Hitology Flashcards
Tissue: Nervous Tissue
Function: allows nerve cells to communicate with each other and send messages to and from the central nervous system.
Location: Brain/spinal cord, peripheral nerves
Unique Characteristic: dendrites, axons, soma, glial cells
Different Types of Muscle Tissue?
Skeletal Muscle- voluntary muscle
Cardiac Muscle- involuntary muscle, found in heart
Smooth Muscle- involuntary muscle
Tissue: Skeletal Tissue
Location: Attached to the skeleton
Function: contractions of skeletal muscle allow for motion because of attachments to the skeletal system
Distinguishing Features: Longitudinal muscle has striations and flat nuclei. Cross sectional muscle has circular looking nuclei and a “cheetah” appearance.
Tissue: Cardiac Muscle Tissue
Location: The heart
Function: Contraction of cardiac muscle pumps blood out of the heart chambers to the pulmonary and systemic circuits.
Unique Characteristic: Look for intercalated discs- gap junctions that aid in cellular communication. These can be seen as dark, vertical lines in the tissue that are parallel to each other.
Tissue: Smooth Muscle
Function: sustained rhythmic contractions
Locations: digestive tract, uterus, blood vessels, bronchi, bladder, internal urethral sphincter, internal anal sphincter, ureter
Unique Characteristic: Look for elongated spindle shaped nuclei, No striations
What are the connective tissues?
●Dense Regular
●Dense Irregular
●Elastic
●Cartilage - Hyaline, Fibro, Elastic
●Adipose
●Reticular
●Areolar
Tissue: Dense Regular Connective Tissue
Function: provides support and withstands stress in one direction
Locations: Tendons, Ligaments
Unique Characteristic: Can appear similar to smooth muscle. Look for the unique “wavy lines” in the connective tissue. In contrast to dense irregular CT, the fibers run in the same direction.
Tissue: Dense Irregular Connective Tissue
Function: Withstands stress in multiple directions
Location: Dermis, fascia, organ coverings, lamina propria of bladder, submucosa of digestive tract
Unique Characteristic: Look for thick pink collagen fibers running in different directions.
Tissue: Elastic Connective Tissue
Function: provide support and resistance to stretch
Location: aorta, arteries, trachea/bronchi, lung tissue
Unique Characteristic: Look for black wavy elastic fibers
Tissue: Hyaline Cartilage
Function: Flexibility and support at smooth surfaces, enables tissues to slide over each other
Locations: articular cartilage (end of long bones), trachea, bronchi, larynx, nose
Unique Characteristic: Look for a glossy appearance and chondrocytes arranged in pairs( “googly eyes”).
Tissue: Fibrocartilage
Function: resists compression
Location: pubic symphysis, intervertebral discs, menisci
Unique Characteristic: Look for chondrocytes arranged in rows, usually has a light pink stain
Tissue: Elastic Cartilage
Function: flexibility
Location: epiglottis, external ear
Unique Characteristic: Looks like hyaline cartilage with black elastic fibers in the background
Tissue: Adipose Connective Tissue
Function: provides cushioning, protects organs, thermoregulation, endocrine functions
Location: hypodermis, surrounding organs
Unique Characteristic: Look for empty white circles
Tissue: Reticular Connective Tissue
Function: provides a network of supportive fibers around certain organs
Location: lymph nodes, spleen, kidney, bone marrow
Unique Characteristic: Look for dense mesh-like fibers. Usually stains brown. More cells than matrix
Tissue: Areolar Connective Tissue
Function: holds organs in place and attaches epithelial tissues to other underlying tissues
Location: blood vessels, surrounding organs
Unique Characteristic: Look for light pink stain, wispy fibers. More matrix than cells
Name: Simple Squamos Epithelium
Function: single layer of cells allow for rapid diffusion and a smooth lining
Location: lungs, blood vessels
Two possible views: cross section (looking down on single layer of squamous cells), or longitudinal
Characteristic: Look for one layer of flattened cells in longitudinal view. In the cross sectional view look for “lily pads” or tiles
Name: Keratinized Stratified Squamous Epithelium
Characteristic: Stringy, whispy on the apical part. Flaking off.
Name: Non-Keratinized Stratified Squamous Epithelium
Name: Simple Cuboidal Epithelium
Function: absorption and secretion
Location: kidneys, glandular ducts, ovaries, thyroid, testes, anterior pituitary gland, pancreas, mammary gland, liver
Characteristic: Look for circular rings (cross section of tubes) or cube shaped cells. The rings look like Lifesaver candies.
Name: Simply Columnar Epithelium
Function: absorption and mucus secretion
Location: digestive tract (non ciliated), bronchioles (ciliated), uterus (ciliated)
Characteristic: Can be ciliated or non-ciliated. Most simple columnar you see in Bio 202L will be non-ciliated. For non-ciliated, look for a brush border (microvilli). Both types will have goblet cells.
Name: Pseudostratified Ciliated Columnar Epithelium.
Also called “respiratory epithelium”
Function: catch foreign debris
Location: Trachea, Bronchi, nasopharynx
Characteristic: Named for its appearance of having multiple layers (this is false, therefore its “pseudo” stratified).
Look for obvious cilia (longer than microvilli), goblet cells, an appearance of multiple layers.
Name: Transitional Epithelium
Function: Allows for stretching in urinary tract
Location: bladder, ureter
Characteristic: Look for circular shaped cells that are evenly distributed and equally spaced apart compared to other epithelial tissues. There should not be much variation between how the cells look from the basal to apical side.
When the epithelium is stretched, its cells appear flattened.
