Cells, Tissues, Organs, Systems Flashcards
Three componants of a cell
Cell Membrane
Cytosol
Organelles
What is this?
The plasma membrane
Outer layer of the cell
Encloses the cytoplasm within it
What is this?
The nucleus is the largest organell
Surrounded by the nuclear envelope
Contains a structure called nucleolus which makes ribosomes
Contains DNA and is found is most cells in the body
What is the Cytoskeleton?
It is a network of protien fibres which give the cell structure and allow it to move
What is this?
Produce enery for the cell through aerobic respiration
Abundent in cells that require a lot of enery e.g. muscles and liver
What is this?
Smooth:
Responsible for synthesysing lipids and steroid hormones. Also drug detoxification
Rough:
Synthesises protiens to be exported from the cell
What is this?
Made up of RNA and protiens
Synthesise protiens using RNA as a template
Ones in the cytoplasm make protiens for inside the cell
Ones in the RER make protienes for export
What is this?
Stack of membrane bound sacs
Recieves protiens from the RER and export them
Protiens are stored in vesicles, these then move to plasma membrane and fuse with it where the contents are then expelled by exocytosis
Also produce liysosomes
What is this?
Spherical vesicles pinched off form the golgi apparatus
Contain enzymes
Function is to break down large molecules withint he cell e.g. DNA,RNA, protiens etc.
What is this?
Cytosol is the watery fluid houseing the organelles
The cytoplasm is everything inside excluding the nucleus
What is this?
The centrosome is part of cell devision, first it duplicates then as division begins they move to opposides of the cell
Epithelial tissue
Lines the surfaces of cavities and tubes
Purpose is transport, diffusion and secretion
Muscle tissue
Generates force through contraction
Nervous tissue
Responsible for communication. Forms networks connecting the brain and spinal to the rest of the body
Connective tissue
Tissues responsible for structure, insultion or protection
Four main types of tissue
Epithelial
Nervous
Muscle
Connective
What are tissues made from?
Cells and extracellular matrix (ECM)
Extracellular matrix (ECM)
The ECM is made and exported by cells to fill the space between cells.
It’s roles include providing structure, forms junctions, regulates migration, changes function of cells, influences development.
It is almost non existant in epithelial tissue but very high in connective tissie.
Epithelial tissue (simple vs stratified)
Loose (areolar) connective tissue
Most abundent, connects and support other tissues such as under the skin and between muscles
Adipose tissue
A type of areolar tissue containing adipocytes (fat cells)
Reticlular connective tissue
Found in lymph nodes and lymphatic organs.
Consists of reticular fibres, reticular cells and white blood cells
Dense connective tissue
Low in cells high in fibres
Fibrous tissue
A type of dense connective tissue which makes up tendons and ligaments
Elastic tissue
A type of dense connective tissue found in organs where a change of shape is common e.g. blood vessels and lungs
Chondrocytes
Cartilage cells embedded in a collegen matrix to make up cartilage
Osteocytes
Bone cells embedded in a mineralised collegen matrix to make up bones
Three types of muscle tissue
Skelletal
Smooth
Cardiac
Skelletal muscle
Myoblasts fuse together to form striated multinucleated muscle fibres
These can contract voluntarily in order to move bones
Smooth muscle
Non striated
Under involuntary control
Useful in propelling contents along tubes through rythmic contractions e.g. gut and ureter
Cardiac muscle
Made up up striated mononucleated fibres
Involutary contractions
Branching cells connect fibres and intercalated discs between cells help propergate waves of contraction
Two types of cells witin nervous system
Neurons - excitable and transmit information
Glial cells - non excitable and support the neurons
Occluding junctions
Seals cells together to prevent molecules leaking to another cell or across a boundary
Anchoring junctions
Function is to connect cells to other cells or to the ECM
Communicating junctions
COntrols the passage of chemical or electrical signals between cells.
Most cells are linked by gap junctions
Can also include chemical synapses
Histology
The process of preparing tissues for study under a microscope.
Cut into thin slices and stained
