Male Reproductive Tract

Information comes from IMS 8405

Objectives

Students will discover parts of all male livestock animalsStudents will learn vocabulary relating to male reproductionStudents will learn the functions of all the parts of male livestock

Introduction

Animal repro is a complex but interesting topic

It requires a basic knowledge of reproductive anatomy and physiology?.

Reproduction is the process of producing offspring for the purpose of continuing a species

The Process (summed up for now)

1. Begins with copulation2. Sperm meets the ovum and forms an

embryo3. Embryo attaches in uterus and stays until

parturition

Bovine Male Reproductive Tract

Equine Male Reproductive Tract

Porcine Male Reproductive Tract

4 Major Functions

1. Production, storage, deposition of sperm2. Production of certain male hormones3. Excrete urine from the bladder4. Serves as passageway

Testes

Testicle Functions

1. Produces the male sex hormone testosterone

– Testosterone causes the development of secondary male characteristics and libido

Testicle Function

2. Produce sperm• Below is bovine sperm

Types of Sperm

Sperm Anatomy

To the right is a dissected sperm cell.

Cattle

Dairy Beef Sheep Swine Horses

Volume (ml) 6 4 1-2 225* - 400 60* - 100

Sperm concentration (billion/ml) 1.2 1.0 3.0 0.2 0.15

Total sperm (billion) 7 4 3 45 9

Motile Sperm % 70 65 75 60 70

Morphologically normal sperm %

80 80 90 60 70

pH 6.5-7.0 6.5-7.0 5.9-7.3 6.8-7.3 6.2-7.8

Testicle Tumor

Crypt Orchid

Definitely a problem – a testicle does not make the trip down through the inguinal canal and becomes trapped with the body of the animal. Sometimes the testicle still produces sperm make the animal viable in reproduction.

If the testicle does not make it, it looks like the one on the left.

Scrotum Functions

Houses testes and protect themHelps regulates the temperature of the testes with help from the cremaster muscle

Scrotum

Testicular temperature is approximately five degrees below the body temperature because sperm must develop under conditions cooler than body temperature.

Epididymis

A long, greatly coiled tube connected to each testicleResponsible for the maturation, storage, and transportation of sperm cells.

Deferent Duct

Known as the vas deferens

Originates from the epididymus and serves as a passageway for sperm to the urethra

Includes the spermatic cord, a protective fibrous sheath consisting of smooth muscles, blood vessels, and nerves.

Vas Deferens

Vas Deferens Cross Section

Seminal Vesicles

Paired accessory glands which secrete seminal fluid

It provides two functions as a protections and transportation medium for the sperm upon ejaculation

Glands of the Tract

1. Prostate Gland– Secretes a thick, milky fluid that mixes with the

seminal fluid and provides nutrition and substance to the ejaculate

2. Cowper’s Gland– Just prior to ejaculation, it secretes a fluid similar to

seminal fluid to cleanse and neutralize the urethra from urine residue which can kill sperm cells.

3. Retractor Penis Muscle

Accessory Sex Glands

http://www.ansi.okstate.edu/course/3443/study/video/bulant3.mov

Pelvic Urethra

The urethra is the passageway or tube which extends from the bladder to the end of the penis

Serves as the transportation route for the semen and urineSemen is sperm + added accessory fluids.

Penis

Penis

The organ that allows copulation

When the penis is in the relaxed state, the rear portion penis forms an S-Shaped curve called the Sigmoid Flexure in certain livestock species.

Sigmoid Flexure

http://www.ansi.okstate.edu/course/3443/study/video/bulerec.mov

Sigmoid Flexure

This curve allows for the retraction and protection of the front portion of the penis

The bull, ram, and boar are termed fibroelastic because they are composed of more connective tissue and depend on less blood for erections

The stallions penis differs in that it is termed vascular and forms no SF when relaxed.

Penis

The sheath is the external portion of the male reproductive tract which serves to protect the penis from injury and infection.

Prepuce is the excess skin around the head of the penis

Penis Fibropapilloma

Often, VD’s can cause major problems in herds!

Back to Sperm

The development of sperm is called spermatogenesis is a process of cell division and maturation that begins with STATIONARY cells called spermatogonium and ends with motile cells called spermatozoa.

The process takes place in the seminiferous tubules of the testes.

Sperm

Sperm cells carry one-half the chromosomes normally found in that species

BACK TO TESTOSTERONE > > > > > > > > >

Testosterone

Made in the interstitial cellsIt is produced in a response to an interstitial cell stimulating hormone which is produced in the anterior pituitary gland in the brain and transported in the blood.Testosterone is an androgen hormoneSecondary male traits from testosterone:– Coarse hair, horns that are long and large at base, a

deep voice, and pronounced muscle development.

This is for the Birds!

The End

Get it in your hard head by studying!