Physiology 3120 Lecture 65: Phys 3120 - Lecture 65
2 May 2018
School
Department
Course
Professor
Human Physiology Lecture 65
Make Reproductive Physiology
Reproductive System: Function
- Produce hormones
- Produce reproductive cells (gametes)
- NOT RESPONSIBLE FOR HOMEOSTASIS
o You can live without the reproductive system
Male Anatomy
- Testis
o Spermatogenesis in the human occurs at a temperature lower than body temperature
why it is important that the testis are outside of the male body
o Core body temperature = 37C
o Spermatogenesis operates optimally at 34C
- Body encompasses the lowering in temperature in two ways
o 1. Ligaments that hold the testis in place move either up or down
▪ Cold day: ligaments move the testis towards the body cavity to warm the testis
▪ Hot day: ligaments move the testis away from the body cavity
o 2. Blood
▪ Warmer blood from the core moves to the testis. As it moves to the testis it comes
across veins coming back from the testis that are colder than core body temperature
• Counter-current exchange system
• Warm blood moving down
• Cold blood moving up
• Heat moves from the arterial blood to the returning venous blood, cooling it
▪ Blood in testis is cooler than core body blood
o ALL AIMED AT KEEPING THE TESTIS AT 34C
- Epididymis
o Primarily responsible for sperm storage
o The testis makes the sperm, when sperm is developed it moves into the epididymis for
storage and maturation!
o Head, middle, and tail region – 3 COMPONENTS!
- Scrotum: temperature regulation
- Vas deferens
o Tube from the epididymis that will take the sperm during sexual arousal out and deliver it
o Transport sperm
o VERY muscular
o Peristaltic movement occurring to help propel sperm to the exit of the body
o Connected to the tail of the epididymis
find more resources at oneclass.com
find more resources at oneclass.com
- ACCESSORY ORGANS
o 1. Seminal vesicles
▪ Underneath the bladder
▪ There are 2 – left and right side
▪ Responsible for contributing volume to the ejaculate. Sperm itself only occupy 10%
of the ejaculate, and the rest of the volume is made by contributions by the
accessory glands
o 2. Prostate gland
▪ Underneath the bladder
▪ Contributes fluid to the ejaculate
▪ When bladder drains through the prostate to join the urethra
▪ Prostate cancer is associated with an increase in size of the prostate. It puts
pressure and – the draining of the bladder
• Report urination problems, pain, etc.
• Detection of a large prostate: use finger to palpate the prostate and
determine its size
o 3. Bulbourethral glands
▪ Contribute small amount of fluid to the ejaculate
- Sperm continues to collect fluid before being expelled!
- Urethra:
o Common passage for sperm and urine
o Different than females
▪ Males only have one common pipe for the passage for the urinary output and
reproductive components (sperm)
▪ Females have a division between the urine and reproductive components
- Vasectomy: By cutting and tying the vas deferens, sperm production continues but the sperm do not
get through!
find more resources at oneclass.com
find more resources at oneclass.com
The male- having your tube ties and the male pill?
- Reversible Vasectomy
o Inject a gel into vas deferens
o Remove the gel if you want to be reproductive again
- Vas deferens is the main vessel for sperm to move forward
- Sperm production does not stop when you cut the vas deferens
o It is just reabsorbed
Accessory Glands
- The accessory glands form the bulk of the ejaculate
- Sperm = 10%
- Accessory organs = 90%
Gland
Volume
Composition
Why?
Seminal vesicles
60%
Alkaline – good for sperm
because they do not like acidity.
Alkaline bathing of the sperm as
a form or production to get the
sperm into the acidic female
reproductive tract
Fructose (energy
source) used to
derive ATP production
in the sperm
ATP
Semenogelin
Coagulation
- Keep the sperm tightly together
Prostaglandins
Promote smooth muscle
contraction as sperm enters
female reproductive tract
Prostate
25%
Acidic
- The alkaline contribution from
the seminal vesicles over rides
the acidity
- Therefore, this is not a major
contribution to the pH of the
ejaculate
Citric acid
- Reason why it is
slightly acidic
ATP
Prostate specific antigen
(PSA)
- Elevated levels
associated with prostate
cancer
Disrupt clot
- Cleaves semenogelin and breaks
the clot up
- During ejaculation the sperm are
held tightly together and enter
female reproductive tract.
Overtime PSA has its effect and
sperm freely move
Bulbourethral
5%
Alkaline
Mucus
Lubrication
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Not responsible for homeostasis: you can live without the reproductive system. Testis: spermatogenesis in the human occurs at a temperature lower than body temperature why it is important that the testis are outside of the male body, core body temperature = 37c, spermatogenesis operates optimally at 34c. Body encompasses the lowering in temperature in two ways: 1. Ligaments that hold the testis in place move either up or down: cold day: ligaments move the testis towards the body cavity to warm the testis, hot day: ligaments move the testis away from the body cavity, 2. Blood: warmer blood from the core moves to the testis. Epididymis: primarily responsible for sperm storage, the testis makes the sperm, when sperm is developed it moves into the epididymis for storage and maturation! Head, middle, and tail region 3 components! Seminal vesicles: underneath the bladder, there are 2 left and right side, responsible for contributing volume to the ejaculate.
