SAR Fundamentals Exam – Complete Practice
Questions With Detailed Answers
What are the three hormones that regulate calcium - answer-- parathyroid
-calcitonin
- vitamin D
What is the function of the parathyroid hormone - answer-- raises plasma Ca2+ levels
- increases osteoclast activity (break down bone) and decreases osteobalst activity (building of bone)
- can stimulate reabsorption of calcium in bone to prevent bone loss
- as bones break down- as the calcium is stored in hydropaitie crystals- when calcium is released so is
PO4 3-. This is removed by the kidneys but in high levels can indicate bone must be reformed
What is the function of calcitonin - answer-- secreted from thyroid gland
in response to high plasma levels of calcium
- prevents osteoclast breakdown of bone
What is the function of vitamin D - answer--hydrolyzed by kidney to become active calcitiol
- aids in increased absorption of calcium from gut, and increased bone response to PTH
What are the three mechanisms of sexual differentiation - answer-genetic, gonadal, phenotypic
Explain the genetic mechanism of sexual differentiation - answer-- determined by the combination of
sex chromosomes at birth
-XX chromosomes
,-XY male
- meiosis: germ cells produce 4 haploid daughter cells (undergoes meosis 1 and meosis 2)
Explain gonadal sexual differentiation - answer-- determined by presence or absence of Y chromosome
- during first 6 weeks of gestation: reproductive system of male and female reproductive
- at week 7 of gestation- sex-determining region of Y-chromosome stimulate production of H-Y antigen
for gonads to differentiate into tested- absence of H-Y stays as ovaries
Explain phenotypic sexual differentiation - answer-- apparent anatomical sex based on gonadal sex
-Androgens present: male
-Androgens absent: female
What are Wolffian ducts? - answer-differentiate into male reproductive ducts
How does hCG affect the wolffian ducts - answer-- hCG presence stimulates the testes to produce
testosterone
- testes also produce mullerian inhibiting factor degrading the mullarian ducts
- testosterone stimulates wolffian ducts to differentiate into male reproductive system
- testosterone also converted to duhydrosterone to form male reproductive system
What are Mullerian ducts? - answer-develop into female reproductive system
How do mullerian ducts differentiate into female reproductive system - answer-- in absence of
testosterone the wolffian ducts degrade
- this leaves the mullerian ducts which devleop into the female reproductive tract and external genitalia
What would happen in absence of testosterone male reproductive organs - answer--would never be
able develop into wolffian ducts and all fetuses would be female
Define cryptorchidism - answer-undescended testes during adulthood- sterility
, What is the function of the testes - answer-site of spermatogenesis
What temp is ideal for spermatogenesis - answer-- not at normal body temperature
- IF TOO COLD: scrotal muscles contract to pull scrotal sac closer to body to warm it up
- IF TOO HOT: scrotal muscles relax and scrotal sac moves away from body
What cells produce testosterone - answer-released from leydig cells
What are the functions of testosterone - answer-- effects of birth (masculinization of the reproductive
tract)
- effects on sex specific tissues after birth (maintains reproductive tract and promotes spermatogenesis)
- other reproductive effects (develops sex drive and controls release of GnRH)
- effects on secondary sex characteristics (voice deepens, male body hair, promotion of muscle growth)
- non-reproductive functions (promotes bone growth at puberty)
Explain the process of spermatogenesis - answer-1. mitotic proliferation (primordial germ cells located
in outer most layer undergo mitotic division to create constant supply of oxygen to germ cells)
2. meosis 1: primary spermatocyte (diploid) forms two secondary spermatocytes (haploid).
3. meosis 2: secondary speramtocytes make two haplois spermatids
- there spermatids are packaged into one spermatozoa (haploid)
What is the acrosome of the spermatozoa - answer-protein on the head that can help breakdown
membrane of the egg allowing for fusion
What are the sertoli cells - answer-nourishment for sperm and site of spermatogenesis (in walls of
seminiferous tubules)
What structural function of the sertoli cells ensures sperm passes through them - answer-connected by
tight junctions therefore developing sperm must pass through them
Questions With Detailed Answers
What are the three hormones that regulate calcium - answer-- parathyroid
-calcitonin
- vitamin D
What is the function of the parathyroid hormone - answer-- raises plasma Ca2+ levels
- increases osteoclast activity (break down bone) and decreases osteobalst activity (building of bone)
- can stimulate reabsorption of calcium in bone to prevent bone loss
- as bones break down- as the calcium is stored in hydropaitie crystals- when calcium is released so is
PO4 3-. This is removed by the kidneys but in high levels can indicate bone must be reformed
What is the function of calcitonin - answer-- secreted from thyroid gland
in response to high plasma levels of calcium
- prevents osteoclast breakdown of bone
What is the function of vitamin D - answer--hydrolyzed by kidney to become active calcitiol
- aids in increased absorption of calcium from gut, and increased bone response to PTH
What are the three mechanisms of sexual differentiation - answer-genetic, gonadal, phenotypic
Explain the genetic mechanism of sexual differentiation - answer-- determined by the combination of
sex chromosomes at birth
-XX chromosomes
,-XY male
- meiosis: germ cells produce 4 haploid daughter cells (undergoes meosis 1 and meosis 2)
Explain gonadal sexual differentiation - answer-- determined by presence or absence of Y chromosome
- during first 6 weeks of gestation: reproductive system of male and female reproductive
- at week 7 of gestation- sex-determining region of Y-chromosome stimulate production of H-Y antigen
for gonads to differentiate into tested- absence of H-Y stays as ovaries
Explain phenotypic sexual differentiation - answer-- apparent anatomical sex based on gonadal sex
-Androgens present: male
-Androgens absent: female
What are Wolffian ducts? - answer-differentiate into male reproductive ducts
How does hCG affect the wolffian ducts - answer-- hCG presence stimulates the testes to produce
testosterone
- testes also produce mullerian inhibiting factor degrading the mullarian ducts
- testosterone stimulates wolffian ducts to differentiate into male reproductive system
- testosterone also converted to duhydrosterone to form male reproductive system
What are Mullerian ducts? - answer-develop into female reproductive system
How do mullerian ducts differentiate into female reproductive system - answer-- in absence of
testosterone the wolffian ducts degrade
- this leaves the mullerian ducts which devleop into the female reproductive tract and external genitalia
What would happen in absence of testosterone male reproductive organs - answer--would never be
able develop into wolffian ducts and all fetuses would be female
Define cryptorchidism - answer-undescended testes during adulthood- sterility
, What is the function of the testes - answer-site of spermatogenesis
What temp is ideal for spermatogenesis - answer-- not at normal body temperature
- IF TOO COLD: scrotal muscles contract to pull scrotal sac closer to body to warm it up
- IF TOO HOT: scrotal muscles relax and scrotal sac moves away from body
What cells produce testosterone - answer-released from leydig cells
What are the functions of testosterone - answer-- effects of birth (masculinization of the reproductive
tract)
- effects on sex specific tissues after birth (maintains reproductive tract and promotes spermatogenesis)
- other reproductive effects (develops sex drive and controls release of GnRH)
- effects on secondary sex characteristics (voice deepens, male body hair, promotion of muscle growth)
- non-reproductive functions (promotes bone growth at puberty)
Explain the process of spermatogenesis - answer-1. mitotic proliferation (primordial germ cells located
in outer most layer undergo mitotic division to create constant supply of oxygen to germ cells)
2. meosis 1: primary spermatocyte (diploid) forms two secondary spermatocytes (haploid).
3. meosis 2: secondary speramtocytes make two haplois spermatids
- there spermatids are packaged into one spermatozoa (haploid)
What is the acrosome of the spermatozoa - answer-protein on the head that can help breakdown
membrane of the egg allowing for fusion
What are the sertoli cells - answer-nourishment for sperm and site of spermatogenesis (in walls of
seminiferous tubules)
What structural function of the sertoli cells ensures sperm passes through them - answer-connected by
tight junctions therefore developing sperm must pass through them
