Reproduction Flashcards
What is the function of the epididymis?
Transports and stores spermatoza produced in testes Epididymis stimulates maturation process of sperm Site of breakdown of sperm if it is not ejaculated
What does the seminal fluid contain?
Bicarbonate (neutralise vaginal acidity),fructose,citrate, fibrinogen, fibrinolytic enzymes
What is the function of bicarbonate in the seminal vesicles?
Helps neutralise the acidic environment of the female reproductive tract
Where is the spermatic cord formed?
Deep inguinal ring
What structures does the spermatic cord contain?
Testicular artery
Pampiniform plexus (veins)
Autonomic and genitofemoral nerves (nervous supply to testicles)
Lymph vessels
Vas deferens
Which nervous systems stimulate erection and ejaculation?
Erection - Parasympathetic
Ejaculation - Sympathetic Point and shoot
What muscles does the penis contain?
2 x Corpora Cavernosa
1 x Corpora Spongiosum
What does the bulbo-urethral gland secrete?
Sugar-rich mucus into urethra for lubrication and contribute to pre-ejaculatory emissions from penis (seminal fluid)
How does the parasympathetic nervous system cause an erection?
Causes vasodilation of blood vessels going into the penis.There is more blood flow into the penis and the enlardged arteries push on the veins which occludes venous outflow and causes an erection.
Why is the testes suspended in the the scrotum?
Keep temperature 2-3 degrees lower than body If temperature increases then sperm production ceases
What is the lymphatic drainage of the testes?
Drains into para-aortic lymph nodes.
What is the vas deferens?
Tube from epididymis into seminal vesicle transporting mature sperm AKA - ductus deferens
Which layer of connective tissue forms the septa of the testes and which contains all blood vessels?
Septa are formed from tunica albuginea
Blood vessels contained in tunica vasculosa
Outline the arterial blood supply and lymphatic drainage of the testes
Arterial blood supply - Testicular arteries from the aorta via spermatic cord Lymphatic drainage - Para-aortic lymph nodes
Which organ can allow male sterilisation by vasectomy?
Vas deferens (minimal incision required)
Outline the lymphatic drainage in the female reproductive tract
Ovaries: para-aortic lymph nodes
Uterus/vagina: lliac, sacral, aortic, and inguinal lymph nodes
What do the ovaries sit inside?
Peritoneal cavity (remainder of organs outside)
What structures in the fallopian tube aid in the movement of the egg into the uterus?
Cilia and spiral muscle
Where does fertilisation of the egg occur?
Ampulla i.e. widest part of fallopian tube
How is the uterus supported?
Levator ani, coccygeus muscles and ligaments (broad, round, uterosacral)
What is the uterus lined by?
Endometrium
List the layers of the uterus
Perimetrium, myometrium (smooth muscle layer sensitive to hormones) and endometrium
Which layer of the uterus is shed during menses and why?
Endometrium Due to vasoconstriction of arterioles → Ischaemia/necrosis causing shedding and haemorrhage of menstruation
Outline the arterial blood supply of the ovaries and uterus/vagina
Ovaries → Ovarian arteries from aorta
Uterus/vagina → Uterine arteries (from internal iliac artery)
How is the sterility of structures above the cervix maintained?
Periodic shedding of the endometrium in the menstrual cycle,thick mucous,narrow os (hole in middle of cervix),pH<4.5
How much mature sperm is produced per second?
Around 1500
Explain why in general, men are continuously fertile?
Spermatogonia undergo differentiation and self-renewal → pool available for subsequent spermatogenic cycles throughout life. The pool of germ cells is not depleted
When does gametogenesis begin in males?
At puberty
Before birth, describe how the number of female gametes changes?
Multiplication of Oogonia to 6 million/ovary Form Primary Oocytes within ovarian follicles (=primordial follicles) These begin meiosis (halted in prophase) Some primordial follicles degenerate (atresia) At birth 2 million/ovary remain
Describe the process of spermatogenesis
Diploid germ cell (spermatogonium) divides to form diploid Primary Spermatocytes via mitosis
Diploid Primary Spermatocytes divide via meiosis to form Haploid Secondary Spermatocytes
Haploid Secondary Spermatocytes divide by 2nd meiosis to form Haploid Spermatids
Haploid Spermatids differentiate to form Haploid Spermatozoa
Does the sperm or the egg determine the sex of the baby?
Sperm
What is the function of the sertoli cell and where is it found?
It is found within the seminiferous tubules of the testes.>It has FSH receptors-Supports the process of spermatogenesis
- Supports developing germ cells by
-Assisting movement of germ cells to tubular lumen
-Transfer nutrients from capillaries to developing germ cells
-Phagocytosis of damaged germ cells - Hormone synthesis
-Inhibin and Activin (feedback on FSH)
-Anti-mullerian hormone (important in development of anatomy in men)
-Androgen-binding proteins
Which reproductive hormones are released by the Testes?
Androgens
-Testosterone
-Dihydrotestosterone
-Androstenedione
Inhibin (inhibits FSH)
-Activin (activates FSH) Oestrogens(from androgen aromatisation)
Which hormone are oestrogens derived from?
Testosterone
What are the functions of oestrogen in males?
Preservation of bone mass, sexual behaviour
What are the names of the cells that have FSH and LH receptors respectively in men?
Sertoli - FSH receptor
Leydig - LH receptor
What is the function of the leydig cell and where is it found?
Found outside of the seminiferous tubules, between them. Inside the testes it has a pale cytoplasm and is rich in cholesterolIt has LH receptors
It has a function in hormone synthesis
-Upon stimulation by LH, it secretes androgen hormones:
-testosterone (oestrogens formed from this)
-androstenedione
-dehydroepiandrosterone (DHEA)–> can be aromatised by aromatase enzyme to form oestrogens
What is the term for the first menstrual cycle in females?
Menarche
What are polar bodies?
Formed as a result of the first and second meiotic divisions in oogenesis.They are haploid and formed along side the secondary oocyte and ootids.Very low cytoplasm structures that get shed.
How does Oogenesis occur?
2nd trimester of pregnancy–>
-Oogonia (germ cells) in foetus undergo mitosis to develop into diploid primary oocytes (forming primordial follicles)
Process haulted until menarche
At menarche–>
-1st meiotic division of primary oocytes to form haploid secondary oocytes and polar bodies (these are shed).
Process haulted until just before fertilisation
After sperm fusion–>
-2nd meiotic division of secondary oocytes to form haploid ootids and polar bodies (these are shed).
-Ootids differentiate to form mature ova which are fertilised
Describe the steps involved in folliculogenesis.
- Primordial follical (Primary Oocyte at birth)
- Primary (preantral) follicle:
-Primary Oocyte and layers of granulosa cells and outer theca cells
3.Secondary (Antral) follicles:
-Fluid-filled cavity (antrum) develops
-Development of FSH and LH receptors - Mature (graafian/preovulatory) follicle:
-Formed towards the end of menstrual cycle
-Forms due to LH surge
-Secondary oocyte formed
5.Ruptures surface of ovary - Formation of corpus luteum (follicle without egg)
-Progesterone and oestrogen (stim by LH/HCG)
-In pregnancy, progesterone and oestrogen production taken over by placenta - If fertilisation occurs–> corpus albicans:
-Placenta produces HCG which keeps corpus luteum alive, to allow continued production of progesterone and oestrogen - If no fertilisation–> corpus luteum degenerates
Which type of follicle is most prevelant in polycystic ovarian syndrome?
Secondary (antral) follicles
What reproductive hormones are produced by the ovaries?
Oestroogens
-Oestradiol (classically measured in a blood test)
-Oestrone
-Oestriol
Progestogens (made by corpus luteum towards end of menstrual cycle)
-Progesterone
Androgens
-Testosterone
-Androstenedione
-DHEA (not in adrenals)
Relaxin (involved in relaxation of ligaments around pregnancy)
>Inhibin (negative feedback on FSH)
If there is no pregnancy, the corpus luteum degenerates and there is a withdrawal of progesterone. What effect does this have?
Vasoconstriction of aterioles in the endometrium causing pain and shedding. This leads to menstruation.