and the external structures: the scrotum and penis. These structures are well-vascularized with many glands and ducts to promote the formation, storage, and ejaculation of sperm Read More …
Meiosis – Anatomy, Structure, Functions
Meiosis is a special type of cell division of germ cells in sexually reproducing organisms used to produce the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome (haploid). Additionally, prior to the Read More …
Reproductive System – Anatomy, Structure, Functions
The reproductive system in females is responsible for producing gametes (called eggs or ova), certain sex hormones, and maintaining fertilized eggs as they develop into mature fetuses and become ready for delivery. A female’s reproductive years are between menarche (the Read More …
Acid-Base Balance – Anatomy, Mechanism, Functions
Acid-base balance is the homeostatic regulation of the pH of the body’s extracellular fluid (ECF).[1] The proper balance between the acids and bases (i.e. the pH) in the ECF is crucial for the normal physiology of the body—and for cellular metabolism.[1] The pH of the intracellular fluid and the extracellular fluid need to be maintained at a constant level. The Read More …
Body Fluids – Physiology, Mechanism, Functions
Body fluids, bodily fluids, or biofluids are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52-55%).[rx][rx] The exact percentage of fluid relative to body weight is inversely proportional Read More …