Lecture 21: Reproductive System I Flashcards
When does the Reproductive system become functional?
At puberty
What are a lot of the sex hormones also produced by?
The adrenal glands
What are the functions of the male reproductive system?
- Produce male gametes, testosterone, and seminal fluid
- Temporary storage for spermatozoa
- Delivery of spermatozoa to the female reproductive tract
What are the four divisions of the male reproductive system?
- Gonads: testes
- Ducts
- Penis
- Accessory glands
What are the Gonads in the male reproductive system?
The testes
What are the Testes responsible for?
Production of sperm and male sex hormone (testosterone)
What are the Ducts responsible for?
Sperm storage, maturation and transportation
What is the Penis responsible for?
The common pathway for urine and semen
What are the accessory glands in the male reproductive system responsible for?
- Production of seminal fluid
* Secretions function in maintenance and maturation of sperm
What separates the thorax and the abdomen?
The diaphragm
What separates the abdominal cavity and the pelvic cavity?
The parietal peritoneum
Where are the Pelvic organs all found in relation to the peritoneum?
They are all found outside the parietal peritoneum
What is the space between the urinary bladder and the rectum known as?
The Rectovesical pouch
What does the descending aorta divide into near the pelvic cavity?
The common iliac vessels
What are the two branches of the common iliac artery?
The external iliac and the internal iliac
Which artery supplies everything in the pelvic cavity?
The Internal Iliac artery
What is the Testis found within?
The scrotum
Why is the Testes found outside the body?
Because production of sperm needs to be at a cooler temperature than the temperature of the body
What occurs in the Epididymis?
Maturation of sperm
Which glands does the Vas Deferens combine with?
- Seminal vesicle
- Prostate
- Bulbourethral gland
What forms the ejaculatory duct?
The vas deferens and the seminal vesicle
Where is the Bulbourethral gland?
Next to the membranous urethra
Which bone do we sit on?
Ischial Tuberosity
What are the boundaries of the Anal Triangle?
The ischial tuberosities and the coccyx
What is found in the Anal Triangle?
The anus
What is found in the Urogenital Triangle?
The scrotum and penis
Which nerve innervates all the Perineal muscles?
The Pudendal nerve (S2, 3, 4)
Which muscle is in the Urogenital triangle?
External Urethral sphincter
What does the External Urethral Sphincter do?
Regulates the urethral opening for urinary continence
Which muscles are in the Anal Triangle?
- Levator ani
* External anal sphincter
What kind of innervation do the External Anal Sphincter and the External Urethral Sphincter have?
Both have somatic innervation by the Pudendal nerve (S2, 3, 4)
What does the External Anal Sphincter do?
Helps to regulate the opening of the anal canal
What does the Levator Ani do?
Supports pelvic organs (pelvic floor)
Which sphincter is more developed in males?
The external urethral sphincter
What do the muscles over erectile tissue do?
Increase blood flow to the genitalia to help with erection
What are the two parts of the penis?
The root and the body
Which part of the penis is the root?
The part that is attached to the body itself
What occurs in the body of the penis?
All the erectile tissue comes together
What are the two types of erectile tissue?
- Corpora Cavernosa
* Corpus spongiosum
Why doesn’t the Corpus Spongiosum become completely hard?
Because that is where the urethra lies
What are the Crus called when they come together?
The Corpora cavernosa
What do the muscles around the erectile tissue do?
Contract in order to fill the erectile tissue
Which muscle is associated with the bulb and spongy erectile tissue?
Bulbospongiosus
Which muscle covers the Crus of the penis?
The ischiocavernosus muscle
What kind of muscle is the Ischiocavernosus muscles and the bulbospongiosus muscle made of?
Skeletal muscle
What are the scrotal cavities separated by?
The scrotal septum
Where do the Gonads develop from?
The abdomen and descend down
Why does the vasculature of the testes come from the abdominal aorta?
Because the develop from the abdomen
Where do the Gonadal arteries come from?
The abdominal Aorta
What serous layers are found in the scrotal cavity?
A parietal and visceral serous layer
What is found in the Scrotal cavity?
The testis and the epididymis
Which muscle is the testis and epididymis wrapped in?
The cremaster muscle
What is the Cremaster muscle a continuation of?
The internal oblique muscle
What does the Cremaster muscle surround?
- Spermatic cord
- Testis
- Epididymis
What does the Cremaster muscle do?
Contract and bring the testes up in response to cold temperature and contract in response to arousal
What is found in the Spermatic Cord?
- Vas deferens
- Testicular artery
- Pampiniform plexus
What is the function of the Pampiniform plexus?
- Temperature control by draining blood
* Circulate hormones in the blood stream
Where does the Spermatic cord go through?
The inguinal canal
What is the Inguinal canal formed from?
The inguinal ligament, the anterior superior iliac spine
What is the Inguinal ring?
The opening from the abdominal canal?
What does Semen consist of?
- Spermatozoa/sperm (gametes)
* Secretions of accessory glands (seminal fluid)
What is Spermatogenesis?
The production of sperm
Where is sperm produced?
In the Testes
What occurs in the Epididymis?
Maturation of sperm
Where does the Ampulla of the Vas Deferens occur?
Right before it gets to the Seminal vesicle
When forms the Ejaculatory duct?
The Vas deferens and the seminal vesicle
What does the ejaculatory duct form?
The prostatic urethra
When does the Prostatic urethra become the membranous urethra/
When it reaches the bulbourethral gland
What are the parietal and visceral region of the testes known as?
- Tunica vaginalis (visceral)
* Tunica vaginalis (parietal)
What do the Tunica Vaginalis in the testes do?
They are serous membranes that produce serous fluids
Why are Testes and Ovaries white?
Because of the white coat of Tunica albuginea
What is the Tunica Albuginea?
A white tough connective tissue that surrounds the testes
What does the Tunica Albuginea contain?
Lots of lymphatics, vasculature, and innervation
What separates the Testis into lobules?
The Tunica albuginea
Which part of the testes produce sperm?
Seminiferous tubules
Where does sperm go from the seminiferous tubules?
To the Rete testis (mediastinum) and then to the Efferent ductules to the epididymis
What enters through the mediatinum?
Vasculature, innervation and lymphatics
What kind of tissue is at the lumen if the seminiferous tubules?
Epithelium
What are the Seminiferous tubules embedded with?
CT with blood, lymph, nerves, and interstitial cells
What do Sertoli cells do?
Support the production of sperm
Where are Sertoli cells found?
At the basal membrane of the seminiferous tubules
What is Spermatocytogenesis?
The differentiation of spermatogonia into primary spermatocytes (mitosis)
What is Spermiogenesis?
Transformation of spermatids into spermatozoa
What does meiosis do?
Reduces diploid chromosomal complement of spermatocytes to form four haploid spermatids
What are the germ cells of sperm?
Spermatogonia
Where does the Cytoplasm of sertoli cells span?
From the cytoplasm all the way to the basal lumen
What do Sertoli Cells do?
Support the development of sperm
How do Sertoli cells support spermatogenesis?
- Support, protect, nourish spermatogenic cells
- Phagocytosis of excess cytoplasm
- Secrete fructose-rich fluid
- Help maintain necessary testosterone levels
- Establish blood-testis barrier
What do Sertoli cells do in the Blood-Testis barrier?
When spermatogonia develop into spermatocytes, spermatids and spermatozoa the body can no longer recognize them and will attack them so the sertoli cells create tight junctions that development of the sperm occurs past the junction
What is the final stage of Spermatogenesis?
Spermiogenesis
What occurs in Spermiogenesis?
The transformation of round spermatid into asymmetric spermatozoon
What changes are made in Spermiogenesis?
- Condensation of nucleus
- Formation acrosome
- Development of flagellum
- Shed of cytoplasm
What does the Acrosomal cap do?
Protects the Spermatozoon but also has enzymes to get through the ovum
What is the tail of the Spermatozoon?
Flagellum
What cells are found in the Seminiferous tubules?
The germ cells, Spermatogonia, and sertoli cells
Where are Myoid cells found?
In the testes but outside the seminiferous tubules
What do Myoid cells do?
Contract and push along the sperm towards to epididymis
What do Leydig cells do?
Produce testosterone
Where are Leydig cells found?
Outside the seminiferous tubules in the connective tissue of the testis
What does Testosterone do?
- Regulate spermatogenesis
- Stimulates development and maintenance of male secondary sex characteristics
- Stimulate growth and metabolism throughout the body
- Influence brain development
What regulates the release of FSH and LH from the pituitary gland?
Gonadotropin releasing hormone
What does FSH do in males?
Stimulates Sertoli cells to support spermatogenesis
What does LH do in males?
Stimulates Leydig cells to produce testosterone
What does Inhibin released by sertoli cells do?
Depresses the anterior pituitary from producing FSH and LH
What does the Epididymis have associated with it?
A lot of connective tissue
Where does the Acrosome become functional?
In the epididymis
What kind of cells is the Epididymis composed of?
Simple epithelium
What two types of simple epithelium is the Epididymis composed of?
- Tall ciliated cells
* Short absorptive cells
What do the Tall ciliated cells of the Epididymis do?
Push sperm along
What do the Short absorptive cells of the epididymis do?
Absorb everything released by maturing sperm
What does the smooth muscle in the epididymis do?
Helps push things through during ejaculation
How many layers of smooth muscle does the Vas Deferens have?
2 layers of smooth muscle
Where does the Vas Deferens go?
From the scrotum, past the inguinal canal, past the urinary bladder, behind the ureters to get to the seminal vesicle
What kind of contractions does the Vas Deferens have?
Peristaltic contractions to go against gravity
What do the glands of the male reproductive system produce?
Seminal fluid
What produces most of the seminal fluid?
The seminal vesicles
What forms part of the seminal fluid?
The prostate gland
What gland does not form any of the seminal fluid?
The bulbourethral gland
What does the Bulbourethral gland do?
Produces an alkaline fluid that neutralizes the penile urethra before ejaculation
What kind of glands are the ones in the male reproductive system?
Exocrine glands mostly
What are the characteristics of the seminal fluid produced by the seminal vesicles?
It is yellow and has mainly coagulation factors, high fructose
What do the coagulation factors produced by the seminal vesicles allow for?
It to survive the acidic vaginal canal because it is clumped together
What do the high fructose produced by the seminal vesicles allow for?
An energy source for sperm to enable movement of sperm towards the ovum
What are a lot of the problems with the prostate associated with?
It epithelium and connective tissue becoming enlarged blocking the passage of urine and semen
which gland contributes 20-30% of seminal fluid?
The prostate gland
What is the consistency of the secretion of the prostate gland?
This and white
Which part of the Urethra does the Prostate gland empty?
The prostatic urethra
What does the secretions of the prostate gland contain?
Hydrolytic enzymes
What do the Hydrolytic enzymes secreted into the semen by the prostate gland do?
Liquify ejaculated clotted semen, release spermatozoa
What do the the Bulbourethral glands do?
Coat and lubricate the urethra before the passage of sperm
What is the composition of the secretions from the Bulbourethral glands?
Thick, sticky alkaline to neutralize penile urethra
What surrounds the erectile tissue?
Tunica albuginea
What is Tunica Albuginea in the penis?
Fibrous CT with dense collagen bundles permitting extension of erectile tissue
What creates a shunt?
The Tunica albuginea that pushes against the blood vessels blocking the blood from returning to the body
Where does the corpora cavernosa receive blood from?
Central arteries
Where does the Corpus Spongiosum receive blood from?
Arterial blood from surrounding tissues
Which muscle is relaxed during E?
Smooth muscle are relaxed
What causes vasodilation of arteries during E?
Parasympathetic stimulation
What blocks venous outflow during E?
The tunica albuginea
What happens during shoot?
Contraction of smooth muscle
What do the Glands in the Penile Urethra do?
Secrete mucus along the urethra to help with lubrication
What kind of tissue does spongy urethra transition between?
Urinary (transitional) epithelium to stratified squamous epithelium in glands of the penis
