Chromosomes are composed up of what ?
DNA and Proteins
Humans have how many chromosomes in normal somatic cells?
46 chromosomes and 23 pairs of chromosomes
Of the 23 pairs of chromosomes, 22 of the pairs are called what?
Autosomes
The 23rd pair of chromosomes are called
Sex chromosomes
What are the two types of sex chromosomes ?
X and Y
Males have __
Females have ___
( X , Y)
Males have one X and one Y chromosome
Females have two X chromosomes
Each human begins life with ___________ reproductive ducts.
Begins life with both male and female reproductive ducts
The male reproduction tract is called
Wolffian system
The female reproductive tract is called
The Mullerian System
When does sexual differentiation begin ?
At 12 weeks of gestation
If the Y chromosome is present
- (____ gene) is expressed and that causes the ___ to ___
TDF
Causes the male gonads to develop
IF the Y chromosome is present
- Cells of the tests secrete ____ causing the _____ to develop
Testosterone
Wolffian duct system to develop
IF the Y chromosome is present
- cells of the testes secrete ____ causing the ____ to degenerate .
Mullerian inhibiting hormone
That causes the Müllerian duct system to degenerate
IF the Y chromosome is present
- Some of the testosterone is converted to _______ causing ___ to develop .
Dihydroxytestosterone causing the external male genitalia to develop
IF the Y chromosome is absent
- The testes will not develop so the ______ will degenerate
Wolfgang duct system will degenerate
IF the Y chromosome is absent
- In the absence of ____ the _____ develops
MIH- Müllerian inhibiting Hormone
The Müllerian duct system will develop
IF the Y chromosome is absent
- in the absences of ______ the _______develops
( gonads )
Dihydroxytestosterone the female external genitalia develops
Where is the sight of spermatogenesis ( sperm production)
Testes - which hold the seminiferous tubules which is the actual place of spermatogenesis
Each testes are subdivided into ___ which house ___ ___.
Lobules
Seminiferous tubules
Each tubule is surrounded by a capsule that contains _____ that are responsible for secretion of ____ .
Interstitial cells - secretion of androgens
The wall of the tubule contains several types of cells: name the 5.
- Spermatogonia
- Spermatocytes
- Spermatids
- Spermatozoa
- Sustentacular cells
Sustentacular cells have 6 functions that are important for sperm development
- Maintenance of the blood - testes barrier
- Support of mitosis and meiosis
- Support of spermiogenesis
- Secretion of inhibin
- Secretion of androgen- binding proteins
- Secretion of MIH
At the outer layer of the tubule wall are the stem cells for ____, ___.
Spermatozoa , spermatogrium
A spermatogorium is a diploid cell that will divide to give rise to ___
Diploid primary spermatocytes
The primary spermatocyte enter meiosis to produce _____.
Haploid gametes ( spermatozoa)
During Meiosis 1 , the_______ divides to produce two ______.
Primary spermatocyte
Haploid spermatids
One primary spermatocyte gives to four ____.
Spermatids
Each spermatids will go through a maturation process Called____ to produce functional gametes
Spermiogenesis
During spermiogenesis, the spermatid losses much of the ____ and develops a ___.
Cytoplasm and develops a flagellum
The structure of a spermatozoa ( 4)
- Head
- Neck
- Mid piece
- Tail
A spermatozoa’s head is
- Tightly pack haploid nucleus
- at the apex of the head is a vesicles filled with digestive enzymes
- this vesicles is called - Acrosomal cap
A spermatozoa’s neck
- connect the head to the mid piece
A spermatozoa’s mid piece
Contains many mitochondria
The Spermatozoa’s tail
Is called the flagellum
_______ leaving the testes are not capable of fertilization.
Spermatozoa
Why are spermatozoa’s not capable of fertilization ?
Other regions of the male reproductive tract are responsible for the functional maturation, nourishment and transport of spermatozoa
Functions of the Epididymis
- Monitor and adjust composition of tubular fluid
- recycling center for damaged spermatozoa
- stores spermatozoa and facilitates maturation: capacitation
The passageway for spermatozoa from epididymis to ejaculatory duct
Ductus deferens
Ejaculatory Duct
- Is continuous with the ductus deferens
- is a passage way from ductus deferens to the urethra
- site of seminal vesicles secretion
Urethra
- common passage way for the urinary system and reproductive system
- spermatozoa are transported from the ejaculatory duct to the outside of the body
Name the three accessory glands of the male reproductive system
- Seminal vesicles
- Prostate gland
- Bulbourethral gland
Seminal vesicles is ___, and the secrete 3 things.
A paired organ Secretes 1. Fructose 2. Prostaglandins 3. Fibrinogen
What determines the sex of a human ?
The presence or absence of the Y chromosome