Human Reproductive System

Bellwork – 5/4/15Define Hypothalamus:Portion of the brain that connects the endocrine and nervous systems, and controls the pituitary gland.Main Idea: Hormones regulate human reproductive systems, including the production of gametes.

Male Reproductive System

Sperm Formation

• MEIOSIS• Form in testes• Temperature important!• Scrotum• Leave testes via epididymus

to the vas deferens

Semen

• Fluids help to transport, feed, and protect sperm

• Seminal vesicles• Prostate gland• Bulbourethral glands

Secondary Sexual Characteristics - Male

• Produced by testosterone– Deeper voice– Axillary and pubic hair– Chest and facial hair– Lengthen bones– Increased size of testes for

sperm production

Bellwork – 5/5/15

Define Fertilization –Process by which haploid gametes combine, forming a diploid cell with 2n chromosomes, with n chromosomes from the female parent and n chromosomes from the male parent.

Bellwork – 5/5/15

Main Idea –A human develops from a single fertilized cell into trillions of cells with specialized functions.

Female Reproductive System

Ovum Formation

• MEIOSIS• Ova are formed before birth• 1 ovum per month is matured

and released from ovaries

Secondary Sexual Characteristics -

Female• Induced by increased LH, FSH,

estrogen, and progesterone hormone levels– Axillary and pubic hair– Widen pelvis– Enlarge mammary tissue– Begin menstrual cycles

Fertilization

• Occurs in upper 1/3 of Fallopian tube

• Once one sperm enters, egg membrane changes

• Fertilized egg = zygote

Menstrual Cycle

• The length of the menstrual cycle can vary from 23 to 35 days.

• Three phases:– Flow phase– Follicular phase– Luteal phase

Flow Phase• Menstrual flow is the shedding of

blood, tissue fluid, mucus, and epithelial cells from the endometrium – the tissue that lines the uterus.

• If fertilization does not take place, outer layers of the endometrium tear away, and blood vessels that supply the tissue rupture.

Follicular Phase

• Anterior pituitary begins to increase production of LH and FSH.

• This stimulates a few follicles to begin to mature in the ovary.

• Inside each follicle is an immature egg – the oocyte.

• Rapid release of LH causes ovulation.

Luteal Phase

• After ovulation, the cells of the follicle change, and the follicle is transformed into a structure called the corpus luteum.

• Corpus luteum breaks down, no longer producing progesterone and estrogen at end of cycle

Menstrual Cycle

• A rapid decrease in hormones triggers detachment of the endometrium, and the flow phase of a new menstural cycle will begin.

Implantation

• Implanted into thick walls of uterus

• Chorion membranes dig into uterus to form placenta

• Embryo supported via umbilical cord

• Once pregnant, progesterone levels stay high in mom

1st Trimester

• Heart develops first• Neural tube develops• All body systems appear by

Week 8 – Now a Fetus

2nd Trimester

• Mostly growth• Looks more like a baby• Some preemies survive at this

stage

3rd Trimester

• More growth• Kicking, rolling,

stretching• Eyes open – Week 32• Lungs mature• Rotates to head-down position

Birth

• Labor– Uterine contractions begin– Cervix dilates to 10 cm.

• Birth– Uterus pushes baby through

vaginal canal• Placenta delivered after

Most of this not fun?