Anatomy and Physiology Flashcards
What are the four types of tissue?
- Muscle
- Nervous
- Epithelial
- Connective
What is the function of muscle tissue?
- Generates the physical force to make the body structures move
- Arranged in bundles
- Plenty of blood vessels
What type of cells provide the ability to move the body in 3 dimensions?
Contractile cells
What is the function of nervous cells?
- Detect changes inside/outside the body
- Initiates and transmits nerve impulses
What is the integumentary system comprised of?
- Skin
- Hair
- Nails
- Accessory structures
What is the epithelium?
Medical term for skin and main portion of the integumentary system
What is the function of epithelial tissue?
- Covers body surfaces
- Lines body cavities, hollow organs and ducts (tubes)
- Forms glands
What is the function of connective tissue?
- Protects and supports body and organs
- Binds organs together
- Stores energy reserves as fat
- Provides immunity
What are the general features of epithelial tissue?
- Cell junctions
- Adherens junctions
- Desmosomes
- Gap Junctions
- Hemidesmosomes
What is the function of cell junctions?
- Provide contact or adhesion between cells
- Maintain paracellular barrier of epithelia and control transport of materials or signals between cells
- dense in epithelial tissue
What do adherens junctions do?
Provide cell-cell adhesions that are continuously assembled/disassembled so cells can respond to changes in the environment
What do desmosomes do?
Form stable adhesive junctions between cells
What is the purpose of gap junctions?
Allow various molecules and electrical signals to pass freely between cells
What is the purpose of hemidesmosomes?
Facilitate the stable adhesion of basal epithelial cells to the underlying basement membrane
What broad categories are epithelial tissue separated into?
- Covering and lining epithelium
- Glandular epithelium
General facts about covering and lining epithelium?
- Covers external surfaces of body and some internal organs
- Lines body cavities, blood vessels and ducts
- Lines interior of respiratory, GI, urinary, and reproductive tract
- Integral part of sense organs for hearing, vision, and touch
What is glandular epithelium?
Secreting portion of glands, such as sweat glands
What is the Apical layer of epithelial tissue?
Most superficial layer of cells
What is the basil layer of epithelial tissue?
Deepest layer of cells
What is the basement membrane of epithelial tissue?
- Thin extracellular structure composed mostly of protein fibers
- Located between epithelium and underlying connective tissue layer
- Helps bind and support epithelium
What are the two ways of classifying epithelial tissue?
- Morphology
- Stratification
What is morphology?
Classification of epithelial tissue based on shape
What is stratification?
Classification of epithelial tissue based on number of layers
What type of epithelium fall under morphology?
- Squamous
- Cuboidal
- Columnar
- Transitional
General facts about squamous epithelium?
- Thin, flat shape allows rapid passages of substances through them
- Can be keratinized or non-keratinized
- Found in areas such as lining of esophagus, mouth, and cervix
General facts about cuboidal epithelium?
- Shaped like cubes or hexagons
- Frequently have microvilli at apical surface
- Function in either secretion or absorption
- Found in areas such as salivary glands and thyroid follicles
General facts about columnar epithelium?
- Taller than wide
- Protect underlying tissue
- Apical surfaces may have cilia or microvilli
- Often specialized for secretion and absorption
- Lines most organs of GI tract, respiratory tract, and fallopian tubes
General facts about transitional epithelium?
- Able to change shape from flat to cuboidal depending on tension and distention of tissue
- Useful for organs such as urinary bladder
General facts about simple epithelium?
A single layer of cells that functions in diffusion, osmosis, filtration, secretion, and absorption
What is osmosis?
Movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration
What is diffusion?
Movement of particles from an area of high concentration to an area of low concentration
What is pseudostratified epithelium?
Simple epithelium that appears stratified because the nuclei lie at different levels and not all cells reach the apical surface
- still simple epithelium because all cells rest on basement membrane
What are the two forms of locomotion provided by cilia?
- Movement of cell itself
- Movement of particles or substances across or around the cell
What does cilia help do in mammals?
Help remove contaminants or move particles by moving fluids across cell layers
What are the uses of microvilli?
- Increase the surface area of a cell by multiplying the area from 2 to 3 dimensions
- Enable absorption and secretion of far more nutrients/material
- Help anchor sperm to egg for fertilization
- May sweep unwanted materials toward an absorptive area of the cell
What is keratin?
Highly insoluble fibrous protein with water-proofing qualities and high friction resistance
What are keratinocytes?
Epithelial cells infused with keratin in the stratum basale of the epidermis
When are keratinocytes no longer living cells?
When they lose their nucleus and organelles to make room for keratin
Where is non-keratinized epithelium found?
- Wet/interior surfaces exposed to considerable wear and tear
- Lining of mouth cavity, tongue, pharynx, esophagus , and vagina
Where is keratinized epithelium found?
- Dry/outer surfaces where resistance to both friction and water is needed
- Outer epidermis consists of keratinocytes that provide protection against water, friction, abrasion, and microorganisms
What are the 3 components of of connective tissue?
- Resident cells
- Extracellular Matrix (ECM)
- Protein fibers
What supports and physically connects other tissue/cells together to form the organs of the body?
Connective tissue
What are fibroblasts?
- Most common cells in connective tissue
- Produce and maintain most of the tissue’s extracellular components
- Synthesizes and secretes collagen and elastin
- Major component of the reparative capacity of connective tissue
What are adipocytes?
- Fat cells/adipose cells/adipose tissue
- Specialized for cytoplasmic storage of lipid as neutral fats
- Majority of cells serve to cushion and insulate the skin and other organs
What are mast cells?
- Components of loose connective tissues
- Function in localized release of compounds important to inflammatory response, innate immunity, and tissue repair
What are collagen fibers?
- Abundant protein
- Very strong and resistant to shear forces
- Key element of all connective tissues, as well as epithelial basement membranes
What are elastic fibers?
- Composed of elastin
- Strength and elasticity
- Have rubberlike properties
- Found in areas such as stroma of lungs
What are reticular fibers?
- Composed of glycogen and glycoprotein
- Provide strength and support in walls of small blood vessels
- Stroma supporting framework of many soft organs (immune system, liver, endocrine glands, spleen)
What are the 3 types of cell membranes?
- Mucous membranes
- Serous membranes
- Synovial membranes
What are the functions of mucous membranes?
- Prevents cavities from drying out
- Resp: traps particles in respiratory tract
- GI: lubricates and absorbs food as it moves through tract
- Derm: helps bind epithelium to underlying structures
What are the functions of serous membranes?
- Lines body cavity that doesn’t open directly to exterior and covers organs that lie within cavity
- 3 types: Parietal, Visceral, Mesothelium
What is parietal serous membrane?
Attached to cavity wall
What is visceral serous membrane?
Part that covers and attaches to the organs
What is mesothelium serous membrane?
Secretes serous fluid and provides lubrication for organ movement
What are the functions of synovial membrane?
- Lines joints
- Composed of areolar connective tissue and adipose tissue with collagen fibers
- No epithelial layer
What are the three layers of skin?
- Epidermis
- Dermis
- Subcutaneous (hypodermis)
What is the epidermis?
- Surface/outermost layer of skin
- Comprised of epithelial tissue
- Primarily consists of continually regenerating keratinocytes
- Lacks any vascular structures and obtains all nutrients from dermal vasculature by diffusion
What are the layers of the epidermis?
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum Basale
What is the stratum corneum layer?
- Cells consist mostly of keratin
- Cells are shed and replaced from below
What is the stratum lucidum layer?
Found only in palms and soles of feet
What is the stratum granulosum layer?
- Losing cell organelles and nuclei
- Infusion of waterproofing lipids
What is the stratum spinosum layer?
Cells beginning to flatten
What is the stratum basale layer?
Stem cell layer, new cells arise here
What is the dermis?
- Layer of skin located between epidermis and subcutaneous (hypodermis) tissues
- Primarily consists of dense irregular connective tissue
- Functions to cushion the body from stress and strain
What always occurs between the stratum basale of the epidermis and the dermis?
Basement membrane
What are the two layers of the dermis?
- Papillary layer
- Reticular layer
What is the papillary layer of the dermis?
- Layer directly underneath the epidermis
- Contains terminal endings of of capillaries, lymph vessels, and sensory neurons
What is the reticular layer of the dermis?
- Thicker than the papillary layer
- Comprised of a dense concentration of collagenous, elastic, and reticular fibers that weave throughout it
What is located within the reticular layer?
- Roots of hair
- Sebaceous glands
- Sweat glands
- Receptors
- Nails,
- Blood vessels
What are melanocytes?
Specialized cells of the epidermis and hair follicle
- Primary function of synthesis and transfer of melanin to adjacent keratinocytes
Where does melanin synthesis occur?
Melanosome, a specialized organelle
What are Merkel cells?
- Expanded dendritic endings in epidermis of glabrous skin that respond to sustained pressure and touch
- Consist of tactile disc and neuron touch sensation
What are dendritic cells?
- Typically found within stratum spinosum
- Form a mobile and dense network of cells to sample any antigens that pass through epidermis
- Represent a large part of skin’s adaptive immunity
What is some information on the accessory structure of hair?
- Comprised of fused keratinized cells surrounded by the hair follicle
- Genetic/hormonal influences largely determine pattern/distribution
- Protection for scalp, eyes, and nostrils
