Cytoskeleton and Cell inclusions Flashcards
Give examples about cell inclusions
- stored food
- colored pigments
- crystals
What are the characteristics of cell inclusion
- temporary components of the cytoplasm
- non-living materials produced as a result of cell activity
- products of cellular metabolism
- exogenous substances which brought into the cell
Give examples about crystals in the cytoplasm
Crystals as oxalate , calcium phosphate and calcium carbonate may be present in the cytoplasm
Why in some conditions crystals present in great amount in the cytoplasm
Present in great amounts in certain cells because of some pathological conditions
Give examples about the stored food in the cytoplasm
- Carbohydrates as glycogen inside certain cells as liver or muscle cells
- fat , stored as small or large globules in certain cells , also stored as small droplets in liver cells
Types of glycogen stored in certain cells as liver and muscle cells .
There are two types of glycogen —> Alpha glycogen particles —>Beta glycogen particles
Types of pigments
- Exogenous pigments —> comes from outside the cell
- endogenous pigments —> it is formed by body cells and perform certain functions in some cells
Some fatty woman may eat large amounts of carrots for doing a regime , their skin may become yellowish in color , what is the name of this condition?
- The condition is called carotenemia —> colouration is due to deposition of carotene pigments in certain connective tissue cells of their skin .
Location of carotene pigments
Present in certain vegetables as carrots 🥕 and tomatoes 🍅
What are dust pigments ?
Small particles of dust may enter the body through the respiratory system . They precipitate in the cells of the lung causing black pigmentation
What are the tattoo marks ?
Colored pigments introduced to the skin by needle pricks , taken by phagocytic cells of the skin , cause permanent colored marks on the skin
Minerals pigments what are they ?
They are small minerals as silver and lead , they may enter the vital cells and may cause silver or lead poisoning , they may enter through respiratory , digestive systems or the skin
Types of exogenous pigments
- carotene pigments
- dust pigments
- minerals
- tattoo marks
Types of endogenous pigments
- hemoglobin pigments
- melanin pigments
- lipofusin or lipochrome pigments
What are the lipofusin and lipochrome pigments ?
They represent a normal end product of wear and tear that resists digestion by lysosomes enzymes
Location of lipofusin or lipochrome pigments ?
They accumulate as residual bodies in the very long-livid cells , such as cardiac muscle cells and nerve cells
Which cell can form melanin pigments
It is formed by melanocyte cells
Location of melanin pigments
It is present in the cells of skin , hair and eye .
Which cell can form haemoglobin pigments
It is formed by red blood corpuscles
What are the derivatives of hemoglobin pigments
Hemosiderin , bilirubin , and biliverdin pigments
Function and contents of cytoskeleton
- forms the skeleton of each cell and is responsible for its specific shape
- it consists of several classes of structural elements
- microtubules
- microfilaments
- microvilli ( tubules and filaments )
Structure of microvilli
Formed of microtubules and microfilaments covered by cell membrane
Function of microvilli
They increase the efficiency of absorption and the surface area of the cell .
Shape of microvilli
They are like projections on the surface of certain cells of the body
Location of microvilli
Located on intestine liver and kidney cells
Function of microfilaments in microvilli of certain cells
- They play a role in their contraction , elongation and shortening
- present also at the basal parts the microvilli of the intestinal epithelium and known as terminal webs
- this terminal webs play a role in the movements of microvilli
Function of microfilaments in cell division
- They form a contractile ring which helps in the separation of the dividing cells
Function of microfilaments in blood platelets
They help in retraction of blood clot
Function of microfilaments in muscle cells
Are responsible for muscular contraction
Function of microfilaments in certain blood cells
They help in their amoeboid movement
Types of microfilaments
- Actin filaments / thin filaments
- myosin filaments / thick filaments
- intermediate filaments
Where we can finde actin/thin filaments and myosin/thick filaments ?
At muscle cells
Where can we find intermediate filaments
Found in variety of cells , they are called neurofirills in nerve cells
Location of microfilaments at cell
At the cytoplasm
Location of microtubules
They are present in all kind of cells
Appearance of microtubules in cross section
Appear as tiny circles
Length and strength of microtubules
They are of variable length and are sufficiently elastic to bend without breaking
Structure of microtubules
- they are cylindrical filamentous structures about 250 angstrom in diameter ( 25 nm )
- formed of protein known as tubulin which present in a soluble form
Function of colchicine in the treatment of cancer
It is a cytotoxic drug which prevents the formation of microtubules of the centrioles in order to stop cell division
Function of microtubules in cell division
They push the pairs of centrioles in order to complete the process of cell division
Function of microtubules in cilia
Concerned in the movement of cilia
Function of microtubules at the cytoplasm
Facilitate the transport of various particles throughout the cytoplasm
The main function of microtubules at the cell
Acts as a skeleton for the cell
