Campbell biology Chapter 46

sexual reproduction

the creation of an offspring by fusions of sperm and egg to form a zygote

sperm

male gamete

egg

female gamete

asexual reproduction

creation of offspring without the fusion of egg and sperm

fission

separation of a parent into two or more individuals of about the same size

fragmentation

breaking of the body into pieces, some or all of which develop into adults

regeneration

regrowth of lost body parts

parthenogenesis

the development of a new individual from a unfertilized egg

ovulation

the release of mature eggs at the midpoint of a female cycle

hermaphroditism

each individual has male and female reproductive systems

fertilization

the union of egg and sperm

gonads

organs that produce gametes

spermatheca

where sperm is stored during copulation

accessory glands

secrete products needed for sperm movement

ducts

carry sperm and glandular secretions

testes

highly coiled tubes surrounded by connective tissue

seminiferous tubules

where sperm form

testes location

outside the abdominal cavity in the scrotum, where the temperature is lower than in the abdominal cavity

epididymis

coiled duct that sperm pass through after the seminiferous tubules

ejaculation

sperm are propelled through the muscular vas deferens and the ejaculatory duct, and then exit the penis through the urethra

semen

sperm plus secretions from three sets of accessory glands

two seminal vessicles

contribute 60% of the total volume of semen

prostate gland

secretes its products directly into the urethra

penis

male sex organ composed of three cylinders of spongy erectile tissue

female external reproductive structures

the clitoris, vulva and two sets of labia

female internal reproductive structures

a pair of gonads and a system of ducts and chambers that carry gametes and house the embryo and fetus

ovaries

the female gonads

follicles

each ovary contains these

oocyte

partially developed egg surrounded by support cells

oviduct or fallopian tube

location where the egg travels from the ovary to the uterus

uterus

Location where the cilia in the oviduct convey the egg. Also called the womb

endometrium

uterus lining, many blood vessels

vagina

a muscular but elastic chamber that is the repository for sperm during copulation and serves as the birth canal

vulva

location where the vagina opens to the outside

labia majora, labia minora, hymen, and clitoris

vulva structures

mammary glands

Not part of the reproductive system but are important to mammalian reproduction

gametogenesis

production of gametes

spermatogenesis

formation of sperm, is continuous and prolific

human gametogenesis

spermatogenesis

anatomy of sperm

head, acrosome, tail, etc

oogenesis defintion

development of mature egg, is a prolonged process

oogenesis diagram

Spermatogenesis differs from oogenesis in three ways.

1) All four products of meiosis develop into a sperm while only one of the four becomes an egg

2) Sprematogenesis occurs throughout adolescence and adulthood

3) Sperm are produced continuously without the prolonged interruptions in oogenesis

testosterone

the main androgen

progesterone and estradiol

The main estrogens

Sertoli cells

nourish developing sperm

leydig cells regulated by

LH

hormonal control of the testes

menstruation

process that occurs if an embryo does not implant in the endometrium, the endometrium is shed

hormones closely link the two cycles of female reporduction

changes in the uterus and changes in the ovaries. uterine cycle and ovarian cycle

ovulation

stage where the follicular phase ends, and the secondary oocyte is released

reproductive cycles of the human female

uterine cycle

ectopoic

abnormal location that cells of the uterine lining can sometimes migrate to

endometriosis

Swelling of cells in response to hormone stimulation results in a disorder called

menopause

the cessation of ovulation and menstruation

estrous cycles

cycles that are characteristic of most mammals

estrous cycles characteristics

endometrium reabsorbed by the uterus, sexual receptivity is limited to a heat period caleld estrus, the length and freuency of estrous cycles vary from species to species

conception

fertilization of an egg by a sperm, occurs in the oviduct

blastocyst

a ball of cells with central cavity

formation of a human zygote

pregnancy or gestation

the condition of carrying one or more embryos in the uterus

trophoblast

the outer layer of the blastocyst

placenta

What forms after the endometrium and trophoblast mingle

placental circulation

organogenesis

development of the body organs

fetus

what the embryo is called after 8 weeks

labor

a series of strong rhythmic uterine contractions that push the fetus and placenta out of the body

three stages of labor

dilation, explusion, and delivery of the placenta

dilation

thinning and opening of the cervix

expulsion

delivery of the baby

lactation

production of mother's milk

three stages of labor picture

contraception

deliberate prevention of pregnancy

3 categories of contraception

preventing release of egg and sperm, keeping sperm and egg apart, and preventing implantation of an embryo

mechanisms of contraception

birth control pills

hormonal contraceptives with a pregnancy rate of less than 1%

tubal ligation

ties off the oviducts

vasectomy

ties off the vas deferens

abortion

termination of a pregnancy

spontaneous abortion

miscarriage

in vitro fertilization (IVF)

mixes eggs with sperm in culture dishes and return the embryo to the uterus at the eight-cell stage