Search results
Results From The WOW.Com Content Network
Vagusstoff (literally translated from German as "Vagus Substance") refers to the substance released by stimulation of the vagus nerve which causes a reduction in the heart rate. Discovered in 1921 by physiologist Otto Loewi , vagusstoff was the first confirmation of chemical synaptic transmission and the first neurotransmitter ever discovered.
Progesterone, secreted by the corpus luteum, inhibits the follicular growth and maintains the pregnancy. The endocrine system coincides with the menstrual cycle and goes through thirteen cycles (and thus thirteen LH spikes) during the course of normal folliculogenesis.
In a reference group representing all women, the 95% prediction interval of the LMP-to-ovulation is 8.2 to 20.5 days. [ 31 ] The average time to birth has been estimated to be 268 days (38 weeks and two days) from ovulation , with a standard deviation of 10 days or coefficient of variation of 3.7%.
In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth —height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed.
The female reproductive system likewise contains two main divisions: the external genitalia (the vulva) and the internal genitalia. The ovum meets with the sperm cell : a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome.
The trophoblasts secrete fluid into the blastocoel. The resulting increase in size of the blastocyst causes it to hatch through the zona pellucida, which then disintegrates. [5] This process is called zona hatching and it takes place on the sixth day of embryo development, immediately before the implantation process. The hatching of the human ...
From the eighteenth week of pregnancy (the second and third trimesters), a woman's body produces hormones that stimulate the growth of the milk duct system in the breasts: Progesterone influences the growth in size of alveoli and lobes; high levels of progesterone inhibit lactation before birth. Progesterone levels drop after birth; this ...
Human chorionic gonadotropin is a glycoprotein composed of 237 amino acids with a molecular mass of 36.7 kDa, approximately 14.5kDa αhCG and 22.2kDa βhCG. [4]It is heterodimeric, with an α (alpha) subunit identical to that of luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), and a β (beta) subunit that is unique to hCG.