RAT 6 Flashcards
What are the 4 types of tissues?
Epithelial, Connective, Muscle, Nervous
Epithelial
Cover and line all body surfaces; form glands
Connective
Kind of cellular velcro; connects all tissues together; bind, support, protect, and allow the transport of substances through the body
Muscle
Composed of cells that can contract and generate force
Nervous
Has ECM cells that can generate, send, and receive messages
What is extracellular matrix (ECM)?
Composed of the substances surrounding the cells in a tissue
What are the 2 main components in ECM?
Ground Substance, Protein Fibers
Important Functions of ECM
- holding cells in their proper positions
- regulating the development, mitotic activity, and survival of cells
- directing cells to their proper places within a tissue
- providing the tissue with the strength to resist tensile (stretching) and compressive forces
What are the 3 types of proteins found in ECM?
- collagen fibers
- elastic fibers
- reticular fibers
What is high tensile strength? Which protein exhibits this?
- maximum stress something can withstand without breaking while being pulled or stretched
- collagen fibers
Distensibilility
Stretched to one and a half times their resting length without breaking
Elasticity
When stretching force is removed, they return to their original length
Which fibers interweave to form a netlike supporting structure?
Reticular
What are the 3 types of junctions that unite cells in a tissue?
- Tight Junctions
- Desmosomes
- Gap Junctions
Tight Junctions
Help to make the spaces between cells impermeable
Desmosomes
Increase the resistance of the tissue to mechanical stress
Gap Junctions
Allow small substances to move from one cell to another
Where are epithelial tissues found?
On every internal and external body surface
What are the functions of epithelial tissues?
Protection
Immune defenses
Secretion
Transport into other tissues
Sensation
How can you identify the nucleus of a cell?
Dark purple
How can you identify ground substances.
Generally either looks clear or has just a slight tinge of color
How can you identify proteins?
Look like wavy or straight lines
How can you identify red blood cells?
Clusters of small, light red, round discs that lack nuclei
Epithelial tissue lacks blood vessels. What is the term for this?
Avascular
How does epithelial tissue get oxygen and nutrients and dispose of waste if it lacks blood vessels?
Oxygen and nutrients from the blood must diffuse up to the cells in the epithelial tissue from the blood vessels in the tissues that are deep to it (connective tissue)
How does this impact the structure of epithelial tissues?
Limits thickness; the stack can rise only so high
How much ECM is found in epithelial tissues?
None
Where is the ECM of epithelial tissue located and what is its function?
Located beneath the cells; basement membrane
What are the 2 parts of the basement membrane?
Basal Lamina
Reticular Lamina
Basal Lamina
ECM of the epithelial tissue and is synthesized by epithelial cells
Reticular Lamina
Manufactured by the connective tissue deep to the epithelial tissue and consists of reticular fibers and ground substance
How could you identify the basal and social surfaces of epithelial tissues?
Basal: edge attached to deeper cells or the basal lamina
Apical: free edge of an epithelial cell or tissue (-top)
What 2 criteria are used to classify epithelial tissues?
- number of cell layers
- shape of the cell in those layers
What are the categories based on number of cell layers?
Single layer: simple epithelial
More than one cell layer: stratified epithelia
What are the 3 basic shapes of epithelial cells?
Squamous cells
Cuboidal cells
Columnar cells
How does the structure of simple epithelial aid in their functions?
Perfect for lining hollow organs and for lining surfaces across which substances must diffuse or be transported
Why is pseudostratified columnar epithelium classified as a simple tissue?
The nuclei of the cells are at different heights and some of the cells are shorter
What are the 2 ways in which substances are transported across simple epithelia?
Paracellular Transport
Transcellular Transport
Paracellular Transport
Substances can leak between the epithelial cells
Transcellular Transport
Substance enters the cell through its phospholipid belayer
Diffuses through the cytosol
Exits through the other surface of the cell
What is a primary function of stratified epithelia?
Very effective protective barriers and they are often found in areas subject to a high degree of mechanical stress
What are the three types of stratified epithelia?
Stratified Squamos Epithelium
Stratified Cuboidal and Columnar Epithelium
Transitional Epithelium
What is a gland? What type of tissue forms glands?
Structure that makes and secretes a product
Epithelial tissue
Which cells make the product in a gland?
Secretory Cells
Exocrine
Release secretions to apical surface of the epithelium
Endocrine
Lack ducts and secrete their products, which are usually hormones, directly into the blood
What are unicellular glands? What is the most common type of unicellular gland? What is the product of this gland?
Single cells to goblet cells to mucous
What is a multicellular gland?
Made of clusters of secretory cells arranged in different ways
What is the primary functions of the pectoral girdle?
Support the upper limb (humerus) and are the sites attachment of numerous muscles
Which bones compose the pectoral girdle?
Clavicle and Scapula
What is the common name for the clavicle?
Collarbone
What are the names of the two ends of the clavicles? With which structure does each articulate?
Sternal end: manubrium
Acromial end: acromion
How does this bone appear if you look down at it from above?
S-shaped
How do most most fractures of this bone occur?
Direct trauma of from falling onto an unstretched arm
What is the general shape of this bone?
Triangular
What are the names for the three edges of the triangle?
Medial
Lateral
Superior borders
What are the names for the three points of the triangle?
Superior
Inferior
Lateral
The spine of the scapula is a continuation of what structure?
Acromion
Is the spine located on the anterior of the posterior side of the scapula?
Posterior
What is the depression located above the spine?
Supraspinous fossa
What is the small indentation where the humerus articulates?
Glenoid fossa
What is the structure that protrudes from the anterior side of the scapula and resembles a bent little finger?
Coracoid process
What is the name of the depression on the anterior side of the scapula?
Subscapular fossa
