Topic 88 - The role of accessory sexual glands in males, male sexual reflexes

Question 1

Words to include in the role of accessory sexual glands in males

Answer 1

• Seminal vesicle (gl. vesicularis ) (ø Ca)
• Prostatae
• Cowper’s gland (gl. bulbourethralis) (ø Ca)
• Ampulla ductus deferentis (ø Sus)
• Seminal plasma
  
  • Spermatozoa
  • Contains essential substances for sperm
• Semen / ejaculate
  
  • Plasma seminalis + spermatozoa

Seminal vesicle (ø Ca)

• Lobes
• Energy supply
• Activation of spermatozoa
• Secrete “washes” sperm out of urethra
• Mucous consistency
  
  • Sol-gel transition
  • “Plug” vagina
• Acts on the female sexual canals
  
  • Uterine contractions

Prostatae

• Lobular gland
• Sperm-motility induction

Cowper’s gland (gl. bulbourethralis) (ø Ca)

• Lobular tuboloalveolar bodies
• Serous acidic secretion
  
  • (sus: viscous)
• Damages sperm
  
  • Sperm motility ↓
  • Sperm agglutination ↑
• Clears urethra from sperm previusly left there

Ampulla ducuts deferentis

• Tubuloalveolar glands
• Ru: Fructose & citric acid secretion
• Eq: Ergothionine & inositol
• Facilitates passage of sperm

Vitality and motility of spermatozoa

• Epididymis
  
  • High partial pressure of CO₂
  • High density of sperms
  • Low accessibility of O₂
  • = Dormant state
    
    • Preservation of sperm cells
• Factor for activation
  
  • Fructose
  • High partial pressure of O₂
  • Elicit movement:
    
    • Massmovement
      
      • Synchronous movement of spermatozoa
    • Individual movement
      
      • Non-directional specific way of a single sperm
• Action from female reproductive ducts:
  
  • Rheotaxis
    
    • Semen moves towards tuba
  • Capacitation

Question 2

Words to include in male sexual reflexes

Answer 2

• Copulation
• Exogenous stimuli
• Endogenous stimuli
• Olfactory
• Visual
• Acoustic
• Tactile
• Cortex-midbrain-spinal cord axis
• Pre-copulatory behavior
  
  • Search for sexual partner
  • “Courtship”
  • Sexual arousal
  • Erection
  • Penile protrusion
• Copulatory behavior
  
  • Mounting
  • Intromission
  • Ejaculation
• Post-couplatory behavior
  
  • Dismount
  • Refractory period
  • Memory

Erection

• Swelling of penis
• Protruding it from prepuce
• Lumbo-sacral vegetative center (regulator)
• Sympathetic effect
  
  • Vasoconstriction inhibition
• Parasympathetic effect
  
  • Vasodilation
  • Engorgement of corpus cavernosum
• Arteries: dilation
• Veins: compression

Intromission

• Introduction and intromission of penis to vagina
• Swelling of erectile tissue (corpus cavernosum)
  
  • Via a. pudenda

Ejaculation

• Afferentation of ejaculatory reflex
  
  • Mechanical stimulation after intromission of penis
  • After-push reflex
  • Afferent nerves project lumbar center of spinal cord
    
    • Ejaculation elicited
• Efferentation of ejaculatory reflex
  
  • Hypogastric plexus leads sympathetic projection
    
    • To ductus deferentis & accessory glands
    • Contraction = propelling of sperm → urethra
  • Motor impulse via n. pudenda interna
    
    • Reaches striated muscle fibers of urethra
    • Contraction of:
      
      • Bulbocavernosus muscles
      • Ischiocarvnosus muscles
      • Urethra constrictor muscles
• Mechanis mo ejaculation:
  
  • Ru:
    
    • Single phase
    • Synchronized process
  • Eq, Car, Sus.
    
    • ​Multiphase
    • Asynchronous steps

Question 3

The role of accessory sexal glands in males

Name the accessory sexual glands in males

Answer 3

• Seminal vesicle (gl. vesicularis) (ø Ca)
• Prostatae
• Cowper’s gland (gl. bulbourethralis) (ø Ca)
• Ampulla ductus deferentis (ø Sus)

Question 4

The role of accessory sexual glands in males

Seminal vesicle

Answer 4

• Ø Car
• Secretory activity is stimulated by testosterone
• Location: cervical part of the urinary bladder
• Role:
  
  • Energy supply
  • Activation of spermatozoa
  • The secrete “washes” sperm out of the urethra
  • The secrete have mucous consistency, and subjected to sol-gel transition after being exposed to air
    
    • The gel the “plugs” the vagina, preventing sperm from returning
  • The prostaglandin content acts on female sexual canals, enchasing uterine contractions → promoting passage of sperm to site of fertilization

Question 5

The role of accessory sexual glands in males

Prostatae

Answer 5

• Branched tubuloalveolar gland with fibromuscular coat
• Secretory activity is stimulated by testosterone
• Location: cervical part of the urinary bladder, around urehtra
• Role: Induction of sperm mobility

Question 6

The role of accessory sexual glands in males

Cowper’s gland (gl. bulbourethralis)

Answer 6

• Ø Car
• Secretory activity is stimulated by testosterone
• Tubuloalveolar glands
• Location: cervical part of the urinary bladder, around urehtra
• Role:
  
  • Damages sperm cells
    
    • ​Motility ↓
    • Agglutination ↑
  • Cleaning the urethra from sperm previously left there, cellular debris and bacteria, which can impair fertilization
  • Sus: forms a barrier at the opening fof the uteral cervical canal, preventing sperm from flowing back

Question 7

The role of accessory sexual glands in males

Ampulla ductus deferentis

Answer 7

• Ø Sus
• Enlargement of ductus deferens, opens to the pelvic urethra
• Role: secretory function facilitates passage of sperm

Question 8

The role of accessory sexual glands in males

Vitality and motlilty of spermatozoa

Answer 8

“Dormant” (anabiotic) state:

• ​Effect of epididymis:
  
  • ​High partial pressure of CO₂
  • High density of sperms
  • Low accessibility of O₂
  • Function: preservation of sperm vitality for 3-4 months
• Effect of ejaculate:
  
  • Activation:
    
    • Fructose as energy source
    • High partial pressure of O₂
  • Activation elecit two types of movement:
    
    • Massmovement​
      
      • ​Semen moves diffusely because a synchronous movement of spermatozoa
    • Individual movement
      
      • ​A single sperm moves in a non-direcition specific way
• Effect of female reproductive ducts:
  
  • ​Rheotaxis → semen moves towards tuba
  • Capacitation: Enzymatic and pH circumstances in the ducts of the female provide basis of special, activating maturation process for spermatozoa

Question 9

The role of accessory sexual glands in males

Transport, capacitation and fertilization

Answer 9

• After ejaculation:
  
  • ​Sus, eq: Directly in the cervix
  • Rest: Into anterior vagina
• Sperms are lost from female truct by retrograde transport and phagocytosis by neutrophils
• Cervix: major barrier of transport, and reservior
• Uterus: Capacitation initiated
• Oviduct: Capacitation completed
• Fertilization: Acrosome reaction → spermatozoon penetrates into the oocyte

Question 10

Male sexual reflexes

Define copulation

Answer 10

• Copulation is a set of reflexes, induced by exogenous and endogenous stimuli:
  
  • ​Olfactory
  • Visual
  • Acoustic
  • Tactile

Question 11

Male sexual reflexes

Where are the reflexes eleicited from?

Answer 11

Reflexes are elicited via cortex-midbrain-spinal cord axis

Question 12

Male sexual reflexes

Name the different phases

Answer 12

1. Pre-copulatory behavior
   
   • Search for sexual partner​
   • Courtship
   • Sexual arouasal
   • Erection
   • Penile protrusion
2. Copulatory behavior
   
   • ​Mounting
   • Intromission
   • Ejaculation
3. Post-couplatory behavior
   
   • ​Dismount
   • Refractory period
   • Memory

Question 13

Male sexual reflexes

Pre-copulatory behavior

Answer 13

1. Search for sexual partner
2. Courtship
3. Sexual arouasal
4. Erection
5. Penile protrusion

Erection

• Preparation:
  
  • Swelling of penis and protruding from the prepuce
• Neural stimulation (symp. and parasymp.):
  
  • ​Regulator: lumbo-sacral vegetative center
  • Sympathetic effect: inhibition of vasoconstriction
  • Parasympathetic effect: vasodilation and engorgement of corpus cavernosum
• Arteries: dilation
• Veins: compression
• Erection is followed by emission
  
  • ​Sperm move up from cauda
• Jumping and embracing reflexes follow the process

Question 14

Male sexual reflexes

Copulatory behavior

Answer 14

1. Mounting
2. Inromission
3. Ejaculation

Intromission

• Introducing and intromission of the penis into the vagina
• Swelling of erectile tissue (corpus cavernosum) of the penis via a. pudenda in state of erection

Ejaculation (reflex arc)

• Afferentation:
  
  • ​Mechanical stimulus of the penis after inmmission, during the “after push” reflex of copulation
• Center:
  
  • ​Lumbal segment of spinal chord
• Efferentation of the reflex acts through:
  
  • Hypogastric plexus
    
    • ​Sympathetic message to smooth muscles of ductus deferens and accessory sexual glands
    • ​Result: propelling of sperm into urethra
  • N. pudenda interna
    
    • ​Motoric impulses stimulates striated muscles of the urethra, transmitting ejaculate from the female sexual ducts
• Ru:
  
  • Single phase
  • Synchronous process
• Eq, Sus, Ca, human:
  
  • Multiphase
  • Asynchronous process