Anatomy Chapter 4 (tissues)

What is tissue?

2 or more types of cells working together to all perform a specific/similar function

What is histology?

study of tissues

What are the four basic types of tissue?

epithelial, connective, muscle, nerve

What are extracellular fluids?

fluids that help distribute nutrients and gases remove wastes, act as internal shock absorbers

What do extracellular fluids include?

interstitial fluids, plasma, and lymph

Where do all tissues arise from?

the 3 germ layers formed during gastrulation

What are epithelial tissues?

tissues that are widespread throughout the body, avascular, cover most surfaces, line hollow organs, body cavities and ducts, form glands

What are the characteristics of epithelial tissue?

named by number of cell layers and shape, have a free surface and a basal lamina (basement membrane)

What is a free surface?

surface of epithelial tissue that is exposed to the outside or an internal open space

What is the basal lamina?

basement membrane, underlies cells, acts as support and an attachment to connective tissue

Why is the basal laminate important?

keeps things from going too far into the body internally

What is simple squamous epithelium?

single layer of thin flattened cells, allows for rapid diffusion across the cell surface

Where can simple squamous epithelium be found?

lungs, blood vessels, areas of rapid diffusion

What is simple cuboidal epithelium?

single layer of cube shaped cells

Where can simple cuboidal epithelium be found?

covering ovaries, lining kidney tubules and ducts, in glands (produces secretions)

What is simple columnar epithelium?

single layer of elongated cells, may be ciliated or have microvilli, primarily acts in absorption or secretion

Where can simple columnar epithelium be found?

uterine lining, stomach, intestine

What is pseudo stratified columnar epithelium?

elongated cells, appear layered are not, all connect to the basal laminate, nuclei of cells at two or more levels, many adorned with cilia

What is a biopsy?

removal of cells/tissue for examination

What is keratinized stratified squamous epithelium?

multiple cell layers in which the apical layer consists of dead squamous cells that are keratinized and are therefore harder cells

What is transitional epithelial tissue?

epithelial tissue that stretches, based on the level of stretch the cells look different, when relaxed: basal cells are more cuboidal and the apical cells are large and round, when stretched: apical cells flatten and look closer to squamous

Where can transitional epithelial tissue be found?

lining bladder and urinary tract

What are tight cell junctions?

cell junction that completely attaches cells to their neighbors, the apical surface of the cells are encircled together

What are gap cell junctions?

cell junction that creates a gap between cells, there is a bridge formed between this gap via connexions, the connexions form pores for a transfer of molecules between cells

What are desmosome cell junctions?

cell junction that acts like a button/snap between cells, each cell has half of the contributing desmosome, provide resistance to mechanical stress, attach at potential stress points

What are tonofilaments?

bundles of tightly packed keratin intermediate filaments in epithelial cells

What is an exocrine gland?

gland that secretes compounds into an external or internal surface

Where can some examples of exocrine glands?

salivary, mammary, and sweat glands

What are endocrine glands?

glands that secrete in tissue fluids or blood

What is an example of an endocrine gland?

pancreas when it secretes insulin

What are tubular glands?

epithelial gland that looks like a tube, has a uniform diameter

What are acing glands?

epithelial gland that forms an expanded sac, NOT a uniform diameter

What are compound glands?

epithelial gland that is branched, can be tubular, acinar, or both

What is holocrine secretion?

full pinching off of the cell, the cell dies and is secreted

What is merocrine secretion?

secretion in which there is no pinching of of the cell, only compounds are secreted

What is apocrine secretion?

secretion in which there is a slight pinching off of the cell in the secretion along with compounds

What are connective tissues?

most abundant tissue in the body by weight, many diverse roles, connect things together

What primordial tissue do connective and epithelial tissues arise from?

mesoderm

What are the major cell types of connective tissue?

fibroblasts, mast cells, and macrophages

What are fibroblasts?

most common cell in connective tissue, large cells, produce fibers and secrete proteins, collagen and elastin

What are macrophages?

immune cells, usually attached to fibers but can move about, engulf and destroy particles/cells and damaged cells

What are mast cells??

part of inflammatory response, contain secretory vesicles, usually located near blood vessels

What are the types of connective tissue fibers?

collagenous, elastic, and reticular

What are collagenous fibers?

connective tissue fiber that is made of collagen protein, thick, there-like, resists tension, think tendons

What are elastic fibers?

connective tissue fiber that is made of elastin protein, think network fibers that are easily deformed/elastic

Where are elastic fibers/elastic connective tissue found?

arteries, trachea, bronchial tubes, lungs

What are reticular fibers?

connective tissue fiber that is made up of very thin collagen fibers, support cells within organs

Where are reticular fibers/connective tissue found?

form the stroma of many organs

What is the stroma of an organ?

cells and tissues that support and give structure to the organs

What are the two dense connective tissues?

regular and irregular

What is regular dense connective tissue?

connective tissue that has orderly, parallel fibers and resists tension, collagenous

Where is regular dense connective tissue found?

tendons, aponeuroses, and ligaments

What are tendons?

connective tissue that connects muscle to muscle or muscle to bone, rope-like

What are aponeuroses?

connective tissue that connects muscle to muscle or muscle to bone, sheet-like

What are ligaments?

connective tissue that is between bones at joints

What is irregular dense connective tissue?

sheet like, collagenous tissue

Where is irregular dense connective tissue found?

joint capsules, skin, bone, cartilage, around organs as capsules

What is adipose tissue?

connective tissue made up of adipocytes and is specialized for fat storage

Where is adipose tissue found?

subcutaneous layers, around kidneys, padding around joints

What is white fat?

mainly in adults, serves as padding

What is brown fat?

more prominent in the fetus and infant (a bit in adults), smaller adipocytes where fate is stored in several small droplets, numerous mitochondria, highly vascularized, involved in heat production

What is cartilage?

connective tissue that is a biphasic material, can grow internally, consists of collagenous/elastic fibers imbedded in chondroitin sulfate matrix, resists tension and compression forces

What is a chondroitin sulfate matrix?

gel-like mix for cartilage

What is a biphasic material?

material made up of two different properties