Unit III Review Flashcards
What does a spermatozoon bind to on the zone pellucida of the secondary oocyte
Sperm receptors
What is seminal fluid
The fluid component of semen (ionic and nutrient composition)
What is hypercapnia
Elevated levels of CO2
How does respiratory alkalosis develop
Hyperventilation which lowers CO2 levels too much
How much weight is gained by the fetus in the last trimester of pregnancy
Up to 7.05 lb
What is acid-base balance
When the production of hydrogen ions in your body is precisely offset by their loss. When acid–base balance exists, the pH of body fluids remains within normal limits.
What are the main events of the proliferation phase
Epithelial cells multiply and restore the uterine epithelium
What are alleles
The various forms of a gene
What percentage of the filtrate produced at the renal corpuscle is reabsorbed at the PCT
60-70 percent
What are the three germ layers called
Ectoderm, mesoderm, endoderm
What are the renal thresholds for glucose and amino acids?
Glucose: 180 mg/dL
Amino acids: 65 mg/dL
What sperm count is considered infertile for a man
<20 million
What are the main structures of the nephron loop
Descending limb and ascending limb
What is the normal level of sodium gains and losses by the body in a day
48-144 mEq (1.1-3.3 g)
What is the chemical equation that shows the reaction between carbon dioxide and water
CO2 + H2O H2CO3 HCO3(-) + H(+)
(Chapter 28)
What are gametes
Male and female reproductive cells
What are the main differences between cortical and juxtamedullary nephrons
The nephron loop of the cortical nephron is shorter.
The longer loop of the juxtamedullary nephron plays an important role in water conservation and the formation of concentrated urine.
Trace the path of sperm from the testes to the external urethral orifice
Testes, epididymis, ductus deferens, ejaculatory duct, membranous urethra, spongy urethra, external urethral orifice
How many secondary oocytes are ovulated in a typical female in the monthly cycle
Typically one
What period of time is referred to as the period of embryological development
First two months after fertilization
What are the causes of over-hydration
- Drinking large volumes of water or infusion of a hypotonic solution
- Inability to eliminate excess water in urine
- Endocrine disorders, such as excessive ADH production
What are the main structures of the collecting system?
Collecting duct and Papillary duct
Explain how autoregulation maintains the GFR
Local blood flow regulation. Changes to the diameters of afferent arterioles, efferent arterioles, and glomerular capillaries maintain GFR
What is electrolyte balance
Electrolyte balance occurs when electrolyte gains equal electrolyte losses
What is another word for child birth
Parturition
What is the cellular trophoblast
The inner layer of the blastocyst
Name the three hormones that mediate physiological adjustments to fluid balance and electrolyte balance
- ADH
- Aldosterone
- Natiuretic peptides (ANP and BNP)
What are the three important organic waste products that are formed in the body?
Urea, creatinine, uric acid
What is the difference between an Oocyte and an ovum
An ovum is a fertilized oocyte
What age does menopause typically take place
45-55
When does the embryonic heart start beating
The third week of development
What is gastrulation
The process by which a third layer forms between the superficial and deep layers
By which day of gestation is the blastocyst completely within the endometrium
Day 10
What is implantation
Begins when the blastocyst attaches to the endometrium of the uterus
What is placentation
Blood vessels form around the blastocyst and the placenta develops
What is the normal pH range of the ECF compartment
7.35 - 7.45
What is a fluid shift
A rapid water movement between the ECF and the ICF in response to an osmotic gradient
What is the most important event that takes place at the renal corpuscle
Filtration
What is genotype
The 46 chromosomes and their genes
What is spermiation
At spermiation, a spermatozoon loses its attachment to the nurse cell and enters the lumen of the seminiferous tubule
If you are in a state of over-hydration, how is homeostasis restored
ANP and BNP reduce thirst, and block ADH and Aldosterone release
What are the two major types of androgens
Testosterone, dihydrotestosterone
What is the function of placental prolactin
Facilitates the conversion from inactive to active status in the mammary glands
What is cryptorchidism
When one or both testes have not descended into the scrotum by the time of birth
What is the dividing line between spontaneous abortion and immature delivery
500g
What are homozygous traits
Receiving the same allele of a particular gene (AA, bb)
What are the main characteristics of the secretions of the seminal glands
- Higher concentrations of fructose
- Prostaglandins which can stimulate smooth muscle contractions
- Fibrinogen to form a semen clot in the vagina
What is glomerular filtration rate
The amount of filtrate the kidneys product each minute
Why are problems due to a lack of bicarbonate ions rare
- Bodily fluids contain large reserves of HCO3-
- Kidneys can generate HCO3-
What are the triggers for renin release by the kidneys
Low renal BP
What is the weight of the fetus at the end of the first trimester
Approximately 14g
If you are in a state of dehydration, what triggers the activation of ADH
Osmoreceptors in the anterior hypothalamus
Beginning at the renal artery, list the sequence of blood vessels that blood has to flow through before the blood reaches the afferent arterioles
Renal arteries, segmental arteries, interlobar arteries, arcuate arteries, cortical radial arteries, (afferent arterioles)
What is embryogenesis
The body of the embryo and internal organs begin developing
What are the main events of the secretory phase
Uterine glands enlarge and accelerate their rate of secretion
What are the three sections of the urethra?
Prostatic urethra, membranous urethra, spongy urethra
Why are the chances of survival much greater for a fetus prematurely delivered in the third trimester
Most of the organ system become able to perform their normal functions without maternal assistance
How long does it usually take a spermatogonium to mature into a free spermatozoon
54 days (?)
What is fertilization
When the male and female gametes fuse
What causes metabolic alkalosis
Increase of HCO3, such as is associated with the production of HCl in the stomach
What stage of development is considered a fetus
9+ weeks
What is gestation
The time spent in prenatal development
What triggers the release of ANP and BNP
Released by cardiac muscle cells in response to abnormal stretching of the heart walls
If you are in a state of dehydration, what triggers the release of aldosterone
Aldosterone is secreted in response to increasing K+ or decreasing Na+ levels in the blood reaching the adrenal cortex, or in response to the activation of the renin–angiotensin-aldosterone system
What is cleavage? When does it begin? When does it end?
Sequence of cell divisions that begins immediately after fertilization, and ends when the blastocyst first contacts the uterine wall.
What is genetics
The study of the mechanisms responsible for inheritance
What is a locus
A gene’s position on a chromosome
What are heterozygous traits
Receiving different alleles for a single gene (Aa, Bb)
What period of time is referred to as the period of fetal development
Week 9 until birth
What is embryogenesis
The formation of a viable embryo
What is transport maximum
The concentration at which transport proteins become saturated
What are other causes of respiratory alkalosis
- Persons adapting to high altitudes, where the low P O2 promotes hyperventilation
- Patients on mechanical respirators
- Persons whose brain stem injuries render them incapable of responding to shifts in plasma CO2 concentrations.
What are the three types of estrogens
Estradiol, estrone, estriol
What are homologous chromosomes
The two members of each pair of chromosomes (AA, Bb, etc.)
List the hormones responsible for elevating calcium ion levels in the body
Parathyroid hormone, Calcitriol
What are the roles of progesterone and estrogens during pregnancy
Progesterone maintains the endometrial lining to continue pregnancy.
Estrogen stimulates labor and delivery
What is organogenesis
The process of organ formation
List the homeostatic functions of the urinary system
Regulate volume and solute concentration of blood
What is hypertonicity
If the osmotic concentration of the ECF increases, that fluid will become hypertonic with respect to the ICF. Water will then move from the cells into the ECF until osmotic equilibrium is restored.
What are the common causes of hyperventilation
Physical stresses such as pain, or psychological stresses such as extreme anxiety
What are the three mechanisms used by the body to stabilize the GFR
Autoregulation, hormonal regulation, autonomic regulation
What is the second trimester and what are the major events that take place during this period
Dominated by the development on organs and organ systems. By the end of this trimester, the fetus looks distinctly human.
What are the major events of the dilation stage
Begins with the inset of true labor, the cervix dilates and the fetus begins to shift forward
What is the primary role of the carbonic acid-bicarbonate buffer system
Prevent changes in pH caused by organic acids and fixed acids in the ECF
List the various hormones that are synthesized by the placenta
Human chorionic gonadotropin, human placental lactogen, placental prolactin, relaxin, progesterone, and estrogens
When does acidosis develop
It develops when the normal plasma buffer mechanisms are stressed by excessive hydrogen ions
What are the main events that take place during menses
Degeneration and shedding of the functional zone
What is differentiation
The formation of the different types of cells necessary for development
What is the weight of the fetus at the end of the second trimester
1.32 lb
Where is the majority of calcium stored in the body
99% stored in the skeleton
Follicle cells thicken and are called _____
Granulosa cells
Why does the maintenance of acid-base balance have to include respiratory and renal mechanisms?
Buffer systems only render H+ harmless, but CO2 needs to be breathed out, and other fluids need to be secreted in urine
What is codominance
Ao + Bo resulting in AB blood type
What is a blastomere
Identical cells produced during cleavage
What is a normal sperm count
20-100 million
How is sodium lost from the body
Eliminated in urine and sweat
What is intracellular fluid
Cytosol
How do red blood cells affect the pH of the ECF compartment
RBCs absorb CO2 and convert it to H2CO3 (Carbonic Acid)
What are the three main functions of the ovaries
- Produce oocytes
- Secrete female sex hormones
- Secrete inhibin
How much calcium does an adult need to consume daily to maintain calcium homeostasis
0.8-1.2 g
(Chapter 27)
What is extracellular fluid
Interstitial fluid, plasma, and other bodily fluids
What is cleavage
Sequence of cell divisions that occurs immediately after fertilization
What is the trimester and what are the major events that take place during this period
Early in the third trimester, most of the organ systems are fully functional. Third trimester characterized by rapid growth and disposition of adipose tissue
What circumstances can lead to prolonged disturbances of acid-base balance
Renal/respiratory malfunction, CNS damage, cardiovascular damage
What are the three major functions of the urinary system?
- Excretion
- Elimination
- Homeostatic regulation
What are the three processes in spermatogenesis
Mitosis, Meiosis, Spermiogenesis
What are the functions of relaxin
- Increases flexibility of the pubic symphysis
- Causes cervix to dilate
- Suppresses release of oxytocin, delays labor
What is the general minimum birth weight for premature delivery
1kg
What are examples of the three general categories of acids in the body
Fixed acid: Sulfuric acid
Organic acid: Lactic acid
Volatile acid: Carbonic acid
(Chapter 29)
What is development
The gradual modification of anatomical structures and physiological characteristics during the period from fertilization to maturity
Which fluid compartment holds most of our body water? Why?
2/3 of body water is in intracellular fluid
What are the effects of acidosis on the nervous system and cardiovascular system
- Nervous system function deteriorates and coma may occur
- Cardiac contractions become weak and irregular, signs and symptoms of heart failure might develop
What is acidosis
pH below 7.35
How is the amniotic cavity formed
The inner cell mast separates and gradually forms the amniotic cavity
List the different types of edema and briefly explain how they occur
Pulmonary edema - increased pressure in pulmonary capillaries
Generalized edema - decrease in blood colloid osmotic pressure
Localized edema - can result from damage to capillary walls (as in bruising), the constriction of regional venous circulation, or a blockage of the lymphatic drainage
What is the first trimester and what are the major events that take place during this period
Embryonic and early fetal development. The beginnings of all major organ systems appear
Give an example of incomplete dominance
Sickle cell anemia that doesn’t show up unless PO2 levels go down
What is capacitation
The process which allows spermatozoa to “swim”
List the three major causes of metabolic acidosis
- Production of large number of fixed or organic acids
- Impaired ability to excrete H+ by the kidneys
- Severe HCO3 loss
What is the main function of the seminiferous tubules
Sperm production takes place in the seminiferous tubules
Which two organ systems play an important role in eliminating hydrogen ions from the body
Kidneys and lungs
When is the first cleavage division completed
Approximately 30 hours after fertilization
What are the important events that take place in meiosis I
The primary spermatocyte divides into two secondary spermatocytes with 23 haploid pairs of chromosomes
Why does prolonged aldosterone stimulation lead to hypokalemia
Countertransport of K+ and Na+ (K+ is secreted while Na+ is being reabsorbed) results in lowered K+ levels in bodily fluids
What are the major events of the expulsion stage
Cervical dilates to 10cm, contractions reach maximum intensity, continues until the fetus has emerged from the vagina
Where are the testes located during fetal development
Adjacent to the kidneys
What are gonads
Reproductive organs that produce gametes and hormones
What are the functions of hPL
(Human Placental Lactogen) Prepares the mammary glands for milk production
What are the products of the testes
Sex hormones called androgens, including testosterone
What accounts for colloid osmotic pressure
Glomerular damage can result in plasma proteins entering the capsular space and cause a capsular colloid osmotic pressure
What is a characteristic of strong acids and strong bases
Dissociate completely in solution
What are the three triggers for the release of renin by the juxtaglomerular complex
- Decreased BP at glomerulus
- Sympathetic innervation of juxtaglomerular cells
- Decrease in osmotic concentration at macula densa
What are autosomal chromosomes
22 pairs of chromosomes - all except the sex chromosomes
What accounts for a higher water content in males versus females
The proportionately larger mass of adipose tissue in adult females, and the greater average muscle mass in adult males (muscle contains 75% water, adipose tissue contains 10%)
What is reabsorbed and secreted at the collecting system? How does it occur?
Alpha-intercalated cells secrete hydrogen ions and reabsorb bicarbonate ions
Beta-intercalated cells secrete bicarbonate ions and reabsorb hydrogen ions
Principal cells are cuboidal cells that reabsorb water and secrete potassium.
(Together, these cells regulate the acid–base balance in the blood)
What are buffers
Dissolved compounds that stabilize the pH of a solution by adding or removing H+
What stage of development is considered an embryo
0-8 weeks
What percentage of the fluid volume that enters the renal corpuscle reaches the DCT
15-20 percent of the initial filtrate volume
Where in the nephron loop is water reabsorbed? How is it reabsorbed?
Descending limb is water-permeable
Ascending limb is impermeable to water
Why are patients who undergo vasectomies not considered sterile for several weeks
Sperm can take a few weeks to clear out of the ductus deferens
What is the average number of spermatozoa that reaches the secondary oocyte
Fewer than 100 reach the isthmus
When does oogenesis begin and end
Begins before birth, accelerates during puberty, and ends at menopause
What is a blastocyst
Cleavage produces two identical blastomeres, and the blastomeres form a blastocyst, a hollow ball.
What are the major solutes that are reabsorbed at the PCT
Na+ and glucose co-transported, water, amino acids, K+, phosphate
What is polyspermy
Fertilization by more than one sperm
What are the characteristics of the secretions of the bulbo-urethral glands
Thick, alkaline mucus to neutralize any remaining urinary acids
What are the major events of reabsorption that take place at the PCT
- Reabsorption of more than 99% of organic nutrients
- Active reabsorption of ions
- Reabsorption of water as solutes leave the PCT and enter surrounding fluid
- Passive reabsorption of water
(5. Active secretion of H+ ions)
Why are dozens of spermatozoa needed to contact the secondary oocyte even though only one spermatozoon can fertilize a secondary oocyte
one sperm does not contain enough acrosomal enzymes to disrupt the corona radiata
What is menarche
The first cycle of the uterine cycle, begins at puberty and ends at menopause
What is alkalosis
pH above 7.45
Why are homeostatic mechanisms that monitor and adjust the composition of body fluids more responsive to changes in the ECF than ICF
ICF, intracellular fluid, is isolated from the rest of the body by the plasma membrane
What are the major events of the placental stage
The uterus begins to decrease in size, which tears the bonds between the placenta and the uterine wall, resulting in the ejection of the placenta
What is the normal level of potassium gains and losses by the body in a day
50-150 mEq (1.9-5.8 g)
List the three limitations of the carbonic acid-bicarbonate buffer system
- It cannot protect the ECF from changes in pH that result from increased or decreased levels of CO2 . A buffer system cannot protect against changes in the concentration of its own weak acid.
- It can function only when the respiratory system and the respiratory control centers are working normally.
- The ability to buffer acids is limited by the availability of bicarbonate ions.
Which layer of the endometrium undergoes changes on a regular basis due to the menstrual cycle
The functional zone
What are teratogens
Factors that result in abnormal development
What are the effects of ADH release?
- Stimulates reabsorption of water at the kidneys
- Stimulates hypothalamic thirst center
What is spermiogenesis
The last step of spermatogenesis, each spermatids matures into a single sperm
What is premature labor
When true labor begins before the fetus has completed development
When does respiratory acidosis develop
When the respiratory system can’t expel all the CO2 produced by the peripheral tissues
What are the three general categories of acids in the body
Fixed, organic, volatile
How many pairs of chromosomes are contained in every somatic cell
23 pairs
List the three factors that influence the tubular secretion of potassium ions
- Changes in K+ concentration of ECF
- Changes in pH (lower pH causes Na+ to be exchanged for H+, instead of K+)
- Aldosterone levels
What is renal threshold
The plasma concentration at which a specific substance or ion begins to appear in urine. Transport maximum determines renal threshold.
What is the main mechanism by which water is transported across cell membranes
Osmotic gradients established by the movement of ions (“Water follows salt”)
What is a typical volume of semen that is released during ejaculation
2-5 mL
List the hormone that is responsible for reducing calcium ion levels in the body
Calcitonin
What is the epididymis
It stores and protects spermatozoa and facilitates their functional maturation
What is phenotype
Anatomical and physical characteristics (as a result of your genes)
List the four major types of carrier-mediated transport
Facilitated diffusion, active transport, cotransport, countertransport
What are the main functions of hCG
Similar to LH, maintains the integrity of the corpus luteum and promotes the continued secretion of progesterone
If you are exercising vigorously and are losing body water at a high rate through sweating, what will happen to the osmotic concentration of your ECF compartment? How does this affect the ICF compartment?
The osmotic concentration of the ECF increases, causing water to flow out of the ICF into the ECF. Since ICF accounts for 2/3 of body water, the loss is not extremely significant at first.
What type of blood flows in the umbilical arteries and umbilical veins
Blood flows from the fetus to the placenta through paired umbilical arteries and returns in a single umbilical vein
How is carbonic acid classified
H2CO3 is a weak acid
What is a secondary oocyte that is fertilized called
Zygote
What are the four general processes of the first trimester
- Cleavage
- Implantation
- Placentation
- Embryogenesis
What is renal compensation
Changes in the rates of H+ or HCO3- secretion and absorption by the kidneys
Why does repeated vomiting and diarrhea often lead to hypernatremia
Significant water loss leads to more concentration of ions in bodily fluids
What is the normal course of events that takes place after a person consumes too much water
A fluid shift will occur, water will move from the ECF to the ICF and both will have increased volumes and lowered osmotic concentrations. Normally, this will block the release of ADH and increase water loss in urine.
What accounts for glomerular hydrostatic pressure
The EFFERENT arteriole’s smaller size creates increased pressure in the glomerulus
Which gland in females contributes the greatest volume of mucous to lubricate the vagina
Greater vestibular
What is amenorrhea
When menarche doesn’t appear by age 16, or if the uterine cycle is interrupted for six months or more
Why does respiratory acidosis lead to metabolic acidosis
Oxygen-starved tissues generate large quantities of lactic acid, and sustained hypoventilation leads to decreased arterial PO2
What is the role of interstitial cells
Produce androgens (hormones including testosterone)
What is penetrance
Percentage of individuals with a certain genotype that actually show the expected phenotype (Not all women with the breast cancer gene actually develop breast cancer)
What is expressivity
The extent to which a certain allele is expressed
What is net filtration pressure
The difference between the net hydrostatic pressure and the blood colloid osmotic pressure acting across the glomerular capillaries
What is a trophoblast
The outer layer of cells of a blastocyst
What is the prenatal period of development
Embryonic development + fetal development
What is reabsorption?
The removal of water and solutes from the filtrate, and their movement from tubular fluid to peritubular fluid
Where in the uterine tube does fertilization usually occur
Fertilization typically takes place near the junction between the ampulla and isthmus of the uterine tube
What structures are enclosed by the spermatic cord
The ductus deferens and the blood vessels, nerves, and lymphatic vessels that supply the testes
What is the role of the enzyme hyaluronidase in fertilization
Released by spermatazoa to break the bonds between follicle cells so a sperm can reach the oocyte
What is the syncytial trophoblast
The outer layer of the blastocyst
Why is a deviation from normal pH values considered dangerous
Changes in H+ concentrations disrupt the stability of plasma membranes, alter the structure of proteins, and change the activities of important enzymes
What are the functions of the uterus
Protect, nourish, and remove wastes for the developing fetus
All gonadal steroids are derived from which lipid
Cholesterol
What is the contribution of the seminal gland to the total volume of semen
60 percent
What is fluid balance
Fluid balance is reached when water gain equals water loss
How is sodium absorbed from the digestive tract
Diffusion and carrier-mediated transport
What is menopause
Termination of the uterine cycle
What is the inner cell mass
A group of cells clustered to one side of the blastocyst
What is transported out of the DCT? How are these molecules transported?
ADH and Aldosterone facilitate active reabsorption of H2O and Na+, respectively. Ca+ is also selectively reabsorbed.
Note: K+ secretion results from active Na+ reabsorption
What are the important events that take place in meiosis II
The secondary spermatocytes divide into four haploid spermatids
What are the major solutes reabsorbed at the nephron loop? Where does this occur?
Descending limb: Impermeable to solutes
Ascending limb: Na+ and Cl- can diffuse across thin portion, and actively transported across thick portion (counter current multiplication creates a concentration gradient)
What are the most important events that take place in Mitosis
Duplication of the spermatogonium, and creation of one primary spermatocyte, and one spermatogonium with 46 chromosomes
What is the postnatal period of development
Birth through maturity
What is secretion?
The transport of solutes from the peritubular fluid to the tubular fluid
What is the difference between diploid and haploid cells
Diploid contain complete pairs of chromosomes, from both father and mother
Haploid contain pairs of only half of the chromosomes
What is the role of the darts and cremaster muscles in ensuring viable sperm production
The cremaster and dartos muscles relax or contract to move the testes away from or toward the body as needed to maintain acceptable testicular temperatures (1.1C or 2F lower than body temperatures)
What are nurse cells
Contained in the seminiferous tubules, they provide a microenvironment that supports spermatogenesis
What is the effect of sympathetic innervation at the kidneys
(1) adjusts rates of urine formation by changing blood flow and blood pressure at the nephron
(2) stimulates the release of renin, which ultimately restricts water and salt loss in the urine by stimulating reabsorption by the nephron
What is a karyotype
The entire set of chromosomes
What causes water to move out of plasma and go into the interstitial spaces in tissues
Capillary hydrostatic pressure
What is inheritance
The transfer of genetic characteristics from generation to generation
Explain the countercurrent multiplication system at the nephron loop
As Na+ and Cl- are transported out of the thick ascending limb, a concentration gradient is created in the peritubular fluid. This concentration gradient results in the movement of water out of the descending limb.
How does respiratory compensation help stabilize the pH of ECF
Respiratory compensation can raise or lower CO2 to affect the Carbonic Acid-Bicarbonate buffer system
