Male Hormones HW Questions Flashcards
Where are leydig cells located?
soft tissue between the seminiferous tubules
Which hormone stimulates leydig cells to produce testosterone?
LH
The hypothalamus secretes ________ which stimulates the anterior pituitary to secrete ________ and _________
GnRH, FSH, LH
What is the name for a group of hormones that have masculinizing effects?
androgens
Which androgens are produced by the testes?
testosterone, dihydrotestosterone, and androstenedione
Which enzyme is needed to convert testosterone into estrogen?
aromatase
Most testosterone is transported in the blood bound to this protein
sex hormone binding globulin (SHBG)
What hormone stimulates fetal testes to produce testosterone?
human chorionic gonadotropin
When does a male infant stop producing testosterone?
10 weeks old
What is cryptorchidism?
undescended fetal testicles
What is the primary effect testosterone has on target cells?
protein synthesis
Are increased RBC production and increased muscle mass a direct or indirect effect of testosterone?
direct
Which derivative of testosterone is directly responsible for primary and secondary male sex charcateristics?
dihydrotestosterone
How does testosterone effect bone matrix?
increases quality and retains calcium
What effect does testosterone have on the development of the male pelvis?
narrowing and lengthening of the pelvic inlet
Which hormone is directly responsible for closure of epiphyseal plates in males?
estrogen
Where are sertoli cells located?
seminiferous tubules
What enzyme produced by sertoli cells converted testosterone into estrogen?
aromatase
Which testicular cell produces androgen binding protein?
sertoli
What is the function of androgen binding protein?
sequester testosterone into the seminiferous tubules
Which hormone produced by sertoli cells inhibits fetal development of the female reproductive tract?
antimullerian hormone
Which hormone produced by sertoli cells has the ability to inhibit the anterior pituitary from secreting follicle stimulating hormone?
inhibin
What is spermatogenesis?
production of sperm
Where does spermatogenesis occur?
seminiferous tubules
What hormones are required to initiate spermatogenesis?
FSH and testosterone
What type of mitotic division begins the first stage of spermatogenesis?
mitosis
What is the significance of one diploid daughter cell remaining at the basement membrane of the seminiferous tubule after mitosis?
permits spermatogonium to grow and divide again
What are the end products of spermatogenesis?
4 unique haploid spermatids
What is spermiogenesis?
end stage of spermatogenesis that converts spermatids into sperm
Where are newly formed sperm released in the seminiferous tubules?
into the lumen
What specific hormone is required for spermiogenesis?
estrogen
High levels of this hormone are found in seminiferous tubular fluid
estrogen
What are the 3 main parts of a mature sperm?
head, mid-piece, flagellum
Where is the acrosome cap located and what does it contain?
head of sperm, proteolytic acid
What is the function of the acrosome cap?
dissolve the zona pellucida
What type of pH environment is hostile to sperm?
acidic
Why are testicles located outside of the body cavity?
requires temp 2 degrees C cooler than body core to produce sperm
Where do sperm mature?
epididymis
Where is sperm stored?
tail end of epididymis and vas deferens
What percentage of semen is sperm?
10%
Which product of semen contains buffers that alter the pH of the female reproductive tract?
prostatic fluid
Which product of semen contains fructose for energy?
seminal fluid
What is the purpose of prostaglandins in seminal fluid?
reverse uterine peristalsis
Which product of semen causes sperm to stick to the vagina wall immediately after ejaculation?
prostatic fluid
Which division of the ANS facilitates an erection?
parasympathetic
Which neurotransmitter is secreted by pudendal nerves to facilitate an erection?
NO
Which type of receptor does NE secrete from T12-L2 nerve roots bind to initiate semen emission?
alpha 1
What process washes cholesterol away from sperm?
capacitation
What process makes sperm membranes more permeable to calcium ions?
capacitation
A sudden increase of this intracellular ion stimulates powerful whiplash motion of flagellum
calcium
Which ion assists the acrosome in releasing enzymes to penetrate the zona pellucida?
calcium
