Chapter 5: Histology Flashcards
Histology
Study of tissues and how they are arranged into organs
4 Tissue Classes
Epithelial
Connective
Muscular
Nervous
Matrix
Extracellular material that surrounds the cell
- Composed of fibrous proteins and a clear gel
3 Primary Germ Layers
Endoderm
Ectoderm
Mesoderm
Endoderm
Innermost layer that gives rise to the mucous membranes of the digestive and respiratory tracts, glands, etc.
Ectoderm
Outermost layer that gives rise to the epidermis and nervous system
Mesoderm
Gives rise to cartilage, bone and blood
*Middle layer that turns into gelatinous tissue called mesenchyme
Epithelial Tissue
Closely ad hearing cells, one or more thick
Cover bodies surface, and line body cavities
6 Functions of Epithelial Tissue
PASSEF
Protection Absorption Sensation Secretion Excretion Filtration
Characteristics of Epithelial
Cells very close, matrix is barely visible
Closest to connective tissue= hight mitosis rate
Basement Layer(Basil Laming)
Between epithelium and underlying connective tissue
Avascular
No room in between cells for blood vessels
*epithelial
Basal Surface
Faces Basement Membrane
Apical Surface
Faces away from Basement Membrane, towards internal cavities
Simple Epithelial Vs Stratified Epithelial
Simple: 1 cell layer- pseudostratified columnar
Stratified: 2-20 + cell layer, deepest layer-attached to Basement Mem , transitional epithelium
Keratinized vs Non-Keratinized Squamous
Keratinized: covered in dead cell layer, packed with keratin-dry, reject water loss from body, resist disease
Non: resists abrasion, resists pathogenic organisms- moist, slippery EX: tongue, vag
Connective Tissue
Most abundant, widely distributed, and variable
Cells occupy less space then matrix
Cells NOT in direct contact
*fibrous, adipose, supportive, fluid
Functions of Connective Tissue
SSHTIPBM
Support Storage Heat Production Transport Immune Protection Physical Protection Binding of Organs Movement
White Fat
Thin margins W/ very little cytoplasm
Most abundant- women have more fat
Provides
- thermal installation
- anchor + cushion organs
- body contours
On slide=chicken wire
Brown Fat
Unusual abundance of blood vessels
6% of infant body weight
Heat generating tissue
- No ATP synthesis
- oxidize Fat and release energy/heat
Ground Substances
Unstructured, gel-like material that fills the space between cells and connective tissue fibers.
*Contains interstitial fluids, cell adhesion proteins, proteoglycans
Formed Elements
3 types
Blood plasma and its cellular components
Leukocytes
Erythrocytes
Platelets
Erythrocytes(RBCs)
Most abundant- transport oxygen and carbon dioxide
Leukocytes(WBCs)
Defense against infection
Larger than erythrocytes
Platelets
Small cell fragments scattered among blood cells
Clotting and secreting growth factors for blood vessel growth/ maintenance
Skeletal Muscle Tissue
Muscle fibers(threadlike cells) attached to bone- contain multiple nuclei attached to plasma mem
*Striated and Voluntary
Function: movement, breathing, swallowing, urination
Cardiac Muscle Tissue
HEART ONLY
Short cells joined by discs(not fibers) W/ one nucleus
Allow rapid flow of excitation, pumps blood
*Striated + involuntary
Smooth Muscle Tissue
Short fusiform shaped cells W/ one nucleus in walls of viscera
Make up “visceral muscle”, controls blood pressure flow
*lacks striations and involuntary
Tight Junction
Cells are linked by cell adhesion proteins in the plasma membranes
Found in epithelial cells
Gap Junctions
Formed by a connexon
Small solutes can pass directly from the cytoplasm of one cell to another
Allows electrical excitation to pass
Desmosomes
Patch that holds cells together
Do not prevent substances from passing, but stop cells from pulling apart
Secretion
Useful in the body
Excretion
Waste product
4 Types Gland Secretion
Serous
Mucous
Mixed
Cytogenic
Serous Secretion
Thin, watery fluid
Mucous
Secrete glycoprotein mucin
Mixed Secretion
Mix of serous and mucous
Cytogenic
Release whole cells
3 Modes of Secretion
Holocrine
Apocrine
Merocrine
Holocrine
Accumulate product then the entire cell disintegrates
Apocrine
Lipid droplet covered by membrane buds from the cell surface
Merocrine
Vesicles release secretion by exocytosis
3 Type Body Membranes
Cutaneous Membrane
Mucous Membrane
Serous Membrane
Cutaneous Membrane
Largest in the body
*Skin
Mucous Membrane
Lines passage that are open to the environment
Serous Membrane
Produce serous fluid
Line inside of body cavities
3 Types of Tissue Growth
Hyperplasia
Hypertrophy
Neoplasia
Hyperplasia
Embryonic and childhood growth
Growth through cell multiplication
INCREASE NUMBERS
Hypertrophy
Skeletal muscles and adipose tissue
Increase in preexisting
INCREASE SIZE
Neoplasia
Development of a tumor
2 Types of Tissue Development
Differentiation
Metaplasia
Differentiation
Development of a more specialization from and function by unspecialized tissue
Development of a cell
Metaplasia
Changing from one type of tissue to another
2 Types of Tissue Repair
Regeneration
Fibrosis
Regeneration
Replacement of dead or damaged cells by the same type of cells
Fibrosis
Replacement of damaged tissue with scars tissue
2 Types of Tissue Death
Atrophy
Apoptosis
Atrophy
Shrinkage of tissue through loss of cell size or number
Apoptosis
Normal death of cell that have completed their function
Dry Gangrene
Common complication of diabetes
Wet Gangrene
Liquefaction of internal organs with infection
Gas Gangrene
Usually from infection of soil bacterium that results in hydrogen bubbles in tissues
Decubitus Ulcer (bed sore/ pressure sore)
Form of dry gangrene where continual pressure on skin of immobilized patient cuts off blood supply
Infarction
Sudden death of tissue when blood supply is cut off
