Chapter 5 Flashcards
What is gender differentiation?
Fertilized off either carries XX or XY chromosomes
-some atypical chromosomal configurations possible
What are hormones?
Chemicals manufactured by the endocrine glands and secreted into bloodstream
What are the 2 kinds of hormone responses?
Quick acting effects
-sexual response
Slower, longer lasting effects
-Blood sugar regulation
What is the difference between the sec chromosomes?
They carry info about how to differentiate in the course of development
Where does fertilization normally occur?
Initial fertilization in distal end of Fallopian tube
Before 7 weeks can you determine if the embryo is a boy and a girl?
Before 7 weeks male and female are identical in structure and are undifferentiated
What happens at the 7th week in male and females?
Chromosomes direct gonads to begin differentiation
Male: undifferentiated gonad develop into testes around week 7
Females: ovaries develop around week 10-11
What are the 2 ducts called?
Wolffian: Male
Mullerian: Women (default)
What is the SRY?
Sex determining region Y chromosome
-if present causes testis determining factor (TDF) to be manufactured and sends message to the mullein ducts that we don’t need them
What happens if SRY isn’t present?
Female gonads develop
What are the key components to help male differentiaiton?
Presence of androgens
- testosterone
- dihydrotestosterone (DHT)
How do you get DHT?
5% of testosterone is converted
In females, what is involve in the further development of the Mullerian ducts into female structures?
Ovaries are involved
-Fallopian tubes, uterus, upper vaginal canal
Wolffian ducts will degenerate
What do the testes secrete?
Mullerian Inhibiting Substance (MIS)
What is MIS?
Causes the degeneration of the mullein ducts that are present in the undifferentiated state of XX and XY embryos
Why do testes secrete testosterone?
To support the further differentiation of the wolddian ducts into male structures
-such as epididymis, vas deferens, ejculatory duct
What is a homologous organ?
Make and female organs develop from the same embryonic tissue
What is an analogous organ?
Male and female have similar function
Where do ovaries begin and when do they move?
Begin at top of abdominal cavity in early gestational development
Week 10 gestation ovaries move down the upper edge of pelvis
-still able where they will be after birth
Where do testes begin and when do they move?
Begin at top of abdominal cavity early in gestational development
Descend through the inguinal canal to ultimate destination in scrotum
What is Cryptorchidism?
Undescended teses
- occur in 2% of males
- Associated with health issues
- impair sperm production later in life
- Increase risk of hernia and cancer
Why is Cryptorchidism associated with health issues?
Undescended testes can become twister in the abdomen
-testicular torsion
Why is Cryptorchidism associated with impaired sperm production?
Intra-abdominal temp too hot and not conducive to sperm viability
How do you treat cryptorchidism?
Surgery at 1 year
What is a hernia?
Something that is somewhere where it isn’t supposed to be
When can men get hernias?
Men with a history of undescended tests and or abdominal surgery will be monitored for hernias throughout their lifetime
What are androgens?
Group of make sex hormones
Where is testosterone made?
Secreted by lending cells in tesitcels
Is testosterone in females?
Found in small amounts in females
-secreted by ovaries and adrenal glands
What are the different forms of estrogen?
Estrone
Estrodiol/s
Estriol
What is progesterone?
A female sex hormone secreted by the ovaries
What produces estrogen and progesterone?
Ovaries
What does the hypothalamus regulate?
pituitary and other health behaviours like eating drinking and sexuality
What does the pituitary regulate?
The gonads
What are the 3 lobes of the pituitary?
Anterior
Posterior
Intermediary
What is the HPG axis?
the hypothalamus pituitary and gonads are considered an axis of influence that function together to regulate endocrine functioning related to sexuality, puberty and gestation
What is FSH regulated by?
GnRH which is secreted by the hypothalamus
-controls sperm production
What is LH regulated by?
GnRH secreted by hypothalamus
-controls testosterone production
Do male hormone levels flux?
No they stay pretty normal due to negative feedback loop within the HPG axis
What happens when testosterone levels are low?
Upregulates hypothalamus production of GnRH and stimulations;ates pituitary to produce more LH (and therefore more testosterone)
What happen testosterone levels are high?
Inhibits hypothalamus production of GnRH and inhibits pituitary production go LH (thus inhibiting testosterone production)
Are FSH levels controlled in the HPG pathway?
FSH levels are not controlled in the negative feedback loop within the axis
Regulation of FSH occurs via the negative feedback loop created between inhibit and testosterone
What is inhibin?
Substance secreted by the testes and ovaries and regulates FSH levels
By inhibiting FHS it inhibits sperm production
Where is inhibit produced?
by Sertoli cells in the testes
What Sio the main function of estrogen?
Functions to influence puberty, maintain integrity of mucous membranes of the vagina, inhibits bone loss, inhibits muscle growth relative to males
What is the main function of progesterone?
Responsible for increasing the lining of the endometrium in preparation for embryo implantation, sustains zygote in early pregnancy until placenta takes over
What do the levels of estrogen and progesterone fluctuate with?
Menstrual cycle
Pregnancy
Menopause
How are the levels of estrogen and progesterone regulated in the body?
Same negative feedback loop of the HPG axis by FSH and LH
What happens when estrogen levels are low?
Up regulates hypothalamus production of GnRH, stimulate pituitary to produce more LH and then more estrogen
What happens when there are high levels of estrogen?
Inhibits hypothalamus production of GnRH, and that inhibits pituitary production of LH and that inhibits estrogen production
What is secreted from the posterior pituitary?
Prolactin and Oxytocin?
Why is prolactin important?
stimulates secretion of the milk by mammary glands (postpartum)
What is oxytocin important?
Stimulates contraction of uterus during childbirth
Stimulates ejection of milk from nipple
Synthetic form. called ptiocin
What is psychological gender?
Assigned gender (gender naming at birth)
Gender identity
-persons subjective internal sense of being male, female or non-binary
What is biological gender?
Chromosomes Gonadal gender Prenatal hormonal genrer and brain differentiations Internal organs External genital appearance Pubertal hormonal gender
What its DSD?
Disorder of specula development
-intersex presentation at brith
What is CAH
Congenital adrenal hyperplasia
- biologically female
- exposed to androgens gestational due to over active adrenal glands (cortisol read as testosterone)
- Leads to masculinization (fused/partially labia minora, enlarged clit)
What is clitoromegaly?
enlarged clit
What is AIS?
Androgen insensitivity syndrome
- biological male
- normal levels of testosterone production but androgen receptors are faulty
- leads to feminization (undescended testes, smaller penile glans)
What is puberty?
Process of further sexual differentiation to become capable of reproduction
- Girls: 8-12
- Boys: 10-14
How do you know someone is going through puberty ?
Signalled by a sudden enlargement and maturation of the gonads, genitalia, secondary sex characteristics and growth in ht
What is adolescence?
Psychological and physiological transition from the behaviour and attitudes of a child to the behaviour and attitudes and responsibilities of an adults
What are the changes in males we see during puberty?
Growth in testes and scrotal sac Penis enlarges Pubic, facial, chest, armpit hair Erections Voice drops Body grows
What are the changes in females we see during puberty?
Brest development
Pubic, armpit, leg hair
Hip bones widen
Do you need to start menstruation to see secondary sex characteristics?
No
What are some rituals of puberty?
Mainly religious ceremonies
Modern day: drivers license or first day?
Old day/continued to day: bar mitzvah or quinceanera
