Diversity of cells and their function Flashcards
What is endocytosis?
A method of incorporating extracellular material into the cell
Describe endocytosis.
- The cell membrane folds in (Invaginates) on itself
- Extracellular material enters this space
- Cell membrane fuses around the material creating a vesicle (Endosome/Endocytotic vesicle)
- Vesicle buds off into cell.
What is exocytosis?
The release of intracellular material into the extracellular matrix.
What is phagocytosis?
The incorporation of bacteria or large particles into a cell to be digested by enzymes from a lysosome.
Name the 4 main types of human tissue.
Epithelia
Muscle
Nervous tissue
Connective tissue
What functions do epithelial cells serve? (6)
- Cover surfaces of the body such as inner linings of hollow organs and the skin
- Form glands for secretion.
- Absorption
- Mechanical barrier (Skin)
- Containment
- Locomotion by cilia
What is the basal lamina?
A basement membrane, A layer of extracellular matrix components to which epithelia cells attach.
What are the three classifications of epithelia according to shape?
- Squamous (Flat)
- Cuboidal (Cube shaped)
- Columnar (Tall and thin)
How are epithelia classed in terms of number of layers, and describe them?
- Simple- One layer
- Stratified- Two or more layers
- Pseudostratified- Appearance of several layers, however all cells are connected to basal lamina
Where is the product from endocrine glands secreted and how is it distributed?
Towards the basal end of the cell to be transported around the body in the CV system.
Where is the product of exocrine glands secreted?
Towards the apical (Top) end of the cell.
How is connective tissue classified (3), and give examples of each?
- Hard connective tissue- Bone and cartilage
- Soft connective tissue- Ligaments, tendons, mesentry, stroma of organs, dermis of the skin.
- Blood and lymph
What are fibroblasts?
Cells which help produce and maintain the extracellular matrix.
What are adipose cells?
Fat cells found predominantly in adipose tissue.
What are osteocytes?
Cells of bone
What are chondrocytes?
Cells of cartilage
How is soft connective tissue classified? (2)
Dense and loose
What is cartilage?
A strong, flexible, compressible semi-rigid tissue.
Cartilage can be divided into three sub groups, what are they?
- Hyaline
- Elastic
- Fibrocartilage
Give an example of where hyaline cartilage may be found.
- Epiphyseal growth plates
- Articular surfaces
- Tracheal rings
- Costal cartilage
How does cartilage receive a nutrient supply?
Cartilage is avascular so receives it’s nutrients by diffusion from adjacent cells through it’s matrix.
What is the Cortex of a bone and what is it made from?
The hard outer shell made of cortical bone.
What is the medulla of a bone and what is it made from?
The porous spongy inner section of a bone made from trabecullar (cancellous) bone.
How does bone receive nutrients?
Bones are penetrated by small canals allowing blood vessels and nerves to supply the bone.
Describe how force is produced during contraction of muscle cells.
Thin actin filaments pass over myosin fibres.
Muscle can be divided up into three major types, name these.
- Skeletal
- Smooth
- Cardiac
What other names are given to Smooth muscle? (2)
Involuntary or visceral muscle
What other names are given to skeletal muscle? (2)
Voluntary or striated muscle.
What is the sarcolemma?
The cell membrane of a striated muscular cell.
What is the function of cardiac muscle?
To form the walls of the heart chamber and the origins of the blood vessels.
What are Glia?
Supporting cells of nervous tissue.
What is the function of nervous tissue? (2)
- Provides a control function
- Allows rapid communication between different areas of the body
What is the meninges?
A connective tissue coat around cells in the Central nervous system.
What is the epineurium?
A connective tissue coat around cells in the Peripheral nervous system.
How are neurones categorised?
Bipolar neurones
Unipolar neurones
Multipolar neurones
Name the principle Glia of the Central nervous system. (4)
Astrocytes
Oligodenocytes
Microglia
Schwann cells
What is the function of astrocytes? (2)
Support and ion transport
What is the function of oligodenocytes?
They produce myelin
What is the function of microglia?
They provide immune surveillance
What is the function of Schwann cells? (2)
Produce myelin and support the axon.
