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CELLS
Presentation byMedha Pandey
List of the cellsAdipocytesa. White adipocytesb. Brown adipocytesChondroblastsNeuronsAmeloblasts
AdipocytesFat storing cellsAlso known as lipocytes, fat cells
Typesa) White adipocytesb) Brown adipocytes
White adipocytes Are monovacuolar or unilocular Major type of adipocytes Accounts for 20% of total body weight in men and
25% in women
MORPHOLOGY OF WHITE ADIPOCYTE
1. Oval or spherical in shape2. 25 to 200 microns3. Contains a large lipid droplet4. Cytoplasm pushed to periphery5. Signet ring like appearance
FUNCTION OF WHITE ADIPOCYTES1. Insulation2. Mechanical cushion3. Source of energy
LOCATION1. Under the skin: subcutaneous fat
2. Surrounding the vital organs: visceral fat
3. Inside bones: bone marrow
BROWN ADIPOCYTESAre multivacuolar or multilocularContain many lipid droplets
LOCATION
1. Abundant in infants2. Upper chest and neck of adults
MORPHOLOGY1. Shape may be oval or polygonal2. Size: 60 microns3. Has considerable amount of
cytoplasm4. Scattered lipid droplets5. Densely packed mitochondria
FUNCTION1. Heat generation2. Burns calories
CHONROBLASTSCells present in the cartilageFound at the end of bones, tips of nose, external
ears, epiglottis and joints (intervertebral) discs of knee
MORPHOLOGY OF CHONDRBLASTS
Cells embedded in lacunaeAre about 4 microns in size
FUNCTION Matrix and other ground substance secretion
Chondrocytes embedded in matrix
NEURONS
neuronsThe term neuron was coined by the German
anatomist Heinrich Wilhelm WaldeyerAlso known as nerve cellsAre electrically excitableCore components of the nervous system,
which includes the brain, spinal cord, and peripheral ganglia
LOCATION1. Axons reach everywhere2. Cell bodies are concentrated on the Central
Nervous System.
Types of neurons
On the basis of function2 TYPES:
1. Sensory neuron2. Motor neuron
Sensory neuronsAlso known as afferent neuronsRespond to sound, light, touch and numerous other
sensory stimulusSend the signal received by sensory organs to spinal
cord or brain
Motor neuronsAlso known as efferent neuronsCause muscle contraction and affect glandsReceive signal from brain and spinal cord
MORPHOLOGY OF THE NEURONS
A Cell Body: contains a nucleus, endoplastic reticulum, mitochondria and other organelles
The Dendrites: are small branches bringing information to the cell body.
The Axon: nerve fiber, is the longest fiber
of the neuron which takes information away from the cell body to the connecting neuron.
Shape and size4 microns (.004 mm) to 100 microns (.1 mm) in
diameter. Their length varies from a fraction of an inch to
several feet.
FUNCTION
allow an organism to sense an stimuli either in external or internal environment
analyze and integrate the stimuli to provide appropriate, coordinated responses in various
organs
conduct nerve impulses from the sense organs and receptors to the central nervous system
Transmit the impulse from CNS to an effector organ so as to react to the stimulus
supply the connection between the afferent and efferent neurons as well as different parts of the central nervous system
AmeloblastsCells in teeth root, are present only during tooth
development
MORPHOLOGY OF AMELOBLAST SIZE: 4 microns in diameter, 40 microns in
lengthLong with hexagonal cross sectionHas a secretory end: Tome’s process which
is a hexagonal pyramid like structureThese cells become functional only after
dentine has been formed by odontoblasts
Functionsecrete the enamel
proteins enamelin and amelogenin
mineralization to form enamel on teeth
LOCATION1. Located on the root of the teeth.
A slide preparation of Ameloblasts showing Tome’s process
REFERENCEShttp://i-need-more.com/amelogenesis-1/
(6 April 2012)http://ajpcell.physiology.org/content/299/6/
C1299/F1.expansion (7 April 2012)http://www.bcb.uwc.ac.za/sci_ed/grade10/
mammal/nervous.htm (9 April 2012)http://www.sportsci.org/encyc/adipose/
adipose.html (9 April 2012)http://www.diabesity.eu/adipocyte.htm (11
April 2012)http://wdict.net/gallery/ameloblast/ (13 April
2012)
THANK YOU
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