Packet 31 Flashcards Preview

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Flashcards in Packet 31 Deck (37):
1

Gonads, ducts, sex glands & supporting structures
Semen contains sperm plus glandular secretions

Male reproductive system

2

Sac of loose skin, fascia & smooth muscle divided into two pouches by septum

Skin contains dartos muscle causes wrinkling

Temperature regulation of testes
--sperm survival requires 3 degrees lower temperature than core body temperature
--cremaster muscle in spermatic cord

scrotum

3

elevates testes on exposure to cold & during arousal (‘shrinkage muscle’)
warmth reverses the process

cremaster muscle in spermatic cord

4

Paired oval glands measuring 2 in. by 1in.
Surrounded by dense white capsule

testes

5

the testes are surrounded by dense white capsule called __
--septa form 200 - 300 compartments called lobules

tunica albuginea

6

lobules in testes are filled with 2 or 3 seminiferous tubules where __ are formed

sperm

7

Descent of testes

Develop near kidney on posterior abdominal wall

Descends into scrotum by passing through inguinal canal
--during 7th month of fetal development
--Guevedoches in D.R.

8

Testes do not descend into the scrotum
--3% of full-term & 30% of premature infants
--Descend spontaneously 80% of time during the first year of life
surgical treatment necessary before 18 months

Cryptorchidism

9

Untreated bilateral cryptorchidism results in

sterility & a greater risk of testicular cancer

10

all stages of sperm development: spermatogonia, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoa
supporting cells called sertoli cells
Leydig cells

seminiferous tubules

11

__ in between tubules secrete testosterone

leydig cells

12

extend from basement membrane to lumen
--form blood-testis barrier
-support developing sperm cells
-produce fluid & control release of sperm into lumen
-secrete inhibin which slows sperm production by inhibiting FSH

sertoli cells

13

Testosterone & DHT bind to receptors in cell nucleus & change genetic activity
Prenatal effect is born a male
At puberty, final development of 2nd sex characteristics and adult reproductive system
sexual behavior & libido
male metabolism (bone & muscle mass heavier)
deepening of the voice

hormonal effects of testosterone

14

**On Test**
how does testosterone effect development

testosterone organizes reproductive system before birth and at puberty testosterone activates development of sexual behavior, male metabolism, voice deepening.

15

Secondary spermatocytes are formed

4 spermatids are formed

spermatogenesis

16

23 chromosomes of which each is 2 chromatids joined by centromere

Secondary spermatocytes

17

each is haploid & unique
all 4 remain in contact with cytoplasmic bridge
accounts for synchronized release of sperm that are 50% X chromosome & 50% Y chromosome

4 spermatids

18

maturation of spermatids into sperm cells

Spermiogenesis

19

release of a sperm cell from a sertoli (sustentacular) cell

Spermiation

20

Hormonal control of spermatogenesis

Puberty
LH
FSH

21

hypothalamus increases its stimulation of anterior pituitary with releasing hormones
anterior pituitary increases secretion LH & FSH

puberty

22

stimulates Leydig cells to secrete testosterone

LH

23

stimulates Leydig cells to secrete testosterone
an enzyme in prostate & seminal vesicles converts testosterone into dihydrotestosterone (DHT-more potent)

LH

24

stimulates spermatogenesis
--with testosterone, stimulates sertoli cells to secrete androgen-binding protein (keeps hormones levels high)
testosterone stimulates final steps spermatogenesis

FSH

25

Male sterilization
Vas deferens cut & tied off
Sperm production continues
Sperm degenerate
100% effective
40% reversible

vasectomy

26

Formed from duct of seminal vesicle & ampulla of vas deferens
About 1 inch long
Adds fluid to prostatic urethra just before ejaculation

ejaculatory ducts

27

Ejaculatory ducts are made of

ampulla of ductus defrens and seminal vesicle

28

Passageway for urine & semen
Prostatic urethra (1 inch long)
Membranous urethra (passes through UG diaphragm )
Penile (spongy) urethra (through corpus spongiosum)

urethra

29

Pair of pouchlike organs found posterior to the base of bladder
Alkaline, viscous fluid (seminal fluid)

seminal vesicles

30

functions of seminal vesicles and their alkaline, viscous fluid

neutralizes vaginal acid & male urethra

fructose for ATP production

prostaglandins stimulate sperm motility & viability

clotting proteins for coagulation of semen

31

Single organ the size of chestnut found inferior to bladder
Many duct openings
Enlarges with age
secretes milky fluid

prostate gland

32

function of prostate gland

increases sperm motility and viability
-citric acid for ATP production & enzymes for seminal liquefaction

33

Paired, pea-sized gland within the UG diaphragm

Bulbourethral or Cowper’s Gland

34

function of Bulbourethral or Cowper’s Gland

Secretes alkaline mucous into spongy urethra
-Neutralizes acids and lubricates

35

Mixture of sperm & seminal fluid

semen

36

semen contains

nutrients, clotting proteins & antibiotic seminalplasmin

37

Typical ejaculate is 2.5 to 5 ml in volume
Normal sperm count is 50 to 150 million/ml
actions of many are needed for one to enter
Coagulates within 5 minutes -- reliquefies in 15 due to enzymes produced by the prostate gland
Semen analysis----bad news if show lack of forward motility, low count or abnormal shapes

semen