Lab 2 - Histology of Cells Flashcards
Epithelial Cell
- Protective, secretory or absorptive surface
- Movement of substances into and out of body
- Found at lining and coverings in the body
Red blood cells
- Bind to oxygen in lungs and carry it to tissues = exchanged for CO2
White blood cells
Identify, capture and eliminate invading pathogens or foreign particles.
Osteoblasts
- OSTEO = BONE
- Bone – producing cells
- Present in bone marrow and other connective tissues
- Synthesize and secrete collagen fibres, and other organic components – used to build extracellular matrix of bone tissue and initiate calcification.
Fibroblasts
- Large, flat branching support cells present in most connective tissue
- Secrete fibres e.g. collagen and some ground substance component of extracellular matrix.
- Wound healing
- Structural framework for tissues
Skeletal muscle cells
- Found attached to skeleton via tendons, or through connective tissue sheet
- Voluntary control - contract and relax
Smooth muscle cells
- Found in walls of internal organs, blood vessels and internal muscles of eye
- Involuntary
- Helps to propel and expel liquid within and from the body
- Helps to regulate diameter of blood vessels
Nerve cells
- Main functional cells of nervous system
- Have long extensions – sensitive to external stimuli = respond to, and communicate information through electrical and chemical signals
Sperm cell
- Found in the male
- Travel to and fertilize ovum
Ovum
- Found in female
- Fuse with sperm cell and form zygote
How do oxygen and CO2 transport across cell membrane and why
Passively
Have no charge
Name three types of integral proteins and examples of these molecules/ions
- Carrier protein
- Protein channel
- Receptor proteins
- Glucose, Sodium and Potassium
If an integral protein requires energy to transport a molecule across the plasma membrane, it is described as….
Active transport
Why do we have cholesterol in our plasma membrane?
Maintain structural stability and fluidity.
- If temperature too low phospholipids prevent them packing close together and if the temperature is too high, it holds phospholipids together.
Which component of the plasma membrane is vital for restoring membrane integrity if the membrane is damaged? and explain how and why it maintains integrity.
Phospholipid bilayer - amphipathic property…
If membrane is damaged it will automatically reform into a bilayer - hyrdophilic heads face out attracting water and hydrophobic tails face away from water repelling it..
IN WATER PHOSPHOLIPIDS AUTOMATICALLY FORM BILAYER DUE TO THIS NATURE
What makes up the glycocalyx, and what function does it serve?
- Sugar coating attached to it, the carbohydrates
- Cell recognition and adhesion – glue
What does the cytoplasm consist of
- Cytosol
- Cytoskeleton
- Inclusions
- Membrane bound organelles
What is the cytoskeleton
Skeleton of cell composed of protein filaments scattered throughout the cytoplasm
What are the 3 type of protein filaments in the cytoskeleton
- Actin filaments
- Intermediate filaments
- Microtubules
What are actin filaments
- Thinnest and shortest
- Thin strands of actin monomers twisted in helix
- Edge of cytoplasm
- Found in muscle cells - movement
- Mechanical support - give shape and strength to cells e,g. integral proteins
What are intermediate filaments
- Thicker than actin
- Very tough and durable - more stable and strong than others
- Prominent in places with mechanical stress
- Rapidly from and fall apart
- Takes up most of cytoskeleton
- Basket around nucleus and extends outwards
- Anchors organelles in places in cell
- Keratin - waterproof barrier
What are microtubules
- Thickest and longest
- Long tubes of tubulin proteins arranged into long tubes - twisted
- Contribute to cell shape and structure
- Facilitate movement of organelles - found in places where you want something extracellular to move around - e.g. tracheae - mucus - trap dirt, photoreceptors - cilia - move
What does the nucleus consist of
- Nucleolus - makes ribosomes
- Nuclear envelope - double membrane around nucleus
- Nucleoplasm - jelly like fluid containing dissolved ions, nutrients and other solutes.
- Chromatin - makes up chromosomes - contains genetic info
Mitochondria
- Most abundant
- Produces energy
- ATP - aerobic respiration - glycloysis
- 0.1 - 0.2 micrometres
Ribosomes
- Very small - 20-30nm
- Makes proteins
- Consists of protein and RNA
- Formed in nucleus, exit through nuclear pores
Rough Endoplasmic Reticulum
- Folds and processes proteins made in the ribosomes
- Found in cells that make protein for export e.g. plasma cells ( antibodies )
Smooth Endoplasmic Reticulum
- Synthesises and processes lipids
- Found in muscle - calcium storage - muscle contraction
What is Endoplasmic Reticulum
Series of thin membrane sacs
Golgi Apparatus
- Series of flat membrane stacks associated with tiny vesicles
- It modifies and packages new lipids and proteins. -
- Makes lysosomes
- Two sides….
- CIS = side facing ER where vesicles from ER fuse
- TRANS = modified and packaged proteins leave from here for transport to other parts of cell.
Lysosomes
- Packaged by Golgi Apparatus
- 0.05 - 0.2 micrometres diameter
- Contains digestive enzymes - phagocytosis
What are the three types of specialised cell - cell junctions
- Gap junctions
- Occluding ( tight ) junctions
- Anchoring junctions - desmosomes
Example of occluding junction
Between epithelial cells lining the digestive tract keep digestive enzymes and microorganisms in the intestine from leaking into the bloodstream
Anchoring junctions
- Adjacent cells joined by joined by fibres from cytoskeleton
- Found in places with mechanical stress
- Stength, support and protection
- Proteins join together, cells can’t pull apart
What are gap junctions
- Directly connect cytoplasms of two different cells = molecules diffuse from one cell to the next e.g. nutrients. This is done by CONNEXONS that connect cells.
- Channels between neighboring cells that allow for the transport of ions, water, and other substances
- Involves integral proteins which fuse to each other - each protein = channel/pore. Gate opens = free movement of molecules
Example of gap junction
- Cardiac muscle, smooth muscle: the electrical signal to contract spreads rapidly between heart muscle cells as ions pass through gap junctions, allowing the cells to contract
- Lens - nutrients by aqueous humour via gap junction as no blood vessels/supplt
What are microfilaments
Contractile element of cytoskeleton
What is mitochondria
Scattered throughout a cell. Moves to where energy is required most
What are inclusions
Stores triglycerides – fat droplets
What is SER
Site of lipid formation
What is microvilli
Extensions of the plasma membrane that increase surface area
What is nucleus
Control centre of cell
What is RER
Packing site for ribosomes
What is nucleolous
Site of protein synthesis for export
What are centrioles
Two rod shaped bodies near the nucleus; involved in microtubule dynamics
What is plasma membrane
External boundary of the cell; regulates flow of materials into and out of the cell; site of signaling.
What is chromatin
Genetic material
What are cytosolic ribosomes
Synthesizes cytosolic proteins
What is lysosome
Contains digestive enzymes
What is an alternative name for gap junctions in cardiac muscle?
Intercalated disk
What organelle does a lysosome bud off from?
Golgi complex
Which filament of the cytoskeleton is thickest?
Microtubules
Which organelles are involved in protein synthesis for export from a cell?
Nucleus, Ribosomes, RER (rough contains the proteins), golgi apparatus and vesicles
