Accessory Glands Seminal Vesicles - PowerPoint Presentation

Slide1

Accessory Glands

Seminal Vesicles

The pair of seminal vesicles are posterior to the urinary bladder.

Contribute about

65-75% of the seminal fluid in

humans

Contain

proteins

, enzymes, fructose, mucus,

vitamin

C,

flavins

,

phosphorylcholine

and

prostaglandins (involved in suppressing an immune response by the female against the foreign semen)

High

fructose

concentrations provide

nutrient energy for the spermatozoa as they travel through

the female

reproductive system.Slide2

Functions of male reproductive organ

To produce, maintain and transport sperm (the male reproductive cells) and protective fluid (semen)

To discharge sperm within the female reproductive tract

To produce and secrete male sex hormonesSlide3

How does the male reproductive system function?

The

entire male reproductive system is dependent on

hormones - chemicals

that stimulate or regulate the activity of cells or

organs

Follicle Stimulating Hormone

(FSH

)- necessary for sperm production.

L

uteinizing

H

ormone

(LH)

– stimulates the production of testosterone.

T

estosterone- also important in the development of male characteristics ( muscle mass and strength, fat distribution, bone mass and sex drive).Slide4

External genital organs

Penis

ScrotumSlide5

External genital organs

PENIS

This is the male organ used in sexual intercourse.

three parts:

-Root- attaches to the wall of the abdomen

-Shaft- the body

-Glans - cone-shaped part at the end of the penis.

Foreskin- loose layer of skin that covers the glans.

This skin is sometimes removed in a process called circumcision. The opening of the urethra, is at the tip of the penis. The body of the penis is cylindrical in shape and consists of three circular shaped chambers. This tissue contains thousands of large spaces that fill with blood when the man is sexually aroused.Semen- the fluid which carries sperm during ejaculation.. Slide6

SCROTUM

This is the loose and pouch-like sac of skin which hangs posterior to the penis. Inside the scrotum are the testicles, also called testes.

-to serve as climate control system for the testes

When extreme cold temperature is detected, the scrotum contract which draws the testes closer to the body.

When a hot temperature is detected in the body, the scrotum relaxes to keep the testes away from the body.Slide7

Internal genital organs

Epididymis

Vas deferens

TestesSlide8

EPIDIDYMIS

This is the long, coiled tube-like structure which is located on the posterior of each testicle.

-to transport and store sperm cells which are produced inside the testes.

-to nurture the sperm until it matures.

During the arousal stage of sexual activity, the contractions of the genitals force the sperm which are contained in the fluid-like semen into the vas deferens. Slide9

VAS DEFERENS

A muscular tube that begins at the lower end of the Epididymis and passes upward along the side of the testis to become part of the spermatic cord. It passes through the inguinal canal, enters the abdominal cavity, and courses over the pelvic brim. From there, it extends back into the pelvic cavity, where it ends behind the urinary bladder. Near its termination, it becomes dilated into a portion called the "

ampulla

." Just outside the prostate gland, the tube becomes slender again and unites with the duct of a seminal vesicle.

Ejaculatory duct, the fusion of prostate gland and the duct of seminal vesicle.Slide10

TESTES

These are the oval-shaped organs found inside the scrotum. They are secured at either end by what is termed as the spermatic cord.

-to produce testosterone.

-to produce sperm cells.

Seminiferous tubules- tubes masses which are coiled together. These tubules function by spermatogenesis. Slide11

SEMINAL VESICLESlide12

Prostate Gland

The prostate gland is a muscular gland that surrounds the first inch of the urethra as it emerges from the bladder.

The smooth

muscle of the prostate gland contracts during ejaculation to contribute to the expulsion of semen from

the urethra.

Stores and secretes a clear, slightly alkaline fluid constituting up to one-third of the volume of semen.Slide13

PROSTATE GLANDSlide14

Bulbourethral

Glands

The

bulbourethral

glands also called Cowper's glands are located below the prostate gland and empty into

the urethra

.

The

alkalinity of seminal fluid helps neutralize the acidic vaginal pHFor secretion of gelatinous seminal fluid that helps lubricate the urethra for spermatozoa to pass through, and to help flush out any residual urine or foreign matter. (< 1% of semen)It is serve to increase the mobility of sperm cells in the vagina and cervix by creating a less viscous channel for the sperm cells to swim through, and preventing their diffusion out of the semen.Slide15
Slide16

Composition of human semen

The components of semen come from two sources: sperm, and "seminal plasma".

Seminal plasma is produced by contributions from the seminal vesicle, prostate, and

bulbourethral

glands.

Basic amines such as

putrescine

,

spermine

, spermidine and cadaverine are responsible for the smell and flavor of semen. These alkaline bases counteract the acidic environment of the vaginal canal, and protect DNA inside the sperm from acidic denaturation.Slide17
Slide18
Slide19

Sperm cell

A spermatozoa are the haploid cell that is the male gamete.

Contribute half of the chromosome number of an individualSlide20

Sperm cell

The sperm is the main reproductive cell in males.

The sperms differ in that each carry a set of chromosomes dividing each into either a male, or female sperm.

The female sperm also differ

phenotypically

in that they have a larger head in comparison to the male sperms. This contributes to the male sperm being lighter, and therefore faster and stronger swimmers than their female counterparts although statistically there is still a 50% chance of an either XY or XX embryo forming.Slide21

Parts of sperm

Tail flagellates - which propels the sperm cell by rotating like a propeller, in a circular motion

Mitochondria in

midpiece

– for ATP generation

Nucleus – carries the genetic material

Acrosome

– releases enzyme to weaken the thick shell formed by

glycoproteins

(zona pellucida)Slide22

Capacitation of sperm

Capacitation

– process in which sperm develop the capability to fertilize

Hypermotility

- change in beat frequency and amplitude of sperm motility

Acrosome

Reaction -

lysosomal enzymes contained within the acrosome are released, causing alteration of the sperm head plasma membrane and weaken the shell, allowing the sperm cell to penetrate it and reach the plasma membrane of the egg.Slide23

Properties of sperm to fertilize the ovum

1. Adequate motility to traverse the female genital tract.

2. Ability to recognize and bind to the ovum and its investments.

3. Ability to penetrate the

zona

pellucida

.

4. Ability to fuse with the plasma membrane of the ovum. Slide24
Slide25

Semen analysis

The most important laboratory test in evaluating the fertility potential in a man is the semen analysis.

]The following are the normal parameters.

Volume 2-5 cc

Sperm density >20 million/cc (avg. 50-60) Motility >60%

Morphology Absence of WBC's, RBC's,

bacteria, agglutination >60% normal forms Slide26

Azoospermia

is the condition in which no sperm are found in the ejaculate.

Cause of

Azoospermia

ductal

obstruction

impaired production of mature sperm

Tests

to know the cause of AzoospermiaThe volume of semen may help identify the level of obstruction, since small volumes, indicate obstruction of the ejaculatory ducts. Testis biopsy will reveal the adequacy of sperm production and the degree of sperm maturation.Slide27

Hormonal Control

Gonadotropin

-Releasing Hormone

Luteinizing Hormone

Follicle Stimulating Hormone

TestosteroneSlide28

Gonadotropin

-Releasing Hormone

Secreted by the hypothalamus to the pituitary

Released in pulses in average of 70-90 minutes and have a half-life of 2-5 minutes

Variation in the pulse frequency regulates the release of FSH and LHSlide29

Luteinizing Hormone (LH)

Secreted by the pituitary gland in response to

GnRH

Stimulates the

Leydig

cells to produce testosteroneSlide30

Follicle Stimulating Hormone (FSH)

Secreted by the pituitary gland

Stimulates the

Sertoli

cells to produce mature sperm with the help of testosterone

Stimulates the protein synthesis in

Sertoli

cells by stimulating

cAMP

and protein kinasesInhibited by inhibin produced by the Sertoli cellsSlide31

Testosterone

Important in sperm production

Male hormone and androgen produced by the

Leydig

cells

Masculinization

of internal and external reproductive tissues

Promotes the growth of the penis and scrotum

Pubertal changes

Enables retraction of foreskin during pubertyBinds with the andogen-binding protein produced by the Sertoli cells Testosterone aromatase Estradiol (E2)Testosterone 5 α reductase Dihydrotestosterone (DHT)Inhibits the production of LH and GnRHSlide32
Slide33
Slide34

Components of Sexual Behavior

- Stimulated by the androgens

Motivation – mainly olfactory inputs; motivation to mate

-Androgen binds to

amygdala

Performance – mainly visual inputs; mating performance

-

Androgen binds to

preoptic

area*Castration reduces motivation and performanceSlide35

ERECTION AND EJACULATION

Male Reproductive SystemSlide36

Penile erection

- a

physiological phenomenon where the

penis

becomes enlarged and

firm

-

complex interaction of psychological,

neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousalSlide37

How an erection

happens

Touch, sights, sounds, erotic

memories and fantasies

cause sexual excitement

.

These stimuli increase signal output from a part of the brain called the

para

-ventricular nucleus

. These signals then pass through special autonomic nerves in the spinal cord, the pelvic nerves and the cavernous nerves that run along the prostate gland to reach the corpora cavernosa and the arteries that supply them with blood.In response to these signals, the muscle fibres in the corpora relax, allowing blood to fill the spaces between them.Muscle fibres in the arteries that supply the penis also relax, and there is an eight-fold increase in blood flow to the penis. The increased blood flow expands the corpora, then stretches the surrounding sheath (the tunica).As the tunica stretches, it blocks off the veins that take blood away from the corpora cavernosa. This traps blood within the penis, the pressure becomes very high and the penis becomes erect.During an erection pressure in the penis is at least twice the pressure of blood in the main circulation. This is possible because the muscles of the pelvic floor contract around the base of the corpora cavernosa. Slide38
Slide39

Cross-section of the penis showing the position of the corpora

cavernosa

.Slide40
Slide41

Erectile Dysfunction

changes in the blood vessels that lessen their ability to deliver blood to the

penis

problems with the nervous system that interferes with the nerves that stimulate an

erection

problems due to certain drugs such as SSRI antidepressants,

antihypertensives

(blood pressure pills),

anticholinergics

, corticosteroids and othershormone problems such as too much prolactin (a pituitary hormone) or low testosteroneSlide42

Solution for ED

Viagra, Cialis or Levitra act to maintain a high concentration of

cGMP

– should not be taken with food and alcohol

60% successful, work only if sexually excited

not successful with low

testorone

(

nitric oxide (NO)

and cGMP)testosterone replacementSlide43

Nocturnal and Morning Erections

Nocturnal erections

- rapid eye movement phase

- 7 times and 25% of sleep in young men

- erection is 70% of the normal (during sexual arousal)

Morning erection

- not related to bladder fullness- loss of morning erection may indicate low in testosterone Slide44

Ejaculation

sufficient level of stimulation = ejaculation

sympathetic nervous system – responsible for semen production

semen ejected to urethra with rhythmic contraction (10-15 contractions)

ejaculation cannot be stopped when contraction started

contraction

= 0.6 seconds interval with increment of 0.1 seconds per contractionSlide45

Refractory Period

immediately following an orgasm, during which time they are unable to achieve another erection, and a longer period again before they are capable of achieving another

ejaculation

during

this time a male feels a deep and often pleasurable sense of relaxation, usually felt in the groin and thighsSlide46

Volume

semen = 0.1 – 10 milliliters

adult

semen volume is affected by the time that has passed since the previous

ejaculation

Hypospermia

= low semen volume that may be caused by ejaculatory duct obstructionSlide47

Quality

last ejaculation

stress levels

testosterone

Oligospermia

– unusually low sperm count

Azoozpermia

– absence of sperm from the semenSlide48

Development (During puberty)

first ejaculation = 12 months from the onset of puberty (through

nuctornal

emission or masturbation)

1mL of semen for the following 3 months

semen is typically clear = fail to

liquify

semen

liquifies

– 12 -14 months after 1st ejaculation = 90% no spermSlide49

Semen development during puberty

Time after first

ejaculation (months)

Average volume

(milliliter)

Liquefaction

Average sperm concentration

(million sperm/milliliter)

0

0.5Noa061.0Noa20122.5No/Yesb50183.0Yesc7024

3.5Yes

c

300

^a

Ejaculate is jellylike and fails to

liquify

.

^b

Most samples

liquify

. Some remain jellylike.

^c

Ejaculate

liquifies

within an hour.Slide50

MALE REPRODUCTIVE PROBLEMSSlide51

TESTICULAR TRAUMA

a

mild injury to the testicles can

cause severe

pain, bruising, or

swelling

occur

when the testicles are struck, hit, kicked, or crushed, usually during sports or due to other

trauma

testicular torsion-- when 1 of the testicles twists around, cutting off the blood supply surgery is needed to untwist the cord and save the testicleSlide52

VARICOCELE

a

varicose vein (an abnormally swollen vein) in the network of veins that run from the

testicles

usually

not harmful, although in some people it may damage the testicle or decrease sperm

production

see his doctor if he is concerned about changes in his testiclesSlide53

TESTICULAR CANCER

 one of the most common cancers in men younger than

40

occurs when cells in the testicle divide abnormally and form a

tumor

if it's

detected early, the cure rate is

excellent

teen

boys should be encouraged to learn to perform testicular self-examinationsSlide54

EPIDIDYMITIS

inflammation

of the epididymis, the coiled tubes that connect the testes with the vas

deferens

 caused by an

infection

and results in pain and swelling next to

one

of the testiclesSlide55

HYDROCELE

occurs when fluid collects in the membranes

surrounding

the

testes

may

cause swelling of the testicle but are generally

painless

surgery

may be needed to correct the conditionSlide56

INGUINAL HERNEA

w

hen

a portion of the intestines pushes through an abnormal opening or weakening of the abdominal wall and into the groin or

scrotum

 may look like a bulge or swelling in the groin

area

can be corrected with surgerySlide57

PRIAPRISM

a

persistent, often painful erection lasting more than four

hours

occurs

when blood flows into the penis but is not adequately

drained

treatment involves draining the blood using a needle placed in the side of the penis

Medications that help shrink blood vessels, which decreases blood flow to the penis, also may be used. surgery may be required to avoid permanent damage to the penisSlide58

PEYRONIE’S DISEASE

bending of the penis during an erection due to a hard lump called a plaque

plaque

often begins as a localized area of irritation and swelling (inflammation), and can develop into a hardened

scar

penile implant can be used in cases where

Peyronie's

disease has affected the man's ability to achieve or maintain an erection.Slide59

non-surgical treatment for

Peyronie's

disease involves injecting medication directly into the plaque in an attempt to soften the affected tissue, decrease the pain, and correct the curvature of the penis.

Vitamin E pills have also been shown to benefit some men with

Peyronie's

disease.Slide60

BALANITIS

inflammation

of the skin covering the head of the

penis

most

often in men and boys who have not been

circumcised

Symptoms include

redness

or swelling, itching, rash, pain, and a foul-smelling dischargeSlide61

If

there is an infection, treatment will include an appropriate antibiotic or antifungal medication

.

In cases of severe or persistent inflammation, a circumcision may be recommended.

t

aking

appropriate hygiene

measures

avoid strong soaps or chemicals, especially those known to cause a skin reaction.Slide62

PENILE CANCER

a

rare form of cancer, highly curable when caught

early

occurs

when abnormal cells in the penis divide and grow uncontrolled. Certain benign (non-cancerous)

tumors

may progress and become cancer

.

Surgery to remove the cancer is the most common treatment.Slide63

PHIMOSIS

condition

in which the foreskin of the penis is so tight that it cannot be pulled back (retracted) to reveal the head of the

penis

treatment may

include gentle, manual stretching of the foreskin over a period of

time

Circumcision- the

surgical removal of the foreskin, often is used to treat

phimosisSlide64

PARAPHIMOSIS

occurs

when the foreskin, once retracted, cannot return to its original

location

Treatment

of

focuses

on reducing the swelling of the

glans

and foreskin. Applying ice may help reduce swelling, as may applying pressure to the glans to force out blood and fluidan injection of medication to help drain the penis may be necessarya surgeon may make small cuts in the foreskin to release itcircumcision- may be used as a treatment for paraphimosisSlide65

SEXUALLY TRANSMITTED DISEASES

Include human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), human

papillomavirus

(HPV, or genital warts), syphilis,

chlamydia

,

gonorrhea

, genital herpes, and hepatitis B

spread from one person to another mainly through sexual intercourseSlide66

HYPOSPADIAS

 - a disorder in which the urethra opens on the underside of the penis, not at the tip

AMBIGUOUS GENITALIA

 - occurs when a child is born with genitals that aren't clearly male or female. In most boys born with this disorder, the penis may be very small or nonexistent, but testicular tissue is present. In a small number of cases, the child may have both testicular and ovarian tissue.

MICRO PENIS-

a disorder in which the penis, although normally formed, is well below the average size, as determined by standard measurements