Kharkov National Medical University Department of Histology, cytology and embryology LECTURE for dentistry students

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

Pupil Lens Iris Ciliary Body Optic Nerve Central Fovea Cornea Sclera Retina Uvea

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

Pupil Lens Iris Ciliary Body Optic Nerve Central Fovea Cornea Sclera Retina Choroid

LIMBUS Iris c onstrictor, dilator muscles regulate pupil Ciliary body muscles relax the lens Anterior chamber Posterior chamber = nutritive fluid Lens Iris Ciliary body

Pupil Lens Iris Ciliary Body Vitreous Body Cornea Sclera Retina Choroid Is dioptric fluid

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

Pupil Lens Iris Ciliary Body Optic Nerve Ora serrata Cornea Sclera Retina Choroid

Sclera Muscles Choroid Retina Vitreous Body

Pigment epithelium III II I

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

Sclera Choroid Rods cones Inner nuc. Ganglionic l. Outer nu. Ganglionic layer Inner nuclear layer Outer nuclear layer Vitreous body

Cham ber Lens Iris- Ciliary body Optic Nerve (blind m.) Central Fovea (yellow m.) Sclera I. Retina photosensitive apparatus Vitreous body II. Cornea dioptric apparatus III.Iris accommodative apparatus

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 Cochlea (C), vestibule (V) the semicircular canal (SC). C V SC

Cochlea is spiral

One section of the cochlea spiral canal V estibular membrane (VM) and basilar membrane (BM) divide canal into scala vestibuli (SV), cochlear duct (CD) and scala tympani (ST). SV VM CD ST BM OC S lig Limbus Sl n m

SV CD ST o VM BM

Scala vestibuli ends with oval window, scala tympani with round, lead to middle ear cochlear duct M E

Cochlear duct CD Three angular, three walls VAS – stria vascularis On the basilar membrane locates Organ of Corti (OC) CD OC Limbus S lig BM SL VAS VM

Organ of Corti OC tm IHC OHC 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). sl pc t bsl bm phcphc

Organ of Corti CD....

tectorial membrane outer hair cells inner h.c. outer phalanger cells inner ph.c. pillar cells o

Mechanism of hearing: under sound tympanic membrane vibrates, ossicles push oval window.

cochlear duct 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.

G M SV SM SV ST H G At the top of the cochlear canal the scala vestibuli connects with the scala tympani – Helicotrema (H), perilymph moves.

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 There are 3 types of cells in taste bud: 1. basal are stem cells, 2. elongated supporting cells 3. actual taste cells contain microvilli These cells are contacted by sensory nerves from below. high med fp tb

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 Elastic Artery Muscles 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, 1-5 smooth. muscle layers, (no) IEL Arteriole

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:

Capillaries

LOCATION Of CAPILLARIES 1. – brain, nerves, muscles 2. – kidney, intestine, endocrine glands 3.– red bone marrow, liver, spleen

capillary venule Vein

HEART

Contains pacemaker cells Purkinje fibers-conduct electrochemical impulses, locate between endocardium and myocardium