Genitourinary System and Endocrinology Flashcards
What bone is the back of the pelvis?
Sacrum
What joints are at the front and back of the pelvis?
Posterior= sacroiliac joints
Anterior= Pubic symphysis
What is the pelvic inlet?
The circular ring that is created by the pelvis bones and joints.
It will vary in shape based on sex. More circular in women and more heart shaped in men (due to child birth so the babies head can fit)
What are the 2 ligaments of the pelvis?
What holes do they create?
Sacrospinous ligament and Sacrotuberous ligament
The greater and lesser sciatic foramen- structures pass through here from the lower limb to the pelvis.
What 2 muscles form the walls of the pelvis?
Piriformis and obturator internus
Where are eggs (female gametes) produced?
In the ovaries (gonads)
What are fimbriae?
They are the boundary between the ovaries and uterine tubes which sweep up the eggs from the ovary and into the uterine tubes.
What are the uterine tubes?
They transport the egg from the ovary to the uterus
What is produced in the testes?
Why are they outside the body?
Sperm
They produce sperm at a temperature slightly lower than body temperature hence why they are in the scrotum outside the body. They retract up towards the body if it gets cold.
What is in the spermatic cord?
Vas deferens (transports sperm to the ureter), artery and vein
What 2 muscles form the pelvic diaphragm?
Coccygeus
Levator ani (collection of 3 muscles)
What is the Pouch of Douglas (rectouterine pouch)?
This is the extension of the peritoneal cavity in the space between the posterior wall of the uterus and the rectum. Fluid can accumulate here when there is infection.
Where is the urinary bladder located in both sexes?
Most anteriorly
What are rugae in the urinary bladder?
These are folds in the membrane of the urinary bladder which increase the surface area so that the bladder can stretch under an increase in volume.
What is the detrouser muscle?
This muscle surrounds the urinary bladder and contracts to help force urine out of the bladder
What are the 2 glands below the bladder?
Prostate gland
Bulbourethral gland
What is the ejaculatory duct?
This duct releases sperm and prostatic fluid from the prostate into the urethra to form semen.
What are the 2 urethral sphincters in men and what is there function?
Internal Sphincter: Neck of the bladder- prevents semen from going into the bladder instead out of of the penis during ejaculation.
External Sphincter: Inferior to the prostate= controls urination
What is the difference between endocrine hormones and paracrine hormones?
What are autocrine hormones?
Endocrine hormones are released into the blood and then travel all over the body while paracrine hormones act on neighbouring cells at a close distance.
Autocrine hormones act on the same cell or a nearby cell that is very close.
What is the link between the hypothalamus and pituitary gland?
The hypothalamus controls the pituitary gland to release certain hormones depending on the signals that it receives.
Where is testosterone produced in men?
Testes (in Leydig cells) and remaining 5% in the adrenal glands
Do women produce testosterone?
Yes although a lot less than men
Why do we not want too much testosterone?
Possible increased risk of prostate cancer
Baldness on the top of male’s head
How is the mechanism of the action of hormones different between a steroid and peptide hormone?
Steroid hormones has a slower effect than peptide hormones but it is more permanent as steroid hormones must bind to to DNA and modify transcription where as Peptide hormones just bind to receptors on the cell surface which triggers a 2nd messenger. Therefore, the effects of a peptide hormone are more rapid but only temporary.
What is the difference between positive and negative feedback?
Positive feedback is when an output of a pathway amplifies the input to the pathway while negative feedback is when an output inhibits the input to the pathway
Where is the pituitary gland in relation to the hypothalamus?
Both structures are found at the base of the brain. The pituitary gland lies inferior to the hypothalamus with the optic chiasm (crossing of the optic nerves) in between.
What are the two lobes of the pituitary gland?
Where is the anterior pituitary in relation to the optic chiasm?
The anterior and posterior pituitary.
They are both on the same side.
What is the stalk connecting the hypothalamus and the pituitary gland called?
Infundibulum
How is the anterior and posterior pituitary glands connected to the hypothalamus?
Anterior lobe= portal vessels connect pituitary and hypothalamic beds
Posterior lobe= nerve fibres originate in the hypothalamus and transport hormones to the posterior pituitary
What 2 hormones are released by the posterior pituitary gland and what do they each do?
How are these hormones released?
What type of reflex do both of these hormones cause?
Oxytocin= Controls milk release from lactating breast. Controls uterine contraction at onset of labour.
ADH (also called vasopressin)= Acts on kidneys to reabsorb water in collecting duct.
They are both released from neurosecretory cells (can both be from either nucleus) in response to nerve impulses in the hypothalamus.
A neuro-endocrine reflex
What are the 6 hormones released by the anterior pituitary lobe?
Growth Hormone,
Prolactin
Adrenocorticotropic hormone (ACTH)
Thyroid stimulating hormone (TSH)
Follice stimulating hormone (FSH)
Luteinising hormone (LH)
What triggers the release of hormones from the anterior pituitary gland?
Releasing hormones from the hypothalamus
E.g.
Corticotropin releasing hormone (CRH)
Gonadotropin releasing hormone (GnRH)
Thyrotropin releasing hormone (TRH)
Growth hormone releasing hormone (GHRH)
Dopamine and Somatostatin inhibit the release of hormones (i.e. SS inhibits growth hormone and Dopamine inhibits Prolactin)
As an adult, will you grow taller if you take excess growth hormone?
No, as growth plates at the ends of bone have fused so you will not grow taller.
What is the effect of GH as adults?
It boosts protein production, promotes the utilization of fat, interferes with the action of insulin to increase blood sugar levels (protects against hypoglycemia)
What are androgens?
A group of hormones that play a role in male traits and reproductive activity but are present in both males and females (just be differing amounts).
Testosterone is the main type of androgen.
Where are the adrenal glands found?
There are 2 and each one sits on each of the kidneys and are enclosed in a fibrous capsule surrounded by fat
What are the 2 layers of the adrenal glands?
Outer= Adrenal cortex
Inner= Adrenal Medulla
What are the 3 distinct zones of the adrenal cortex?
Mineralocorticoids (aldosterone)- influence salt and water balance
Glucocorticoids (Cortisol)- anti-inflammatory
Gondocorticoids (androgens)- secrete androgens
What types of hormones are those released by the adrenal cortex?
How are different hormones produced from the same starting molecule?
They are all steroid hormones so are derived from cholesterol and therefore work by altering transcription of mRNA in protein synthesis.
Even though all the hormones are produced from cholesterol, different enzymes lead to different hormone products.
What are the main hormones produced in the adrenal glands in males?
DHEA, DHEA-S and androstenedione.
Insignificant amounts (about 5%) of testosterone is made in the adrenal glands.
What controls the synthesis of testosterone in the adrenal glands?
The anterior pituitary gland releases ACTH.
Do the ovaries make testosterone? What is it immediately converted to?
Yes but it is immediately converted to oestogren
What is the primary source of testosterone in females?
The adrenal glands- secrete half the total androgenic requirement
What is the effect of excessive production of adrenal androgens in females? How can these be reversed?
This results in masculinisation of females (e.g. acne, facial hair, breast shrinkage)
Anti-androgen drugs block androgen receptors and therefore alleviates some of the symptons
What are the 2 major functions of the testes?
What controls these functions
Spermatogenesis- process by which sperm cell development occurs
Steroidogenesis- the process by which cholesterol is converted to steroid hormones (e.g. testosterone)
Both functions under hormonal control from the anterior pituitary gland by:
LH and FSH
How is sperm produced?
Spermatozoa are produced by the testes in the seminiferous tubules. Sperm develop from spermatogonia, which are surrounded and facilitated by large Sertoli cells. The sperm then leaves the seminiferous tubules (site of sperm formation). This happens from Leydig cells which surround Sertoli cells and they are a type of connective tissue which secrete testosterone. Sperm then enters the epididymis where they gain motility and pass to the vas deferens. The sperm combine with prostate fluid and seminal vesicle secretion to create semen
What is androgen binding protein?
This is produced by the Sertoli cells and binds to testosterone which carries testosterone out of the seminiferous tubules and into the epididymis where a high conc of testosterone is required for sperm maturation
If testosterone doesn’t bind to androgen binding proteins, where does it go?
It is released into the blood and binds to Sex hormone binding globulin (SHBG) and albumin where it is then converted to DHT, Androstenedione and Estradiol (a type of oestrogen).