Anatomy And Physiology Flashcards
How long is a female urethra?
3-4cm
Tissues involved in second degree perineal tear
Perineal skin
Vaginal epithelium
Perineal body
Tissues involved in 3rd degree perineal tears
External and internal anal sphincters
Tissues involved in 4th degree perineal tears
Extends into anal mucosa
How are perineal tears managed
Sutured
>1st and 2nd degree = in the ward
>3rd and 4th degree = in theatre
What is the length of a vagina?
Posterior wall = 9-10cm
Anterior wall = 7,5cm
What lubricates the vagina?
There are no glands in the vagina. It is lubricated by secretions from the cervix and the bartholins glands, and vaginal transudate from capillaries
What are the normal dimensions of a uterus?
Length 6-8,5cm
Width 3-6cm (in transverse plane)
Depth 2-6cm
+-50g
What epithelium lines the endometrium?
Columnar epithelium (single layer)
What are the components of the broad ligament?
Mesosalpinx
Mesometrium
Mesovarium
What’s the most common position of the uterus?
Anteversion and anteflexion
What is the lymphatic drainage of the cervix?
Drains to the iliac LN situated on the external iliac vessels and in the obturator foramen
What are the phases of the menstrual cycle?
1)Follicular phase
2)Ovulatory phase
3)Luteal phase (always 14 days)
4)Mentruation
What is oogenesis?
The process of maturation of a primary oocyte into a mature oocyte
What phase of mitosis does the oogonia freeze in inutero? When do they continue their mitosis?
Prophase 1 (primary oocyte)
Meiosis continue at the start of menstruation and finish just before ovulation (starts at puberty)
The second meiotic division occurs at the time of sperm penetration
2 meiotic divisions x 1oocyte = 1 mature ovum + 3 polar bodies
Describe the follicular phase of the menstrual cycle.
At the beginning of the follicular phase, FSH stimulates a bunch of oocytes to mature. The maturing oocytes produce oestrodiol and the granulosa of the oocytes produce Inhibin A. Both oestrodiol and Inhibin A cause a negative feedback on the pituitary resulting in decreased FSH. The dominant follicle is selected as it has the most FSH receptors and higher oestrodiol levels allowing it to survive the low FSH environment.
FSH withdrawal causes a surge in LH, and the FSH then functions to up-regulate the LH receptors.
Describe the events in the Ovulatory phase of menstrual cycle
There is a surge in LH which causes the release of the ovum from the mature oocyte. (Within 36hours of onset of surge, and 10-12hours after peak) There is a increase in prostaglandins (stimulating follicular wall degeneration) and progesterone (terminates LH surge by negative feedback)
What are the normal parameters of the menstrual cycle?
Length of cycle = 24-36days
Volume = 5-80ml
Duration = <8days
Regularity = variation <7-9days
When is the window of fertility?
Ovum lasts 12-24hours after ovulation in tubes
Sperm survive +-5days in tubes
Therefore window = 5days before ovulation
When is the window of implantation?
The fertilised ovum is in the tubes for 6-10 days before enters uterus.
Window = 6days after LH surge for +-4days
Define puberty
The process in which secondary sexual characteristics and reproductive capability develop in adolescence, resulting in the ability of human to reproduce.
What hormones spike in puberty?
LH and FSH =
Oestrodiol
Testosterone
Progesterone
What are the effects of increased oestrodiol at puberty?
Breast development
Growth acceleration
Ovulation
Menstruation
What factors influence timing of puberty?
Ethnic
Genetic
Physical health/exercise
Diet
Mental health
What staging is used for breast and pubic hair development in puberty?
Tanners staging
What is precocious puberty?
The onset of pubertal development at an age that is 2-2,5 standard deviations earlier than the population norm defined by onset of menstruation and secondary sexual characteristics before the age of 8years old
Thelarche?
Breast development
During which stage in the Tanner staging does the first menstrual period occur?
Stage 4-5
How do you determine bone age in a child?
X-ray of let wrist
What medical treatments can be used to treat precocious puberty?
GnRH analogues (downregulates endogenous secretion by applying constant stimulation to pituitary) = FIRST LINE
Define delayed puberty?
The failure to develop secondary sexual characteristics by age 13
OR
Absence of menarche by age 16
OR
When menarche does not occur five or more years after the onset of pubertal development
Anechoic?
No u/s waves are reflected back = black
Hyperechoic?
Lots of u/s waves are reflected back = white
Haematometria?
Collection of blood in the uterus mostly due to imperforate hymen
