Essentials of Anatomy and Physiology Fifth edition Seeley, Stephens and Tate Slide 2.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 19: Reproductive System

Mammary Glands Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Present in both sexes, but only function in females  Modified sweat glands  Function to produce milk  Stimulated to increase in size by sex hormones (estrogens)

Anatomy of Mammary Glands Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Areola –pigmented area  Nipple – protruding central area of areola  Lobes – internal structures  Alveoli– clusters of milk producing glands  Lactiferous ducts – connect alveolar glands to nipple

The Mammary Glands Figure 24.22a, b

Reproductive Physiology: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Information originally from research by Alfred Kinsey, 1938  Research continued by Masters and Johnson in the 60’s and 70’s  Includes self reports and physiological data  Lots of volunteers!!

Phases of Sexual Response: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Excitement  Reflex response (parasympathethic!)  Plateau  Increased response  “sex flush”

Phases of Sexual Response: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Orgasm  Wave-like muscle contraction  Sympathetic N.S.  0.8 contractions per second  Resolution  Return to homeostasis  Refractory period

Physiologic effects of orgasm: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Measurable increases in:  heart rate  blood pressure  respiratory rate/volume (!)  vasocongestion  myotonia  cramps

Menstrual (Uterine) Cycle: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cyclic changes of the endometrium  Regulated by cyclic production of female hormones  Stages of the menstrual cycle  Menses: “day 0” of cycle  Proliferative stage  Secretory stage

Hormonal Control of the Ovarian and Uterine Cycles: FYI Slide 16.39a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 16.12a, b

Hormonal Control of the Ovarian and Uterine Cycles: FYI Slide 16.39b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 16.12c, d

Hormone Production by Ovaries: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Estrogens  Produced by follicle cells  Cause secondary sex characteristics  Enlargement of accessory organs  Development of breasts  Appearance of pubic hair  Increase in fat beneath the skin  Widening and lightening of the pelvis  Onset of menses

Hormone Production by Ovaries: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Progesterone  Produced by the corpus luteum  Production continues until LH diminishes in the blood (by negative feedback)  Helps maintain pregnancy

Stages of Pregnancy and Development: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Fertilization  Embryonic development  Fetal development  Childbirth

Fertilization: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The oocyte is viable for 12 to 24 hours  Sperm are viable for 12 to 48 hours  Sperm cells must make their way along uterine tube to find ovum  “lured” by chemical signals from oocyte

The Zygote: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  First cell of a new individual  The result of the fusion of DNA from sperm and egg  The zygote begins rapid mitotic cell divisions  The zygote stage occurs as it moves toward the uterus in the uterine tube

The Embryo: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Developmental stage from first mitosis until the ninth week  Enters the uterus at the ~64-cell state  Floats free in the uterus 2-4 days  Uterine secretions are used for nourishment

The 100-cell Blastocyst: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Primary germ layers are eventually formed  Ectoderm – outside layer  Mesoderm – middle layer  Endoderm – inside layer  Implants in the wall of the uterus (by day 14 after conception)

Primary Germ Layers: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 16.16

Development After Implantation: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Embryonic and maternal cells form placenta  The embryo is surrounded by the amnion (a fluid filled sac)  An umbilical cord forms to attach the embryo to the placenta

Development After Implantation: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 16.16

The Fetus (Beginning of the Ninth Week): FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  All organ systems are formed by the end of the eighth week  Activities of the fetus are growth and organ specialization  A stage of tremendous growth and change in appearance

Childbirth (Parturition): FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Labor – the series of events that expel the infant from the uterus  Initiation of labor  Estrogen levels rise  Uterine contractions begin  Oxytocin is released by the pituitary  Causes smooth muscle contraction

Stages of Labor: FYI Slide 16.62a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Dilation  Cervix becomes dilated  Uterine contractions begin and increase  The amnion ruptures

FYI Childbirth: FYI Parturition – 266 days after fertilization Labor – events that expel the infant from the uterus Figure 24.27a, b

Stages of Labor: FYI Slide 16.62b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Expulsion  Infant passes through the cervix and vagina  Normal delivery is head first  Placental stage  Delivery of the placenta

FYI Childbirth: FYI Figure 24.27c, d

Developmental Aspects of the Reproductive System: FYI Slide 16.64a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Gender is determined at fertilization  Males have XY sex chromosomes  Females have XX sex chromosomes  Gonads do not begin to form until the eighth week  The determining factor for gonad differentiation is testosterone

Developmental Aspects of the Reproductive System: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Reproductive system organs do not function until puberty  Puberty usually begins between ages 10 and 15  The first menses usually occurs about two years after the start of puberty  Most women reach peak reproductive ability in their late 20s

Developmental Aspects of the Reproductive System: FYI Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Menopause: ovulation and menses cease  Ovaries stop functioning  There is a no equivalent of menopause in males, but there is a steady decline in testosterone