Cell histology Flashcards
(88 cards)
1
Q
he smallest entity capable of independent existence. It is the basic morphologic and functional unit of all living things
A
Cell
2
Q
Numerous species of unicellular organisms
A
germs- disease causing bacteria, parasites ex: entamoeba histolytica= amoebiasis)
3
Q
how do humans start
A
single cell (fertilized ovum or zygote).
4
Q
union of spermatozoon and ovum (male and female gametes respectively)
A
fertilization
5
Q
Combination of tissues that form a more complex functional unit
A
Organ`
6
Q
Combination of cells with the same general function
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Tissue
7
Q
Group of organs that have interrelated functions
A
Organ System
8
Q
human cells (eukaryotic cells) share a common basic structure.
A
mass of cytoplasm
- cell membrane
- nucleus encased by nuclear envelope
9
Q
- delimits cell from outside
- protective cover
- determines what can enter and exit
- binding sites and receptor for enzymes
- cell recognition
highly impermeable structure that does not allow molecules aside from water, gases and some molecules to pass freely
A
Cell Membrane (plasmalemma)
10
Q
Cell Membrane
A
- 2 layers of phospholipids
head and 2 tails
11
Q
head of cell membrane
A
globular and polar (hydrophobic)
glycerol (outer region)
12
Q
Tail= Saturated and unsaturated fatty acid
A
Nonpolar (Hydrophobic) One tail contains saturated FA The other tail contains unsaturated FA Has a slight kink but otherwise straight Linkage between the head and the tail involves covalent bonds
13
Q
- half mass of the cell membrane
- transport substances
- signal transduction
- cell recognition
A
protein
14
Q
2 types of protein
A
transmembrane protein
peripheral membrane
15
Q
Loosely attached to the inner or outer surfaces of the membrane
A
peripheral membrane
16
Q
Project out of the inner and outer surfaces of the membrane
A
Transmembrane proteins
17
Q
whats in the cell membrane
A
cell membrane mainly contains proteins, phospholipids but also cholesterol and polysaccharides such as glycolipids and glycoprotein
18
Q
- almost as many as phosolipid
- in irregular spaces
- makes cell m. less permeable to water soluble
- harmful if excess in blood = plaques
A
CHOLESTEROL
19
Q
- in the forms of glycolipids & glycoproteins
- project out of the cell to form a coating called Glycocalyx
- nvolved in cell-to-cell recognition, cell-to-cell adhesion
- immune response
A
polysaccharides
also known as the unit membrane
20
Q
of matrix (cytosol) where formed elements are embedded (organelles, inclusions & fibrillar structures)
A
CYTOPLASM
21
Q
viscid, translucent and colloidal substance which is the site of important biochemical processes
- suitable environment for organelles to work
>70% water: inorganic
A
Matrix
22
Q
- alwayys in cytoplasm
- has specific functions
all cells have organelles - ## except rbc and lens fiber
A
Formed elements (organelles)
23
Q
Typical organelles in a human cell :
A
Mitochondria Ribosomes RER & SER Golgi Apparatus Lysosome Peroxisome Centrosome (contains centrioles)
24
Q
he cell “powerhouse”
They are able to produce energy because the
- hotdog-shape or rod like spherical
- Mitochondria can only be produced from existing mitochondria.
A
Mitochondria
25
on what does rbc and muscle cells rely
| who dont have mitochondria
Glycolysis
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Distributes proteins throughout the cell
Smooth ER
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Site of
synthesis of protein for cell maintenance
and metabolic processes
- synthesis of protein component
- packages proteins for rer
Golgi Apparatus
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Source of the microtubules for cell use
| -Microtubule Organizing Center (MTOC
Centrosome (MTOC)
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- recycles protein
- prtects function from foreign bodies
- phagocytosis
- heterophagy
- autophagy
Lysosomes
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Prevent degradation of the neuron through
its detoxification function
-Catalase = H2O2 O2 +H2O
Peroxisomes
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- form part of the proteins of structures that are needed to be renewed (microtubules/ microfilaments)
- form cytplasmic matrix
-
ribosomes
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Most extensive membrane-bound structure in the cytoplasm
-
RER & SER
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There are ribosomes and polyribosomes attached to its membranes
Rough ER-
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responsible for bone ressorption which releases their hydrolytic enzymes extracellularly
Osteoclast
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Digestion of substances foreign to the cell
Heterophagy
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Digestion of unneeded organelles or any structures within the cell
Autophagy
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most important phagocytes are
neutrophils and macrophages
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LYSOSOMAL ENZYMES
Digest all cellular organic matter
Active at pH 5
Inactive at pH7.2 (cytosol)
39
formed by tubular structures known as microtubules
- Source of mitotic spindle fibers (mitosis), Cilia of ciliated cells and tail of sperm cells (flagella)
-
CENTRIOLE
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Inclusions
```
Fat droplets
glycogen
zymogen granules
pigment granules
crystals
dust particles
```
41
Temporary inert cellular structures which may or may not be membrane bound
Some are harmful and some are useful
INCLUSIONS
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- specialized in storing lipids.
- occupy more than 90% of the cell
-
Fat Droplets (Lipid droplets)
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- The storage form of carbohydrates
- present in many cells, particularly abundant in liver and muscle cells.
-
Glycogen (Glycogen Granules
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- membrane bound proteins from golgi complex released by the cell to the extracellular space via exocytosis
Zymogen Granules
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Pigment Granules
- melanin
- hemosiderin
- lipochrome
-
46
- Brown to black coloration of the skin
is present in nerve cells of substantia nigra & locus coeruleus in the
Melanin
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- Brown pigment which is the product from the lysosomal digestion of hemoglobin
- Residual bodies= membrane bound
Hemosiderin
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Yellowish-brown pigments in long-lived cells such as the muscle cells in the myocardium, Sertoli cells in the testes, neurons and
Lipochrome
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Rod shaped but can also occur in other shapes
No known function
Probably degenerative cells as they are presently
present in interstitial cells of Leydig in testes & Sertoli cells of testes)
Crystals
50
Brown to black membrane-bound structures
Numerous in a smoker’s lungs and in people who live in a dense dusty environment
Dust Particles
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A complex network of fibrillar elements that forms the structural framework' or skeleton of the cell.
CYTOSKELETON
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3 types of fibrillar elements classified to diameter
- MICROFILAMENTS
- INTERMEDIATE FILAMENTS
- MICROTUBULES
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- present in all cells
- a lot in peripheral area to provide internal cellular support
- actin makes up 10-15% of total cellular protein
MICROFILAMENTS
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- Not exclusively seen in cytoplasm
Some are present in the nucleus
- has 5 major types
-
INTERMEDIATE FILAMENTS
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Major types (Cytoplasm) INTERMEDIATE FILAMENTS
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Keratin
Desmin (skeleton)
Vimentin
Neurofilament
Glial filament (glial fibrillary acidic protein: GFA)
```
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a type of intermediate filament
- in epithelial cells
- Protects cells from mechanical and oher stresses
Keratin
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a type of intermediate filament
- found in muscle
- man in smooth muscles
- maintain cell archi and structure
desmin (skeleton)
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```
a type of intermediate filament
- in mesenchyme derived cells
- scattered all over cytoplasm
- help maintain cell shape
-
```
vimetin
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a type of intermediate filament
- in nerve cells
- cell body and process of neurons
- parelle to axis
neurofilament
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a type of intermediate filament
- in neuroglial cells
- facilitates internal support
glial filament
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the thickest among the three
- Hollow pipes assembled/ disassembled in the centrosome
- 13 tubulin molecules.
- In the cytoplasm = support of the cell
Embedded in organelles = movement
Comprises the centrioles, mitotic spindles, cilia of ciliated cells and flagellum of sperm cells
MICROTUBULES
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- largest structure
- in all cells except rbs
- round
- nucleated,
- nucleus data bank
-
Site for RNA production needed for the protein synthesis which cytoplasmically occur
rRNA (ribosomal)
mRNA (messenger)
tRNA (transfer)
NUCLEUS
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nuclear envelope (nuclear membrane)
- 2 unit membranes (outer and inner nuclear
- fluid filled
- nuclear pores are round opening 100 pores
NUCLEAR ENVELOPE
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A fibril protein layer is associated with the inner surface of the inner nuclear membrane
-Serves as mechanical support of nucleus
Stabilizes nuclear pores
Fibrous Lamina
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- made of nucleoplasm/ nuclear sap
- Chromosomes are embedded here
- chromosomes are referred to as chromatin/ chromatin materials (INTERPHASE)
Nucleolus is usu
NUCLEAR MATRIX
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- Nucleus of all human cells contain 46 chromosomes (
- 23/46 is inherited from the moth, half from father
- Numbered according to length 1-22
-Female sex chromosomes are homologous, male are not
CHROMATIN
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Chromatin forms granules or clumps
- takes up stains
- darker
* - not all produce RNA
Heterochromatin
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```
Areas that do not take up stains
Made up of portions of chromosomes which are
- no stains
- lighter color
- mrna and trna made here
```
Euchromatin
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All DNA molecules in the human cell
HUMAN GENOME
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-DNA in chromosomes
Larger than mitochondrial genome
Largely referred to human genome
Database of coding sequences for all protein and nucleic acid
Chromosomal genome
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DNA in mitochondria
Contains coding sequences for proteins and enzymes it needs and for replication
- 5% encode for genes.
Mitochondrial genome
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- Only seen at interphase
- Only 1 nucleolus in nucleus
- Absent in cells that do not synthesize proteins or may synthesize small proteins
-
NUCLEOLUS
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Site of ribosomal subunit synthesis
- Nucleolar organizing region
- Pars fibrosa
- Pars Granulosa
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NOR – circular pale are surrounded by electron-dense filament
- Site of gathering of chromosomes which have NOR
- Refers to gene coding for rRNA
Nucleolar organizing region
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Electron-dense area surrounding NOR
| Consists of rRNA from NOR
Pars fibrosa
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Granular area surrounding Pars fibrosa
| The rRNA from pars fibrosa will get linked to proteins
Pars Granulosa
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One of the most important activities of a cell is the production or synthesis of proteins.
- protein is essential to cells
- catalyze biochemical reactions and hormones and hormone-like substances
-
PROTEIN SYNTHESIS
PROTEIN = POLYPEPTIDE CHAIN CONTAINING AMINO ACIDS LINKED VIA PEPTIDE BONDS
78
where is the amino acid code sequence produced
nucleus
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Amino acid into polypeptide chain happens in the
cytoplasm
80
Diffusion, ion channels, carrier transport and active pump transports =
- bigger molecules transported via bulk transport
CELL MEMBRANE TRANSPORT
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Liquid substances are passing through the membrane
MICROPINOCYTOSIS
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Solid substances are passing through the membrane
PHAGOCYTOSIS
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chemical
| Engulf microscopic or small amount of liquid
MICROPINOCYTOSIS
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Engulf large amount of liquid
MACROPINOCYTOSIS
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Entry of molecule into the cell
ENDOCYTOSIS
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Exit of molecule out of the cell
| Most materials transported out of the cell ar
EXOCYTOSIS
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First accumulates in cell apex then later released simultaneously in response to stimulus
REGULATED SECRETION
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The secretory granules are released immediately after they leave the golgi complex
CONSTITUTIVE SECRETION
