Human Development summary
(exam 1+2+3)
1
,Lecture 2a | Male reproduction 3
Lecture 2b | Female reproduction 7
Lecture 3 | Endocrinology 11
Lecture 4 | Fertilization 14
Lecture 5 | Week 1 & 2 of development (part 1) 17
Lecture 6 | Fertile or not 19
Lecture 7 | Gene expression 22
Lecture 9 | Week 2 of development (part 2) 24
Lecture 10 | Teratogens 27
Lecture 11 | Zebra sh development 29
Lecture 12 | Week 3 & 4 of development 32
Lecture 13 | Twinning and genetics 36
Lecture 15 | Body cavities 40
Lecture 16 | Genetics, sex & gender 41
Lecture 17+18 | Urogenital system 46
Lecture 19 | Cardiovascular system 1 52
Lecture 20 | Cardiovascular system 2 56
Lecture 21 | Skeleton 58
Lecture 22 | Lungs (and digestive system) 62
Lecture 23 | Prenatal diagnostics 64
Lecture 24a | Development of the brain 68
Lecture 24b | Development of the brain 72
Lecture 25 | Peripheral nervous system 75
Lecture 26 | Plasticity & hormonal in uence of the brain 77
Lecture 27 | 2nd+3rd trimester & birth 80
2
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,Lecture 2a | Male reproduction
- Human reproductive system:
- Male and female reproductive system
- Female produces 1 gamete per month: retains and nurtures zygote
- Male disseminates large quantities of games: produces 1/2 billion sperm per day
- Functions in gamete
- Production
- Storage
- Nourishment
- Transport
- Fertilization: fusion of male and female gametes to form zygote
- Gonads: organs that produce gametes and hormones
- Ducts: receive and transport gametes
- Accessory glands: secrete uids into ducts
- Perineal structures: external genitalia
- Sides and sections:
- Cranial — head
- Dorsal — back
- Caudal — tail
- Ventral — belly
- Anterior (front) vs posterior (back)
- Inferior (bottom) vs superior (top)
- Sagittal plane: cut inferior to superior; separating left from right
- Coronal plane: cut inferior to superior; separating anterior from posterior
- Transverse plane: cut horizontally
- Proximal: close to center of body
- Distal: far from center of body
- Parasagittal: cut parallel to midsagittal section but displaced to right/left of midline
- Male reproductive system:
- Gonads (reproductive organs): produce gametes and hormones (testes)
- Ducts for transport of gametes (vas/ductus deferens)
- Accessory organs ( uid production); 3 glands:
- Seminal vesicles
- Prostate gland
- Bulbourethral glands (Cowper)
- External genitalia (penis and scrotal sac that encloses testes)
- Pathway of spermatozoa: testis within epididymis -> ductus deferens -> ejaculatory
duct and penile urethra
> Fluids secreted from seminal vesicles, prostate gland, and bulbourethral glands
> Spermatozoa development require temperature ~1.1ºC lower than normal body
temperature; cremaster and dartos muscles relax/contract to regulate
temperature
- Inguinal canals are passageways through abdominal musculature for testes descent;
closed later in life; risk of Inguinal Hernia
- Brain, hormones and male reproductive system:
- Hypothalamus -> (anterior) pituitary -> adrenal glands / testes -> reproductive glands
- Gonadotropin-releasing hormone (GnRH) stimulates secretion of gonadotropic
hormones (FSH+LH) from anterior pituitary, which stimulate production of testosterone;
circulating testosterone acts as negative feedback loop to down-regulate GnRH
expression
- Adrenocorticotropic hormone (ACTH), also made by pituitary, stimulates androgen
synthesis in adrenal gland
- Testosterone and dihydrotestosterone bind to androgen receptor, causing increased
expression of androgen-responsive genes and leading to cell growth
3
fl fl
, - Structure of testes:
- Seminiferous tubules: spermatozoa production, via rete testis to ependymis
- Tunica albuginea is connective tissue that supports blood+lymphatic vessels, drains
e erent ductules which transport spermatozoa to ependymis
- Spermatogenesis:
- Begins at puberty when hormones become active
- Seminiferous tubules:
- Contain spermatogonia (= male germ cells)
- Stem cells involved in spermatogenesis
- Production of spermatozoa
- Contain sustentacular/Sertoli cells
- Sustain+promote development of sperm
- Development from outside to inside (lumen) of cell: spermatogonia (division by
mitosis), one of which proceeds to primary spermatocytes (division by meiosis)
-> secondary spermatocytes -> spermatids -> spermatozoa
> Development of spermatozoa alongside sustentacular cells
- Gamete production (haploid cells) are produced from diploid cells
- Some spermatogonia continually duplicate themselves (via mitosis; type A) throughout
a male’s reproductive life (maintain population) = self renewal; symmetric division
- Other spermatogonia (type B) are destined to develop into sperm (via meiosis) = when
di erent fates; asymmetric division
> Meiosis:
- Products are not identical to parent cell or to each other
- Males produce spermatozoa
- 2 rounds of division necessary
- Recombination (crossing over during late prophase) occurs in rst steps ->
creates 4 di erent copies of each chromosome every time meiosis occurs
> Crossing over can happen during tetrad (= matched set of 4
chromatids)
- To increase genetic variation in zygote due to fusion of maternal+paternal
DNA, segregation + independent assortment, recombination, random
fertilization
> First chromosomes and then alleles randomly distributed
> Number of di erent types of gametes = 2n (n being number of
homologous pairs)
- Maternal+paternal chromosomes come together in process of synapsis
- Meiosis I is reductional division: reduces number of chromosomes from
diploid to haploid
- Meiosis II is equational division: number of chromosomes is unchanged
- 5 steps in spermatogenesis (9 weeks for complete development):
1. Stem cells (spermatogonia) divide by mitosis
- To produce 2 diploid daughter cells: 1 remains as spermatogonium,
second di erentiates into primary spermatocyte
- Occurs throughout adult life
- 1 daughter cell from each division remains in place for future division
2. Primary spermatocytes
- Begin meiosis I
- Form secondary spermatocytes when meiosis I nished
3. Secondary spermatocytes
- Di erentiate into spermatids (meiosis II nished, but immature gametes)
4. Spermatids
- Di erentiate into spermatozoa = spermiogenesis
5. Spermatozoa
- Lose contact with wall of seminiferous tubule = spermiation
- Enter uid in lumen
4
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(exam 1+2+3)
1
,Lecture 2a | Male reproduction 3
Lecture 2b | Female reproduction 7
Lecture 3 | Endocrinology 11
Lecture 4 | Fertilization 14
Lecture 5 | Week 1 & 2 of development (part 1) 17
Lecture 6 | Fertile or not 19
Lecture 7 | Gene expression 22
Lecture 9 | Week 2 of development (part 2) 24
Lecture 10 | Teratogens 27
Lecture 11 | Zebra sh development 29
Lecture 12 | Week 3 & 4 of development 32
Lecture 13 | Twinning and genetics 36
Lecture 15 | Body cavities 40
Lecture 16 | Genetics, sex & gender 41
Lecture 17+18 | Urogenital system 46
Lecture 19 | Cardiovascular system 1 52
Lecture 20 | Cardiovascular system 2 56
Lecture 21 | Skeleton 58
Lecture 22 | Lungs (and digestive system) 62
Lecture 23 | Prenatal diagnostics 64
Lecture 24a | Development of the brain 68
Lecture 24b | Development of the brain 72
Lecture 25 | Peripheral nervous system 75
Lecture 26 | Plasticity & hormonal in uence of the brain 77
Lecture 27 | 2nd+3rd trimester & birth 80
2
fi fl
,Lecture 2a | Male reproduction
- Human reproductive system:
- Male and female reproductive system
- Female produces 1 gamete per month: retains and nurtures zygote
- Male disseminates large quantities of games: produces 1/2 billion sperm per day
- Functions in gamete
- Production
- Storage
- Nourishment
- Transport
- Fertilization: fusion of male and female gametes to form zygote
- Gonads: organs that produce gametes and hormones
- Ducts: receive and transport gametes
- Accessory glands: secrete uids into ducts
- Perineal structures: external genitalia
- Sides and sections:
- Cranial — head
- Dorsal — back
- Caudal — tail
- Ventral — belly
- Anterior (front) vs posterior (back)
- Inferior (bottom) vs superior (top)
- Sagittal plane: cut inferior to superior; separating left from right
- Coronal plane: cut inferior to superior; separating anterior from posterior
- Transverse plane: cut horizontally
- Proximal: close to center of body
- Distal: far from center of body
- Parasagittal: cut parallel to midsagittal section but displaced to right/left of midline
- Male reproductive system:
- Gonads (reproductive organs): produce gametes and hormones (testes)
- Ducts for transport of gametes (vas/ductus deferens)
- Accessory organs ( uid production); 3 glands:
- Seminal vesicles
- Prostate gland
- Bulbourethral glands (Cowper)
- External genitalia (penis and scrotal sac that encloses testes)
- Pathway of spermatozoa: testis within epididymis -> ductus deferens -> ejaculatory
duct and penile urethra
> Fluids secreted from seminal vesicles, prostate gland, and bulbourethral glands
> Spermatozoa development require temperature ~1.1ºC lower than normal body
temperature; cremaster and dartos muscles relax/contract to regulate
temperature
- Inguinal canals are passageways through abdominal musculature for testes descent;
closed later in life; risk of Inguinal Hernia
- Brain, hormones and male reproductive system:
- Hypothalamus -> (anterior) pituitary -> adrenal glands / testes -> reproductive glands
- Gonadotropin-releasing hormone (GnRH) stimulates secretion of gonadotropic
hormones (FSH+LH) from anterior pituitary, which stimulate production of testosterone;
circulating testosterone acts as negative feedback loop to down-regulate GnRH
expression
- Adrenocorticotropic hormone (ACTH), also made by pituitary, stimulates androgen
synthesis in adrenal gland
- Testosterone and dihydrotestosterone bind to androgen receptor, causing increased
expression of androgen-responsive genes and leading to cell growth
3
fl fl
, - Structure of testes:
- Seminiferous tubules: spermatozoa production, via rete testis to ependymis
- Tunica albuginea is connective tissue that supports blood+lymphatic vessels, drains
e erent ductules which transport spermatozoa to ependymis
- Spermatogenesis:
- Begins at puberty when hormones become active
- Seminiferous tubules:
- Contain spermatogonia (= male germ cells)
- Stem cells involved in spermatogenesis
- Production of spermatozoa
- Contain sustentacular/Sertoli cells
- Sustain+promote development of sperm
- Development from outside to inside (lumen) of cell: spermatogonia (division by
mitosis), one of which proceeds to primary spermatocytes (division by meiosis)
-> secondary spermatocytes -> spermatids -> spermatozoa
> Development of spermatozoa alongside sustentacular cells
- Gamete production (haploid cells) are produced from diploid cells
- Some spermatogonia continually duplicate themselves (via mitosis; type A) throughout
a male’s reproductive life (maintain population) = self renewal; symmetric division
- Other spermatogonia (type B) are destined to develop into sperm (via meiosis) = when
di erent fates; asymmetric division
> Meiosis:
- Products are not identical to parent cell or to each other
- Males produce spermatozoa
- 2 rounds of division necessary
- Recombination (crossing over during late prophase) occurs in rst steps ->
creates 4 di erent copies of each chromosome every time meiosis occurs
> Crossing over can happen during tetrad (= matched set of 4
chromatids)
- To increase genetic variation in zygote due to fusion of maternal+paternal
DNA, segregation + independent assortment, recombination, random
fertilization
> First chromosomes and then alleles randomly distributed
> Number of di erent types of gametes = 2n (n being number of
homologous pairs)
- Maternal+paternal chromosomes come together in process of synapsis
- Meiosis I is reductional division: reduces number of chromosomes from
diploid to haploid
- Meiosis II is equational division: number of chromosomes is unchanged
- 5 steps in spermatogenesis (9 weeks for complete development):
1. Stem cells (spermatogonia) divide by mitosis
- To produce 2 diploid daughter cells: 1 remains as spermatogonium,
second di erentiates into primary spermatocyte
- Occurs throughout adult life
- 1 daughter cell from each division remains in place for future division
2. Primary spermatocytes
- Begin meiosis I
- Form secondary spermatocytes when meiosis I nished
3. Secondary spermatocytes
- Di erentiate into spermatids (meiosis II nished, but immature gametes)
4. Spermatids
- Di erentiate into spermatozoa = spermiogenesis
5. Spermatozoa
- Lose contact with wall of seminiferous tubule = spermiation
- Enter uid in lumen
4
ffff
ff ff fl ff ff fifi fi
