MHS 3102: Chapter 25 - Reproduction
Terms in this set (65)
includes the anatomical and genetic (XY vs. XX) differences between males and efmales
What are the primary sex organs (
What do gonads do?
produce sex cells called
(ova and sperm)
secrete sex steroid hormones
What are accessory reproductive organs?
includes ducts, secretory glands, and external genitalia
What are the primary sex hormones? What do they play roles in?
in males and
estrogens and progesterone
sex hormones play roles in:
-the development and function of reproductive organs
-sexual behavior and drives
-the growth and maturation of many other non-reproductive system organs and tissues
What do the testes do? Where do they lie?
the testes produce
and lie within the scrotum
What is the system of ducts thru which the sperm are delivered to the exterior of the body?
epididymis, ductus deferences, ejaculatory duct, and urethra
How are sperm carried out of the body?
during ejaculation suspended in
What are the male accessory sex gland?
seminal vesicles, prostate gland, bulbourethral glands
they empty their secretions into the ducts during ejaculation
sack of skin that suspends the testes and epididymus outside of abdominopelvic cavity
What temperature are the testes kept at? Why is this important?
external positioning of scrotum keeps testes approximately 3 degrees celsius lower than core body temperature
required for efficient sperm production
What two sets of muscles are controlled by thermoreceptors in scrotum?
- smooth muscle underlying scrotal skin => allows testes to descend further away from body
- skeletal muscle that encloses testes
-contraction => lifts them toward body
What do the
contain that is the site of sperm production?
Where do the sperm leave the testes?
which carries sperm out o ftestes
What does the
Penis = male copulatory organ
Consists of a
and a free
that ends in the
internal penis: the
and three cylindrical bodies
during sexual arousal, a
PNS reflex promotes release of
) into erectile tissue arterial vascular
What is erection initiated by?
initiated by sexual stimuli, erotic sights, sounds, and smells
erection can be induced or inhibited solely by emotional or higher mental activity
inability to attain or sustain a rigid erection
epididymis contracts, expelling sperm into vas defers
-sperm mix w/ seminal vesicles
-provides a transport medium and nutrients (
), protects and activates sperm, and facilitates their movement
of semen neutralizes the acid environment
What is a
cutting and ligating the vas deferens
What forms semen?
sperm mixing with accessory gland secretion
seminal vesicles: secrete alkaline fluid that is ~60% of sperm voluem
prostate gland: secretes milky fluid containing citrate, enzymes, and
prostate-specific antigen (PSA)
-plays a role in activating sperm
What volume of semen is ejected? How much sperm is this?
2-5 mL of semen =
52-100 million sperm/ml
Erection is ______ nervous system & ejaculation is ________
erection = parasympathetic
ejaculation = sympathetic
the generation of the pool of immature reproductive cells (gametocytes) from primordial germ cells (PGCs)
-males begins week 7 of gestation and continues to puberty
-efmales begins week 8 and finishes at week 20-22
the sequence of events which produce mature sperm in seminiferous tubules of testes
takes ~24 days
each cell has two sets of chromosomes (one maternal, one paternal) and is
(2n chromosomal number)
-humans have 23 pairs of chromosomes
gametes have 23 chromosomes and are
-formed by meiosis
maturation of round spermatids to form sperm
spermatids lose excess cytoplasm and form a tail, becoming sperm
sperm = only self-propelling cell in human
What are the three major regions of pserm?
- contains nucleus and has helmet-like
cap containing hydrolytic enzymes that allow sperm to penetrate the egg
- contains many mitochondria spiraled around the tail microtubule filaments
- a typical microtubule flagellum extending from centriole
What hormones are involved in regulation of testicular function?
: stimulates pituitary gland to secrete:
: follicle stimulating hormone
: luteinizing hormone
: exerts negative feedback control on hypothalamus and pituitary
What does LH do?
stimulates production and release of testosterone
What does FSH do?
stimulates production and release of
androgen-binding protein (ABP)
=> necessary to stimulate spermiogenesis
is a positive regulator of FSH release
on hypothalamus and pituitary result from?
rising levels of
inhibit from Sertoli cells
synthesized from cholesterol in Leydig cells
it must be transformed to exert its effects on
to have effects in some neurons
deficiency of testosterone causes sex organs to atrophy
declines w/ age but is still present
What changes are caused by up regulation of testosterone?
appearance of pubic, axillary, and facial hair
enhanced growth of chest and keeping of voice
skin thickens and becomes oily
bones grow and increase in density
skeletal muscles increase in size and mass
is basis of
What can result from declining number of Leydig cells in males w/ age?
decreased sex drive
prostate gland enlargement
loss in skeletal muscle mass
What are the primary female reproductive organs?
-source of female gametes (
-make and secrete female sex hormones (
estrogen and progesterone
What are the accessory organs in females?
uterine (fallopian) tubes, uterus, vagina, breast
Why is the breast not a true reproductive organ?
bc its not required for reproduction to occur
paired organs on each side of uterus help in place by several ligaments
What is embedded in ovary cortex?
What is found within ovarian follicles? What cells are associated with it?
= immature egg
cells associated w/ each oocyte:
- proliferate during
- make estrogen and progesterone
What is the site of fertilization?
- also called Fallopian tubes
uterine tubes receive the ovulated oocyte and is site of fertilization
How is the oocyte propelled to uterus?
peristalsis of muscular and ciliary action
What does the uterus consist of?
- major portion
- narrow neck which projects into vagina
- communicates with vagina and uterine body
What do cervical glands secrete?
secrete thick mucus that covers the external os and blocks sperm entry (except during ovulation = middle of menstrual cycle)
What are the three layers of the uterine wall?
- outermost layer
- 3 interlacing layers of smooth muscle
- mucosal lining
mucosal lining of uterine cavity
-has numerous uterine glands that change in length as the endometrium thickness changes
: undergoes cyclic changes in response to hormones and is shed during menstruation
: permanent layer that expands to form new functionalis after menstruation
provides passage for birth, menstrual flow, and is organ of copulation
pH of 3.8-4.5 due to metabolism of vaginal flora
What female structure is analogous to male scrotum?
- elongated, hair-covered, fatty skin folds
- lie within majora
What female structure is analogous to male bulbourethral glands?
greater vestibular glands
- pea-size glands flanking vagina opening
What female structure is analogous to male prostate glands?
What female structure is analogous to corpus cavernous?
What produces milk during lactation?
- milk glands pass milk to
which open externally at nipple
pigmented skin surrounding nipple
attach breast to underlying muscle fascia
Primary oocytes begin meiosis but arrest in ___________
How long does it take to complete oogenesis?
~300 days - usually only one oocyte per ovarian cycle survives (others undergo apoptosis)
If penetrated by sperm (
), the secondary oocyte completes meiosis II, yielding:
-one large ovum (functional gamete)
-a tiny second polar body that degenerates
How does a female reach reproductive maturity in terms of hormones?
during childhood, ovaries grow and secrete small amounts of estrogens that inhibit release of GnRH
as puberty nears, hypothalamus becomes less sensitive to estrogen and GnRH is released; FSH and LH are released by pituitary, which act on. the ovaries
these events continue until an adult cyclic pattern of FSH and LH is achieved and menarche (first menstrual cycle) occurs
The menstrual (uterine) and ovarian (oocyte) cycle proceed _____________ and have an average duration of _____
What are the two phases of ovarian cycle phases?
- period of ovarian follicular growth (1-14 days)
- period of corpus luteum activity (14-28 days)
Unlike the situation in males, where the role of GnRH/FSH/LH and their negative feedback control is to maintain the testosterone level constant and promote continuous spermatogenesis, the cyclic nature of the female menstrual and ovarian cycles require _________
require dynamic changes in hormone levels throughout the cycles
What hormonal events occur during
ovarian cycle - follicular phase
day 1-14: GnRH stimulates release of FSH / LH
FSH/LH stimulate follicle growth/maturation
-LH stimulates thecae cells to make androstenedione
-FSH stimulates mitosis of follicular cells
Rising estrogen levels and inhibin decrease the release of FSH and LH
Estrogen levels increase and shift positive feedback effect on the pituitary, causing LH surge
What hormonal events occur during
follicular cycle - follicular phase
Day 14: LH surge triggers a decrease in estrogen production and remodels the mature follicle which leads to its rupture
-OH transforms the remains of ruptured follicle into a
=> shuts off FSH and LH release
Days 26-28: if there is no fertilization and embryo implantation, corpus luteum stops producing ormones which ends blockade of FSH and LH
-corpus luteum degenerates into
a new ovarian cycle starts