Diversity of Cells and their Function - Lecture 2 Flashcards
How can material cross the cell membrane?
Diffusion
Pumps and Channels
Vesicular Transport
What is Endocytosis?
Material from the extracellular fluid being incorporated into the cell
What is the mechanism of endocytosis?
Cell invaginates
Creates pseudopodia
Membrane fuses
Forms an Endosome
Process governed by receptors
What are the three steps of endocytosis?
- Invagination
- Fusion
- Budding
Describe Phagocytosis?
Bacteria/ Large particle joins the surface
Triggers receptors of Pseudopodia
The pseudopodia and form a phagosome
The phagosome binds with a lysosome forming a phagolysosome
Material is digested
How is tissue preserved so it may be viewed down a microscope? (5)
Cut very thinly - to allow light through
Impregnated with a support material
For waxing: It has to be dehydrated (via xylene)
Sample then placed in an organic solvent and then placed into hot wax.
Thin sections are then cut on a microtome and put onto microscope slides
The wax is washed out and the tissue is rehydrated
What are the two Tissue stains used?
Haematoxylin
Eosin
What is Haematoxylin?
Haematoxylin is a basic dye that has an affinity for acidic molecules, stained bluish purple
What is Eosin?
Eosin is an acidic dye that has an affinity for basic molecules, stained pink/red
What are the basic types of tissue? (4)
- Epithelium
- Connective
- Muscle
- Nervous
Where are Epithelia found? (3)
Found were the outside meets inside.
Used to line hollow organs
Form glands
How do epithelia cells gain nutrients?
All are non-vascular cells and gain nutrients from capillaries
What are Polarised cells?
They are different at the apical and basal ends
What are the functions of Epithelia cells? (5)
Mechanical Barrier Chemical Barrier Absorption Secretion Containment
What are the types of Epithelia?
- Squamous
- Cuboidal
- Columnar
Name the layers of Epithelia Cells?
Simple - one layer
Stratified - two or more layers
Psuedostratified - appears to have more than one, but only has one.
What are endocrine glands?
Endocrine Glands: Products secreted towards the basal lamina then disturbed to the vascular
system
What epithelia secrets products?
Glandular epithelia
What are exocrine glands?
Products secreted towards the apical end, they then go to the lumen, internal
space, or into a ducts
What type of glands are duct glands?
Exocrine glands
What are the types of connective tissue?
Soft connective tissue
Hard connective tissue
Blood and lymph.
What does connective tissue consist of?
Extracellular Matrix
Cells
What is the Extracellular matrix of connective tissue made from?
Reticular Fibres Elastic Fibres Collagen Ground Substance Tissue fluid
What is the Ground Substance in the Extracellular Matrix of Connective Tissue?
An amorphous space occupying material made of huge unbranched polysaccharide molecules (glycoaminoglycans)
What cells are found in Connective Tissue?
Fibroblasts
Adipose Cells
Osteocytes
Chondrocytes (cells of the cartilage)
What are three types of Cartilage?
Hyaline
Elastic
Fibrocartilage
What is the shaft of the bone called?
The Diaphysis
What is the Diaphysis made from?
Cortical Bone
What are the ends of bone called?
Epiphyses
What are Epiphyses made from?
Cancellous/Trabecular Bone
What are the types of muscle?
Smooth
Cardiac
Skeletal
Describe Smooth Muscle.
Smooth muscle is elongated spindle shapes.
No striations can be seen.
What is Involuntary Muscle?
Skeletal Muscle
Describe Skeletal Muscle.
Striated Muscle
Multi-nucleated
Nuclei located at the periphery
What is the cell membrane of Skeletal Muscle?
The Sarcolemma
Describe Cardiac Muscle.
Has Striations
Attach to neighbouring cells via Intercalated Discs
What does Nervous tissue consist of?
Neurones
Support cells (Glia Cells)
What is the connective tissue coat in the central nervous system?
The Meinges
What is the connective tissue coat in the peripheral nervous system?
The Epineurium
What are the Glia Cells in the Central Nervous System?
Astrocytes
Oligodenrocytes
Microglia
What are the Glia Cells in the Peripheral Nervous System?
Schwann cells
What is the function of Astrocytes?
Astrocytes: used for support and for ion transport
What is the function of Oligodenrocytes?
Oligodenrocytes: used to produce myelin
What is the function of Microglia?
Microglia: provide immune surveillance.
What is the function Schwann cells?
Schwann cells: Produce myelin and support axons.