Anatomy of the male reproductive system and Breast

Question 1

functions of the male reproductive system functions as a system

Answer 1

• Production, maturation, and storage of sperm
• Delivery of sperm into the female reproductive system
• Excretion of urine

Question 2

Functions by organ(s)

Answer 2

• Gonads - Testes: produce sperm and testosterone
• Ducts: transport, store, and mature sperm
• Accessory sex glands: secrete liquid portion of semen
• Supporting structures -Penis: passage for excretion of urine and ejaculation of sperm

Question 3

Urethra

Answer 3

• The terminal duct
• Conveys both sperm and urine
• Passes through:
inferior portion of the prostate,
deep muscles of the perineum
Penis
• Opening is called the external urethral orifice

Question 4

Bulbourethral glands

Answer 4

• Produces fluids during arousal to protect
sperm:
- alkaline substance to neutralise acids in
urethra and vagina
- mucous to lubricate tip of penis an urethra

Question 5

Penis

Answer 5

• Contains urethra as passageway for urine and
semen
• Method to deliver semen
• Consists of:
- Body
- Root
- Glans
• Supported by two ligaments continuous with
fascia of penis:
- Fundiform ligament; inferior part of linea alba
- Suspensory ligament of penis; from pubic
symphysis

Question 6

Semen

Answer 6

• Mixture of sperm and semen made up of secretions from seminiferous tubules and accessory glands
• Provides medium to transport and give nutrients to sperm
• Also contains antibacterial agent to kill bacteria

Question 7

Sperm production - Spermatogenesis

Answer 7

involves Mitosis and Meiosis
Mitosis – somatic cell division
• Stem cell (46 pairs of chromosomes) – divides into two daughter cells (23 pairs of chromosomes)
• Diploid cells – one stays a stem cell, one enters meiosis called primary spermatocyte
Meiosis – two cycles of division
• At then end of Meiosis I cells now 2 secondary
spermatocytes (23 chromosomes and a pair of
duplicate chromatids)
• Meiosis II produces 4 haploid spematids – each have 23 individual chromosomes (one from each pair)
• Last step of Spermatogenesis – each spermatid
matures into a spermatozoon (sperm) with a
flagellum (tail)
Takes about 5 weeks to complete

Question 8

Blood supply

Answer 8

• The breast is highly vascular
• Predominantly supplied by internal mammary arteries derived from internal thoracic
artery
• Lateral thoracic and thoracoacromial arteries
(branches of the axillary artery) as well as posterior intercostal arteries (branches of the thoracic
aorta).

Question 9

Lymphatic drainage

Answer 9

• Originates from lobules to subareolar plexus – Sappey’s Plexus
• 75% of lymph drainage to axillary nodes
• Drainage by 3 main routes
• The lymphatic drainage of the breast is of great importance in the spread of carcinoma

Question 10

Cyclic
changes

Answer 10

• Oestrogen levels increase vascularity of breast tissue and stimulate proliferation of ductal and acinar tissue
• Effect sustained during luteal/secretory phase
• Progesterone levels increase and contribute to breast changes
• Dilation of ducts and conversion of acinar cells to secretory cells
• Breast volume may increase by 10 – 30mL

Question 11

Post pregnancy

Answer 11

• Breast has capacity to regress to a resting stage after cessation of lactation and the undergoes same cycle of expansion and regression in subsequent pregnancies