Dr. Houston (GU) Flashcards
What are the normal sites fo relative constriction of ureter? (3)
- Urteropelvic junction
- Crossing iliac vessels and pelvic brin
- Traversing bladder wall
According to review session: Ureteropelvic Junction is mc site of obstruction in nephrolithiasis
- How does the ureters implant on the bladder?
- What is the trigone?
- Ureter: goes posterior and attaches on back side
- Trigone: triangle of ureters and urethra and has stretch receptors that will fire to make you want to pee (afferent imput)
- Where is the ducuts deferens?
- Where is the bladder?
- DD: a long, muscular tube that carries sperm from the epididymis to the ejaculatory duct.-> superior to bladder
- Bladder: is superior/posterior to pubic symphysis
- What is the difference when the bladder is full and empty?
- What is the muscle of the bladdder?
- Wht does the bulbourethral gland do?
- When the bladder is full it pushed up against the parietal perioneum
- Detrusor muscle
- Bulb: Pre-ejac fluid that neutralizes the urethra so sperm does not get damage and mositens the penis glans
What are the different parts of the urethra?
Know that the ejac duct meets into the prostatic urethra (past exam question)
What does a cystoscopy do?
- The interior of the bladder and its three orifices can be examined with a cystoscope, a lighted tubular endoscope that is inserted through the urethra into the bladder.
- The cystoscope consists of a light; an observing lens; and various attachments for grasping, removing, cutting, and cauterizing
What are the different muscles compressing the urethra? What is their role?
All compresser sphincter to prevent unwanted leakage
* Internal urethral sphincter
* Pubovesicalis
* External urethral sphincter
* Compressor urethrae
Prostatic Enlargement
* Because benign enlargement or benign prostatic hyperplasia (BPH) is common when?
* An enlarged prostate projects into what? What does that cause?
* What lobe and zone is mainly affected? (on Dr. Lees review)
- common after middle age
- projects into the urinary bladder and impedes urination by distorting the prostatic urethra.
- The middle lobule (transitional zone) usually enlarges the most and obstructs the internal urethral orifice.
Prostatic Cancer
* Common in who?
* **What region and zone is affected? ** (dr. lees review)
* This may be what on exam?
* What happens in advance stages?
- Prostatic cancer is common in men older than 55 years of age.
- **In most cases, the cancer develops in the posterolateral region (peripheral zone) **
- This may be palpated during a digital rectal examination A malignant prostate feels hard and often irregular.
- In advanced stages, cancer cells metastasize (spread) to the iliac and sacral lymph nodes and later to distant nodes and bone.
Prostatectomy
* The prostatic plexus, closely associated with what? What does it give passage of?
* A major concern regarding prostatectomy what?
* What is TURP
- The prostatic plexus, closely associated with the prostatic sheath, gives passage to parasympathetic fibers, which give rise to the cavernous nerves that convey the fibers that cause penile erection.
- A major concern regarding prostatectomy is that impotency may be a consequence.
- All or part of the prostate, or just the hypertrophied part, is removed (transurethral resection of the prostate [TURP]).
Past Exam Question
What are the voluntery muscles of urethra?
- External uretheral sphincter
- Compressor urethrea
How do the seminous vesicles, eject ducts meet and come together?
- Sperm travel from the epididymis through the ductus deferens.
- The ductus deferens joins with the duct of the seminal gland.
- They form the ejaculatory duct.
- The ejaculatory duct passes through the prostate gland and opens into the prostatic urethra.
Sterilization of males
* What is the common method?
* What do they do in this procedure?
* What happens to the sperm? (2)
- The common method of sterilizing males is deferentectomy, usually called a vasectomy.
- During this procedure, part of the ductus deferens is ligated and/or excised through an incision in the superior part of the scrotum.
- Hence, the ejaculated fluid from the seminal glands, prostate, and bulbourethral glands contains no sperms.
- The unexpelled sperms degenerate in the epididymis and the proximal part of the ductus deferens.
What is the sympathetic nerve inn of the bladder?
- Spinal Segments: The sympathetic nerves originate from the lumbar segments L1 and L2 of the spinal cord.
- Hypogastric Ganglion: From the sympathetic chain, the fibers synapse in the hypogastric ganglion.
- Hypogastric Nerve: Postganglionic fibers from the hypogastric ganglion travel via the hypogastric nerve to the bladder and internal sphincter.
- Symapthetic fiber to internal urethral sphincter: Contraction to not have leakage (relax in order to pee)
What is the parasympathetic nerve inn of the bladder?
- Spinal Segments: The parasympathetic nerves originate from the sacral segments S2, S3, and S4 of the spinal cord.
- Pelvic Nerve: These preganglionic fibers form the pelvic nerve.
- Bladder and Internal Sphincter: The pelvic nerve innervates the bladder and internal sphincter, promoting bladder contraction and relaxation of the internal sphincter during urination.
What is the somatic nerve inn for urinary bladder?
- Pudendal Nerve: The somatic innervation is via the pudendal nerve, which also originates from the sacral segments S2, S3, and S4.
- External Urethral Sphincter: The pudendal nerve controls the external urethral sphincter, allowing voluntary control over urination.
Past exam question
What is the autonomic nervous system in the processes of erection and ejaculation?
Point: Erection->Parasympathetic Nervous System:
* The parasympathetic nerves, originating from the sacral segments S2, S3, and S4, are responsible for the process of erection.
* These nerves release nitric oxide, which causes vasodilation and increased blood flow into the corpora cavernosa of the penis, leading to an erection.
Shoot: Ejaculation-> Sympathetic Nervous System:
The sympathetic nerves, originating from the lumbar segments L1 and L2, control ejaculation.
* The process involves two stages: emission and expulsion.
What is the overview of oogenesis and spermatogenesis?
What regulates LH and FSH in male repro?
Hypothalamic GnRH regulates both LH and FSH secretion
What does LH and FSH regulate?
LH and FSH regulate testosterone secretion and sperm production
Fill in
Explain what happens when the environment, drugs and age effect the brain centers for male reproduction. (include the feedback mechanisms)
Testis are the site of what?
Testis is the site of sperm and seminal fluid formation
Leydig (interstitial) cells:
* Where are they located?
* What do they produce?
* What hormone binds to them?
- in interstitium of the testes, between seminiferous tubules
- produce testosterone.
- LH binds to receptors on these cells
Sertoli cells (nurse cells):
* Where are they located?
* What hormone binds to them?
* What do they support?
* Contain what receptors? (2)
* produce low levels of what?
* What do they also produce? What does this regulate?
- located within the seminiferous tubules
- FSH binds to receptors on these cells
- support spermatogenesis
- contain FSH and testosterone receptors
- produce low levels of estradiol
- also produces activin, follistatin, and inhibin that regulate the secretion of FSH.
Where are spermatogina and maturing sperm located? Explain the process
- Spermatogonia are located in the basal compartment and maturing sperm in the adluminal compartment (closest to the lumen).
- Spermatocytes are formed from the spermatogonia and cross the tight junctions into the adluminal compartment; they mature into spermatozoa.
Explain leydig and sertoli cells and their relationship
Leydig cells:
* secrete testosterone into blood and onto seminiferous tubules
* Stimulated by LH from ant. pit.
* Inhibited by excess testosterone
Sertoli cells:
* Secrete ABP to bind and concentrate testosterone in seminiferous tubules
* FSH also stimulates tehe secretions of inhibin from sertoli cells, which has negative feedback to only FSH
How the pampiniform plexus regulate temperature of testes?
Pampiniform plexus: an extensive network of veins from the testes that surrounds the testicular artery and spermatic cord
* Countercurrent heat exchanger—without the pampiniform plexus, warm arterial blood would heat the testis and inhibit sperm production
* Removes heat from the descending arterial blood
* By the time it reaches the testis, the blood is 1.5° to 2.5°C cooler
What is the pathway for erection reflex in males?
What is NO derived from? What does it cause?
- nitric oxide (NO) is derived from the nerve terminals innervating the corpora cavernosa, the endothelial lining of penile arteries, and cavernosal sinuses
- Causes smooth muscle relaxation-> penile erection
What is the psychogenic or reflexogenic pathway?
- Seminal emission moves the sperm and associated fluids how?
- Contraction of the internal bladder sphincter is via what? What does this cause?
- Seminal emission moves the sperm and associated fluids from the cauda epididymis and vas deferens into the urethra.
- Contraction of the internal bladder sphincter (by α1-adrenergic sympathetic stimulation) prevents the ejaculate from traveling up the urethra and into the bladder, known as retrograde ejaculation
What is ejaculation?
Ejaculation is the expulsion of the semen from the penile urethra; it is initiated after emission.
Explain the process of spermatogenesis (picture)
Male germ cells, which undergo extensive morphologic changes in cell shape and, ultimately, meiosis to produce the haploid spermatozoa.
- What does the head of the sperm contain?
- The tail is divided into three regions?
Head:
* Nucleus contains haploid set of chromosomes
* Acrosome—enzyme cap over the apical half of the
nucleus that contains enzymes that penetrate the egg
(acrosome reaction)
Tail:
* Midpiece contains mitochondria around axoneme of the flagella, produces ATP for flagellar movement
What is testosterone converted into in males?
Testosterone is converted to dihydrotestosterone (DHT), the most biologically active androgen, and to estradiol, the most biologically active estrogen (to prevent osteoclast)
What cells produce testosterone and what is it derived from?
Testosterone is primarily synthesized in Leydig cells and is derived from cholesterol, involving many enzymatic steps.
* The adrenal cortex, ovaries, testes, and placenta produce steroid hormones from cholesterol.
* The major steroid produced by the testis is testosterone, but other androgens, such as androstenediol, androstenedione, and DHEA, as well as a small amount of estradiol, are also produced.
What are the different conversions of testosterone in extratesticular sites?
