4.1 testis and scrotum (workbook)

Question 1

what does the male reproductive system consist of?

Answer 1

paired testes
duct system
accessory sex glands
penis

Question 2

what is the function of the paired testes?

Answer 2

produce spermatozoa (sperms)

Question 3

what do the paired testes contain?

Answer 3

cells that produce the sex hormones

Leydig + Sertoli cells - mainly Leydig

Question 4

what is the function of the duct system within the male repro system?

Answer 4

transport spermatozoa to urethra

Question 5

what is the function of the accessory sex glands within the reproductive system?

Answer 5

supply the fluid components to the semen

Question 6

what is the human testis?

Answer 6

a compound tubular gland

Question 7

what encloses the human testis?

Answer 7

a thick fibrous capsule - tunica albuginea

Question 8

posteriorly, what does the tunica albuginea form? function?

Answer 8

forms the mediastinum testis that contains many interconnected channels which provide passageways for the sperms to enter the duct system

Question 9

deep to the tunica albuginea, what is found?

Answer 9

strong CT septa extend into the testis, dividing it into about 250 pyramid-shaped lobules

Question 10

what does each lobule within the testis contain? function?

Answer 10

between 1-4 highly convoluted seminiferous tubules, in which spermatozoa are produced

Question 11

what are the testes contained within?

Answer 11

the scrotal sac

Question 12

what does the scrotum consist of?

Answer 12

a layer of skin and superficial fascia

Question 13

what does the superficial fascia of the scrotum contain?

Answer 13

the dartos muscle

Question 14

underneath the thick tunica albuginea, what is evident?

Answer 14

seminiferous tubules

Question 15

what is each seminiferous tubule surrounded by?

Answer 15

a layer of connective tissue with flattened myofibroblasts and an inner basement membrane

Question 16

what are the seminiferous tubules lined by?

Answer 16

a complex stratified epithelium: seminiferous epithelium

Question 17

what does the seminiferous epithelium lining seminiferous tubules contain?

Answer 17

2 types of cells:
Sertoli cells (supporting cells)
spermatogenic cells (germ cells)

Question 18

where are Sertoli cells found?

Answer 18

fixed to the basement of the seminiferous tubules (within the stratified epithelium)

Question 19

how are numbers of Sertoli cells different from spermatogenic cells?

Answer 19

Sertoli cells are far less numerous than spermatogenic cells

Question 20

what do the cytoplasm of each Sertoli cells form?

Answer 20

an elaborate system of processes that extend upward to the luminal surface, surround the spermatogenic cells and fill all the spaces between them

Question 21

what does the apical region of each Sertoli cell contain?

Answer 21

complicated recesses into which the heads of sperms appear to be embedded

Question 22

how are spermatogenic cells arranged?

Answer 22

in rows between and around the Sertoli cells

Question 23

what are the most primitive spermatogenic cells?

Answer 23

the spermatogonia

Question 24

where are the spermatogonia found?

Answer 24

rests on the basement membrane of seminiferous epithelium

later stages located successively higher levels in epithelium

Question 25

where do primary spermatocytes lie?

Answer 25

adjacent to spermatogonia, but nearer the lumen

Question 26

what do the primary spermatocytes have nuclei like?

Answer 26

the nuclei have variable appearances that represent the stages of the first meiotic division

Question 27

where are secondary spermatocytes seen?

Answer 27

rarely seen in the seminiferous epithelium, because of their short 1/2 life

Question 28

what do secondary spermatocytes form?

Answer 28

divide rapidly (secondary meiotic division - post fertilisation) to form spermatids

Question 29

how do spermatids appear?

Answer 29

lightly stained round nucleus, located nearer the lumen of the seminiferous tubule

Question 30

what do spermatids mature into?

Answer 30

spermatozoa

Question 31

how do spermatozoa appear?

Answer 31

deeply staining heads of which appear to be embedded in cytoplasm of the Sertoli cells and their tails hang into the lumen of the seminiferous tubule

Question 32

describe the development stages of spermatogenic cells (germ cells)

Answer 32

``` spermatogenic cells (germ): spermatogonia (primitive) --> primary spermatocytes --> secondary spermatocytes -- (secondary meiotic division) --> spermatids -- (mature) --> spermatozoa ```

Question 33

what is spermatogenesis?

Answer 33

the process by which spermatogenic cells (germ) undergo cell proliferation and maturation and are transformed over a period of time into spermatozoa

Question 34

between the seminiferous tubules, what is there?

Answer 34

loose CT containing interstitial (Leydig) cells

Question 35

where are Leydig cells seen?

Answer 35

in isolated clusters / in rolls along small blood vessels | Sertoli in BM of seminiferous tubules

Question 36

how do Leydig cells appear?

Answer 36

have large spherical nuclei with eosinophilic sections (stains red)

Question 37

what do the nuclei of Leydig cells contain?

Answer 37

small amounts of PERIPHERALLY located chromatin and 1 / 2 prominent NUCLEOLI

Question 38

where does spermatogenesis occur?

Answer 38

in seminiferous tubules | between and around Sertoli cells

Question 39

where does steroidogenesis occur?

Answer 39

in Leydig cells

Question 40

how is spermatogenesis and steroidogenesis linked?

Answer 40

occur in separate histological compartments within testis, but compartments are functionally and physiologically interaction (Leydig cells produce testosterone, which diffuses into seminiferous tubules, for Sertoli cells to produce enzymes?)