Topic 2.2 (male anatomy)

Question 1

describe the location of the testes

Answer 1

descend ouside body into the scrotum

Question 2

describe the tract of sperm in the testes

Answer 2

rete tubule -> effrent ducts -> caput (head) epidiymis -> corpus (body) epididymis ->cauda (tail) epididymis

Question 3

what is the spermatic cord made from

Answer 3

arteries and veins, the testicular artery branches from the abdominal aorta, which is rather straight until it passes the inguinal canal, from there it becomes convoluted.
ductus defrons and surronded by the cremaster muscle

Question 4

describe the pempinform plexus

Answer 4

highly convulated network of artiers and veins that cup the testes (spermatic cord). the unit to form a single vein that connects to the caudal vena cava.

Question 5

describe the scrotum

Answer 5

dual lobbed sac supporting/ protecting testes. made from four layers: Skin tunica dartos, scrotal fascia and parietal vaginal tunic

Question 6

list the four layers of the scrotum

Answer 6

skin, tunica dartos, scrotal fascia and parietal vaginal tunic.

Question 7

what do the testes consist of (four things)

Answer 7

They consist of testicular capsules, parenchyma, mediastinum and rete tubules.

Question 8

descibe the testicular capsule

Answer 8

suborgan that covers the testes (two layers: visceral vaginal tunic and tunica albuginea)

Question 9

describe the parenchyma in the testes

Answer 9

Made from the seminiferous tubules, interstitial cells of Leydig, capillaries, lymphatic vessels, connective tissue. The parenchyma refers to the specific mass of glands, supported by connective tissue networks. Divided into the tubular (seminiferous tubules and all the material inside) and interstitial compartment (made from material outside the seminiferous tubules)

Question 10

describe the tubulus contortus

Answer 10

a portion of the seminiferous tubule where spermatogenesis predominantly takes place. It is composed of a basement membrane and a layer of seminiferous epithelium. And surrounded by contractile peritubular cells.

Question 11

descrbe the excurrent duct

Answer 11

The excurrent duct is made from the efferent duct, epididymal duct, and ductus deferens.

Question 12

describe the epididymak duct

Answer 12

Epididymal duct is 30 - 60 meters and surrounded by smooth muscle which pumps the sperm along the duct. In the tail of the duct the smooth muscle is inactive during sexual excitation.
In the head of the epididymis head the sperm encounters a cytoplasmic droplet (proximal cytoplasmic droplet). The sperm then moves to the middle of the epididymis which it then encounters the translocating cytoplasmic droplet. Then once it reaches the tail it reaches the distal cytoplasmic droplet.

Question 13

Describe the ampullae

Answer 13

The ampullae are enlargement of the ductus deferens that link to the pelvic urethra, the expansion is to accommodate for the mucosa added.

Question 14

Descibe the Vesicular glands

Answer 14

Vesicular glands are paired and sit dorso-cranial to the pelvic urethra.

Question 15

Describe the prostate gland

Answer 15

Prostate gland is close to the junction between the bladder and pelvic urethra. It has two structural forms which depend on the age of the creature. Firstly the corpus prostate which is when it lies outside the urethralis muscle and is visible in a heart (boar) / H (stallion) shape. The other is the disseminate prostate in which granular tissue spreads along the dorsal and lateral walls of the pelvic urethra.

Question 16

describe the bulbourethral gland

Answer 16

The bulbourethral gland is a paired organ on either side of the pelvic urethra near the ischial arch, they are very small and dense.
they fill with blood at time of erection

Question 17

describe the penis

Answer 17

Penis is made from three segments, the base which is attached to the ischial arch, shaft (main portion) and the glans penis, which is the end.

Question 18

describe the Glans penis

Answer 18

Glans penis holds many nerves on the tip and is the homologue of the clitorus fossa.

Question 19

describe the tip of the penis

Answer 19

tip of the peins has a spongy rectile tissue called the corpus cavernosum, this makes up most of the penis interior, ventral of this surrounding the penile urethra is the corpus spongiosum(also spongy erectile tissue)

Question 20

describe the ischiocavernosus muscles

Answer 20

in the root of the penis connecting the penis to the ischial arch, it causes erections.

Question 21

deescribe other muscles associated with the penis

Answer 21

Urethralis (striated surrounding pelvic urethra, it moves the seminal fluid and sperm)
Bulbospongiosus (overlaps the root of the penis and ventral/caudal surfaces, it empties the extrapelvic part of the urethra)
Ischiocavernosus,
Retractor penis.

Question 22

function of the spermatic cord

Answer 22

Provide vascular, lymphatic and neural connection to the body. Provide a heat exchanger and house the cremaster muscle. The pampiniform plexus (vascular bundle that cups the testis) keeps it around 4 -6 degrees for spermatogenesis to occur, this is achieved via a countercurrent exchange

Question 23

function of the scrotum

Answer 23

Scrotal skin is a temperature sensor and cooling system.

Question 24

function of scrotal skin

Answer 24

Lots of sweat glands to maintain temperature, innervated with sympathetic nerves, it connects to the hypothalamus which adjusts secretion. (evaporative cooling aka swamp cooler)

Question 25

function of the tunica dartos

Answer 25

Ability to elevate testes for long periods of time. This smooth muscle lies below the scrotal skin and adjusts contraction to suit the skin temperature. (testes held close to the body during cold temperatures) androgen controls the development of these muscles.

Question 26

function of the testes

Answer 26

The tests are paired primary reproductive organs, they produce spermatozoa and androgen testosterone (as well as inhibin, estrogens, and proteins for spermatozoal function. They produce fluid originating from the seminiferous tubules. This fluid suspends the spermatozoa and facilitates their ejection from the testes. The fluid contains sertoli cells.

Question 27

function of the testicular capsule

Answer 27

This undergoes change in response to hormones and neurons. As well has smooth muscle that pumps rhythmically, thought to help move the sperm.

Question 28

function of the mediastinum

Answer 28

Central connective tissue in the core of the testis, it houses ducts called the rete tubules. Dense connective tissue helps prevent compression or collapse of the rete tubules.

Question 29

function of Interstitial cells of Leydig

Answer 29

Produces testosterone in the parenchyma.

Question 30

function of the rete tubule

Answer 30

channels of which sperm is transported out of the testes

Question 31

function of tubule contortus

Answer 31

portion of the seminiferous tubules where spermatogenesis takes place

Question 32

function of Sertoli cells

Answer 32

Anchored to the basement membrane they surround developing germ cells. Nurture developing sperm, each sertoli cell has a maximum amount of sperm it can nurture.the are susceptible to FSH and testosterone. They can produce Androgen binding protein, testosterone transport protein, sulfates glycoproteins, transferrin.

Question 33

function of peritubular cells

Answer 33

able to contract they surrond the tubule contortus they aid in the secretion of sertoli cells which helps new sperm move to the rete tubules.

Question 34

Cremaster muscle

Answer 34

Supports the testes and follows the length of the spermatic cord. Aid in controlling testicular temperature, by contracting (promote venous return) /relaxing to produce a pump action, increasing blood flow.

Question 35

function of Epididymis

Answer 35

Produces seminal plasma

Question 36

Blood testis barrier function?

Answer 36

Prevent the auto immune system from destroying the developing germ cells. It is made from two layers, a seminiferous tubule and the sertoli cell junctional complex. The junction complex (tight junction) serves as a second barrier against immune cells and immunoglobulins.

Question 37

what are the two segment of the blood testis barrier

Answer 37

seminiferous tubule and the sertoli cell junctional complex.

Question 38

function of the excurrent duct

Answer 38

Allows for final maturation, storage and delivery. Ejactulation is from a combined effort from the epididymis and the ductus deferens. Rete fluid is thinned in the epididymis and thus the head there is less sperm then in the tail, where it is most concentrated.

Question 39

funtionc of seminal plasma

Answer 39

Not crucial for fertility but for delivery in the uterus.

Question 40

function of accessory sex gland

Answer 40

Produces seminal plasma, secreted into the pelvic urethra.

Question 41

function of the vesicular gland

Answer 41

stores and secrete similar fluid into the pelvic urethra

Question 42

function of the bulbourethral glands

Answer 42

Produce viscous secretions that are the gel-like fraction of the ejaculate, it also causes the seminal fluid to coagulate once ejaculated.

Question 43

function of the penis?

Answer 43

copulatory organ which is made from three parts, bas, shaft and glans penis

Question 44

function of the glans penis

Answer 44

filled with nerves and the point of ejaculation

Question 45

what is unique about animal which have retractible penis?

Answer 45

Animals whose testes are located inside the body do not have a scrotum.

Question 46

why might marien animal not need to worry about tempreture regulation of the testes

Answer 46

Some mariene animals have testes inside the body

Question 47

describe the uniques mechanisms of animals with a fibroelatic penis

Answer 47

Species which have a fibroelastic penis have a sigmoid flexure, which is an S shaped configuration along the shaft. This allows it to be retracted into the body until erect. It is maintained by the retractor penis muscles which are attached dorsally to the coccygeal vertebrae and attached ventrally to the ventrolateral side of the penis. Contracted = inside. Relaxed = outside

Question 48

how dose scrotum tempreture effect industry

Answer 48

Scrotum temperature affects the sperm's motility, affecting reproductive rates. this can be used to manipulat animals fertiliy, especially artifical insemination.

Question 49

what is the pampiniform plexus

Answer 49

serves as a pulse pressure eliminator, the pressure is eliminated between the inguinal ring and the surface of the testis so the blood entering has little to no pressure.

Question 50

leydigs have receptors for what hormone

Answer 50

LH, this stimulates testosterone production