Chapter 28: The Male Reproductive System Flashcards
(63 cards)
1
Q
gametic cell
A
- Reproductive/Sex cells
- Each gametic cell has a total number of 23 chromosomes within it’s nucleus.
2
Q
gametes
A
egg and sperm cells
3
Q
Haploid number (N or n)
A
Half the total number of chromosomes
4
Q
somatic cells
A
- Non-reproductive cells (all the various cells in the body except for the reproductive cells)
- Each somatic cell has a total number of 46 chromosomes within it’s nucleus.
5
Q
Diploid number (2N or 2n)
A
Total number of chromosomes
6
Q
2 Types of Cellular Division:
A
- Mitosis
2. Meiosis
7
Q
Mitosis
A
- cell division that results in the formation of 2 identical cells
- allows for growth, maintenance and repair of tissues
- somatic cells undergo this type of division
8
Q
Meiosis
A
- cell division that results in the formation of 4 non-identical cells (2 stages: Meiosis I and Meiosis II)
- allows for the formation of gametes (egg and sperm)
- also known as gametogenesis: spermatogenesis and oogenesis
9
Q
What type of cells undergo mitosis?
A
somatic cells
NOTE: Not all somatic cells have the ability to divide (neurons, for example are amitotic)
10
Q
What type of cells undergo meiosis?
A
only gametic cells undergo meiosis
11
Q
Spermatogenesis
A
the formation and development of sperm in the seminiferous tubules of the testes
12
Q
Structure of Sperm:
A
consists of head, middle piece and tail
13
Q
Head of a Sperm
A
- covered by a cap called the Acrosome
14
Q
Acrosome
A
stores enzymes needed to penetrate the outer surface of the egg allowing the sperm to penetrate the egg
15
Q
Middle Piece of a Sperm
A
contains mitochondria for the synthesis of ATP (needed for motility)
16
Q
Tail of a Sperm
A
only human cell that contain a flagellum which propels the sperm
17
Q
What are the components of the reproductive system?
A
- gonads
- accessory ducts
- accessory glands and organs
- external genitalia
18
Q
Gonads
A
(Reproductive Organs)
- produces gametes and hormones
Female: Ovaries
Male: Testes
19
Q
Accessory Ducts
A
receives and transports the gametes
20
Q
Accessory Glands and Organs
A
secrete fluids into the reproductive accessory ducts or into other excretory ducts
21
Q
The Accessory Ducts in the Male Reproductive System include:
A
- Epididymis
- Ductus Deferens (Vas Deferens)
- Ejaculatory Duct
- Urethra
22
Q
The Accessory Glands and Organs in the Male Reproductive System include:
A
- Seminal Vesicles
- Prostate Gland
- Bulbourethral Glands
23
Q
The External Genitalia in the Male Reproductive System include:
A
- Penis
- Scrotum
24
Q
Testes
A
- paired organs that are the primary sex organ of the male reproductive system
- each testis has the shape of a flattened egg (roughly 2 inches long and 1 inch thick)
- the testes hang within the scrotum
25
Each testis is composed of
seminiferous tubules and epididymis
26
Seminiferous Tubules
site of sperm (spermatozoa) production
27
Seminiferous Tubules contain
- Sperm cells at various stages of meiosis
| - Large Sertoli Cells (Sustentacular Cells) that play a key role in spermatogenesis
28
Large Sertoli Cells (Sustentacular Cells)
- produces important proteins (secretion of Inhibin, Androgen-Binding Protein (ABP))
- promote spermatogenesis when stimulated by FSH
- surround and envelope the sperm cells as they divide providing nutrients and chemical stimuli that promote their development
29
Epididymis
site of sperm maturation, protection and storage
30
Interstitial Cells (Cells of Leydig)
- large cells found in between the seminiferous tubules
| - produce Androgens (Testosterone)
31
Spermatozoa travels from the
epididymis -> vas deferens -> ejaculatory duct -> urethra
32
What are the three important accessory glands in the male reproductive system?
1. seminal vesicles (2)
2. prostate gland (1)
3. bulbourethral glands (2)
33
Seminal Vesicles
- a tubular gland about 6 inches
- contribute to about 60% of semen volume
- secretions are slightly alkaline which help to neutralize acidity of the vagina
34
Seminal Vesicle fluids contain
- fructose (a monosaccharide)
- vitamin C: provides a food source for the spermatozoa and prostaglandins which can stimulate smooth muscle contractions along the male and female reproductive tract
35
Prostate Gland
- a doughnut-shaped gland about 1.6 inches in diameter
| - produces prostatic fluid that contributes about 20-30% of semen volume
36
Bulbourethral Glands (Cowper’s Glands)
- spherically-shaped glands about 0.5 inches in diameter (about the size of peas)
37
What do bulbourethral glands secrete?
- secrete a thick, alkaline mucus
- helps neutralize the acidity of urine in the urethra and helps lubricates urethra and the glans penis (tip of the penis)
38
When Seminal Vesicle fluids mix with spermatozoa...
they begin beating their flagella (tails) and become highly motile
39
Penis
- a tubular organ
| - eliminates urine and introduces semen into the female’s vagina during sexual intercourse
40
Erectile Tissue of the Penis
- composed of 3 cylindrical, separate columns:
- Corpora Cavernosa (2)
- Corpus Spongiosum
- consists of 3-dimentional maze of vascular channels
* In order to cause erection, constriction has to happen
41
Testosterone
most important androgen
42
Semen =
spermatozoa + seminal fluid
43
Scrotum
- out pouching of the abdominal wall
- it is the supporting structure of the testes
- lies outside the body and suspends the testes:
- allows the testes to be 3 degrees F below normal body temperature
- necessary for spermatogenesis and
hormone production to occur
44
Effect of increased temperature on the testes
(like going into a sauna) will cause the cremaster muscle to relax, therefore, the testes will drop or move further away from the body
45
Effect of decreased temperature on the testes
(like jumping into a cool pool) or sexual arousal will cause the cremaster muscles to contract, therefore, pulling the testes up
46
Erectile Dysfunction (ED):
the inability to achieve or maintain an erection
47
effects of testosterone:
- stimulation of bone and muscle growth
- establishment and maintenance of male secondary sex characteristics (low pitched voice, facial, axillary and pubic hair)
- maintenance of accessory glands and organs
- spermatogenesis
48
Peristaltic contractions of the accesory ducts move
the spermatozoa along these ducts
49
emission
- point just before ejaculation
| - seminal fluid mixes with spermatozoa in the ejaculatory duct and the urethra
50
Can neurons be replaced?
since neurons lose their ability to divide, any loss of a neuron is permanent and irreplacable
51
Formation of sperm cells (spermatogenisis)
- begins at the "rims" or the peripheri of the seminfierous tubules and move towards the center
52
Amitotic
Inability to divide
53
Trace the path followed by sperm cells from formation to ejaculation.
```
Remember: SEVEN UP!!
S- Seminiferous tubules
E- Epididymis
V- Vas deferens
E- Ejaculatory duct
N- NOTHING (just here to help us remember SEVEN UP)
U- Urethra
P- Penis
```
54
Erection
- when the penis becomes firmer, engorged and enlarged.
- is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal or sexual attraction
55
Ejaculation
The expulsion of seminal fluid from the urethra of the penis during an orgasm
56
Explain how the scrotum and the descent of the testes aid in sperm cell formation.
- The descent of the testes to the scrotum is significant in sperm cell formation because the scrotum can help adjust temperature of the testes and protect them.
- If the testes have never descended and remained in the abdominal cavity, they would experience pressure changes in the body cavity and have their sperm productivity reduced. ??
57
Describe what occurs during male ejaculation
- Ejaculation occurs as powerful contraction of two muscles.
- The muscles along sides of the penis contracts to stiffen the penis.
- The muscle wraps around base of the penis contracts to push toward the urethral opening.
- The contraction of these two muscles is controlled by neurons in the inferior lumbar and superior sacral segment of the spinal cord.
- The smooth muscle at prostate also contracts to prevent the passage of urine through the erect penis.
??
58
smegma
a waxy material produced by glands found in the prepuce
59
LH
stimulates interstitial cells to secrete testosterone
60
FSH
stimulates sertoli cells to secrete inhibin and androgen binding protein
61
Vasodilation of blood vessels in the penis causes
more blood flow, therefore causing an erection
62
Erection is due to parasympathetic or sympathetic?
parasympathetic division
63
Is ejaculation due to parasympathetic or sympathetic?
sympathetic division
