Chapter 4 Flashcards
Histology
The study of tissues
4 types of tissues
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial tissue
- 2 functions
- 4 characteristics
- how does intracellular juntions help and what does it allow for
- 3 cell shapes
- number of layers
- Protection: covers and line the body; forms glands
- cellularity, avascularity, regeneration, polarity
- it helps to keep epithelia tightly packed and allows for communication b/n cells
- squamous, cubodial, columnar
- stratified and simple
glands
structures that produce fluids secretions
Cellularity
cells are closely packed together
-very little extracellular material
Avascularity
- definition
- how do they obtain nutrients
- Lack blood vessels
- obtain nutrients by diffusion or absorption
Regeneration
- Able to undergo mitosis
- growth rates are higher than many other cells in the body
Polarity
Has 2 surfaces
- Exposed - apical
- Attached - basal
Simple epithelium
- how many layers
- durable or fragile
- location
- 1 layer
- fragile because they are thin
- inside of the body
Stratified epithelium
- how many layers
- durable or fragile
- many layers
- durable because they can handle mechanical and chemical stress
Pseudostratified
- what do the nuclei look like
- each cell is attached to what
- is it stratified
- location
- looks like they are in layers
- basement membrane
- not stratified
- respiratory tract
Simple squamous
- structure
- properties
- function
- 3 locations
- single layer of flat cells
- thin
- adapted for diffusion
- alveoli, blood vessels, mesothelium (lines ventral body cavity)
Stratified squamous
- structure
- function
- 3 locations
- many layers of cells (basal layer-cubodial; surface layer-flat)
- protection:can handle mechanical and chemical stress
- surface of skin; lining of mouth, esophagus and anus; keratinized (not alive) vs non-keratinized
Simple cubodial
- structure
- function
- 3 locations
- single layer of cube-shaped cells
- secretion and absorption
- glands and ducts; portions of kidney tubules; thyroid gland
Stratified cubodial
- structure
- function
- 3 locations
- very rare, look like circles
- secretion and absorption
- lining of some ducts in sweat; mammary glands
Transitional epithelia
- structure
- properties
- function
- location
- stratified: cube-like cells when organ is relaxed; flat cells when organ is distended
- cells can change shape; is able to extend
- good when volumes need to change
- urinary bladder
Simple columnar
- structure
- function
- 3 locations
- Single layer of columnar cells
- secretion and absorption
- small and large intestine and stomach
Pseudostratified columnar
- structure
- function
- 3 locations
- all cells sit on basement membrane even though it looks like multiple layers
- protection and secretion; contains goblet cells and cilia
- respiratory tract
Connective tissue
- definition
- 5 functions
- connect epithelial tissues to rest of body
1. Form structural framework for body
2. Transport fluids
3. Protection of organs
4. Interconnecting other types of tissue
5. Energy reserve
3 characteristics of connective tissue
- Cells are widely spread out
- vascular (many blood vessels)
- Very diverse composition of matrix (hard (bone) to liquid (blood))
connective tissue is composed of 3 things
- cells (macrophages, adipocytes, mesechymal cells, melanocytes, mast cells and fibroblasts)
- fiber (collagen, elastic and reticular)
- ground substance
Macrophages
Phagocytes
Adipocytes
Fat cells
Mesenchymal cells
Act as stem cells to replenish tissue
Melanocytes
Pigment producing cells
Mast cells
Produce heparin and histomines (immune function-anti inflammatory)
Fibroblasts
produces fiber
Collagen fibers
long, straight and unbranched (most common)
Elastic fibers
branched and wavy - can be stretched
Reticular fibers
Fine collagen fibers that form a branching interwoven framework
Ground substance
- fluid ranges from viscous to solid
- Fills spaces b/n cells and surrounds CT fibers
- Produced by CT cells
3 types of connective tissue
- connective tissue proper
- fluid connective tissue
- Supporting connective tissue
Connective tissue proper
-2 types
- loose (occupies space around organs, packing material, viscous matrix, few fibers)
- Dense (lots of fibers, less matrix)
Fluid Connective tissue
- 2 types
- matrix
- blood
- lymph
- aqueous solution
Supporting connective tissue
- bone (solid matrix)
2. cartilage (semi-solid matrix)
representative connective tissue
-5 types
- Areolar
- adipose tissue
- reticular tissue
- dense regular
- desnse irregular
areolar (loose)
- Structure
- function
- location
- loose array of several kinds of cells, primarily elastic and collagen fibers, semifluid matrix
- least specialized
- b/n skin and deeper structures
Adipose tissue
- Structure
- 4 functions
- 5 locations
- fat cells have a “signet ring” shape, little cytoplasm, large fat droplet
- provides padding
- Shock absorber
- insulates
- stores energy
- provides padding
- Deep to skin, butt, breasts, around eyes, around other organs
Reticular tissue
- Structure
- function
- what is it sometimes referred to as
- 5 locations
- irregular network of reticular fibers
- provides a supporting framework in various organs
- “stroma”
- liver, kidney, spleen, lymph nodes and bone marrow
Dense regular
- Structure
- function
- location
- parallel bundles of collagen fibers b/n rows of fibroblasts
- provides attachment, very strong
- tendons, ligaments, aponeurosis (flat tendon)
Dense irregular
- Structure
- function
- 3 locations
- Collagen fibers arranged irregularly in bundles around fibroblasts
- provides strength to resist forces applied from many different directions
- dermis of the skin, capsules of organs, nerve and muscle coverings
Supporting connective tissue
- 3 types of cartilage
- definition
- Hyaline
- elastic
- fibrocartilage
- provides strong framework to support rest of body
Hyaline cartilage
- Structure
- function
- 4 locations
- Chondrocytes in lacunae in a homogeneous glossy matrix; avascular; most abundant
- provides stiff yet flexible support, reduces friction b/n bony surface
- b/n ribs and sternum; covers bones at joints; makes up larynx, trachea, and bronchi; nasal septum
Elastic cartilage
- Structure
- function
- 3 locations
- numerous elastic fibers; avascular
- provides support, flexible
- External ear, epiglottis, auditory tube
Fibrocartilage
- Structure
- 2 functions
- 2 locations
- very little ground substance; matrix - densely interwoven collagen fibers; avascular
- Absorbs shock and prevents bone-to-bone contact
- b/n spinal vertebrae and pubic bones, meniscus (knee joint)
