Unit 2 Flashcards
What is epithelial tissue?
sheet/surface that covers a body surface or lines body cavity. 2 types include covering/lining and glandular
What are the traits of epithelial tissue?
Cellular: cells packed together, little ECM, packed via tight junctions and desmosomes
Polarity: apical-basal polarity, basal lamina secreted by epithelium, reticular lamina secreted by CT
avascular: lack of blood vessels, still nourished via diffusion
regenerative: lots of mitosis
main function: protection, absorption, filtration, excretion, secretion, and sensory receptors
Explain simple squamous epithelium
1 layer of flat cells, great for exchange (ex: alveoli, air sacs in lungs), good lining (ex: endothelium in vessels), shape of cell determines where it’s found
Explain simple cuboidal epithelium
1 layer of boxy cells, good for exchange (kidney tubules), secretion, and absorption
explain simple columnar epithelium
1 layer of tall cells, good for absorption and secretion (ex: line intestine)
explain pseudostratified ciliated columnar epithelium
1 layer of tall and smushed cells, often with cilia, secretes and absorbs (ex: lines the trachea and most of respiratory tract)
explain stratified squamous epithelium
multiple layers with flat cells on top, most protective, most common, can be keratinized(at surface ex: epidermis) or not keratinized (basal layers ex: inside mouth)
explain stratified cuboidal
many layers with boxy cells on top, in sweat glands and mammary glands
explain stratified columnar epithelium
multiple layers with tall cells on top, in part of male urethra, pharynx, and glandular ducts
explain transition epithelium
variest in number of layers (3-6) based on how stretched it is, cells at free edge are domed (ex: bladder and ureters)
glandular epithelium
1 or more cells that make and secrete a particular product. Can be endocrine or exocrine glands
endocrine epithelium
secrete hormones into blood, “ductless”, diffuse into endocrine system, secretions can vary between amino acids, peptides, glycoproteins, and steroids
exocrine glands
secrete to body surface (ex: swer glands). Can be unicellular or multicellular. Multicellular are divided by shape of secreting part (gland can be tubular or alveolar, or duct can be simple or compound) and secretory style (merocrine: exocytosis or holocrine (bursting) (ex: intestinal: simple and tubular, mammary: compound and alveolar, sweat gland: merocrine, sebaceous gland: holocrine)
What are traits of connective tissue?
supporting, binding, lots of EXM, insulating, storage of reserve fuel, transporting, vascularization varies with different subtypes (adipose=high vascularization, cartilage= little vascularization)
What are the parts that are in connective tissue?
Extracellular matrix: interstitial fluid, cell adhesion protein (also sugars for adhesion), and proteoglycans for stiffness
Fibers: collagen(white, thick, stronger than steels, main part of tendons and ligaments, strongest, most prevalent), elastic (yellow, elastin, flexible, in lung, skin, blood vessel walls) and reticular(thin bundles of collagen wrapped around blood vessels, support soft tissues)
What kind of cells are in connective tissue?
In CT proper: fibroblasts and fibrocytes
in cartilage: chondroblasts and chondrocytes
in bone: osteoblasts and osteocytes
in blood: hematopoietic and red/white blood cells
Also home to adiopctyes, mast cells (for inflammatory response heparin and histamine), and phagocytes (macrophages and neutrophils)
What are the types and functions of connective tissue proper?
Loose include: areolar (packaging for organs, acellular, lots of ECM, around vessels, supporting/binding other tissues, holding body fluids, defending against infection, storing nutrients as fat) adipose tissue(protection, keeps heat in body, energy storage, highly vascularized, and found in breast), and reticular (scaffold for lymphatic organs, found in spleen)
Dense include: dense regular (parallel collagen fibers, fibroblasts, and small amount of ground substance, poorly vascularized, in tendons, ligaments) and dense irregular (mesh of collagen, reticular layer of dermis)
Cartilage includes: hyaline(most common, structural support, little cushion at end of long bones, ex: costal cartilage, tracheal cartilage, tip of nose) elastic (flexibility in shape, binds but snaps back, ex: pinna), fibrocartilage (shock absorption, between hyaline cartilage and dense regular CT, ex: intervertebral discs)
bone: supports and protects, stores fat and calcium, lots of nerves, blood vessels, and collagen
blood: transport of O and CO2, nutrients, waste products, hormones, plasma, RBC (40%), and WBC (1%)
What are the traits of muscle tissue?
Cellular, vascular (need O to make ATP), excitable, generate force and movement
What are the types and functions of muscle tissues?
Skeletal muscle: striated, large cylindrical cells, multiple nuclei per cell
Cardiac muscle: striated, intercalated discs, one nucleus per cell
smooth muscle: one nucleus per cell, not striated, ex: walls of hollow organs
What are the traits of neural tissue?
little ECM, well vascularized, excitable, includes PNS and CNS
What cells are in nervous tissue?
Supporting cells (glial cells, frequent, nonconducting, insulate, support, and protect neuron) and neurons (fire impulses, less numerous, respond to stimuli)
what are the functions of the integument?
Protection from trauma and infection, regulate temp and water levels, sensation, and Vit. D synthesis
What are the different cell types and what are their functions in epidermis?
Keratinocytes: most numerous, lots of keratin protein, important part of desmosomes, made in stratum basal
Melanocytes: make melanin, in lower layer, has process that distributes melanin to keratinocytes that use pigment to shade DNA of nucleus
Langerhan’s cells: protective and a type of macrophages
Merkel Cells: tactile cell attached to sensory afferent, in epidermal-dermal junction
What are the layers and functions of the epidermis?
Stratum Basale: germinating layer, only one cell thick, keratinocytes, merkel cells, and melanocytes, 1 daughter cell gets pushed up skin after mitosis
Stratum Spinosum: several layers thick, keratinocytes, contain thick intermediate filaments that resist tension and are anchored to desmosomes
Stratum Granulosum: thin, darkly stained, grainy, lots of keratin
Stratum Lucidum: only in thick skin, transparent layer of dead cells
Stratum corneum: thick layer of flat, dead cells
What is some general information about the dermis?
It’s mostly made of dense irregular CT, 2 layers, cells within are: fibroblasts, migratory cells, vascular, secreting part of sweat glands, sebaceous glands secret sebum into hair follicle,nerve fibers, and sensory cells
What are characteristics of the papillary layer of the dermis?
top layer of dermis, 20% of dermis, mostly areolar CT, papilla=bump, tactile.meissner’s corpuscle
What are the characteristics of the reticular layer of the dermis?
bottom layer, 80% of dermis, dense irregular CT, lots of collagen bundled in irregular patterns that can create dermal-epidermal ridges or cleavage lines
What are the different skin colorations?
Melanin: darker skin pigment, freckles/moles, made by melanocytes
Carotene: yellowish/orange color, accumulates in stratum corneum and hypodermis
hemoglobin: redish pigment of blood that is visible in fair skinned individuals
What are the different terms to describe skin colorations?
cyanosis: blue, low O
erythema: redness, when inflammatory response, fever, or embarrassment occurs
jaundice: yellow, liver dysfunction
hematoma: black/blue bruise, clotted blood in hypodermis
What are the functions of hair?
insulation, protection, sensation, and social signals
What are the types of hair?
Vellus: soft baby hair, body hair on female
Terminal: coarse hair, scalpe, eyebrows
Describe the lengthwise and cross-section parts of hair?
Lengthwise: Shaft (projection from skin, keratinization is complete) and root (within follicle, keratinization not complete, has hair bulb that contains hair papilla)
hair in cross-section: shape is either round (in straight hair) or flat (in kinked hair) and the layers are: medulla (middle part, big cells, air spaces, soft keratin), cortex (many cells, provides color), and cuticle (flattened cells overlap in a thin layer)
Describe the follicle?
Bag that hold hair root and sensory receptor neurons. Follicle wall includes: epithelial root sheath (inner layer), connective root sheath (outer layer), and hair matrix (mitotic growth zone, on top of hair papilla). Also includes arrector pili muscle and hair squeezes sebum into follicle
what are the functions of nails?
scratch and to pick up small things
What tissue are the nails in?
epidermis
Describe the nail bed
Skin where the nail sits, deep epidermis, entails nail matrix and lunula
What is the eponychium?
cuticle
What is the hyponychium?
space under nails edge (where dirt accumulates)
describe an eccrine sweat gland
is a simple, tubular gland that secretes in a merocrine (exocytosis) style. They are all over the body, lots on forehead, hands, and feet, and sweat contains: water, salts, acid, dermcidin (pathogen killing protein) and antibodies
describe an appocrine sweat gland
in axillary and anogenital regions, secrets via merocrine and ducts empty into hair follicles, secretes fatty, protein rich sweat, they mature in puberty
What are the types of skin cancer? describe them
basal cell carcinoma: least malignant, most common, surgical removal is cure 99% of time
squamous cell carcinoma: 2nd most common, keratinocytes of stratum spinosum are cancerous, grows fast and metastasis, if caught early and removed it can be cured
melanoma: cancer of melanocytes, most dangerous because it’s highly metastatic and resistant to chemo
describe sebaceous oil glands
most of body but not in thick skin, simple and alveolar structure, puts lubricating sebum into follicle and fights microbes, holocrine secretory function, arrector pili contractions force sebum out
describe ceruminous glands
line ear canal (make ear wax which catches debris, repels insects, and lubricates ear drum), specialized apocrine gland
What are the function of bone?
Support, shape, protect soft tissues, store calcium and fat, hematopoiesis, anchorage, and hormone production
describe osteons
one cylinder with several concentric lamellae and central canal, osteocytes in lacunae, lacunae are connected by canaliculi
Where is the perforating canal?
perpendicular to central canal
what are circumferential lamallae
on outside of bone, individual rings within osteon
What are interstitial lamellae
incomplete parts between osteons
What are the parts of spongy bone? Describe them
trabeculae: bars of bone, no osteon, doesn’t have osteocytes, or matrix
red marrow: between traveculae, important for hematopoiesis, lots in flat bones
What are the different microscopic and chemical components of bone?
Cells- osteogenic stem cells: differentiate into any of cell types
osteoblast: builds
osteocyte: mature bone cell, maintains
osteoclasts: breaks down bone, multinucleated, ruffled edge
bone matrix- 2/3 inorganic/minerals: hydroxyapatite is main mineral, gives hardness and 1/3 organic (lots of C) that has lots of collagen and gives bone tensile strength