Physio- Chapter 23: Reproduction

Somatic cells have how many pairs of chromosomes

23 pairs (46 total chromosomes)- diploid (2n)

Gametes are are what

sperm and ovum

Gametes have how many chromosomes

23 only - haploid (1n)

What does meiosis result in

production of genetically unique haploid daughter cells

What occurs in Meiosis I

chromosomes separate (create haploid cell at end)

• prophase I

  • synapsis of homologous chromosomes (tetrad formation)

  • crossing over

• Metaphase I

• Anaphase I

• Telophase I

What occurs in Meiosis II 

Chromatids separate

• prophase II 

• Metaphase II 

• Anaphase II 

• Telophase II

what do the testes od the male reproductive system do

produce sperm and secrete hormones

What is the ductal system of the male reproductive system

ducts that move sperm to outside of the body

what makes up the ductal system

epididymis

vas deferens

ejactulatory ducts

urethra

what does the epididymis do

sperm storage and maturation

what does the urethra do

carries sperm out of body

What are accessory sex glands

add fluid/ a transport medium to sperm

what are the accessory glands of the male reproductive system

seminal vesicles 

prostate gland 

bulbourethral glands

What are the supporting structures of the male reproductive system

• penis- passageway to get sperm out of body 

• scrotum

  • the scrotum protects the testes and regulates their temp

What is the seminiferous tubules of the testes

site of sperm production

what cell types does seminiferous tubules contain

• spermatogenic cells

• sertoli

• leydig (interstitial) cells

What are sertoli cells and what do they do?

• contain FSH receptor

• support and protect spermatogenesis

• produce inhibin (selectively inhibits FSH)

• blood-testis barrier(protects from toxins) - tight junctions b/e sertoli cells

What are leydig cells, what do they produce 

• interstitial cells that contain LH receptors 

• produce testosterone 

  • LH stimulates leydig cells to release testosterone

During Meiosis, synapsis and crossing over occurs during what phase

prophase I of meiosis I

What does spermatogonia(2n) go through

mitosis

Mitosis of spermatogonia

one daughter cell stays at basement membrane; one differentiates into primary spermatocyte

meiosis of spermatogenesis 

meiosis I: 

• primary spermatocyte

  • synapsis and crossing over

Meiosis II:

• secondary spermatocyte (1n)

• spermatids (1n)

• spermatozoa

What is spermiogenesis

the maturation of sperm

Where does spermiogenesis occur

occurs in the lumen, more specifically in the epididymis (major storage & maturation occurs)

Head of sperm contains what

• contains haploid DNA (nucleus)

• Acrosome (proteolytic enzymes to help sperm digest through layers and penetrate ovum/oocyte)

Midpiece of sperm contains what 

mitochondria (produce energy (ATP) to swim up to uterine tube where most fertilization occurs)

Tail of sperm is the only cell in the human body with what

flagella (provides motility/ help sperm swim)

What does the epididymis do

• sperm maturation (~14 days)

• stores sperm for months

What are the vas deferens (ductus deferens)

• propels sperm to urethra

• stores sperm for months

What are the ejaculatory duct 

eject sperm and seminal vesicle fluid into urethra

Urethra

shared passageway for semen and urine to exit the male body

What are the regions of the urethra

• prostatic urethra (through prostate)

• membranous urethra

• penile (spongy) urethra

What are the accessory glands

semen made up of sperm and fluids from three sex glands

• seminal vesicles

• prostate gland

• bulbourethral gland

Where is the seminal vesicle 

 behind the urinary bladder

What does the seminal vesicle secrete and what is that made up of

alkaline, viscous fluid

• fructose

• clotting proteins

• prostaglandins

what does fructose make

ATP

what do clotting proteins do

keep sperm clumped together, increase concentration of sperm in semen

what do prostaglandins prevent 

bacterial attachment 

Where is the prostate gland located/ what does it surround

beneath the bladder and surround prostatic urethra

What does the prostate gland secrete and what id it made up of

secretes milky, slightly acidic solution

• citric acid- energy/ ATP

• clotting enzymes act on fribrinogen

• proteolytic enzymes- inactivate clotting for sperm to leave semen

• seminalplasmin- protect from pathogens

What are bulbourethral glands

• also called Cowper’s glands

• pea-sized structures

what does bulbourethral glands secrete

alkaline fluid 

mucus 

In a vasectomy, which of the following structures are cut? will a man continue ejaculate?

Ductus (vas) deferens; yes

What does the penis do

deposits semen into the female reproductive tract

what are the 2 main regions of the penis

• shaft

• gland penis (tip)

What are the two different erectile tissue types 

• corpora cavernosum 

• corpus spongiosum

What does the corpora cavernosum do

• dorsolateral

• fills with blood (to make penis hard) during erection

What does the corpus spongiosum do

• ventral

• surrounds penile (spongy) urethra

  • keeps urethra open during ejaculation

Erection is a _____ refllex

parasympathetic

What are the 3 events for semen to leave the body 

1. erection 

2. emission

3. ejaculation 

Erection is the sacral spinal cord

• postaganlioinic parasympathetic neurons

• nitirc oxide causes vasodilation

• corpora cavernosa fills with blood →