reproductive system Flashcards
1
Q
what is the primary role of the reproductive system?
A
produce offspring
2
Q
what is the reproductive system made up of?
A
primary sex organs plus accessory reproductive organs (ducts, glands and external genitalia
3
Q
what are the roles of the male reproductive system?
A
- manufacture sperm
- deliver sperm to the female reproductive system
4
Q
what is the penis designed to do?
A
deliver sperm to the female reproductive tract
5
Q
what are the 3 cylindrical columns of erectile tissue in the penis?
A
- dorsal: 2x corpus cavernosa
- ventral: 1x corpus spongiosum
6
Q
how does an erection occur?
A
- blood vessels dilate
- increased blood flow to penis
- vascular channels become engorged with blood
- erection of penis occurs
7
Q
what is the scrotum?
A
sac of skin housing the testes outside abdominal cavity of the body
8
Q
what is the scrotum essential for?
A
temp regulation of testes
9
Q
what are the two types of muscle that regulate temp in the scrotum?
A
- dartos muscle (smooth muscle)
- cremaster muscle (skeletal)
10
Q
what does the dartos muscle do in the scrotum?
A
contracts to make scrotum wrinkled and thick, decreases heat loss
11
Q
what does the cremaster muscle do in the scrotum?
A
contracts to bring scrotum and testes closer to body
12
Q
what is the lobule in the testes the site of production for?
A
sperm production
13
Q
what is the testes internally divided into?
A
into about 250 lobules
14
Q
what are the functions of the epididymis in the male reproductive system?
A
- stores, nourishes and protects spermatozoa
- facilitates functional maturation
- recycles damaged sperm
- ejaculates sperm
15
Q
what does the epididymus surround?
A
the posterior edge of the testes and is a series of coiled tubes (6m)
16
Q
where are sperm stored?
A
tail of the epididymus
17
Q
where are sperm ejaculated into from the epididymus?
A
ductus deferens
18
Q
what tubes does sperm travel through from the testes to the outside of the body?
A
- epididymus
- ductus/vas deferens
- ejaculatory ducts
- urethra
19
Q
what accessory glands create secretions while sperm is ejaculated?
A
- seminal vesicles
- bulbourethral gland
- prostate
20
Q
what do seminal vesicles do?
A
release a viscous fluid which makes up 60-70% of semen volume and contains substances that enhance sperm mobility/ability to fertilise ovum
21
Q
how much does the prostate gland fluid account for in the semen volume?
A
30%
22
Q
is ejaculation a parasympathetic or sympathetic response?
A
sympathetic
23
Q
what does the bulbospongiosum muscle do?
A
contracts to eject semen at a rate of 500cm/s
24
Q
what is the process of producing sperm called?
A
spermatogenesis
25
where does the production of sperm occur?
seminiferous tubules of the testes
26
how long does each mature sperm take to produce?
about 10 weeks
27
how many pairs of chromosomes do most body cells contain?
23 pairs
28
what are the major structural regions of sperm?
- head
- midpiece
- tail
29
what is the head of the sperm responsible for?
genetic region; nucleus and vesicle containing enzymes that enable the sperm to penetrate an ovum
30
what is the midpiece of the sperm responsible for?
metabolic region; mitochondria, energy production
31
what is the tail of the sperm responsible for?
locomotor region; flagellum creates movement
32
what does semen consist of?
- 5% epidymal secretions
- 60% seminal vesicles
- 30% prostate secretions
- 5% bulbourethral secretions
33
what do the testes make?
sperm and hormones
34
what is the interaction of the production of sperm and hormones in the testes called?
hypothalamic-pituitary-gonadal (HGP) axis
35
in the HGP axis what hormone does the hypothalamus release?
gonadotrophin-releasing hormone (GnRH)
36
what does gonadotrophin-releasing hormone in the HGP axis signal?
release of FSH and LH from anterior pituitary
37
what does FSH stimulate in the male reproductive system (HGP axis)?
intestitial (leydig) cells in the seminiferous tubules to produce sperm
38
how does increased testosterone levels inhibit GnRH and FSH/LH release?
negatively feedback to inhibit
39
what occurs in the male reproductive system if the is an absence of GnRH, LH and FSH?
the testes will atrophy and sperm and testosterone production will cease
40
what are some things testosterone does after puberty?
- stimulates spermatogenesis
- increases size of penis
- enhance ability to maintain erection and ejaculate
41
what are some male secondary sex characteristics that are not directly involved in reproduction?
- enhanced hair growth
- deepened voice
- increased skeletal and muscle mass
- increased metabolism rate
42
what is the main role of the female reproductive system?
- produce and release gametes
- nurture a developing foetus
- give birth
43
what does the external structures of the vulva involve?
- labia majora
- labia minora
- vestibule
- clitoris
44
what is the labia majora?
two fatty skin folds
45
what is the labia minora?
two thin hair free skin folds the enclose the vestibule
46
what is the vestibule in the female reproductive system?
greater vestibular glands release mucus to lubricate intercourse
47
what is the clitoris?
erectile tissue, richly innervated, sexual arousal
48
what structures make up the female duct system?
- vagina
- uterus
- uterine/fallopian tubes
49
is the female duct system continuous?
no
50
is the male reproductive system continuous?
yes
51
what does the vagina provide a passageway for?
- eliminate menstrual fluids
- receive penis during intercourse
- expel foetus during child birth
52
what keeps vagina free from infection and hostile to sperm?
acidic enviro
53
what is the uterus?
hollow, thick muscular organ that receives, retains and nourishes offspring
54
what does the uterus consist of?
- body (major region)
- fundus (top region)
- cervix (joins to the vagina)
55
what do glands in the mucosa of the cervix secrete?
mucous that block the spread of bacteria into the uterus from the vagina, also blocks sperm expect at mid cycle
56
how come sperm is able to enter the uterus mid cycle?
mucous becomes less viscous
57
what are the three layers the uterine wall is composed of?
1. permimetrium
2. myometrium
3. endometrium
58
what is the permimetrium layer of the uterine wall?
outermost layer
59
what is the myometrium layer of the uterine wall?
bulky, middle muscular layer
60
what layer of the uterine wall contracts to expel baby?
myometrium
61
what is the endometrium layer of the uterine wall?
inner, mucosal layer that allows for implantation of fertilised egg
62
what are the two layers of the endometrium layer of the uterine wall?
functional layer (stratum functionalis) and basal layer (stratum basalis)
63
what does the functional layer of the endometrium layer of the uterine wall undergo?
cyclic changes due to ovarian hormones and is shed during menstruation
64
what is the basal layer of the endometrium layer of the uterine wall unresponsive to?
ovarian hormones
65
what regenerates the functional layer of the endometrium layer of the uterine wall after menstruation?
basal layer
66
what do the ovaries do?
- produce gametes (oocytes)
| - secrete female sex hormones(oestrogen and progesterone)
67
what are the female gametes called?
oocytes
68
what does each ovary consist of?
- medulla
| - cortex
69
what is the medulla of the ovary?
inside region which is highly vascularised
70
what is the cortex of the ovary?
outside region where follicles are matured to release oocytes
71
where are oocytes produced?
ovaries
72
what are the oocytes a female has at birth called?
primary oocytes
73
what are the oocytes recruited each month called?
secondary oocytes
74
what are the two phases of the ovarian cycle?
- follicular phase (day 1-14)
| - luteal phase (day 15-28)
75
what occurs in the luteal phase of the ovarian cycle?
periods of corpus luteal activity
76
what occurs in the follicular phase of the ovarian cycle?
follicle growth, ovulation occurs at the end of this stage
77
how long does the luteal phase normally last in the ovarian cycle?
14 days
78
what triggers ovulation?
increasing levels of oestrogen stimulate surge in LH
79
what triggers the release of FSH and LH during the follicluar phase of the ovarian cycle?
GnRH
80
what stimulates follicle maturation in the follicular phase?
FSH
81
what does the LH surge transform ruptured follicles in the luteal stage into?
corpus luteum
82
what does the corpus luteum produce?
oestrogen, progesterone and inhibin
83
what occurs in the luteal phase if fertilisation does not occur?
the corpus luteum degenerates, hormone levels decline and cycle begins again
84
what is the uterine (menstrual) cycle driven by?
oestrogen and progesterone released by the ovaries
85
what are the three phases of the uterine cycle?
- menstrual phase (menses)
- proliferative (pre-ovulatory) phase
- secretory (post-ovulatory) phase
86
what days does the menstrual phase of the uterine cycle occur?
1-5
87
what days does the proliferative phase of the uterine cycle occur?
6-14
88
what days does the secretory phase of the uterine cycle occur?
15-28
89
are progesterone and oestrogen levels high or low during the menstrual phase of the uterine cycle?
low
90
what occurs in the menstrual phase of the uterine cycle?
shedding of the functional layer of the endometrium, painful menstruation, dysmenorrhoea
91
what occurs in the proliferative (pre-ovulatory) phase of the uterine cycle?
- rebuilding of endometrium
- cervical mucous becomes less viscous
- ovulation occurs at the end of this phase
92
what occurs at the end of the proliferative phase of the uterine cycle?
ovulation
93
what stimulates and sustains the proliferative (pre-ovulatory) phase of the uterine cycle?
ovarian oestrogen
94
when does the secretory phase of the uterine cycle occur?
immediately after ovulation
95
what is the proliferative phase stimulated by?
progesterone and oestrogen from the corpus luteum
96
what occurs in the proliferative phase of the uterine cycle?
endometrium prepares for implantation
97
what is amenorrhoea?
cessation of menses
98
what does oestrogen do at puberty?
promote oogenesis and increase growth of vagina, uterus and uterine tubes
99
what do oestrogen and progesterone work together to do?
- regulate uterine cycles and changes in cervical mucus
- oestrogen repairs functional layer
- progesterone promotes blood vessels and gland growth/secretion
- maintain pregnancy and breast growth
100
what are female characteristics not involved in reproduction induced by female hormones?
- growth of hair in pubic and axilliary regions
- growth of breasts
- widening of pelvis
- increased subcutaneous fat (hips and breasts)
101
how are the mammary glands functional in females?
produces milk to nourish newborn
102
what part of the mammary gland produces milk?
lobules
103
how long can the secondary oocyte survive for?
12-24hrs
104
how long can sperm survive in the female reproductive tract?
up to 3 days
105
for fertilisation to occur when must intercourse occur?
on day of ovulation or few days prior
106
what does capacitation do to the sperm?
enhances sperm mobility and prepares sperm for penetration of the oocyte
107
what does capacitation do to the cap of the acrosome?
thins, in the readiness to release enzymes
108
how long does capacitation take to occur?
8-10hrs
109
once sperm reaches the ovum what must they weave through to reach the zona pellucina?
granulose cells of the corona radiata
110
what is the zona pellucida?
thick gylcoprotein coat surrounding oocyte
111
when sperm bind to the zona pellucida what does this cause?
rise in calcium levels resulting in breakdown of acrosomal membranes, that digest holes in layer
112
is a sperm that arrives earlier or later more likely to fertilise ovum?
later
113
when the sperm has digested through the zona pellucida what does it bind to?
special receptors on the oocyte membrane
114
after the sperm binds to the receptors what occurs?
the sperm and oocyte fuse and the sperm's DNA is released into oocyte
115
what does DNA being released into the oocyte stimulate?
cortical reaction, where calcium levels increase causing destruction of sperm receptors and hardening zona pellucida
116
why does the zona pellucida harden after fertilisation?
prevents further entry of sperm
117
where does fertilisation usually occur?
distal end of the uterine tube
