Download Ciliary body

Kharkov National
Medical University
LECTURE for dentistry students
Department of
Histology, cytology and
embryology
SENSORY System
CARDIOVASCULAR System
SENSORY System
Organ of Olfaction (Smell)
is located in the nasal mucosa
Consists of:
1. Supporting cells
2. Basal cells (renewal)
3. Olfactory cells having cilia and axons
forming nerve
The Eye. Visual organ
＊
fibrous tunic
the wall
contains
vascular uvea
neural retina
eyeball
contents:
lens, vitreous body,
aqueous humor
Sclera
Uvea
Retina
Cornea
Central
Fovea
Pupil
Lens
Iris
Ciliary Body
Optic Nerve
I. Fibrous tunic has two main portions
sclera: dense regular connective tissue
cornea: thicker,
5 layers:
outer corneal epithelium
Bowman's membrane
stroma
Membrane of Descemet
endothelium
Cornea
contains free nerve
endings
permeable,
avascular,
transparent
outer
II. Uvea – loose con.t. 3 parts:
• Choroid is nutritive
• Ciliary body keeps lens
• Iris is diaphragm with pupil
Sclera
Choroid
Retina
Cornea
Central
Fovea
Pupil
Lens
Iris
Ciliary Body
Optic Nerve
LIMBUS
Iris
• Iris constrictor,
dilator muscles
regulate pupil
• Ciliary body
muscles relax the
lens
• Anterior chamber
• Posterior chamber
= nutritive fluid
• Lens
Ciliary body
Sclera
Choroid
Retina
Cornea
Vitreous
Body
Pupil
Is
dioptric
fluid
Lens
Iris
Ciliary Body
III. Retina
• 10 layers of neurons and their processes
• chain of 3 neurons:
layer of visual cells (rods and cones) – outer
nuclear,
layer of bipolar cells – inner nuclear,
layer of ganglionic cells.
pigment cells (outermost)
2 sheaths
9 layers of neurons and processes
Sclera
Choroid
Retina
Cornea
Ora
serrata
Pupil
Lens
Iris
Ciliary Body
Optic Nerve
Vitreous Body
Retina
Choroid
Sclera
Muscles
III
10
9
8
7
II
6
5
I
4
3
2
The way of light waves
•
•
•
•
•
•
•
Through the cornea
Anterior chamber
Pupil
Posterior chamber
Lens
Vitreous body
Through all layers of the retina to rods and
cones
Vitreous body
Ganglionic layer
Ganglionic
l.
Inner
Innernuclear
nuc. layer
Outer
nuclear
Outer
nu. layer
Rods cones
Choroid
Sclera
Sclera
Vitreous body
I. Retina
II. Cornea
photosensitive
apparatus
dioptric apparatus
Cham
ber
Central
Fovea
(yellow m.)
Lens
III.Iris
IrisCiliary body
accommodative apparatus
Optic Nerve
(blind m.)
Organ of Hearing and Equilibrium
• Ear contains:
• External ear
• Middle ear
• Inner ear = labyrinth
External Ear
Middle Ear
Middle Ear. Auditory (Eustachian)
tube leads to nasopharynx
auditory
tube
Inner ear = labyrinth
is located in the temporal bone
contains cochlea (organ of hearing),
vestibule and semicircular canals, (organ
of equilibrium)
Inner Ear
Vestibule, semicircular canals,
cochlea
Inner Ear
• Bony labyrinth is filled with perilymph
• Contains:
• Membranous labyrinth is filled with
endolymph
Section of the
inner ear
C
SC
V
Cochlea (C), vestibule (V) the semicircular canal (SC).
Cochlea is spiral
SV
One section of
the cochlea
spiral canal
VM
CD
Limbus
OC
Sl
n
S lig
BM
ST
Vestibular membrane (VM) and basilar
membrane (BM) divide canal into
scala vestibuli (SV),
cochlear duct (CD) and
scala tympani (ST).
m
SV
VM
CD
BM
ST
Scala vestibuli ends with oval window, scala
tympani with round, lead to middle ear
cochlear duct
ME
Cochlear duct CD
VAS
Three angular,
three walls
VM
CD
OC
VAS – stria
vascularis
Limbus
S lig
BM
SL
On the basilar membrane locates
Organ of Corti (OC)
Organ of
Corti
OC
OHC
tm
sl
IHC
phc
bm
pc
t
bsl
The tectorial membrane (tm) covers 3 outer hair cells (OHC)
and 1inner hair cell (IHC) .
At the centre the pillar cells (pc) form tunnel (t).
Hair cells are supported by phalangeal cells (phc).
Organ of Corti
CD
. . .
.
tectorial membrane
outer hair cells
inner h.c.
outer phalanger cells
pillar cells
inner ph.c.
Mechanism of hearing:
under sound tympanic membrane vibrates,
ossicles push oval window.
perilymph moves through helicotrema to round
window,
calls movement of endolymph of cochlear
duct and tectorial membrane which irritates hear cells.
Nerve fibers take impulse.
cochlear duct
H
At the top of the cochlear
canal the
SV
SM
scala vestibuli connects
with the
scala tympani –
Helicotrema (H),
ST
G
SV
M
perilymph moves.
G
Organ of equilibrium is similar to
o.Corti, locates in the semicircular canals and
vestibule, gives information about the force of gravity,
acceleration and position of a head
Organ of Taste
• There are taste buds in the epithelium of
the tongue papillae.
Taste bud
fp
tb
There are 3 types of cells in taste bud:
1. basal are stem cells,
2. elongated supporting cells
high
med
3. actual taste cells contain microvilli
These cells are contacted by sensory nerves from below.
Taste sensations
• Tip of the tongue - sensitive to sweet and
salt
• Lateral edges
- sensitive to sour
• Posterior portion - sensitive to bitter
The Cardiovascular System
3 parts:
• 1. the heart
pumps blood
2. MACROCERCULATION – transport
3. MICROCERCULATION – exchange of
metabolites, oxygen
Generalized Structure of Blood Vessels
intima
adventitia
Types of vessels, because of
hemodinamic conditions
• ARTERIES: elastic, muscular-elastic,
muscular
• VEINS: muscular, unmuscular
• CAPILLARIES: 1. continuous,
2. fenestrated, and 3. sinusoidal
Elastic Arteries
• Thick-walled arteries near the heart;
the aorta and its major branches
– Contain elastin in all three tunics
– Withstand large blood pressure
Muscular Artery
Muscles
Elastic Artery
Elastic
Muscular Arteries and Arterioles
• Muscular arteries – far from heart,
where pressure smaller
– Have thick tunica media with more
smooth muscle and less elastic tissue
• Arterioles – smallest arteries; lead to
capillaries
– Control flow into capillaries, contain
circular muscle
Arteriole
Arteriole, 1-5 smooth. muscle layers, (no) IEL
Veins
• Veins – have lower blood pressure and
thinner walls than arteries
– Valves which prevent backflow of blood
2 types:
• Muscular – locate below the heart
• Unmuscular – above
• Venule – similar to capillary, but wider
Capillaries
• Capillaries are the smallest blood vessels
– Wall one cell thick – endothelium on basal
lamina
• Types: 1.2.3.
Capillaries
1.
2.
3.
LOCATION Of CAPILLARIES
• 1. – brain, nerves, muscles
• 2. – kidney, intestine, endocrine glands
• 3.– red bone marrow, liver, spleen
Vein
capillary
venule
HEART
• Contains pacemaker cells
• Purkinje fibers-conduct
electrochemical impulses, locate
between endocardium and myocardium