male and female reproduction lecture notes

primary sex organs

gonads, produce gametes, testes in males and ovaries in females

secondary sex organs

organs other than gonads that are necessaary for reproduction

external genitalia

located in the perineum, most are externally visible except for the accessory glands of female perineum

internal genitalia

located in the pelvic cavity, except the testes and some associated ducts in the scrotum

secondary sex characteristics

features that distinguish the sexes and influence male attraction

23

how many pairs of chromosomes do our cells contain?

5 or 6

gonads begin to develop at _____ weeks as gonadal ridges

mesonephric ducts

in males they develop into the reproductive tract and the paramesonephric ducts degenerate

paramesonephric ducts

in females they develop into the reproductive tract and the mesonephric ducts degenerate

genital tubercle

____ becomes the head/glans of the penis or glans clitoris

urogenital folds

pair of ____ encloses male urethra helping to form the penis or forms the labia minora

labioscrotal folds

pair of _____ becomes either scrotum or labia major

12

by week _____ either male or female genitalia are distinctly formed

homologous

male and female organs that develop from the same embryonic structure are _____

cremaster

when it is cold, the _____ contracts to hold the testes closer to the body; when warm, the _____ relaxes and testes are further from the body

dartos fascia

smooth muscle contracts when cold, wrinkling the scrotum and holding testes against the warm body; this reduces the surface area of the scrotum and heat loss

pampiniform plexus

this venous plexus surrounds testicular artery; countercurrent blood flow removes heat from descending arterial blood, to be carried away by ascending venous blood

testes

combined endocrine and exocrine glands that produce sex hormones and sperm

tunica albuginea

white fibrous capsule covering the testes

seminiferous tubules

septa from the capsule divide testis into 250 to 300 lobules each with 1 to 3 _____ where sperm are produced

interstitial endocrine cells

what produces testosterone in between the seminiferous tubules?

nurse cells

protect germ cells and promote their development

blood-testis barrier

prevents antibodies and immune cells from attacking germ cells

rete testis

network that the seminiferous tubules lead to which collects sperm form the tubules

efferent ductules

about 12 small ciliated ducts collecting sperm from rete testes and transporting it to the epididymis

eididymis

site of sperm maturation and storage, includes a head, body, and tail

ductus deferens

tube between epididymis and seminal vesicle

ejaculatory duct

2 cm duct formed where ductus deferens and duct of seminal vesicle merge

prostatic, membranous, and spongy/penile

what are the three regions of the male urethra?

seminal vesicles, prostate, and the bulbourethral glands

what are the three sets of accessory glands in the male reproductive system?

corpus spongiosum

a single line along the ventral side of the penis, encloses the penile urethra, distal end enlarges and forms the glans penis, proximal end is a dilated bulb ensheathed by bulbospongiosus muscle

corpus cavernosum

two sides that diverge like arms of a Y, each arm (called a crus) attaches penis to pubic arch, covered with ischiocavernosus muscle

puberty

period from onset of pituitary gonadotropin secretion (10 to 12 years old) until first ejaculation of viable sperm (14 years old)

adolescence

period including puberty and extending to when a person attains full adult height

libido

sex drive

follicle-stimulating hormone and luteinizing hormone

what are the two gonadotropins secreted by the anterior pituitary?

gonadotropin-releasing hormone

what stimulates the anterior pituitary to secrete FSH and LH?

head and tail

what are the two parts of the spermatozoon?

acrosome

enzyme cap over the apical half of the nucleus that contains enzymes that penetrate the egg

middle piece

portion of the tail that contains mitochondria around axoneme of the flagella, produces ATP for flagellar movement

principal piece

portion of the tail that is the axoneme surrounded by sheath of supporting fibers, constitutes most of the tail

endpiece

portion of the tail that is the very narrow tip of the flagella

semen

fluid expelled during ejaculation

seminal plasma

mixture of glandular secretions coming mainly from seminal vesicles, prostate, and bulbourethral glands

infertility

sperm count less than 20 million/mL

orgasm/climax

short but intense reaction that is usually marked by the discharge of semen (ejaculation)

emission and expulsion

what are the two phases of ejaculation?

emission

sympathetic nervous system stimulates peristalsis which propels sperm through ducts as glandular secretions are added

expulsion

semen in urethra activates somatic and sympathetic reflexes that stimulate muscular contraction that lead to expulsion

resolution phase

body variables return to normal

refractory period

period following resolution in which it is usually impossible for a male to attain another erection or orgasm

ovaries, uterine tubes, uterus, and vagina

what are the internal genitalia of the female reporductive system?

clitoris, labia minora, labia majora, subcutaneous glands, and erectile tissues

what are the external genitalia of the female reproductive system?

ovaries

what are the primary sex organs of the female reproductive system?

ovaries

female gonads that produce egg cells and sex hormones

ovulation

bursting of the follicle and releasing of the egg

uuterine tubes

canals about 10 cm long leading from ovary to uterus

infundibulum, ampulla, and isthmus

what are the three regions of the uterine tubes?

mesosalpinx

superior margin of broad ligament

uterus

thick muscular chamber that opens into the roof of vagina

fundus, body, and cervix

what are the three regions of the uterus?

cervical canal

passage that connects lumen of uterus to vagina

cervical glands

secrete mucus that prevents the spread of microorganisms from vagina to uterus

perimetrium, myometrium, and endometrium

what are the three layers of the uterine wall?

perimetrium

outermost layer, thin serosa of simple squamous epithelium and loose connective tissue

myometrium

middle muscular layer, constitutes most of the uterine wall, composed mainly of smooth muscle, less muscular and more fibrous near cervix, produces labor contractions

endometrium

inner mucosa, simple columnar epithelium, populated with leukocytes and macrophages, has a functional layer and a basal layer

functional layer

superficial half to two-thirds, shed in each menstrual period

basal layer

deep layer, stays behind and regenerates a new functional layer with each menstrual cycle

endometrium

during pregnancy, _____ is the site of attachment of the embryo and forms the maternal part of the placenta from which the fetus is nourished

vagina

distensible muscular tube 8 to 10 cm in length, allows for discharge of menstrual fluid and receipt of penis and semen and the birth of baby

vaginal rugae

transverse friction ridges at lower end of vagina

hymen

mucosal folds across vaginal opening

vulva

what is the external genitalia of a female collectively called?

mons pubis

mound of fat over pubic symphysis bearing most of the pubic hair

labia majora

pair of thick folds of skin and adipose tissue inferior to mons

labia minora

thin hairless folds medial to labia majora

clitoris

erectile sensory organ of the female reproductive system

vestibular bulbs

erectile tissue deep to labia majora

greater vestibular glands

open into vestibule, keep vulva moist and provide lubrication

paraurethral glands

open into vestibule near the external urethral orifice

breast

mound of tissue overlying pectoralis major

mammary gland

develops within the breast during pregnancy, remains active in the lactating breast, atrophies when a woman ceases to nurse

body

conical to pendulous in shape with nipple at its apex

axillary tail

extension of breast toward armpit, lymphatics in this region are important as a route for breast cancer metastasis

areola

circular colored zone surrounding the nipple

areolar glands

intermediate between sweat glands and mammary glands, secretions protect the nipple from chapping and cracking during nursing

suspensory ligaments

attach breast to dermis of overlying skin and fascia of the pectoralis major

leptin

acts as adiposity signal to brain, if too low GnRH not secreted

estrogens

feminizing hormones with widespread effects on the body

FSH

_____ stimulates ovarian follicles and they begin to secrete estrogen, porgesterone, inhibin, and a small amount of androgen

thelarche

onset of breast development and earliest noticeable sign of puberty

pubarche

appearance of pubic and axillary hair, sebaceous glands, and axillary glands

menarche

first menstrual period

anovulatory

first few menstrual cycles are _____

progesterone

primarily acts on the uterus preparing it for possible pregnancy in the second half of the menstrual cycle

inhibin

selectively regulates FSH secretion

climacteric

midlife change in hormone secretions

menopause

cessation of menstruation

2 million

female is born with about ______ eggs, climacteric begins when there are about 1,000 follicles left