Histology Study Guide Flashcards
What is a tissue? What are the 4 types in the human body?
a group of specialized cells working together to perform a certain specific function
- muscle tissue
- nervous tissue
- epithelial tissue
- connective tissue proper
What are the 2 forms of epithelium? Give an example of each.
- glandular epithelium:secretory tissue that covers the glands(ex: salivary glands)
- covering/lining epithelium: tissue that lines the internal and external surfaces of the body (ex: skin)
Be prepared to distinguish the 5 characteristics of epithelial tissue.
- polarity
- specialized contacts
- regeneration
- avascular
- supported by connective tissue
Define polarity. Be prepared to label the apical and basal surface of a pictured sample.
has two surfaces, both of which differ in function and structure
- apical surface: free/upper side
- basal surface: attached/bottom side. attaches to basal lamina
What is a basement membrane? What two layers does it contain? What does it do?
- separates the epithelial tissue from connective tissue
- contains basal and reticular lamina
- it resists stretching/tearing, reinforces epithelial sheet, defines epithelial boundary
What does it mean to be avascular but innervated?
no blood supply/blood vessels but has nerves
What stimulates the start of epithelial regeneration?
loss of the apical-basal polarity/breaks in lateral contacts
How do you classify epithelial tissue? Be prepared to classify a sample from a picture.
by the # of layers and by the shape of the individual cells. you refer to the epithelial tissue based on its apical (top) layer
What is the function of transitional epithelia? Where might you find it?
- forms the lining of the hollow urinary organs.
- found in bladder, ureters, urethra
- cells can change shape to expand in order to hold fluid
What is a gland? How do you classify glands? Be prepared to classify a gland by structure from a picture (like on slide 23!)
1+ cell that makes and secretes an aqueous fluid-a secretion
can classify by site of product release (internal-endocrine or external-exocrine) and the relative number of cells involved (unicellular or multicellular)
Know the differences between endocrine and exocrine glands. And know a few examples of each.
Endocrine: don’t have ducts, secrete into interstitial fluid. secrete hormones that travel through blood to reach organs. example: pituitary glands
Exocrine: secrete into ducts, secretions are released onto body surfaces (like skin) or into body cavities (mucus, sweat, oil, salivary glands)
What are some functions of connective tissue? What are the 4 types?
Binding, support, protection, insulation, reserve fuel, transportation of substance
- Bone
- Cartilage
- Connective tissue proper
- Blood
What is something found in all types of connective tissue? What are its components?
- all connective tissue derives from mesenchyme
- its 3 main elements are ground substance, fibers, and cells
- ECM = ground substance and fibers
Define ground substance. List the 3 types of fibers – what does each type look like?
unstructured gel like material that fills space between cells and where solutes diffuse between blood capillaries and cells
FIBERS:
- collagen: strong and thick (most abundant) high tensile strength
- elastic: long and thin allows stretch and recoil
- reticular: short, fine, highly branched, offer give
What kinds of cells can be found in connective tissue? What’s the difference between a “blast cell” and a “cyte cell”?
- blast cells
- cyte cells
- fat cells
- white blood cells
- mast cells
- macrophages
cyte cells are more mature and less active than blast cells and become a part of and maintain the ECM, while blast cells secrete ground substance and ECM fibers
List the 3 types of LCT. Know what each type is used for and where it is found.
- Areolar: supports and binds other tissue (packing material) found between skin and muscles (looks stringy)
- Adipose: energy storage, shock absorption, insulation, found under your skin and between internal organs (looks like bubbles)
- Reticular: stroma, acts as support for free blood cells, macrophages, mast cells in lymph nodes, the spleen, bone marrow (looks like a grapefruit)
List the 3 types of DCT. Know what each type is used for and where it is found.
- Regular: high tensile strength, closely packed bundles of collagen fibers, appears wavy and organized, found in tendons and ligaments (ACL)
- Irregular: tangled and disorganized, resists tension from many directions, found in dermis, fibrous joint capsules, fibrous coverings of some organs
- Elastic: looks like a rough wall, found in ligaments connecting with adjacent vertebrae and found in walls of the large arteries (places that are very elastic)
Is cartilage vascularized? Innervated?
cartilage is avascular and not innervated
What are the 3 types of cartilage? Be familiar with where you could find each type.
- hyaline: tips of long bones, nose trachea, larynx, ribs
- elastic: ears and epiglottis
- fibrocartilage: in the knee and intervertebral discs
What is an osteon? A lacuna?
osteon: individual structural units of the bone
- lacunae: cavities within the matrix where osteocytes reside
Are bones vascularized? What is formed within bones?
bones are vascularized and forms blood cells
What is the ECM of blood? When do you see fibers in blood?
ECM of blood = plasma
- you see fibers in blood during blood clotting
What are the 3 types of muscle tissue? Which of these types are voluntarily controlled? Involuntarily?
- skeletal (voluntary)
- smooth (involuntary)
- cardiac (involuntary)
What structural element facilitates the contraction of muscles?
myofilaments
What is in an intercalated disc?
special joints where cardiac muscle cells are joined (represented by faint lines in cardiac muscle)
What two types of cells are found within nervous tissue? Which of these types has the ability to generate and transmit impulses?
- neurons (have the ability to generate and transmit electrical impulses)
- glial cells: protect and insulate neurons
What makes up a membrane? What are the 3 types?
composed of 2+ tissue types - epithelium bound to underlying connective tissue proper
- cutaneous membranes
- mucus membranes
- serous membranes
Be familiar with what makes up each type of membrane. For example, stratified squamous epithelium + thick dermis = cutaneous membrane (skin).
- cutaneous: stratified squamous epithelium + thick dermis
- mucous: epithelial sheet lies over a layer of loose connective tissue called a lamina propria
- serous: simple squamous epithelium (mesothelium) lying on a thin layer of areolar connective tissue
What’s the difference between tissue regeneration and fibrosis?
in tissue regen, the original function is restored and the same tissue regrows. in fibrosis, the destroyed tissue is replaced by scar tissue (DCT) and the original function is lost
What are the 3 steps of tissue repair?
- inflammation stage
- organization restores blood supply
- regeneration and fibrosis
What kinds of tissues have high, moderate, and low capacities to regenerate?
high capacity: epithelial tissues, bone, areolar tissue, dense irregular connective tissue, blood-forming tissue
moderate capacity: smooth muscle, dense irregular connective tissue
low capacity: cardiac muscle, nervous tissue
