Spermatogenesis steps, hormonal regulation and abnormalities

1. Gono Bishwabidyalay
Nolam, Saver, Dhaka
3rd
semester Final Exam
Assignment on: Physiology & Nutrition-I
(Pharm 2306)
Assignment topic: Spermatogenesis steps,
Hormonal regulation & Abnormalities
Submitted To: Page limit: 02
Dr. Munjiba Shams
Professor
Department of physiology & Nutrition
GSVMC
Submitted By:
Md. Nazmul Islam Tanmoy
Class Roll: 74
Exam Roll: 2064
Batch: 32nd
Department of pharmacy, GB.
Submission date: 26th
June 2021

2. Spermatogenesis
Spermatogenesis is the maturation process from primitive germ-cell to mature
gamete in male.
Stages of spermatogenesis:
Spermatogenesis has three different stages:
a. Spermatocytogenesis: It is the process by which spermatogonia proliferate to
primary spermatocyte.
b. Meiosis cell division phase: In this phase the primary spermatocyte, after
replication their DNA undergoes of their first meiotic or, 1st maturation division and
gives rise to two secondary spermatocytes.
These cells then undergo 2nd maturation or
meiotic division and gives rise to two
spermatids. As a result of the two
maturation divisions spermatid contains 23
chromosomes and n amount of DNA.
c. Spermiogenesis: In this process the
spermatids undergo a series of changes
resulting in the production of the
spermatozoa.
These changes are:
i. Formation of acrosome.
ii. Condensation of nucleus.
iii. Formation of neck, middle piece & tail.
iv. Sheding of most of the cytoplasm.
Hormonal Regulation of Spermatogenesis:
1. Testosterone: Secreted by the Leyding cells located in the interstitium of testis, is
essential for growth and division of germinal cells in forming sperm.
2. Lutenizing hormone (LH): Secrețed by anterior pituitary gland and stimulate the
Leydig cell to secrete testosterone.
3. Follicle stimulating hormone (FSH): Secreted by the anterior pituitary gland,
stimu-late the sertoli cells and without this stimulation the conversion of the
spermatids to sperm (the process of spermiogenesis) will not occur.

3. 4. Growth hormone: Growth hormone specifically promotes the early division of
spermatogonia and also maintain the metabolic function of testis.
5. Estrogen: Formed from testosterone by the Sertoli cells when they are stimulated
by FSH, are probably essential for conversion of the spermatids to sperm (Process of
spermioenesis) and helps in maturation of sperm.
Diagrammatic regulation of spermatogenesis:
Gin RH
+ + +
Abnormalities: Sperm count Abnormalities;
Normal count 120 million / ml [<20 million / ml → sterile]
Aspermia: → Absence of semen
Azoospermia: → absence of sperm
Hypospermia: → low semen volume
Hyperspermia: → high semen volume
Oligozoospermia: → Very low sperm count
Asthenozoospermia: → poor sperm motility
Teratozoospermia: → sperm carry more morphological defects than usual
Necrozoospermia: → all sperm in the ejaculate are dead
Leucospermia: → a high level of white blood cells in semens (> 1 million / cc)
Hypothalamus
Inhibin Androgen
AP
FSH LH
Leyding cell
Sertoli cell
Androgen Binding
Protein (ABP)
Seminiferous
Tubules
Androgen 2ndary sex characters
& metabolic effect
Accessory
reproductive organ
Spermatogenesis