Ch. 25-29 A&P
What type of fetal testing provides results within a day or so of the test?
chorionic villus sampling
At how many weeks of pregnancy can chorionic villus sampling (CVS) be safely performed?
10 weeks
At what age are both amniocentesis and chorionic villus sampling routinely ordered when a woman is pregnant to test for Down syndrome?
35 years old
Using the information provided in this figure, what is the probability of producing a homozygous dominant offspring?
25%
Using the information provided in this figure, what is the probability of producing an offspring who can roll their tongue?
75%
Which of the following is NOT the tongue-roller genotype?
tt
Using the information provided in this figure, what is the probability of producing an offspring who CANNOT roll his or her tongue?
25%
Using the information provided in this figure, what is the genotype of a homozygous recessive offspring?
tt
Using the information provided in this figure, what is the probability of producing an offspring whose phenotype is that of tongue-roller?
75%
Continuous phenotypic variation between two extremes results from _________.
polygenic inheritance
Three genes control skin color. How many possible combinations of skin color result from those three genes?
64
Which of the following exemplifies polygenic inheritance?
height
How many chromatids are present in a tetrad?
4
During what phase of meiosis do the tetrads align together along the metaphase spindle?
metaphase I
If a cell has a diploid number of 22, how many total chromosomes should it have?
22
When one chromatid segment has formed a chiasma with a homologous chromatid segment, what is the result?
recombinant chromosomes
What do chiasmas promote?
genetic variability
For a cell with a five homologous pairs, calculate how many different gamete types can result from meiosis.
32
During metaphase of meiosis I, the alleles determining each trait are distributed to different gametes. What is this called?
segregation
What is the name of the condition when a person has inherited the genotype HH?
homozygous dominant
In this figure, hair color genes and eye color genes are located on the same chromosome. Since these genes are transmitted as a unit to daughter cells during mitosis, we describe these genes as ____________.
linked
Which statement best describes the function of the urethra?
The urethra transports urine from the bladder to the outside of the body.
What region of the male urethra runs through the urogenital diaphragm, extending about 2 cm from the prostate to the beginning of the penis?
intermediate part of the urethra (membranous urethra)
What type of epithelial tissue forms the mucosa layer of the urinary bladder?
transitional epithelium
Which pressure is the chief force pushing water and solutes out of the blood and across the filtration membrane of the glomerulus?
hydrostatic pressure in glomerular capillaries (HPgc)
Which of the following is the volume of filtrate formed each minute by all of the glomeruli of the kidneys?
glomerular filtration rate (GFR)
Calculate the net filtration pressure if blood pressure in the glomerulus is unusually high, around 68 mm Hg.
23 mm Hg
What hormone promotes active tubular secretion of potassium ions in the late distal convoluted tubule (DCT) and collecting ducts?
aldosterone
In what part of the renal tubule are aquaporins scarce or absent so that water CANNOT be reabsorbed?
ascending limb of the nephron loop
In what part of the renal tubule does parathyroid hormone (PTH) promote the reabsorption of calcium ions?
distal convoluted tubule (DCT)
Which of the following promotes the formation of dilute urine?
decreased osmolality of extracellular fluids
Which statement best describes the effect diuretics have?
Diuretics increase urinary output.
Where does antidiuretic hormone (ADH) exert its effects to promote water reabsorption?
collecting duct
Which region of the kidney is characterized by the presence of cone-shaped pyramids? Select from letters A-D.
B
What region subdivides to form two or three major calyces and several minor calyces? Select from letters A-D.
C
Which letter represents the most superficial region of the kidney? Select from letters A-D.
A
What arteries branch off the arcuate arteries?
cortical radiate (interlobular) arteries
Which vessel is present in the arterial pathway as blood flows into the kidney but NOT present in the venous pathway exiting the kidney?
segmental
Which vessels supply the cortical tissue of the kidney with blood?
cortical radiate arteries
What two structures constitute the renal corpuscle?
glomerulus and glomerular (Bowman's) capsule
Which of the three parts of the renal tubule is formed by cuboidal epithelial cells bordered by dense microvilli?
proximal convoluted tubule
In which kidney region are all renal corpuscles located?
renal cortex
Which of the following is NOT characteristic of the cortical nephrons?
The glomerulus of the cortical nephron is closer to the cortex-medulla junction.
Where does the efferent arteriole of the juxtamedullary nephron carry blood to?
vasa recta
Which capillary bed produces filtrate?
glomerulus
What is the function of the macula densa cells of the juxtaglomerular complex (JGC)?
The macula densa cells monitor the NaCl content of the filtrate entering the distal convoluted tubule.
Where is filtrate produced in the nephron?
glomerulus
What vessel directly feeds into the glomerulus?
afferent arteriole
This chemical equation shows the reaction of a strong acid and weak base in the bicarbonate buffer system. Provide the products of the following reaction. HCl + NaHCO3 -->
H2CO3 + NaCl
Which chemical buffer system is the only important system in the extracellular fluid (ECF) that resists short-term changes in pH?
bicarbonate buffer system
In order to buffer a strong acid into a weak acid, which has a less dramatic effect on pH, what chemical should be used as the buffer?
weak base
Which of the following regulates the secretion of K+ into the filtrate?
aldosterone
What is the most important trigger for aldosterone release?
renin-angiotensin-aldosterone mechanism
What results from increased levels of aldosterone?
increased Na+ reabsorption
In a given day, what is the typical value for water intake?
2500 ml
What accounts for the route through which most fluid is lost in a day?
urine
How much water is generated per day from cellular metabolism?
250 ml
Which of the following is NOT involved in triggering the thirst mechanism?
increase in blood pressure
What receptors does the brain use to detect changes in osmolality?
osmoreceptors
What hormone helps to maintain extracellular fluid (ECF) osmolality when concentrations become too high?
antidiuretic hormone (ADH)
What type of water imbalance increases the amount of fluid in all compartments?
hypotonic hydration
Which of the following conditions promotes edema?
hypoproteinemia
What is the hallmark of hypotonic hydration?
hyponatremia
Where is the majority of water stored in the human body?
intracellular fluid (ICF) compartment
Select the person in the following list who would have the highest percentage of water in his or her body.
a 6-month-old baby boy
During pregnancy, which hormone is responsible for stimulating maturation of the breast for lactation?
human placental lactogen (hPL)
What role does oxytocin play in promoting labor?
Oxytocin stimulates the uterus to contract.
Which of the following serves as the trigger to begin the vigorous, rhythmic contractions of true labor?
prostaglandins
What is released from fetal lungs in the weeks before delivery to soften the cervix in preparation for labor?
surfactant protein A (SP-A)
How long does the expulsion stage typically last in a first birth?
50 minutes
During what stage is the afterbirth delivered?
placental stage
The softening and thinning of the cervix during the dilation stage is known as ___________.
effacement
What does the hormone relaxin promote?
Relaxin promotes the relaxation, widening, and increased flexibility of the pelvic ligaments and pubic symphysis.
Due to the increased bulkiness of the anterior abdomen and the change in a pregnant woman's center of gravity, what type of spinal curvature do many pregnant women develop?
lordosis
Which fetal vascular shunt directly connects the right atrium to the left atrium so as to bypass the nonfunctional lungs?
foramen ovale
Which fetal vascular shunt bypasses the pulmonary circuit by connecting the pulmonary trunk to the aorta?
ductus arteriosus
The dermatome is one of the three somites of the mesoderm. What does the dermatome form?
dermis of the skin in the dorsal part of the body
From what germ layer is the serosae of the coelom derived?
mesoderm
From what germ layer are the somites derived?
mesoderm
Which of the following arises from the endoderm?
mucosal lining of the gastrointestinal tract and respiratory tract
Which of the following is derived from the somites of the mesoderm?
vertebrae and ribs
Which germ layer gives rise to the nervous system?
ectoderm
Which of the following takes oxygenated blood to the liver from the placenta?
umbilical vein
Which extra-embryonic membrane protects the developing embryo against physical trauma and helps maintain a constant homeostatic temperature?
amnion
Which of the following implants in the mucosa of the endometrium?
blastocyst
What is the 16-cell stage known as?
morula
How much time passes after fertilization until implantation occurs?
7 days
Which of the following is the multicellular cytoplasmic mass formed from the trophoblast as it implants into the endometrium?
syncytiotrophoblast
What releases human chorionic gonadotropin (hCG)?
trophoblast
What membrane does the trophoblast form after implantation?
chorion
Together, what do the decidua basalis and the chorionic villi form?
placenta
What is the function of the placenta?
The placenta functions as a nutritive, respiratory, excretory, and endocrine organ for the developing embryo.
Once sperm are deposited into the vagina, sperm motility must be enhanced and they must be prepared to release hydrolytic enzymes from their acrosomes. What is this process called?
capacitation
What does the cortical reaction prevent?
polyspermy
What is the event that results when the maternal and paternal chromosomes combine?
fertilization
Which of the following cells is released during ovulation?
secondary oocyte
Why CAN'T polar bodies be fertilized?
Polar bodies lack nutrient-containing cytoplasm.
How many functional gametes are produced by oogenesis?
one functional gamete
What event occurs during the proliferative phase?
ovulation
During what phase of the female's uterine (menstrual) cycle is the uterine lining shed?
menstrual phase
What hormone promotes ovulation?
luteinizing hormone (LH)
What part of the female duct system is the usual site of fertilization of the ovulated oocyte?
uterine (fallopian) tube (oviduct)
Which layer of the uterine wall is made of smooth muscle?
myometrium
Which specific layer of the uterus is shed during menstruation, approximately every 28 days?
stratum functionalis of the endometrium
Specifically, what encloses the vestibule which houses the openings of the urethra and vagina?
labia minora
Which structure of the female's external genitalia has erectile tissue like the penis?
clitoris
What are the two fatty, hair-covered skin folds that run posteriorly from the mons pubis?
labia majora
What part of the breast produces milk?
alveoli
The mammary glands belong to which of the following systems?
integumentary system
What is the pigmented ring of skin situated slightly below the center of each breast?
areola
Which of the following inhibits the release of FSH from the anterior pituitary and GnRH from the hypothalamus when the sperm count is high?
inhibin
Which of the following keeps the concentration of testosterone in the vicinity of the spermatogenic cells high to stimulate spermatogenesis?
androgen-binding protein (ABP)
Which hormone promotes the formation of secondary sex characteristics such as the appearance of pubic, axillary, and facial hair, enhanced hair growth on the chest, and a deepening voice?
testosterone
Why does meiosis involve two nuclear divisions rather than one, as in mitosis?
Meiosis reduces the chromosome number by half.
At what point during meiosis do homologous chromosomes pair up?
prophase I
During meiosis, what does crossover promote?
Crossover promotes increased genetic variability among gametes.
Which of the following results from spermiogenesis?
sperm
Which of the following is the haploid cell produced as a result of meiosis I?
secondary spermatocyte
Which of the following cells is returned to the basal lamina to continue the pool of dividing germ cells?
type A daughter cell or spermatogonium
Which of the following is the site where sperm are stored until they are ejaculated?
tail of the epididymis
Which cells produce androgens such as testosterone?
interstitial endocrine (Leydig) cells
Which of the following is housed within the spermatic cord?
testicular arteries and veins
Which portion of the penis is removed through a procedure known as circumcision?
prepuce (foreskin)
Which of these male accessory ducts transports both sperm and urine?
urethra
During vasectomy, what accessory duct is cut as a form of birth control?
ductus (vas) deferens