Diversity of Cells and Their Function Flashcards
1. Describe the 4 basic tissue types: epithelium, connective tissue, muscle and nervous tissue 2. Describe the 3 basic cell shapes found in covering epithelia and the 2 main types of layer structure. 3. Describe the 3 major types of muscle tissue and compare them in terms of structure, function and location in the body 4. Describe the different types of connective tissues in terms of types, relative amounts, and arrangement of cells, fibres and ground substance 5. Discuss nervous tissue as b
What are the 4 basic tissue types?
Epithelium
Connective Tissue
Muscle
Nervous Tissue
Functions of Epithelium
Functions
- Mechanical barrier
- Chemical barrier
- Absorption
- Secretion
- Containment
- Locomotion
What are the polarised epthelial surfaces?
- Apical: faces the lumen of a tube or the external environment
- Basal: attaches to the basement membrane
What is epithelium?
Where, blood?, backed
-Cover surfaces of the body, lines hollow organs, forms glands
-non vascular
-Backed by a basal lamina (basement membrane) - thin layer of specialised extracellular material between the basal surface of epithelial cells and the underlying tissue
How to Classify Epithelium
2 steps
Cell shape
- Squamous: flattened
- Cuboidal: cube
- Columnar: tall and thin
Number of layers
- Simple: one layer
- Stratified: 2+ layers
- Pseudostratified: multiple layers, all in contact with basal lamina
Microvilli
Epithelium surface specialization
- termed a ‘brush border’
Cillia
Epithelium surface specialization
-like little hairs
-core of microtubules
-Cilia are longer and thicker than microvilli
-Cilia can move while microvilli cannot
Keratinized
Endocrine
Glandular epithelia
- product secreted towards basal end of cell and distributed by vascular system
- ductless
Exocrine
Glandular epithelia
- product secreted towards apical end of cell
- ducted
What is Soft connective tissue?
types
- Tendons, ligaments
- Loose: loosely packed fibres separated by ground substance
- Dense: densely packed bundles of collagen fibres
Type?
Soft connective tissue
Dense regular: fibres aligned
Type?
Soft connective tissue
- Dense irregular: fibre bundles run in many directions
What is Hard Connective Tissue?
types of cartalige
- Strong, flexible, compressible, semi-rigid tissue
- 3 types of cartilage - hyaline, elastic, fibrocartilage (defined by extracellular matrix)
4 Hyaline Cartilage sites
Hard Connective Tissue
- Articular surfaces
- Tracheal rings
- Costal cartilage
- Epiphyseal growth plates
cancellous vs cortical bone
-Outer shell of cortical bone makes up shaft - diaphysis
-Cancellous/trabecular bone occupies ends - epiphyses (looks like aero/ meshwork)
Muscle Tissue Specialised Role
- Specialized to generate force by contraction
- Force is movement of actin fibres over myosin fibres
- 3 types
What are the 3 types of muscle tissues?
+ description
- Smooth muscle: involuntary, non-striated
- Skeletal muscle: voluntary, striated, multinucleated
-
Cardiac: involuntary, striated, single nucleus at centre of fibre
- Has intercalated discs - contain many intracellular junctions for stability
Nervous tissue Description
- Control function and allow for rapid communication between different parts of the body
- Consists of neurons and their supporting cells (glia)
- Glia outnumber neurons by about 10:1 in CNS
- Surrounded by connective tissue coat:
- Meninges in CNS
- Epineurium in PNS
Name the 3 types of neurons
Multipolar
Bipolar
Pseudounipolar
y
Bipolar: one dendrite one axon
y
Multipolar: most common, many dendrites one axon
y
Pseudounipolar: short process gives rise to axon in both directions
Glia of the CNS
- Astrocytes: provide support, involved in ion transport
- Oligodendrocytes: produce myelin
- Microglia: immune surveillance
Glia of the PNS
Schwann cells: produce myelin and support axons
