Download Chapter 18 Male Reproductive System

组织胚胎学课件
七年制英文医学班专用
中国医科大学
基础医学院
组胚—英文教学组
Chapter 18
Male Reproductive System
1. Components:
---testis:
produce the male germ cells- gametes(sperm)
produce androgen-testosterone
---gernital ducts: store and conduct the sperm
epididymis
ductus deferens
ejaculatory duct
---accessory gland: their secretion join into semen
seminal vesicle
prostate
bulbourethral gland
penis
2. Testis
1) General structure:
① Capsule:
a. tunica vaginalis:
visceral layer-serosa
b. tunica albuginea: thick, DCT
/mediastinum testis: albuginea became thicker
at posterior aspect
/septum: thin septa extend radiately from
mediastinum testis to divided the parenchyma
into lobule
② Lobule
a. seminiferous tubule:
/highly coiled
/30-70cm long, 150-250 mm in D
/begin as free blind end →run to posterior
→become into straight tubule(tubules rectus)
→enter
mediastinum
testis→rete
testis→efferent
duct→connect
with
epididymal duct
b. testicular interstitial tissue: LCT between
seminiferous tubule
2) Seminiferous tubule: 30-70cm long, 150250um in D
---specific stratified epithelium: spermatogenic
epi.(seminiferous epi)
spermatogenic cells
Sertoli or supporting cell
myoid cell: under basal lamina
① Spermatogenic cell:
---5-8 layers
---4 types of cells
a. spermatogonium
---outerest layer, one
layer
---structure:
/round, ellipsoid cell
/12um
/round N, deep stained
---classification:
type A:
-dark type A(Ad): ovoid, deep-stained N, stem
cell
-Pale type A(Ap): ovoid, pale-stained N,
differentiate into type B
type B: round N, chromatin granules are
distributed under nucleus membrane, division
and differentiate into primary spermatocyte
b. primary spermatocytes
---diploid(2n)cell
→duplicate DNA
→ tetraploid cell(4n)
→division
---structure:
round cell, become largest, 18 um, left the
basal layer
N: large, round, on different stage of
division(the prophase of meiotic division up to
22 days)
---through first meiosis divides into two secondary
spermatocyte(2n, 23X or 23Y)
c. secondary spermatocyte:
---nearer the lumen
---structure:
round cell, 12um
N: round deep-stained
hard to see- short lived(divide quickly)
---through secondary meiosis divides into
two spermatid(1n, 23X or 23Y)
d. spermatid
---structure:
smallest cell, 8um
located at innerest layer
---through spermiogenesis:
become into spermatozoa
spermatid
e. spermatozoa:
---structure of spermatozoa:
60 um length
head: -pear-shaped
-flattened
-nucleus
-acrosome
tail: flagallum (centriole)
-neck
-middle
segment:
mitochondria sheath
-principal segment
-end segment
---the processes of spermiogenesis
i. condensation and elongation of N
ii. formation of the acrosome
-cover the anterior and lateral portion of N
-contain hydrolytic enzymes for fertilization
iii. formation of flagellum: for motility
iv. formation of mitochondria sheath
v. discharge of useless organelle and
cytoplasm
② Sertoli cell
---structure:
LM:
/columnar or pyramidal cell
/rest on basal lamina
/extending into lumen
/no clear boundary
/elongated N: triangular, ovoid, paler-stained,
with prominent nucleolus
EM:
/SER(more),
RER(some), Golgi
/mito, lysosome
/MT, MF,
/glycogen, lipid droplet
/tight junction: basal
abluminal compartment
compartment
and
---function:
a. support, protect, nourish, regulate and
release germinal cell
b. secret androgen-binding protein; bind to
androgen, maintain the level of androgen
concentration of lumen
c.
phagocytose degenerated cell and
spermiogenic residual bodies
d. constitute the blood-testis barrier
a.
blood-testis barrier
/components:
endothelium
basal lamina of endothelium
CT
basal lamina of seminiferous tubule
tight junction of sertoli cell
/function:
protect the seminiferous cells from autoimmune reaction
resistant to most harmful factors( radiation,
body temperature, infection)
3) interstitial tissue:
---LCT
---Leydig cell:
structure:
LM: -in groups
-large, polygonal-shaped cell, with round N
-acidophilic cytoplasm
EM: steroid-hormone secreting cell’feature
function: secrete testosterone- androgen
4) tubule rectus and rete testis
---tubule rectus: simple cuboidal or low
columnar epi.
---rete testis: simple cuboidal epi.
Chapter 16
Eye and Ear
1. Eye
1) The wall of eyeball
① Fibrous tunic: DCT
---cornea:
---sclera: DCT
---corneal limbus(corneoscleral limbus)
Cornea:
/anterior 1/6 of fibrous tunic, transparent, bulges
slightly anteriorly
/connect with sclera
/five layers:
corneal epithelium:
i. stratified, squamous non-keratinising
epithelium
ii. 5-6 layers of regular arranged cells
iii.
basal
cells
have
remarkable
regenerating ability
iv. rich in nerve terminal
anterior limiting lamina:
i. a clear uniform membrane, 1016um thick
ii. contain collagenous fibrils and
matrix
iii. cannot regenerate
corneal stroma: corneal propria
i. constitute 90% of corneal thickness
ii.
composed of layers of collagenous
fibrils
iii. keratocyte: similar to fibroblast
iv. matrix, no BV
posterior limiting lamina:
i. a clear homogenous membrane, 5-10
um thick
ii.
consists of collagenous fibril and
matrix
corneal endothelium:
i. simple squamous epi.
ii. EM: mito, pinocytotic vescles, Golgi
and RER
iii.Active
function
of
transporting,
synthesizing and secreting protein
* transparency of the cornea: due to
absence of BV
non-pigmented epi,
regular organization of collagen fibrils
maintenance of hydration of ground
substance
② Vascular tunic(uvea): LCT with BV and
melanocytes
---iris
---ciliary body
---choroid
③ retina:
---pigment epithelium:
outerest layer
simple low columnar epi:
-culomnar cell: thin, long processes at apical
surface
-round or ovoid N
-EM: SER, Golgi, rough round or ovoid
pigment granules
-function:
i. protect visual cell
ii. involve in replace of membranous
disc
iii. store vitamin A and involve in the
synthesis of rhodopsin
---visual cell:
photoreceptor cell
/cell body:
/inner process: form synapse with bipolar cell
and horizontal cell
/outer process:
-outer segment: contain membranous disc
-inner segment: contain mito, RER, Golgi and
MT
/rod cell:
-110,000,000-120,000,000
-deep-stained N
-outer process: cylindrical
-outer segment: membranous disc-invagination
of cell membrane but separated with cell
membrane(exfoliated and ingested by
pigment cell) -rhodopsin(visual purpke)= 11cisretinal(retinene) + opsin
-inner process: spherule(end in a terminal
expansion)
-feel dim light
/cone cell:
-6,500,000-7,000,000
-large N, paler-stained
-outer process: conical
-outer segment: membranous disc, not
separated, no exfoliation of disks
-iodopsin(photopsin)=
11-cisretinal
+
opsin(different)
-inner process: pedicle
-feel blight light(red-558nm, green-531nm, blue419nm)
---bipolar cell:
/large N
/contain RER,mito and Golgi
/dendrite: synapse with photoreceptor and
horizontal neuron
/axon: form synapse with dendrite of ganglion
cell
/classification:
-rod bipolar cell
-midget bipolar cell
-flat bipolar cell
---ganglion cell:
/multipolar neuron:
/dendrite: synapse with bipolar, amacrine
cell and interplexiform cell
/axon: make up optic nerve
/classification: midget ganglion cell and
diffuse ganglion cell
---interneurons:
/located in layer of bipolar cell
/horizontal cell, amacrine cell, interplexiform cell
---radial neuroglia cell: Muller cell
/neuroglial cell
/thin and long cell, with ovoid, deep-stained N
/processes: end at outer limiting membrane and
inner limiting membrane
/function: supporting, protecting, nourishing and
insulating function
Under LM: retina can be divided into ten layers
i.
layer of pigment epithelium: pigment
epithelial cell
ii. layer of rods and cones
iii. outer limiting membrane: outer processes of
Muller cell
iv. outer nuclear layer: N of visual cells
v. outer plexiform layer: inner process of visual
cell, dendrites of bipolar cell and processes of
horizontal cell
vi. inner nuclear layer: cell body of bipolar
cell, horizontal cell, amacrine cell and
interplexiform cell and Muller cell
vii.inner plexiform layer: axon of bipolar cell,
dendrites of ganglion cell, processes of
amacrine cell and interplexiform cell
viii. layer of ganglion cells: cell body of
ganglion cell
ix. layer of optic fibers: axons of ganglion
cell
x.inner limition membrane: formed by
connection each other of inner processes of
Muller cells
* macula lutea:
/definition: a small area of retina at posterior
polar of retina, contains a yellow pigment and
is non-vascularised, so called yellow spot
/3mm in D
/central fovea: shallow depression, 1.5mm in D
/thinnest retina: 0.1mm
/contain only cone cell, no rod cell
/one visual cell connects with one bipolar cell,
and one bipolar cell forms synapse with one
ganglion cell
/have most clear vision
* papilla of optic nerve: optic disc
/1.5 mm in D
/3 mm medial to macula lutea
/place where the optic nerve leave out
/no photoreceptors: so called blind spot
2. Ear
---the external ear
---the middle ear
---the inner ear
1) inner ear: labyrinth
---osseous labyrinth: a system of canals
and cavities in compact bone
the vestibule
semicircular canal
cochlea
---membranous labyrinth: usually lined by
simple squamous epi. except:
membrane semicircular canal: crista
ampullaries
saccule and utricle: macula utriculi and
macula sacculi
cochlear duct: spiral organ
-triangular in cross-section
-three walls:
i. roof: vestibular membrane
ii. outer wall: stratified columnar epi. with
BV distributed- stria vascularis(secrete
endolymph) and spiral ligament
iii. floor: osseous spiral lamina and
membranous spiral lamina – basilar
membrane
a. crista ampullaris:
---supporting cell:
/columnar, with basal ovoid nucleus, rest
on basal lamina
/microvilli, granules: lipid-liked and
glycosaminoglycan granules
---hair cell:
/amongat supporting cell
/pear-shaped: short neck and globular base
/has about 50-110 stereocilia and one
kinocilium(embedded in cupula)
/terminal of peripheral process of neuron of
vestibular nerve ganglion distributed at basal
portion of hair cell
---cupula:
gelatinous
mass
of
mucopolysaccharide substance
---function: receptors for kinetic balance, feel
angular acceleration or deceleration of the
head
b. macula utriculi and
macula sacculi:
macula acustica
---supporting cell
---hair cell: 30-60 stereocilia and one kinocilium
---otolithic
membrane:
gelatinous
mucopolysaccharide substance containing
small crystalline bodies of calcium carbonate
---function: receptors of static balance, feel
linear acceleration or deceleration and
change in position of the head
c. spiral organ: Corti organ
---supporting cell:
pillar cell:
-two rows: inner and outer pollar cell: tall,
columnar in shape,
-inner tunnel
phalahgeal cell:
-inner phalangeal cell: one row, is situated
next to inner pillar cell
-outer phalangeal cell: 3-5 rows, lateral to
the outer pillar cells
-tall columnar cells rest on basilar
membrane
-phalangeal process: enclosed the low
part of hair cell
---hair cell:
-inner hair cell: a row of pear-shaped cell,
supported by inner phalangeal cell
-outer hair cell: 3-5 rows, supported by outer
phalangeal cell
-“V” or “W” shaped-arranged stereocilia on free
surface
---peripheral processes of neuron of spiral
ganglion distribute at basal portion of hair cell
---tectorial membrane
---auditory string: 2000, located in basilar
membrane, collagen-liked thin filament
---function: receptor of sound