Reproductive System, Pregnancy, and Development Exam 4

Ductus arteriosus

A blood vessel in a fetus that bypasses pulmonary circulation by connecting the pulmonary artery directly to the ascending aorta

Nitric oxide

A gas released by the endothelial cells to promote blood flow

Prostate

A gland surrounding the neck of the bladder in male mammals and releasing prostatic fluid.

Oxytocin

A hormone released by the posterior pituitary that stimulates uterine contractions during childbirth and milk ejection during breastfeeding.

Thecal cells

A layer of cells surroudning the granulosa cells of the follicles in an ovary. Thecal cells help produce the estrogen secreted from the follicle during the first phase of the ovarian cycle.

Inhibin

A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.

Placenta

A structure that allows an embryo to be nourished with the mother's blood supply

Primary follicle

An immature ovum enclosed by a single layer of cells

What is the stimulus for an infant's first breath after birth?

CO2 - cental acidosis (H+) - stimulates respiratory control centers to trigger first inspiration. Surfactant needs to be secreted by the infants' type II cells to help lung inflation.

What physiological changes occur in the mother during pregnancy?

Cardiovascular: increase BP & cardiac output Respiratory: increase tidal volume (normal breathing) Urinary: increase urine formation

Foramen ovale

Connects the two atria in the fetal heart

Ductus venosus

Connects the umbilical vein to the inferior vena cava

If implantation does not occur, what is the series of events that lead to menstruation?

Corpus luteum degenerates (loss of estrogen, progesterone) arterioles kink and spasm, vasodilation (rupturing of vessels), endometrium sheds

What structure is cut during a vasectomy and how is it a form of male birth control?

Ductus (vas) deferens; does not allow sperm to propel during ejaculation

Corpus luteum

Endocrine tissue which produces hormones, estrogen, and progesterone which prepares the uterine lining for receiving an embryo

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

Why does the risk of chromosomal abnormalities increase with the age of the mother?

Errors in meiosis are more likely to occur as one grows older

Menopause is associated with a decrease in what hormone?

Estrogen

How does an erection form and how is it maintained until climax?

External stimulation, or arousal, initiates an erection (enlargement/stiffening of penis due to blood in the corpus cavernosa and spongiosum). Supplying arterioles dilate during arousal. PNS stimulates the release of nitric oxide (vasodialtion). Enlargement of penis blocks veins (outflow of blood). Increases HR & BP (SNS)

.Identify the relative concentrations of estrogen, progesterone, LH, and FSH during the follicular phase, at ovulation, and during the luteal phase. What is occurring in the menstrual cycle during these stages, focusing on the endometriallayer of the uterus?

FOLLICULAR STAGE: increase in concentrations of estrogen, LH, and FSH just before ovulation. Increase of progesterone during ovulation LUTEAL PHASE: granulosa cells enlarge and with thecal cells form a corpus luteum (secretes estrogen), transformation stimulated by LH - progesterone Decrease in LH & FSH, increase in estrogen & progesterone The endometrial layer sheds (increase progesterone, increase vascularization)

Describe the positive feedback loop that drives contractions during labor.

Fetus determines own birthdate. During the first few weeks of pregnancy, fetal secretion of cortisol stimulates placenta to secrete more estrogen. Fetal oxytocin (from posterior pituitary) causes placenta to produce prostaglandins (powerful uterine muscle stimulants) Series of strong contractions, increase in frequency (positive feed back loop) oxytocin stimulated contraction and release of prostaglandins

Fimbriae

Fingerlike projection of the uterin (fallopian) tubes that drape over the ovary.

Angiogenesis

Formation of new blood vessels

Identify the glands that contribute to semen? In general, what are the functions of these constituents?

Glands: seminal (motility, fertilization), prostate (activation), bulobourethral (lubrication, neutralize) Functions: sperm mobility, activation of sperm, lubrication, neutralize environment of urethra, nutrients (energy source for mitochondria to create ATP), defense against female (immune, neutralize acidity, coagulation, thinning)

Describe, in detail, sperm production and maturation in the testes.

GnRh turns into LH and FSH. LH: targets interstitial cells, interstitial cells release testosterone. FSH: targets sustenocytes, sustenocytes release ABP (keeps testosterone localized)

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Human chorionic gonadotropin (hCG)

Human chorionic gonadotropin is a hormone produced by an embryo following implantation. The hormone helps maintain the uteral lining during pregnancy. The presence of HCG is detected in pregnancy tests.

What is a common hormone involved in negative feedback with GnRH release in both sexes?

Inhibin inhibits FSH production

Stratum functionalis

Lines the uterine cavity and sloughs off during menstruation

Antrum

Lower portion of the stomach filled with amniotic fluid

What organs are bypassed during fetal development? What structures shunts the blood away from them and what do they become after birth?

Lungs: foramen ovale (hole in atria to left side, systemic) & ductus arteriosum (right side jumps into systemic) Liver: ductus venosus

Compare and contrast meiosis in spermatogenesis vs. oogenesis.

Meiosis: reduction in/mix up of genetic material, genetic recomposition, variation of genes Spermatogenesis: 4 sperm result Oogenesis: primary oocytes form from oogonia and begin meiosis I before birth (halt division in prophase I) 1 egg results

Prostaglandins

Modified fatty acids that are produced by a wide range of cells.

Myometrium

Muscle layer of the uterus

Cremaster muscle

Muscle that pulls the scrotum closer to the body in cold temperatures and relaxes to let the testicles be farther away from the body in warmer weather

Ductus (vas) deferens

Muscular passageway conveying sperm to the ejaculatory duct; in the spermatic cord

Amniocentesis

Needle puncture of the amniotic sac to withdraw amniotic fluid for analysis

Pampiniform plexus

Network of veins that surrounds the testicular artery within the scrotum; absorbs heat from the arterial blood entering the testes; derived from the testicular vein.

What is the main cause of chromosomal abnormalities (during meiosis)?

Nondisjunction: failure of chromosomes to separate

Primordial follicle

One layer of cells around oocyte

Bulbourethral gland

One of the two glands in the male reproductive system that add fluid to the semen during ejaculation

Describe the structural changes that occur from the primordial follicle to the vesicular follicle.

PRIMORDAL: squamous cells PRIMARY: cuboidal cells (granulosa cells) directly produce estrogen (FSH) SECONDAY: thecal cells increase granulosa cells, increase estrogen VESICULAR: antrum (fluid filled space)

Secondary follicle

Primary oocyte + multiple layers of granulosa cells

What hormone is involved in milk production? Milk release?

Prolactin is involved in milk production Oxytocin is involved in milk release

In both sexes, what are characteristic changes associated with the cardiovascular system after climax? Do both sexes have a refractory period after climax?

Rapid HR & increased BP; No. Only males

Stratum basalis

Replaces stratum functionalis each month

Seminal gland

Secretes fluid that makes up much of the volume of semen

Dartos muscle

Smooth muscle; wrinkles scrotal skin; pulls scrotum close to body

Peritoneal cavity

Space between the parietal and visceral peritoneum

Prolactin

Stimulates milk production

Corpus spongiosum

Surrounds urethra and expands to form glans and bulb

How does a blastula keep the corpus luteum around to keep producing p rogesterone/estrogen until the placenta takesover?

The blastula implants itself into the uterine wall, producing human chorionic gonadotropin (hCG) which protects the endometrium and keeps the corpus luteum around to steadily produce hormones until the placenta takes over.

What are chorionic villi? What are they a part of?

The chorionic villi are part of the border between maternal and fetal blood during pregnancy (fetal blood supply).

Sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

Parasympathetic nervous system

The division of the autonomic nervous system that calms the body, conserving its energy

Where is the oocyte (ovum) released into during ovulation and how does it make its way into and through the fallopian tubes?

The fluid of the abdominal cavity. Fimbriae (fingerlike extensions at the end of the fallopian tube) create a current for the ovum to follow into the fallopian tube.

Granulosa cells

The majority of the cells surrouding an oocyte in a follicle. Granulosa cells secrete estrogen during the follicular phase of the ovarian cycle (before ovulation).

Describe why and how a lower temperature is kept in the testes.

The scrotum (sac of skin that hangs outside of the abdominal cavity) has a built-in thermostat that keeps the testes and sperm at the correct temperature. Spermatogenesis requires a temperature that is three to five degrees Fahrenheit below body temperature for optimal sperm production. If it becomes too cool on the outside, the cremaster muscle, in conjunction with the dartos muscle, will contract to bring the testes closer the body for warmth. The cremaster muscle's (skeletal) function (involuntary) is to raise and lower the testes in order to regulate scrotal temperature for optimal spermatogenesis and survival of the resultant spermatozoa. Dartos (smooth muscle) acts to regulate the temperature of the scrotum. It does this by contracting to wrinkle the scrotal skin. This reduces the surface area available for heat loss. Temperature regulation is important for optimal spermatogenesis.

How do thecal cells contribute to estrogen levels?

Thecal cells stimulate androgen production which increases the number of granulosa cells an as a result, increase estrogen levels...

Corpus cavernosa

Two columns of erectile tissue in the shaft of the penis

Human papilloma virus (HPV)

Virus transmitted by direct sexual contact that causes an infection that can occur on the skin or mucous membranes of the genitals

Put the following in the correct order: zygote, morula, blastocyst, gastrula. Describe the general structure of each andidentify which form is present during implantation.

Zygote (cleavage), morula (ball of cells), blastocyst, gastrula (3 germ layers).