Lecture

The Pelvic CavityBony Pelvis

Reproductive Organs

The Pelvic Girdle

• Paired hip bones • Os coxae or coxal

bones– Ilium– Ischium– Pubis

• Articulate w/each other in anterior midline– Pubic symphysis

The Bony Pelvis

• Pelvic girdle attaches to axial skeleton by some of the strongest ligaments in the body

• Sacrum and coccyx form part of pelvis

Pelvis

• 2 os coxae• Sacrum• Coccyx• Features

– Pelvic brim– Pelvic inlet– Pelvic outlet– True/false

pelves

http://www.boa.ac.uk/BOAimage_bank.htm

True vs. False Pelvis

False• Lies above pelvic

brim/inlet• Contains abdominal

organs

True• Lies below pelvic brim• Contains colon,

rectum, bladder, ovaries and uterus

• Limited inferiorly by pelvic diaphragm

Pelvic Diaphragm• Consists of levator ani

and coccygeus muscles

• Seals opening of bony pelvis

• Supports pelvic organs• Pierced by rectum,

urethra, vagina

Articulations

• Ilia – Articulate with

sacrum

• Hip– Acetabulum with

head of femur

• Pubic symphysis– R and L os coxae

Note: Bone features will be studied in lab

Male vs. Female Pelvises

Sexual Dimorphism

• Female– Cavity broad, shallow

– Bones lighter, thinner

– Pubic angle larger

– Coccyx flexible, straight

– Ishcial tuberosities shorter, everted

– Pelvic inlet wide, oval

• Male– Cavity narrow, deep– Bones heavier, thicker– Pubic angle narrower– Coccyx less flexible,

curved– Ischial tuberosities

longer, face medially– Pelvic inlet narrow,

heart-shaped

Functions of Pelvis

• Attachment of lower limb to axial skeleton

• Support visceral organs• Transmit weight of

upper body– To limbs when upright

– To ischial tuberosities when sitting

http://www.oum.ox.ac.uk/children/animals/pelvis.jpg

Reproductive Embryology

• Identical structures in male and female

• Gonadal ridges develop on dorsal abdominal wall– future ovaries or testes

• Wolffian ducts – future male ducts

• Müllerian ducts– future female ducts

Reproductive Embryology

• External Genitalia– Genital tubercle

(projection on perineal surface)

– Urethral groove

– Urethral folds

– Labioscrotal swellings

• Ridges testes– Wolffian ducts

• Epididymis

• Ductus deferens

• Ejaculatory duct

– Müllerian ducts degenerate

Male Embryology

• Ridges ovaries

• Müllerian ducts– Uterine tubes– Uterus– Superior vagina

• Wolffian ducts degenerate

Female Embryology

• Week 8– Tubercle enlarges

forming penis

– Urethral folds fuse midline forming penile urethra

– Labioscrotal swellings fuse midline forming scrotum

Male Embryology

• Tubercle forms clitoris• Urethral folds do not

fuse - form labia minora

• Labioscrotal swellings do not fuse – form labia majora

Female Embryology

Homologous Structures

• Male– Testes– Penis– Penile urethra– Scrotum

• Female– Ovaries– Clitoris– Labia minora– Labia majora

Descent of the Ovaries

• Ovaries– Gubernaculum guides

descent

• Ovarian ligament

• Round ligament

– Reach pelvis

• Broad ligament

http://www.cancerhelp.org.uk/cancer_images/3secvers2.gif

Descent of the Testes

• Through pelvis to scrotum

• Bring blood vessels and nerves

• Guided by gubernaculum

Descent of the Testes

• Pushes through abdominal wall forming inguinal canal

• Vaginal process– Outpouching of

peritoneum

– Tunica vaginalis after closing off

Descent of the Testes

• Complete by 1 month post birth

Puberty

• ~Age 10 – 15

• Reproductive organs grow to adult size

• Reproduction becomes possible

• Occurs under influence of rising levels of testosterone and estrogen

Male Puberty

Enlargement of testes and scrotum

• All accessory structures attain adult size

• Spermatogenesis

http://www.ppae.ab.ca/templates/ppae/images/puberty.gif

Secondary Sex Characteristics

• Hair– Pubic– Axillary– Facial– Other

• Larynx• Skin

– Apocrine sweat glands– Sebaceous (oil) glands

• Somatic– Bones length and

density

– Skeletal muscle size and mass

• Basal metabolic rate• Libido

Female Puberty

Budding of breasts• Reproductive structures

attain adult size• Menarche ~ 2 years after

onset of puberty• Ovulation ~ 2years after

menarche

http://www.ppae.ab.ca/templates/ppae/images/puberty.gif

Secondary Sex Characteristics

• Hair– Pubic– Axillary

• Fat Deposition– Hip– Breast

• Skin– Apocrine glands– Sebaceous glands

• Somatic– Growth spurt (3–5 yrs)

– Widening, lightening of pelvic girdle

Male Reproductive Organs

• Primary sex organ– Production of gametes and sex hormones

– Testis

• Secondary or accessory sex organs– External Genitalia

• Penis and scrotum

– Ducts

• Epididymis, vas deferens, ejaculatory duct, urethra

– Glands

• Seminal vesicle, prostrate, bulbourethral

External Genitalia - Scrotum

– Sac• Skin

• Superficial fascia

• Septum

– Contain testes– Temperature

regulation

Scrotal Muscles

• Dartos– Superficial

fascia

– Puckering of scrotum

• Cremaster– Bands of skeletal

muscle

– Internal oblique

– Elevate testes

http://www.meddean.luc.edu/lumen/meded/grossanatomy/abd/inguinal/end.gif

Testes• 1 x 1.5 inches• Coverings

– Tunica vaginalis

• Parietal layer, serous fluid, visceral layer

– Tunica albuginea

• Fibrous capsule

• Extends inward forming septa

http://www.cancer-concerns.com/images/testes1.gif

Testis

• Lobules– 1-4 seminiferous

tubules

– Tubulus rectus

• Blood supply– Testicular artery

– Testicular veins

– Pampiniform plexus

Seminiferous Tubules

• “Sperm factories”• Spermatogenic cells

– Germ cells at basal membrane

– Sperm released into lumen

Other Cells

• Sustenacular cells – Sertoli cells– Lumen of

seminiferous tubules

– Provide nutrients– Move cells

toward lumen– Secrete testicular

fluid

http://it.stlawu.edu/~mtem/devbiol/atlas/TESTIS4.JPG

Other Cells

• Myoid cells– Smooth muscle-like

– Around tubules

– Squeeze sperm and fluid through tubules

• Interstitial cells– In loose connective

tissue

– Secrete male hormones

Epididymis

• Seminiferous tubules• Tubulus rectus • Rete testis

– network of branching tubes

• Efferent ductules• Epididymis

Epididymis

• Comma-shaped organ arching over posterolateral testis

• Head, body tail

– Efferent ductules form part of head

– Duct of epididymis forms head, body and tail

– 20 feet

Ductus Deferens or Vas Deferens

• Epididymis

• Through scrotum

• Enters pelvic cavity through the abdominal wall

• Descends along posterior wall of bladder

• Ampulla (distal end) joins with duct of seminal vesicle forming short ejaculatory duct

The Spermatic Cord

• Tube of fascia• Scrotum through

inguinal canal• Contents

– Vas deferens

– Testicular vessels

– Nerves

Seminal Vesicles

• Posterior surface of bladder

• Secretes viscous fluid accounting for 60% of volume of semen

• Duct joins vas deferens forming ejaculatory duct which empties into prostatic urethra

http://www.bartleby.com/107/illus1160.html

Prostate

• Inferior to bladder

• Contains urethra• Milky secretion

– ~1/3 of semen

http://www.harthosp.org/cancer/prostate.htm

Bulbourethral Glands

• Cowper’s glands• Within urogenital

diaphragm• Empty into spongy

urethra• Produce mucus for

lubrication and neutralization of traces of acidic urine

Urethra

• Bladder• Prostate

– Prostatic

• Urogenital diaphragm– Membranous

• Penis– Spongy or penile

• Function– Sperm to female

reproductive tract• Anatomy

– Root• Attached end

– Shaft or body• Free end

– Glans• enlarged tip

– Prepuce - foreskin– Spongy urethra

External Genitalia - Penis

Penis – Erectile Bodies

• Spongy tissue

– Smooth muscle

– Connective tissue

– Vascular spaces

• Corpus spongiosum

– Single

– Midventral

• Corpora cavernosa

– Paired

– Dorsal

http://www.walgreens.com/images/image_popup/thumbs/dia7_erectilethu.jpg

Penis – Erectile Bodies

• Corpus spongiosum– Proximally – bulb

• Secured to urogenital diaphragm by bulbospongiosus muscle

– Distally – forms glans

• Corpora cavernosa– Proximally – crura

• Anchored to pubic arch by ischiocavernosus muscle

– Most of mass of penis

Penis• Arterial supply

– Branches of internal pudendal (branch of internal iliac)

• Innervation– Sensation via branches of pudendal nerve (sacral

plexus)– Autonomic – hypogastric plexus

• Parasympathetic - engorgement of blood in erectile bodies - erection

• Sympathetic - contraction of smooth muscle in ducts, glands, and bulbospongiosus muscle - ejaculation

Semen

• Sperm– 50 – 130 million/ml

• Fluid– Transport

– Nutrients

– Chemicals

http://www.inicia.es/de/Karin1964/tubosemen.jpg

Spermatogenesis• Occurs in seminiferous

tubules• Spermatogonia = stem

cells• Spermiogenesis =

maturation of spermatids into spermatozoa– Develop head,

midpiece and tail– Newly formed sperm

detach from epithelium and enter lumen of tubule

– Controlled by FSH & testosterone

Male Perineum• Contains

– Scrotum, root of penis, and anus

• Boundaries– Pubic symphysis,

coccyx, ischial tuberosities

• Muscles– See diagram– Urogenital diaphragm

deep transverse perineus and sphincter urethrae

Female Reproductive Organs

• Primary sex organ– Ovary

• Secondary or accessory sex organs– External genitalia or vulva

• Labia majora

• Labia minora

• Clitoris

• Mons pubis

Female Reproductive Organs

• Secondary or accessory sex organs – Internal genitalia

• Ducts

– Oviducts

– Uterus

– Vagina

• Glands

– Greater vestibular gland

Ovaries

• Size– ~1 x 1½ inches

• Function– Produce female

hormones– Produce gametes– Store gametes

http://yourmedicalsource.com/library/infertility/INF_whatis.html

Ovary

• Tunica albuginea

• Cortex– Oocytes

• Medulla– Connective

tissues, nerves, blood vessels

Ovary

• Arterial Supply– Ovarian arteries

– Ovarian branches of uterine arteries (arise from internal iliac arteries)

• Venous drainage– Ovarian veins to IVC

Ovarian Ligaments

• Ovarian ligament– Remnant of

gubernaculum• Suspensory ligament

– Ovaries to pelvic wall– Ovarian arteries,

veins, and nerves• Broad ligament

– Uterus and oviducts– Large fold of

peritoneum

Oviducts• Uterine or Fallopian tubes• Infundibulum

– Funnel-like– Fimbrae with cilia

• Ampulla & Isthmus– Ciliated– Smooth muscle

• Peristalsis– Mucosa

• Ciliated cells• Nonciliated cells

– nourish ova

The Uterus

• Gross Anatomy– Fundus

– Body

– Isthmus

– Cervix

• Wall – Perimetrium

– Myometrium

– Endometrium

Uterine Blood Supply

• Uterine arteries (int. iliac)

• Arcuate branches of uterine arteries

The Cervix

• External os– Nulliparous vs.

parous

• Cervical canal• Internal os

http://www.pennhealth.com/health_info/pregnancy/graphics/images/en/19726.jpg

http://www.rhtp.org/images/clip_image002_000.jpg

Vagina• Wall – 3 layers

– Adventia

– Muscularis

– Mucosa

• Rugae

Vagina

• Location– Inferior to uterus

– Anterior to rectum

– Posterior to bladder

External Genitalia

• Mons pubis– Fatty pad over pubic

symphysis

• Labia majora – Fatty skin folds

• Labia minora– Hairless folds within

labia majora

http://www.eastwoodward.org.uk/images/medical/external-female-genital-organs.gif

External Genitalia

• Vestibule – opening for urethra and vagina

• Clitoris– Crura

– Prepuce

– Corpora cavernosum

– No corpus spongiosum

http://stb.msn.com/i/EF/EF832F915763C7420898F7A8DC782.jpg

Perineum• Contents

– Urethra– External genitalia– Anus

• Boundaries– Pubic symphysis– Coccyx– Ischial tuberosities

• Central tendon– Perineal body– Muscle insertion– Episiotomy

Perineum• Contains

– Urethra, ext. genitalia, and anus

• Boundaries– Pubic symphysis,

coccyx, ischial tuberosities

• Muscles– See diagram

– Urogenital diaphragm deep transverse perineus and sphincter urethrae

Central tendon

perineal body – muscle insertion

Glands

• Greater vestibular glands– Bartholin’s

– Mucus

Oogenesis

Fertilization – Formation of Zygote

• Path of Sperm– Seminiferous tubules

– Tubulus rectus

– Rete testis

– Efferent ductules

– Duct of epididymis

– Vas deferens

– Urethra

– Vagina

– Uterus

– Oviduct

• Path of Ovum

– Ovary

– Peritoneal cavity

– Infundibulum

– Oviduct

• Path of Zygote

– Oviduct

– Uterus

• Path of Fetus

– Uterus

– Vaginafertilization