Ch. 23 Prep for Lecture Exam

Oxytocin is a hormone involved in labor and delivery and the functioning of the mammary glands. What endocrine gland secretes oxytocin?

Posterior Pituitary

Time from fertilization to birth Time from birth to death

Prenatal Postnatal

What is the function of hCG (human chorionic gonadotropin)?

Prevents the corpus luteum from degenerating

What hormone stimulates the production of milk in the mammary glands?

Prolactin

What chemical stimulates the sperm's tail movement for propulsion through the uterus and uterine tube?

Prostaglandins

Which hormone could be used to induce labor?

Prostaglandins

Complete the sentences describing physiological adjustments that occur to the newborn's cardiovascular system.

The blood vessels of the UBMILICAL CORD close off. The UBMBILICAL ARTERIES become the medical umbilical ligaments The UMBILICAL VEIN closes of and eventually becomes ligamentum teres also called the ROUND LIGAMENT New born circulation changes lead to the closure of the FORAMEN OVALE. In adults, FOSSA OVALIS marks the location of the fetal shunt DUCUTS ARTERIOSUS between pulmonary trunk and aorta constricts. Overtime becomes the LIGAMENTUM ARTERIOSUS DUCTUS VENOSUS constricts and over time becomes the ligamentum venosum.

Which vessel carries oxygen rich blood from the placenta to the fetus?

Umbilical vein

- is the length of time that a human can theoretically live - is the realistic projection of how long an individual will live

- Life span - life expectancy

- Aging is the breakdown of structures and slowing of functions - Aging is the appearance of new substance or new activities

- Passive - Active

The hormone __________ suppresses uterine contractions. The hormone __________ stimulates uterine contractions.

- Progesterone - Prostaglandins

Put the steps involved in maintaining the uterine lining in order.

-Trophoblast cells secrete hCG - hCG maintains corpus luteum - Corpus continues to secrete estrogen and Progesterone - E and P promote growth, development, and maintenance.

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Label the structures associated with the site of gas and nutrient exchange between maternal and embryonic blood.

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Using your observation of developing structures, place the images of developing fetuses into the correct chronological order. (Note that images are not to scale.)

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How many chromosomes are contained in a secondary oocyte prior to fertilization?

23

Which primary germ layer gives rise to many of the mucous membranes, including those of the digestive tract, respiratory tract, and urethra?

Endoderm

How many days after fertilization does the blastocyst implant into the endometrium?

6-7 days

Which of the following are the extra-embryonic membranes?

Allantois yolk sac Amnion Chorion

t what point does an embryo become a fetus?

At about 8 weeks of development

What is the time frame of the neonatal period?

Birth to four weeks

What is the classification of this structure?

Blasocyst

At what stage of development does implantation occur?

Blastocyst

In what stage of postnatal development does a human take its first steps?

Childhood

Which of the embryonic membranes develops into the fetal portion of the placenta?

Chorion

Identify the structures indicated in this figure showing the development of the extra-embryonic membranes.

Chorion Chorion villus ectoderm Mesoderm Endoderm

What is the name of the thin, watery fluid secretion from the mammary glands that is rich in antibodies and is produced during the first days after birth?

Colostrum

What maternal structure helps form the placenta?

Decidua Basalis

Which of the following describes senescence?

Degenerative changes that occur with age

What term refers to the continuous process of change during the life of an individual?

Development

What fetal structure shunts blood between the pulmonary artery and aorta?

Ductus arteriosus

Secretion of human chorionic gonadotropin (hCG) occurs during what time frame during pregnancy?

During early pregnancy, through the fourth month

Name the hormone secreted during pregnancy that, when at high levels, causes the ducts of the mammary glands to grow and branch.

Estrogen

Name the process illustrated in the figure.

Fertilization

What term describes the union of a sperm cell with a secondary oocyte?

Fertilization

What three fetal structures are no longer needed once the baby is born and breathing?

Foramen ovale Ductus arteriousus Ducuts venosus

The process of __________ involves the movement of embryonic cells to form a mesoderm between the ectoderm and endoderm layers of cells.

Gastrulation

What term describes an increase in the size of a structure due to increase in the number and size of cells?

Growth

Place each of the terms in the proper category, indicating whether they are involved in the promotion or inhibition of labor.

INHIBITS LABOR - Decrease in estrogen - Increase in progesterone PROMOTES LABOR - Increase in oxytocin - Increase in prostaglandin - Uterine smooth muscle contraction - Stretching uterine wall

Complete the sentences describing different types of twins.

If two secondary oocytes are ovulated during one cycle and both are fertilized, the resulting offspring are called FRATERNAL twins. Another term is DIZYGOTIC twins, in reference to the numbers of zygotes formed If two inner cell masses form within a single blastocyst, each producing an embryo, the resulting offspring are IDENTICAL twins. Since they arise from one zygote they are also referred to as MONOZYGOTIC twins.

What is the name of the stage of development that occurs from four weeks to one year old?

Infancy

What developmental structure forms the primary germ layers during the embryonic stage?

Inner cell mass

What is the placental membrane and what is its role?

Layer through which nutrients and gases are exchanged between embryonic and maternal blood

What percentage of sperm deposited in the vagina reach the secondary oocyte?

Less than 1%

What is the last primary germ layer to form?

Mesoderm

What hormone stimulates uterine contractions during labor?

Oxytocin

structures that secrete hormones important in the maintenance of pregnancy

Placenta ...

What hormone is released from the corpus luteum that allows greater movement at the pubic symphysis and sacroiliac joints as the time of birth approaches?

Relaxin

Complete the sentences describing the time frame that fetal structures are at high risk for birth defects.

The embryo first becomes susceptible to nutritional inadequacies at the THIRD week The CNS is at high risk from the 3rd to the 16th week The EYE is at a high risk from 4th week to the 8th week The HEART is at high risk from the 3rd to the 6th week The PALATE is at high risk from the 6th to the 9th week.

Why is a newborn at risk for dehydration and electrolyte imbalance?

The kidneys are unable to concentrate urine

What is the amniochorionic membrane?

The membrane formed by the fusion of the chorion and amnion

Why does the first breath of a newborn need to be a forceful breath?

The newborn's lungs are collapsed

Complete the following sentences describing the transport of sperm in the female reproductive tract prior to fertilization.

The sperm must travel to the UTERINE TUBES where fertilization will take place. The uterus and cervix contain THIN WATER secretion that promotes sperm transport. Produced in response to the hormone ESTROGEN. Lashing of the sperm tails is stimulated by PROSTAGLANDINS in the semen. This chemical also STIMULATES contractions in the uterus and uterine tubes. 200-600 million sperm initially deposited, only a few HUNDRED sperm make it to the oocyte.

Fetal circulation, Flow of blood from the placenta through the circulation and back to the placenta

The umbilical VEIN transports oxygen RICH blood to the liver and the DUCUTS VENOSUS a vessel that bypasses the liver The bypass drains into the INFERIOR VENA CAVA where it mixes with oxygen POOR blood before entering the heart Most blood from the right atrium is shunted into the left atrium through the FORAMEN OVALE Blood can be shunted from the pulmonary trunk to the aorta through the DUCTUS ARTERIOSUS Blood then travels through the aorta to the UMBILICAL ARTERY.

Complete the sentences describing growth and development.

The uniting of an egg and sperm is known as FERTILIZATION The process of GROWTH involves an increase in the number and size of cells During the process and DEVELOPMENT, the organism changes in appearances as it moves through the phases of life Period of time from fertilization to birth- PRENATAL Period of time from birth to death- POSTNATAL

The figure shows an alveolar gland. What is the function of the pink cells indicated by the arrows?

To eject milk into ducts

What is the most immediate need of a newborn?

To obtain oxygen

What group of cells within a zygote are involved in the formation of the placenta?

Trophoblast

Fetal hemoglobin has greater attraction for oxygen than does adult hemoglobin.

True

Which of the following describes the path of sperm cells, from ejaculation to the egg cell?

Vagina Cervix Uterus Uterine tubes

The product of fertilization is called a(n) __________.

Zygote

Upon the mingling of the pronuclei in a fertilized oocyte, the cell is now called

Zygote

What is the correct sequence of stages during the cleavage period?

Zygote Morula Blastocyst Embryo

The developing embryo goes through a stage in which it is a hollow ball of cells. This hollow ball of cells is called a(n) __________.

blastocyst