Detail anatomy of human cell

1. Human cell Anatomy
By:
Saifullah Email ID: optomsaif.4all@hotmail.com
FIACLE, M.PHIL OPTM, MPH, BS OPTM
Assistant Professor Optometry
PIO, Al-Shifa Trust Eye Hospital
Pakistan Institute of Ophthalmology 1

2. To know about
Cell - Introduction
Microscopic cellular anatomy
Structure of Cell organelles
Their functions
Their respective Clinical
Anatomies
Fundamental processes of a cell
Types of Cells
Topicstobecovered

3. CELL
 All living organisms are composed of CELLS.
 The basic structural, functional and biological
unit of all known living organisms(Cell theory).
 Building blocks of life.
 Replicate independently
 60-100 trillion cells make up an adult human
body & size ranges from 50 t0 150 micron
Cell theory(proposed by Schleiden & Schwann) states that,
• The cell is the basic unit of structure and organization in organisms.
• Cells arise from pre-existing cells.
Origin:
Latin: “Cella”
Meaning: “Smallroom”

4. CELLMEMBRANE
Phospholipid bilayer with protein molecules embedded
Phospholipids:
• Head - electrically charged – hydrophilic - on outer surface of the membrane
• Tail - no charge – hydrophobic - towards middle of themembrane

5. Types pf proteins:
• Transverse membrane proteins - Integral proteins: traverse
the entire thicknessof membrane - has diffusion channels
• Surface membrane proteins - Peripheral proteins: penetrate
partly through membrane
Functions of membrane proteins:
• Immunological identity
• Hormone receptors
• Acts as enzymes
• Transportation across cell membrane
Outer surface - Glycoprotein layer - Glycocalyx or Cell
coat
• Tissue antigens, major histocompatibility antigens are located
on cell coat.
Carbohydrate chains bound to proteins -
Glycoproteins
Carbohydrate chain bound to lipids - Glycolipids

6. CYTOPLASM
 Jelly-like aqueous substance
Formed by 80% of water
Two zones:
• Ectoplasm - Peripheral part-beneath cell
membrane
• Endoplasm - Inner part- between ectoplasmand
nucleus
Contents:
• Cytosol : Clear liquid portion (Soluble part)
• Other structures: Organelles, Inclusion bodies,
Cytoskeleton (Non-soluble part)
Can be compared with jello-fruit for understanding purpose

7. ORGANELLES
Permanent components of cells
Membrane bound
Contain enzymes
Participate in cellular metabolic activity
It includes:
• Mitochondria
• Endoplasmic reticulum
• Golgi apparatus
• Ribosomes
• Lysosomes
• Peroxisomes
• Centrosomes

8. MITOCHONDRION
Sausage shaped
Double membrane bound
Five parts:
• The outer membrane
• The intermembrane space - the space
between the outer and inner membranes
• The inner membrane
• The cristae space – the infoldings of the
inner membrane
• The matrix - space within the inner
membrane
Site of aerobic respiration

9. Power house of cell – Production of cellular energy as ATP
Metabolically active cells(muscle cells, liver cells) have more
mitochondria
Its matrix contains single circular DNA molecule, few RNA
protein synthesis
Role in the synthesizing membrane bound proteins

10. ENDOPLASMICRETICULUM
Series of interconnecting membranous canals
Continuous with the outer nuclear membrane
Flattened, membrane-enclosed sacs or tube-like
structures - Cisternae
Space inside of the ER– Lumen (Diameter: 400-
700Ǻ)
Types:
1. Rough Endoplasmic Reticulum
2. Smooth Endoplasmic Reticulum

11. Smooth EndoplasmicReticulum
Devoid of ribosomes
 Synthesizes
• Lipids
• Glycogen
• Steroid hormones
 Associated with
detoxification of drugs

12. Rough Endoplasmic Reticulum
Large double membrane sheets of
RERare continuous with the outer
layer of the nuclear envelope.
Studded with ribosomes
Ribosomes are membrane bound
Responsible for the assembly of
many proteins - Translation
Site of protein synthesis viz.
Enzymes and hormones

13. GOLGI APPARATUS
Supranuclear organelle
Stacks of closely folded
flattened membranous sacs –
Cisternae (Diameter:0.5-1.0μ)
 A mammalian cell has 40-100
stacks (4-8 cisternae per stack)
In close association with ER
Two main compartments:
• Convex Cis face or the forming
face
• Concave Trans face or the
maturing face

14. Site of Protein packaging
and processing
Site of formation of
glycoproteins and
glycolipids
Storage of secretory
vesicles
A major collection and
dispatch station of protein
products received from the
endoplasmic reticulum

15. RIBOSOMES
Large ribosomal
subunit
Tiny electron dense granules
Two major components:
• Small ribosomal subunit
• Large ribosomal subunit
-(forms proteins from amino acids)
Distribution:
• Cytosol
• Nucleus
• Nucleolus
• RER(outer surface)
Small ribosomal
subunit

16. LYSOSOMES
Lysis-Solution Soma-Body
Membrane bound vesicles
Formed by the process of
packaging in Golgi apparatus
Contain hydrolytic enzymes-
optimally active at acidic pH
Intracytoplasmic digestion
Phagocytic activity viz.
macrophages, neutrophils

17. PEROXISOMES
 Microbodies
 Membrane bound vesicles
 Derived from the endoplasmic reticulum
 Replication by fission
 Surrounded by a lipid bilayer membrane enclosing
the crystalloid core
 Contains Oxidative enzymes:
• catalase
• urate oxidase
• D-amino acid oxidase
Functions:
• Beta oxidation
• Detoxification of hydrogen peroxide
• Oxygen utilization
• Myelin formation
• Bile acids production

18. CENTROSOMES
 Dense cytoplasmic region having
centrioles - Centrosomes
 Two cylindrical bodies at right
angles to each other – Centrioles
 Found near nuclear membrane
 Centriole –27 microtubules in 9 bundles
 A Bundle has 3 microtubules – Triplets
 Formation of spindles during cell division

19. CYTOPLASMICINCLUSIONS
Temporary components of certain cells
May or may not be membranebound
Examples:
• Lipid droplets- in cells of adipose tissue, liver, adrenal
cortex
• Glycogen- in cells of liver, skeletal muscles
• Proteins assecretory granules- in secretory glandular
cells
• Melanin pigment-in cells of epidermis, retina,
basal ganglia
• Lipofuscin(derived from secondary lysosomes)- in cells of
cardiac muscles, brain cells of elderly people

20. CYTOSKELETON
 Elaborate network of filamentous
proteinaceous structures throughout the
cytoplasm
 From the nucleus to the plasma membrane
 Three main kinds of cytoskeletal filaments:
• Microfilaments
• Microtubules
• Intermediate filaments
 Microfilaments:
• polymers of actin, myosin
• cell shape, support, contraction & movement
 Microtubules:
• made of tubulin(α &β)
• intracellular transport, mitotic spindle
 Intermediate filaments:
• made of various proteins
• structural and mechanical support

21. NUCLEUS
Large sphere shaped
Nuclear envelope has two
parallel membranes(outer
& inner)
Space between two membranes –
perinuclear space
Outer membrane continuous with RER
Nuclear envelope interrupted by minute
pores – nuclear pores
Viscous liquid inside(nuclear
matrix) – Nucleoplasm
Loose and indistinct network of
nucleoprotein fibres - chromatin

22.  Chromatin contains
• DNA
• Histone proteins
• Non histone proteins
• RNA
 During cell division,
Chromatin replicates and becomes more tightly
coiled
 Functional units of chromosomes –genes
 Total complement of genes –genome
 Genome or genetic code is required for protein
synthesis in the body
 Nucleo
•
lu
H
s
ighlyrefractile spherical structures within
nucleus
• non-membrane bound
• Compressed mass of amixture of RNA
granules & proteins
• Site for active ribosomal RNA synthesis

23. FUNDAMENTALPROCESSESOFA CELL
oCell Division -
oCell Growth -
oMaturation - The terminal stages of differentiation ofcells
o Apoptosis - A process of programmed cell death
The process by which a parent cell divides into two or more
daughter cells
Cell development; Increase in cytoplasmic and organelle volume &
genetic material during cell cycle
O Differentiation
-The process where a cell changes from one cell type to another

24. The body cells are broadly divided into two
types:
• Somatic cells
• Germ cells
Somatic cells are essential for growth,
development, regeneration and
maintenance of various tissues of the body.
Germ cells are essential for the production
of gametes.

25. SOMEOFTHESOMATICCELLS
Osteocyte Blood cells Stem cell

26. Muscle cell
Smooth muscle cell
Adipocytes
Skin cells
Squamous cells from
skin surface

27. Neurons
Active
Endothelial cells
Cancercell
Cervical cancer cell dividing

28. GERM
CELLS

29. STEM CELLS
TOTIPOTENT
STEM CELLS
PLURIPOTENT
STEM CELLS
MULTIPOTENT
STEM CELLS
OLIGOPOTENT
STEM CELLS
UNIPOTENT
STEM CELLS
1

30. RED BLOOD
CELLS
(Erythrocytes)
WHITE CELLS
(Leukocytes)
EOSINOPHIL
PLATELETS
(Thromocytes)
NEUTROPHIL BASOPHIL
LYMPHOCYTES
MONOCYTE
GRANULOCYTES
AGRANULOCYTES
2
BLOOD CELLS

31. SENSORY
NEURONE
RELAY
NEURONE
MOTOR
NEUTRONE
3
NERVE CELLS

32. CARDIAC
CELLS
SKELETAL
CELLS
SMOOTH
CELLS
4
MUSCLE CELLS

33. 5
CARTILAGE
composed ofspecialized
cells called
CHONDROCYTES

34. OSTEOGENIC
CELLS
OSTEOBLAST OSTEOCLAST
OSTEOCYTE
6
BONE CELLS

35. KERATINOCYTES MELANOCYTES
LANGERHANS
CELLS
MERKEL
CELLS
7
SKIN CELLS

36. FATS CELLS
BROWN
ADIPOCYTE
WHITE
ADIPOCYTE
BEIGE
ADIPOCYTE
8

37. EPITHELIAL CELLS
SQUAMOUS
EPITHELIUM
COLUMNAR
EPITHELIUM
CUBOIDAL
EPITHELIUM
9

38. ENDOTHELIAL CELLS
UMBILICAL VEIN
ENDOTHELIAL
CELLS
MICROVASCULAR
ENDOTHELIAL
CELLS
1
0

39. SEX CELLS
SPERM
OVA
OR
EGG CELLS
11