Histo Final (week 1-midterm) Flashcards
What is histology
Study of microscopic structure and function of cells and associated tissues
Function of cell
Carry out vital processes
(Absorption, assimilation, respiration, irritability, conductivity, growth, reproduction and excretion)
What is Endocytosis
Uptake of materials into the cell
Pinocytosis
Cell drinking
Phagocytosis
Cell eating
Exocytosis
Expulsion of materials out of the cell by fusing vesicle membrane with cell membrane
Cell membrane surrounds cell aka plasma membrane; function?
Semipermeable so provides barriers that regulates transports in and out of the cell
Cytoplasm includes what and its function is to?
Includes organelles and vacuoles
Function: provide a medium in which other organelles function
What is produced in the nucleus
DNA and RNA
5 components of a nucleus
Nucleolus
Nucleoplasm
Nuclear envelope
Chromatin
Nuclear pores
What produces RNA and nucleotides and is contained in the nucleus
Nucleolus
Chromatin contains
Chromosomes
Fluid portion that contains proteins
Nucleoplasm
A double membrane that surrounds the nucleus in the cell
Nuclear envelope
Function of the endoplasmic reticulum is to
Modify store segregate and transport proteins the cell manufacturers
Rough er contains
Ribosomes
Smooth er contains
Enzymes for manufacturing lipid molecules and steroid hormones
The function of this is to sort, condense, package and deliver proteins received from the rough ER
Golgi apparatus
Mitochondria is considered the
Powerhouse of the cell
Delicate threadlike structures of protein; deal with cell motility
Microfilaments
Helps maintain shape of the cell and provides strength to cilia, flagella, centrioles and mitotic spindle
Microtubules
Intermediate filaments are thicker and threadlike. They are important in
Intercellular junctions
Inclusions are metabolically inert substances and are aka
Temporary storage units of lipids and melanin pigmentation
Tight junctions (water tight) prevents
Movement of fluid
Location of tight junctions
Lining of small intestine
Gap junctions allow for
Exchange of substances
Location of gap junctions
Muscle of heart
Digestive tubes
What attaches cell to the basement membrane
Hemidesmosomes
In dental where can Hemidesmosomes be found
Gingival tissue adhering to tooth surface OR epithelium to CT in basement membrane of oral mucosa
What binds cells together by creating soot welds between membranes
Desmosomes
4 life cycles of a cell
Interphase
Mitosis
Cytokinesis
Differentiation
Describe the 3 phases of interphase
G1- initial resting and growth phase
S- DNA replication
G2- 2nd resting /growth phase
Mitosis stages in order
Prophase
Metaphase
Anaphase
Telophase
What disappears in prophase
Nuclear membrane and nucleolus
Describe what happens in metaphase
Chromosomes arrange midway between centrioles in a line
In anaphase what splits and migrates to opposite poles
Chromosomes separate and pull individual chromosomes to opposite poles
Telophase is the division into 2 daughter cells. What appears and disappears during this phase
Nucleoli appears
Microtubules disappear
Differentiation refers to
Less specialized cell becoming more specialized
4 types of tissues
Epithelial
Connective
Muscular
Nerve
Function of epithelial tissue
Covers/lines external/internal systems
Tissue absorption, secretion, sensory.
Describe how cells are packed in epithelial tissue. Does it have a blood supply?
Tightly packed cells
AVASCULAR = no blood supply
What is the turnover time of the oral mucosa
14 days
List and describe cell arrangements
Simple- 1 layer
Stratified- 2 or more layers
Pseudostratified- one layer but looks like 2
4 cell shapes
Squamous (flat)
Cuboidal (cube)
Columnar (rectangular columns)
Transitional (changes shape/stretch)
Dead layer
Tough, fibrous, opaque, waterproof.
Resists friction and provides first line of defense
Keratin
Hair like projections that propels substances along
Cilia
What type of epithelium has a filtering function on moist surfaces
Simple squamous epithelium
What type of epithelium contributes to secretion and where can it be located
Simple cuboidal epithelium
Location: ducts of various glands; salivary glands.
What type of epithelium contains goblet cells (secrete mucin; may be ciliated)
Simple columnar epithelium
Location of non ciliated simple columnar epithelium
Stomach, large/small intestine, cervical canal
Location of ciliated simple columnar epithelium
Uterus, fallopian tubes, lungs, make reproductive
This type of epithelium moistens, warms and cleans lining membranes. It can be located in the nasal cavity and upper respiratory tract
Pseudostratified columnar epithelium
Stratified squamous non keratinized epithelium is kept moist by ____ to prevent ___
Bodily secretion to prevent drying out
Locations of stratified squamous non keratinized epithelium
Buccal and alveolar mucosa, central side of tongue, soft palate, flood of mouth and sulcular epithelium
Stratified squamous keratinized epithelium is located on dry or wet surfaces. 5 layers are?
Stratum corneum (dead layer)
Stratum granulosum
Stratum spinosum
Stratum basale
Stratum lucidum (palms/ soles, not in oral cavity)
Locations of stratified squamous keratinized epithelium
Free gingiva, attached gingiva m, hard palate, dorsal of tongue, lips
Thin, acellular structure that is located between the epithelium and connective tissue
Basement membrane
What are the 3 layers of the basement membrane
Lamina lucida (clear layer)
Lamina densa (dense layer)
Reticular Lamina (collagen/reticular fibers)
Which 2 of the 3 layers of the basement membrane make up the basal lamina
Lamina lucida and lamina densa
Function of connective tissue
Provides support for softer body parts and binds structures together
What are the major cell types found in CT
fibroblasts
Macrophages (monocytes)
Mast cells (basophils)
What is the most common cell type in CT? What does it synthesize ?
Fibroblast
Synthesizes protein fibers and intercellular substances
Most common white blood cell
-phagocytes, important in fighting infection
Macrophages (monocytes)
Mast cells (basophils) are active in?
What may they release
*hint; they are located near blood vessels
Active in allergic response
May release heparin and histamine
