Histology & Genetics Flashcards
Epithelial Tissue Function
Protection, secretion, excretion, absorption, filtration, and sensation
Lumen
The internal space of a hallow organ or space surrounded by secretory cells
Apical Surface
The uppermost surface of an epithelial cell, typically exposed to the lumen
Basal Surface
The lower surface of an epithelial cell exposed to the basement membrane
Basement Membrane
Thin layer of various binding structures between the deepest epithelial cells and the underlying connective tissue
Cilia
Slender, hair-like extensions used for the movement of substances such as mucus
Microvilli
Finger-like extensions that increase cellular surface area
Simple Squamous Epithelium
One-layer thick, flat cells bulging at nucleus
Simple Cuboidal Epithelium
One-layer thick, cube-shaped around a central shape (lumen). May contain microvilli or cilia
Simple Columnar Epithelium
One-layer thick, long rectangular or cylindrical cells. Often have microvilli and may possess goblet cells
Pseudostratified Columnar Epithelium
Appears multi-layered but is only one-layer thick. Rectangular or cylindrical-shaped, often ciliated and contains goblet cells
Keratinized Stratified Squamous Epithelium
Multi-layered, cells become increasingly flat towards surface. Surface contains layer of compact dead cells without nuclei. Basal cells may be cuboidal or columnar
Non-keratinized Stratified Squamous Epithelium
Multi-layered, cells become increasingly flat towards surface. Basal cells may be cuboidal or columnar
Stratified Cuboidal Epithelium
Multi-layered, cube-shaped or round
Transitional Epithelium
Multi-layered, cells at apical surface are rounded. Some cells may be binucleated, may appear thinner when stretched
Connective Tissue Function
Binding of organs, support, physical protection, immune protection, movement, storage, heat production, and transport
Extracellular Matrix/Ground Substance
Gel-like substance found between cells and fiber
Goblet cells
Secrete mucus and may be found in respiratory tract and lining of stomach
Collagen Fibers
Made of collagen & a principal component of connective tissue. Structural protein in fiber form that provide strength and resists stretching
Elastic Fibers
Composed of protein elastin which stretches under tension and returns to its original length when released. Responsible for resilience of organs such as skin, lungs, & arteries
Reticular Fibers
Fine, branching collagen fibers. Form a sponge-like framework for spleen and lymph nodes
Types of Loose Connective Tissue
Areolar, adipose, and reticular
Areolar Tissue
Loose arrangement of collagenous and elastic fibers, numerous blood vessels
Adipose Tissue
Adipocytes (large, empty looking cells with thin margins) and nucleus pressed to plasma membrane while lipid occupies majority of cell. Blood vessels present
Reticular Tissue
Loose network of reticular fibers and cells, numerous leukocytes (immune cells)
Types of Dense Connective Tissue
Dense regular connective tissue, dense irregular connective tissue, and elastic connective tissue
Dense Regular Connective Tissue
Densely packed, parallel, often wavy collagen fibers. Slender fibroblast nuclei, scarcity of blood vessels and ground substance
Dense Irregular Connective Tissue
Densely packed collagen fibers running in random directions, few visible cells, scarcity of blood vessels and ground substance
Elastic Connective Tissue
Modified dense regular connective tissue containing a high proportion of elastic fibers
Types of cartilage
Hyaline cartilage, elastic cartilage, and fibrocartilage
Hyaline cartilage
Clear, glassy matrix, non-visible collagen fibers, chondrocytes enclosed in lacunae. Typically covered in perichondrium
Elastic Cartilage
Elastic fibers form web-like mesh amid lacunae, always covered by perichondrium
Fibrocartilage
Parallel collagen fibers, rows of chondrocytes in lacunae between collagen fibers. No perichondrium present
Types of bone
Compact bone & cancellous bone
Compact bone
Collagen fiber matrix that has been calcified to form hard tissue around central canals, osteocytes in lacunae, lacunae interconnected by canaliculi
Osteon
A structural unit of compact bone consisting of a central canal surrounded by concentric cylindrical lamellae (layer) of matrix
Central Canal
Runs longitudinally through long bones for blood vessels and nerves to travel
Canaliculi
Channels running between lacunae allowing communication between osteocytes (mature bone cells)
Lacunae
Spaces for cells to reside
Lamellae
Onion-like layers surrounding the central canal
Cancellous Bone
Lighter, less dense bone. Contains trabeculae which form irregular cavities that contain red bone barrow
Trabeculae
Plate-like bony extensions
Blood
Erythrocytes appear as pink discs, leukocytes appear with variously shaped nuclei, platelets appear as cell fragments with no nuclei, ground substance of blood plasma
Erythrocytes
Red blood cells/RBCs
Leukocytes
White blood cells/WBCs
Plasma
Watery matrix
Homologous Chromosomes
23 paired chromosomes (46 total chromosomes) of which 22 are autosomal pairs
Autosomes
Any chromosome except the sex chromosomes. Inherited without regard to the sex of the individual
Alleles
Different forms of a gene at the same locus on homologous chromosomes. Take the form of dominant or recessive
Gene
An information-containing segment of DNA that codes for specific traits and has a specific location on a chromosome
Homozygous
Having identical alleles at the same gene locus of two homologous chromosomes (AA or aa)
Heterozygous
Having non-identical alleles at the same gene locus of two homologous chromosomes (Aa)
Dominant
Produces protein responsible for visible trait & represented by a capital letter
Recessive
Expressed only when both alleles are recessive & represented by a lower case letter
Genotype
Paired alleles that an individual possesses for a particular traits/an organism’s genetic makeup (CC, Cc, cc)
Phenotype
An organism’s physical traits (Cleft chin vs. uncleft chin)
Sex chromosomes
Determine an individual’s sex (normal female has XX, normal male has XY)
X-linked Inheritance
Refers to traits carried on the X chromosome
Heredity
The transmission of genetic characteristics from parent to offspring
Punnett Square
A diagram that shows the crossing of parental alleles and their potential outcomes
Histo
Tissue
Inter
Between
Stit
To stand
Ecto
Outer
Endo
Inner
Meso
Middle
Derm
Skin
Epi
Upon
Theli
Nipple
Squamo
Scale
Fibro
Fiber
Blast
Producing/forming
Macro
Big
Phage
Eater
Leuko
White
Cyte
Cell
Colla
Glue
Gen
Producing
Reti
Network
Ite/icul
Little
Areola
Little space
Chondro-/Chrondri
Cartilage
Lacuna
Lake, cavity
Hyal
Glass
Peri
Around
Osteo
Bone
Erythro
Red
Dendri
Tree
Sphinc
Squeeze, bind tightly
Myo
Muscle