unit 15 ~ learning guide name:bclearningnetwork.com/lor/media/bi12/learning... · penis _____....

BCLN BIOLOGY 12 – Rev July 2014

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Unit 15 ~ Learning Guide Name:________________ INSTRUCTIONS Complete the following notes and questions as you work through the related lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions about anything that you don't understand BEFORE you write the unit test.

U15 NOTES: REPRODUCTIVE SYSTEMS (web notes)

Male Reproductive System Testes (male gonads)

Produce _________________

Produce _______________________________

Found in a sac called the __________________

Suspended outside of the body cavity for ______________________________________

Testes wall made of fibrous connective tissue (divides the testes into lobules/chambers)

inside chambers are long tubes (70cm) called the ________________________________ This is the actual site for ______________________________________.

Interstitial cells secretes androgens "_______________________" Spermatogenesis: Sperm Development Sperms cells are derived from undifferentiated cells called SPERMATOGONIA (sing. Spermatogonium), which lie just on the outside wall of a tubule and divide mitotically, always producing new spermatogonia. Some newly formed spermatogonia move away


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from the outer wall to increase in size and become primary spermatocytes, which undergo meiosis, a type of cell division. Primary spermatocytes, with 46 chromosomes, divide to give 2 secondary spermatocytes, each with 23 chromosomes. Secondary spermatocytes divide to produce 4 spermatids, also with 23 chromosomes, but each only having one chromatid. Spermatids then differentiate into sperm (spermatozoa). Also present in the tubules are the SERTOLI cells, which support, nourish and regulate the spermatogenic cells. Male Reproductive Structures Epididymis

___________________________________________________________.

Seminal Vesicle

_______________________________________.

Cowper's Gland

Pea-sized organs that lie posterior to the prostate on either side of the urethra.

____________________ ___________________.

Prostate Gland

A single dough-nut shaped gland that surrounds the upper portion of the urethra just below the bladder.

Older men can have their prostate become enlarged and urination becomes quite painful (surgically fixed)

___________________________________________. Urethra

_____________________________________________________. Ductus Vas Deferens

________________________________________________________________.


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Penis

______________________________________________________. Sperm Structure/Function

1. Formed in the seminiferous tubules of the testes 2. Mature and stored in the epididymis 3. Stored in the Vas Deferens 4. Enters the urethra just prior to ejaculation 5. Accessory glands (prostate, Cowper's gland, and seminal vesicle) add secretions

to semen. 6. Semen and sperm exit through the penis

SOURCES: 1. Seminal Vesicle 2. Prostate Gland 3. Cowper's Gland

FUNCTION:

1. Produce basic fluid, pH 7.5 (slightly basic) is ideal for healthy sperm and thus, a basic fluid is needed to _______________________ _______________________________________________________.

2. Provides ______________________________________ for sperm. 3. Contains ____________________________ - chemicals which cause

the uterus to contacts. 4. Aids in the _____________________________________ to the egg

(mucous) 5. ________________________

Parts of the Sperm

1. Head:

contains 23 chromosomes

________________ attached = type of _________________.

contains __________________________.

digests the ________________________ ______________________________ so sperm can penetrate.

2. Middle Piece:

Contains mitochondria - ___________ ________________

3. Tail: ____________________________________________


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Function of Testosterone

1. Essential for development of ______________________________________________

2. Essential for the development of ____________.

spermatogenic cells take up ____________ which stimulate their activity.

3. Increase testosterone

concentration at puberty causes ________________ ______________________________________________

4. Secondary sex Characteristics

facial hair

_________________

pubic hair

oil and sweat

gland secrete(=stinky)

larynx expands (voice changes)

increase muscular strength

_____________________

sex drive

NOTE: Side effect is baldness if genetically predisposed


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Hormonal Control of Testosterone Hypothalamus releases GnRH (______________ ______________________________________) GnRH causes anterior pituitary to release 2 gonadotropic hormones:

1. FSH (____________________________)

promotes spermatogenesis in the seminiferous tubules

2. LH (______________________________)

promotes production of testosterone in interstitial cells

NEGATIVE FEEDBACK

Increase testosterone concentration in the blood

causes the ____________________________ to

make _______________ and therefore,

__________ testosterone is produced.

Decrease testosterone concentration in the blood

causes the __________________________ to

make more LH and therefore, more testosterone is ____________________.

Increase concentration of stored sperm causes an increase in production of

____________________ and decreases production of FSH, therefore production of

sperm ______________________.

Decrease concentration of stored sperm causes a _____________________________

_______________________________________________ and more FSH, therefore

____________________ is produced


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Female Reproductive Structures Cervix

Narrow end of uterus leading to the vagina.

dilates _______________ to allow baby to exit.

Clitoris

female sensory organ; homologous to the male penis.

provides sensitivity during intercourse.

Labia major and Labia minor

protective folds of skin. Vestibule

cleft between the labia minor.

contains opening (orifices) to the urethra and vagina.

Fimbriae

Finger-like projections of the _________________________________________ __________________________.

along with cilia in the oviducts, they cause a _______________ which sweeps the egg ___________________________________.

Oviduct

conducts _________ towards the _______________________

also called the _____________________________ or uterine tube. Ovaries

produce _________________________________________________________. Uterus (Womb)

________________________________________________________________. Vagina

Receives penis during sexual intercourse and serves as a _____________________________.


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Functions of Estrogen

1. Stimulates growth of ___________ ______________________________________________.

2. Egg maturation

3. Secondary Sex Characteristics:

armpit hair/pubic hair

_________________________________________________________________

enlarged _______________ _____________ (wider hips)

breast development (requires _______________ as well)

Ovarian Cycles Day 1 -13 Follicular Phase

1. Hypothalamus produced a GnRH to stimulate ____________________________ _____________________________________.

2. FSH and LH from pituitary gland stimulates ________________________________________________________________.

3. Primary follicle (46 chromosomes) contains primary ________________ which

divides. (produced ___________________________) One oocyte get most _______________________________________ (called a secondary oocyte, which is inside the now secondary follicle).

4. Other oocyte called the _________________________ disintegrates.

5. The secondary follicle grows into a __________________ (vesicular) Follicle.


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Day 14 Ovulation

6. Grafian Follicle __________ (ovulation) LH is at its highest and triggers ovulation.

Day 17 - 28 Luteal Phase

7. The follicle has lost its oocyte (or "egg") and forms into ____________________ ________________________________________________________________

the corpus luteum ____________________________________________

___________________________________________________________ If pregnancy does not occur: _________________________________ breaks down

(about 10 days) If pregnancy does occur: Corpus Luteum remains for 3 - 6 months and

continues to produce _________________. Cycle will repeat.

Uterine Cycle Day 1 - 5 Menstruation

1. Low levels of sex hormones (_____________________________________ has just disintegrated).

2. ______________________________ (lining of Uterus) breaks down. 3. Cells of the endometrium, blood vessels, and blood are ____________________

_____________________________________ and exit the vagina. 4. A flow of blood (____________________________) passes out of the vagina

during a period called menstruation. Day 6 - 10 Proliferative Phase

5. Increase ___________________________ by the ovarian follicle causes the _________________________ to rebuild.


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Day 14

6. ____________________________________________ (release of egg). Day 15 - 28 Secretory Phase

7. Increase level of progesterone by the __________________________________. 8. Endometrium doubles in thickness and becomes highly vascularized. 9. Glands produce _______________. 10. Now prepared to receive embryo.

If no pregnancy. The corpus luteum degenerates, decrease in progesterone production occurs and the endometrium breaks down. Cycles continues.


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Hormonal Control FSH

Hypothalamus secretes GnRH (____________________ _________________________________________) and causes the anterior pituitary to secrete.

______ (days 1 - 13) ______ (days 14 - 28)

FSH causes ___________ _____________________Maturing follicles produce ____________________

Increase in estrogen concentration causes the ____________________________ ______________________________________________.

Start of Day 1 – 13

Increase FSH ______________________________________

Decrease FSH _______________________________________ LH

LH is released _______________________

Large spike - day 14 – ovulation

(15 - 28) Causes the _____________________________________

Corpus luteum _______________________________

Increase in progesterone cause anterior pituitary gland to stop producing LH.

Day 15 - LH increases and progesterone _______________.

Day 28 - LH decreases and progesterone ________________.

YOU SHOULD CLICK ON THE LINK TO REVIEW THE FEMALE REPRODUCTIVE SYSTEM BEFORE YOU PROCEED ANY FURTHER.


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Oxytocin and Positive Feedback Oxytocin ___________________________________. Contact of the fetal head with the cervix stimulates the release of oxytocin. Oxytocin causes the uterus to contract and contraction of the uterus causes the release of more oxytocin. Oxytocin also causes ______________________________________________. Lobules containing milk contract forming milk into ducts which lead to the nipple. Implantation

Implantation occurs in the ______.

Fertilization occurs in the _______.

Embryo embeds itself in the _____________ several days after fertilization.

Membrane surrounding the embryo produced a hormone called HCG

(________________________________________________). The Placenta

then develops. It is found immediately in blood and a few days later in the urine.

o HCG is the hormone detected by ________________________ (about

one week following implantation)

HCG prevents the breakdown of the _____________________________. The

Corpus Luteum produced progesterone that keeps the

_________________________ from breaking down.

FSH and LH production is inhibited which

________________________________________________________________.


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Placenta

Contains both _____________________________________and is the area where

____________________________________________. There is no exchange of

_______________. Diffusion of gases and wastes and nutrients occur across the

_____________________________.

Placenta produces __________ which maintains the corpus luteum. The corpus luteum

continues to produce ______________________________, which prevents breakdown

of the _____________________, and estrogen which keeps new eggs from developing.

YOU SHOULD CLICK ON THE LINK TO REVIEW AND COMPLETE THE REPRODUCTIVE

SYSTEM PROBLEM SET BEFORE YOU PROCEED ANY FURTHER.


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U15 PRACTICE: REPRODUCTIVE SYSTEMS

1. Label the following diagram of the male reproductive system. Provide a brief

description of each structure's function below the diagram. Please be neat. (20

marks)

2. Why does sterility result if the testes do not descend into the scrotum? (2 marks)

3. What is spermatogenesis and where does it occur? (2 marks)


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4. Where are the interstitial cells located? What is the function of these cells? (2 marks)

5. Identify the parts of a mature sperm and state the function of each part. (8 marks)

6. Explain how the hypothalamus and anterior pituitary gland function together to

regulate sperm and testosterone production. Please explain the entire feedback

loop using your own words/phrasing. (7 marks)


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7. Label the following diagram of the female reproductive system. Provide a brief

description of each structure's function below the diagram. Please be neat. (10

marks)


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8. Give two ways that the oviduct aids the passage of the egg towards the uterus. (2 marks)

9. List five different effects of estrogen on the female body. (5 marks)


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10. Complete the following table in relation to the female reproductive cycle. (13

marks)

Hormone Full Name Source Effects

GnRH

FSH

LH

Estrogen Estrogen

Progesterone Progesterone

11. The Ovarian Cycle:

a. Identify the name given to Days 1-13 of the ovarian cycle and describe the

changes in hormones and ovarian structures that occurs during this time.

(3 marks)


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b. Identify the name of the event that occurs on Day 14 of the ovarian cycle

and specifically identify how hormone levels are responsible for

influencing its occurrence. (2 marks)

c. Identify the name given to Days 15-28 of the ovarian cycle and describe

the changes in hormones and ovarian structures that occurs during this

time. (3 marks)

12. The Uterine Cycle:

a. Identify the name given to Days 1-5 of the uterine cycle and describe the

changes in hormones and uterine structure that occurs during this time. (3

marks)


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b. Identify the name given to Days 6-13 of the uterine cycle and describe the

changes in hormones and uterine structure that occurs during this time. (3

marks)

c. Identify the name given to Days 15-28 of the uterine cycle and describe

the changes in hormones and uterine structure that occurs during this

time. (3 marks)

13. Pregnancy and birth:

a. Define implantation. (1 mark)

b. What hormone is released from the membrane surrounding the embryo to

prevent corpus luteum from degenerating? (1 mark)


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c. Why is it important to prevent the corpus luteum from degenerating

following implantation? (1 mark)

d. What tissues does the placenta originate from? What are the hormonal

and physical functions of the placenta? (3 marks)

e. Why do the levels of estrogen and progesterone remain high during

pregnancy and why is this important? (2 marks)


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f. What are the functions of the hormone oxytocin and where does in

originate? Describe positive feedback as it relates to this hormone. (4

marks)

~ END OF BIOLOGY 12 UNIT 15 LEARNING GUIDE ~


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UNIT 15 ANSWER KEY U15 PRACTICE: REPRODUCTIVE SYSTEMS

1. Label the following diagram of the male reproductive system. Provide a brief description of each

structure's function below the diagram. Please be neat. (20 marks)

Testes = produce sperm and testosterone

Scrotum = hold testes away from body at a slightly lower temperature than body

temperature as this is ideal for healthy sperm production

Epididymis = stores sperm as they mature

Seminal vesicle = contributes to seminal fluid

Cowper's gland/Bulbourethral gland = contributes to seminal fluid

Prostate gland = contributes to seminal fluid

Urethra = conduct sperm (and urine) out of the body)

Vas deferens = carries sperm form testes to urethra

Penis = organ of copulation

Urinary bladder = stores urine

Erectile tissue/Corpora Cavenosa = fills with blood to create an erection


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2. Why does sterility result if the testes do not descend into the scrotum? (2 marks)

If testes remain within body they are held at a temperature that is too high to

produce healthy sperm.

3. What is spermatogenesis and where does it occur? (2 marks)

= production/development of sperm and it occurs in the testes

4. Where are the interstitial cells located? What is the function of these cells? (2 marks)

= also known as Leydig cells, they are adjacent to the seminiferous tubules within

the testes where they produce testosterone

5. Identify the parts of a mature sperm and state the function of each part. (8 marks)

Head = contains DNA and the acrosomal cap that contains enzymes helps sperm to

penetrate egg

Mid-piece = contains mitochondria to provide ATP to power flagella movement

Tail/Flagella = propels sperm

6. Explain how the hypothalamus and anterior pituitary gland function together to regulate sperm

and testosterone production. Please explain the entire feedback loop using your own

words/phrasing. (7 marks)

The hypothalamus release Gonadotropin Releasing Hormone (GnRH) which then

causes the anterior pituitary to release Follicle Stimulating Hormone (FSH) and

Luteinizing Hormone (LH). FSH causes Sertoli cells of the testes to help sperm

development while LH causes Interstitial (Leydig) cells of testes to release

testosterone. Testosterone further stimulates Sertoli cell of testes to help sperm

development. However, as testosterone levels rise they have a negative feedback

effect on the hypothalamus and anterior pituitary such that the release of GnRH,

LH and FSH are blocked. With these hormones blocked, less testosterone is

released and testosterone levels begin to fall until they reach such levels that the

negative feedback effect is lost and the cycle begins again, thus maintaining

homeostasis within the male reproductive system.


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oviduct

ovary uterus

cervix

vagina

7. Label the following diagram of the female reproductive system. Provide a brief description of

each structure's function below the diagram. Please be neat. (10 marks)

Fimbriae = sweep egg into oviduct as it is released from the ovary

Oviduct = typical site of fertilization, conducts egg to uterus

Ovary = produce eggs and sex hormones (estrogen and progesterone)

Uterus = site where fetus develops

Cervix = entry way between vagina and uterus

Vagina = receives penis during sexual intercourse, canal where menstrual fluid exit

body, canal where fetus exits body

fimbriae


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8. Give two ways that the oviduct aids the passage of the egg towards the uterus. (2 marks)

- Mucous layer lining the oviduct secretes substances that aid in egg movement

- Peristalsis (rhythmic contractions) move egg along the oviduct toward the uterus

9. List five different effects of estrogen on the female body. (5 marks)

- Stimulates breast development during puberty

- Stimulates maturation of uterus during puberty

- Prepares uterus to nourish a developing fetus

- Helps maintain bone density

- Development of secondary sex characteristics of females including breasts,

wider hips, greater fat deposition, development of arm pit and pubic hair

10. Complete the following table in relation to the female reproductive cycle. (13 marks)

Hormone Full Name Source Effects

GnRH

Gonadotropin

Releasing

Hormone

hypothalamus Causes pituitary gland to release LH and

FSH

FSH

Follicle

Stimulating

Hormone

Pituitary gland Causes ovaries to produce a mature

follicle (egg)

LH Luteinizing

Hormone Pituitary gland Causes ovary to release egg

Estrogen Estrogen ovary

Lower levels stimulate endometrium

development in uterus, high levels prevent

GnRH release

Progesterone Progesterone ovary Stimulates endometrium development in

the uterus, high levels inhibit LH release


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11. The Ovarian Cycle:

a. Identify the name given to Days 1-13 of the ovarian cycle and describe the changes in

hormones and ovarian structures that occurs during this time. (3 marks)

= Follicular Phase

= hypothalamus releases GnRH causing anterior pituitary to release FSH and

LH which causes egg maturation

b. Identify the name of the event that occurs on Day 14 of the ovarian cycle and specifically

identify how hormone levels are responsible for influencing its occurrence. (2 marks)

= Ovulation = egg released

= high levels of LH trigger this event

c. Identify the name given to Days 15-28 of the ovarian cycle and describe the changes in

hormones and ovarian structures that occurs during this time. (3 marks)

= Luteal Phase

= corpus luteum secretes estrogen and progesterone which influence the

uterine cycles

= if pregnancy does not occur the corpus luteum disintegrates, estrogen and

progesterone levels drop and menstruation (uterine cycle) occurs

12. The Uterine Cycle:

a. Identify the name given to Days 1-5 of the uterine cycle and describe the changes in

hormones and uterine structure that occurs during this time. (3 marks)

= Menstruation

= low levels of estrogen and progesterone lead to endometrium (lining of

uterus) breaking down and being expelled from body

b. Identify the name given to Days 6-13 of the uterine cycle and describe the changes in


= Proliferative Phase

= increased production of estrogen by the maturing egg in the ovary lease to

rebuilding of the endometrium in preparation for the potential of a

fertilized egg implanting


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c. Identify the name given to Days 15-28 of the uterine cycle and describe the changes in


= Secretory Phase

= increased levels of progesterone released by the corpus luteum in the

ovary causes the endometrium to double in thickness, become highly

vascularized and to produce mucus such that it is ready to receive a

fertilized egg (embryo)

13. Pregnancy and birth:

a. Define implantation. (1 mark)

= when a fertilized egg (embryo stage) embeds itself in the endometrium of

the uterus several days after the fertilization event

b. What hormone is released from the membrane surrounding the embryo to prevent corpus

luteum from degenerating? (1 mark)

= the Human Chorionic Gonadotropin hormone (HCG) which is what pregnancy

tests are designed to detect

c. Why is it important to prevent the corpus luteum from degenerating following

implantation? (1 mark)

= if the corpus luteum disintegrates too early the estrogen and progesterone

levels will drop causing the endometrial lining (and the implanted embryo) to

be shed…effectively a miscarriage

d. What tissues does the placenta originate from? What are the hormonal and physical

functions of the placenta? (3 marks)

= maternal and fetal tissues

= produces HCG hormone to maintain the corpus luteum

= movement of nutrients from mother's blood to fetal blood, movement of

waste from fetal blood to mother's blood

e. Why do the levels of estrogen and progesterone remain high during pregnancy and why

is this important? (2 marks)

= remain high due to maintenance of corpus luteum by HCG hormone

(produced by placenta)

= necessary to prevent shedding of the endometrial lining and developing

fetus


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f. What are the functions of the hormone oxytocin and where does in originate? Describe

positive feedback as it relates to this hormone. (4 marks)

= oxytocin causes the uterus to contract which then initiates a positive

feedback loop causing further release of oxytocin and further contractions

and so on until the baby is delivered

= oxytocin also is released in response to a baby suckling and causes the

mammary glands to release milk

= oxytocin is released from the posterior pituitary

unit 15 ~ learning guide name:bclearningnetwork.com/lor/media/bi12/learning... · penis _____....

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