Reproductive Systems This is posted online Take notes if you need to – but DO NOT COPY WORD FOR WORD

Human Sperm

Human Egg

Sperm fertilizing Egg

Hormones Hormones are substances that act like messenger in the body. They travel through the bloodstream and cause certain cells to respond in specific ways Hormones are substances that act like messenger in the body. They travel through the bloodstream and cause certain cells to respond in specific ways Several hormones regulate the reproductive system Several hormones regulate the reproductive system

Puberty Puberty is first experienced during the early to mid-teens – it is when hormonal signals change the body so that it is able to reproduce Puberty is first experienced during the early to mid-teens – it is when hormonal signals change the body so that it is able to reproduce When puberty begins, the pituitary gland at the base of the brain starts to produce FSH (follicle stimulation hormone. When puberty begins, the pituitary gland at the base of the brain starts to produce FSH (follicle stimulation hormone.

Puberty Cont. FSH travels through the bloodstream to the gonads (testes and ovaries) FSH travels through the bloodstream to the gonads (testes and ovaries) FSH signals the testes to produce sperm and the ovaries to produce mature eggs. FSH signals the testes to produce sperm and the ovaries to produce mature eggs. Other hormones help in the development and maintenance of additional characteristics associated with being distinctly male or female – these are call SECONDARY SEXUAL CHARACTERISTS Other hormones help in the development and maintenance of additional characteristics associated with being distinctly male or female – these are call SECONDARY SEXUAL CHARACTERISTS

Puberty in Males Other cells in the testes start to produce testosterone during puberty Other cells in the testes start to produce testosterone during puberty Testosterone directs the development of secondary sexual characterizes, such as the deepening of the voice, facial, underarm and pubic hair, and the broadening of shoulders Testosterone directs the development of secondary sexual characterizes, such as the deepening of the voice, facial, underarm and pubic hair, and the broadening of shoulders

Puberty in Females FSH also stimulates the ovaries to produce estrogen, which is also a reproductive hormone and responsible to secondary sexual characteristics FSH also stimulates the ovaries to produce estrogen, which is also a reproductive hormone and responsible to secondary sexual characteristics Female secondary sexual characteristics include deposits of fat in the breasts and hips and the growth of the pubic and underarm hair Female secondary sexual characteristics include deposits of fat in the breasts and hips and the growth of the pubic and underarm hair

Hormones and the Menstrual Cycle Before and after ovulation, the female reproductive system undergoes changes in a cycle that last approximately one month Before and after ovulation, the female reproductive system undergoes changes in a cycle that last approximately one month This cycle that normally last 28 days is called the menstrual cycle This cycle that normally last 28 days is called the menstrual cycle

Hormones and the Menstrual Cycle Cont. The pituitary hormones “tell” the ovaries what to do and the ovarian hormones “tell” the uterus what to do The pituitary hormones “tell” the ovaries what to do and the ovarian hormones “tell” the uterus what to do This type of communication between different parts of the body is called feedback This type of communication between different parts of the body is called feedback Positive feedback means that actions are stimulated or begun, while negative feedback occurs when action are inhibited or prevented Positive feedback means that actions are stimulated or begun, while negative feedback occurs when action are inhibited or prevented

Hormones and the Menstrual Cycle Cont. Two other important hormones in the menstrual cycle are luteinising hormone (otherwise known as LH) and progesterone. Two other important hormones in the menstrual cycle are luteinising hormone (otherwise known as LH) and progesterone. LH is released by the pituitary gland while progesterone is released by the ovary LH is released by the pituitary gland while progesterone is released by the ovary

Hormones and the Menstrual Cycle Cont. Turn to page 86 in your text Turn to page 86 in your text Read through figure 3.8 – The effects of hormones during stage of the menstrual cycle Read through figure 3.8 – The effects of hormones during stage of the menstrual cycle

Hormones and the Menstrual Cycle Cont. After an egg is released, the female’s body waits for a signal (sperm or fertilization) After an egg is released, the female’s body waits for a signal (sperm or fertilization) If a fertilized egg does not reach the uterus, progesterone is reduced in the bloodstream which cause the uterine lining to break down If a fertilized egg does not reach the uterus, progesterone is reduced in the bloodstream which cause the uterine lining to break down The lining is shed from the body in the process known as menstruation The lining is shed from the body in the process known as menstruation

Menstruation The menstrual flow consisting of mainly dead cells and blood continues for approximately four to seven days The menstrual flow consisting of mainly dead cells and blood continues for approximately four to seven days When the progesterone level decreases substantially, the pituitary gland increase its production of FSH and the menstrual cycle starts over again. When the progesterone level decreases substantially, the pituitary gland increase its production of FSH and the menstrual cycle starts over again.