Chapter 4: Tissue level of organization
True or false: There are a larger number of glial cells than neurons.
true
In ______ connective tissue, individual bundles of collagen fibers extend in all directions in a scattered meshwork.
Dense Irregular
In ______ connective tissue, collagen fibers are packed tightly and aligned parallel to an applied force.
Dense Regular
Perichondrium
Dense irregular connective tissue membrane covering cartilage
Where would you find stratified squamous epithelium?
Epidermis of skin
reticular fibers
Fibers made of collagen protein that are very thin and branched. Forma tightly woven fabric that joins connective tissue to adjacent tissues.
elastic fibers
Flexible and "stretchy" fibers that add elasticity to tissue
Plasma
Fluid portion of blood
intercellular junctions
Intercellular junctions are structures between cells that allow neighboring cells to form strong connections with each other, prevent passage of materials, or establish rapid communication between adjacent cells.
smooth muscle tissue
Involuntary muscle is found in the intestines where it pushes food along the digestive tract. Also found in arteries and veins. -cells are fusiform (spindle shaped), short, non-striated, and contain one centrally located nucleus -found in walls of stomach, urinary bladder, and blood vessels
Nonkeratinized stratified squamous
apical cells have no keratin but instead are alive and moist. LOCATION: mouth, espohagus, tongue, vagina
apocrine secretion (what and where)
apical portion of cytoplasm pinches off to form secretion; eg mammary and ceruminous glands
What type of gland secretes a mixture of cell fragments and the product the cell synthesized before its disintegration?
holocrine
The___________ membrane is the largest body membrane and contains stratified squamous epithelium.
cutaneous
The skin is composed of 2 main layers
epidermis and dermis
What are the four types of tissues?
epithelial, connective, muscle, nervous
Adipocytes
fat cells
squamous cells
flattened and scale-like
The three types of connectives include
fluid connective tissue supporting connective tissue connective tissue proper
ground substance
fluid or semi-fluid portion of the matrix in CT
simple cuboidal epithelium is found
forming the kidney tubules and ducts of most glands
cardiac muscle tissue
involuntary muscle found only in the heart wall (myocardium) -cells are short, bifurcated, and striated, with one or two centrally located nuclei; intercalated discs between cells
ground substance
nonliving material produced by connective tissue cells consisting of protein, carbohydrates and water. may be viscous, semisolid, or solid primary composition of most connective tissues
The two embryonic connective tissues?
mesenchyme and mucous connective tissue
The embryonic ______ forms all connective tissues.
mesoderm
germ layer that forms all connective tissues
mesoderm
stratified epithelium
more than one layer of cells; more durable; primarily for protection (named based on shape of cell at apical surface)
Criteria used to classify multicellular exocrine glands include ______.
morphology (form and structure), method of secretion, and type of secretion
these glands occur in mammary glands, pancreas, and salivary glands
multicellular exocrine glands
functions of connective tissue
physical protection support and structural framework binding of structures storage transport immune protection
type of connective tissue one would find in the stroma of lymph nodes, in the spleen, the thymus and in bone marrow
reticular
name is an example of a holocrine gland?
sebaceous gland (oil producing glands in skim)
exocrine glands
secrete chemical substances into ducts that lead either to other organs or out of the body ex. goblet cell- unicellular exocrine gland found in the small intestine and upper respiratory tract
endothelial cells
specialized simple squamous cells lining the blood and lymphatic vessels (also lines the heart)
Muscle tissue is controlled primarily by ______.
the nervous system
collagen fibers
"cable-like" long, unbranched, extracellular fibers strong, flexible, and resilient to stretching form ~25% of the body's protein = most abundant great for withstanding enormous forces in one directions (eg tendons and ligaments)
Adhering junctions
-Encircles the cell deep to the tight junction -Microfilaments act like a purse string to stabilize the apical surface of the epithelial cell -allows for transfer of materials from one cell to another laterally
goblet cells
-a column-shaped cell found in the respiratory and intestinal tracts, which secretes mucin (main component of mucus) -single cell exocrine gland -typically found in simple columnar and pseudostratified ciliated columnar epithelium
fibroblasts (appearance and function)
-abundant, large, relatively flat cells, often with tapered ends -produce fibers and ground substance of the extracellular matrix
connective tissue
-body tissue that connects, supports, or binds body organs -most abundant, diverse, and widely distributed tissue - cells are spread out compared to epithelial cells
tight junctions
-encircles the cell towards apical surface - seals off intercellular space and prevents substances from moving between epithelial cells. - forces all material to move through the cell as opposed to between the cells - found between cells near the apical surface -"occluding belt"
cellularity of epithelial tissue
-epithelia are composed almost entirely of cells -cells separated by a minimal amount of extracellular material
fixed macrophages (appearance and function)
-large cells derived from monocytes in blood; reside in extracellular matrix after leaving blood -phagocytize foreign material
free macrophages (appearance and function)
-mobile phagocytic cells formed by monocytes of the blood - phagocytize foreign material
Adipocytes (appearance and function)
-single large lipid droplet within cell and cellular components pushed to one side -store lipid reserves
plasma cells (appearance and function)
-small cell with a distinct nucleus derived from activated B-lymphocytes -form antibodies that bind to foreign substances, bacteria, viruses found in intestinal walls, spleen, and lymph
Mast cells (appearance and function)
-small cells with granule filled cytoplasm -release histamine (dilate blood vessels/increase blood flow) and heparin (inhibits clotting) to stimulate local inflammation
mesenchymal cells (appearance and function)
-stellate or spindle shaped embryonic stem cells -divide in response to injury to produce new connective tissue cells
neuroepithelium
A type of epithelium that is specialized to perform a particular sensory function; these provide the senses
Sacs that produce secretions of multicellular exocrine glands are ______.
Acini
avascularity of epithelial tissue
All epithelial tissues lack blood vessels; the cells receive their nutrients by diffusion from underlying tissues
Desmosomes
Anchoring junctions that prevents cells subjected to mechanical stress from being pulled apart; button like thickenings of adjacent plasma membranes connected by fine protein filaments
Heparin
Anticoagulant
Ligaments
Connect bone to bone
Tendons
Connect muscle to bone
The fibrous structure called a ____________ encloses most multicellular exocrine glands.
Capsule
Hormones
Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another
epithelial tissue is derived from what germ layer?
Ectoderm, mesoderm, or endoderm
These glands have ducts and excrete their products onto the surface of the skin or into the lumen.
Exocrine
classification of exocrine glands
Exocrine glands are classified by (1) morphology, (2) type of secretion, and (3) method of secretion. (1) simple if they have a single unbranched duct compound if they have a branched duct. tubular have uniform diameter in secretory portion acinar secretory cells form a flared sac tubuloacinar has both tubular and acinar secretory cells (2) serous secrete non viscous, watery fluid mucous secrete mucin which forms mucous (w/water) mixed produce a mixture of both serous and mucous (3) merocrine secretions packaged in secretory vessels and cell is not damaged in secretion process apocrine accumulates secretion in apical portion of cytoplasm. apical portion is secreted with cytoplasm. cell then repairs itself to begin again holocrine the entire cell disintegrates as the secretion
apocrine glands
Exocrine glands that have cytoplasm in their secretions. - Composed of cells that accumulate their secretory products with the apical portion of their cytoplasm; the secretion of these glands contains the apical portions of the cells.
holocrine glands (what and where)
Exocrine glands whose secretions are made up of disintegrated cells; eg sebaceous glands (oil producing gland in the skin)
intercalated discs of cardiac muscle
In cardiac muscle, the structures that join cells and have desmosomes and gap junctions
The apical cells of this type of epithelium are dead, lack nuclei, and are filled with tough, protective keratin.
Keratinized stratified squamous
Some salivary glands are considered ______ glands because they contain both serous and mucous cells.
Mixed
General functions of epithelial tissue?
Physical protection, selective permeability, secretion, and sensation
functions of basement membrane
Providing physical support for the epithelium Anchoring the epithelium to the connective tissue Acting as a barrier to regulate the movement of large molecules between the epithelium and the underlying connective tissue
This type of exocrine gland produces sweat, milk, tears, or digestive juices.
Serous glands
The walls of the larger ducts of most exocrine glands, such as the sweat glands, is formed by ______.
Stratified Cuboidal Epothelium
The connective tissue framework of a multicellular exocrine gland is called the ______.
Stroma
Innervation
Supply or distribution of nerves to a specific body part
True or false: An exocrine gland with both secretory tubules and secretory acini called a tubuloacinar gland.
TRUE
types of intercellular junctions
Tight junctions Adhering junctions Desmosomes Gap junctions
This type of epithelium's appearance can vary depending on if it has been stretched or relaxed. Where is it typical found?
Transitional Found lining bladder and ureter
True or false: Areolar connective tissue is found nearly everywhere in the body.
True
True or false: Most connective tissue cells are not in direct contact with each other.
True
True or false: Stratified columnar epithelium is relatively rare in the body and is found in the membranous segment of the male urethra.
True
Lymphocytes and neutrophils (appearance and function)
WBCs that enter connective tissue attack foreign materials (lymphocytes) or directly combat bacteria (neutrophils)
what is extracellular matrix composed of?
Water, protein fibers, and dissolved molecules (e.g. glucose, oxygen)
simple epithelium
a single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption
If the secretory portion of a gland forms an expanded sac, the gland is called ______.
acinar
A multicellular exocrine gland consists of ______.
acini and at least one duct
characteristics of connective tissue
all connective tissues have cells, protein fibers, and ground substance diversity due to different ratios of the above and different types of protein fibers
Morphology is a(n) ______ classification of an exocrine gland.
anatomic
Platelets
blood clotting, aspect of formed elements in blood
cuboidal cells
boxlike, approximately as tall as they are wide
What are the characteristics of epithelial tissue?
cellularity, polarity, attachment to a basement membrane, avascularity, innervation, high regeneration capacity
Which type of protein fiber, in connective tissue, is the most abundant type of protein in the body and appears pink under the microscope when stained with hemotoxylin and eosin?
collagen
protein fibers in connective tissue and characteristics of each
collagen fibers- strong and stretch resistant elastic- flexible and resilient reticular- interwoven framework
multicellular exocrine glands
composed of a duct and a secretory portion (acinus) most are enclosed in a fibrous capsule (extensions of of this capsule are called septa which partition the gland into compartments called lobes, further smaller division results in lobules. Connective tissue framework is called the stroma which supports and organized the parenchyma which is the functional secretion cells of the gland.) -these glands occur in mammary glands, pancreas, and salivary glands
fibroblasts/fibrocytes
connective tissue proper
the three categories of connective tissues in adults?
connective tissue proper supporting connective tissue fluid connective tissue
Wandering cells in CT (function and types)
continuously move and are involved in immune protection and repair of damaged extracellular matrix. primarily leukocytes (WBCs) -mast cells, plasma cells, free macrophages, other leukocytes
hylaline cartilage location
costal cartilage, ends of long bones, fetal skeleton, nose, larynx, trachea the most common cartilage in body and also the weakest
Periosteum
dense irregular connective tissue membrane covering long bones
Histamine
dilates blood vessels to increase blood flow
germ layers that form tissues?
ectoderm, mesoderm, and endoderm
_______________ connective tissue has branching elastic fibers and more fibroblasts than loose connective tissue in addition to packed collagen fibers.
elastic
parenchyma cells of exocrine glands
functional secretion cells of the gland that are typically simple cuboidal or columnar epithelial cells
endocrine glands
glands that secrete chemicals called hormones directly into the bloodstream
Glands
individual cells or multicellular organs composed predominantly of epithelial tissue with the specialized function of secretion. -endocrine- lack ducts and secrete their products directly into the interstitial fluid and blood. secrete hormones -exocrine- typically originates as invagination of the epithelial tissue that burrows deeper into the connective tissue and maintain a duct to the outer surface
The uppermost layer of skin is composed of ________.
keratinized stratified squamous epithelium
basement membrane layers and contents
lamina lucida and lamina densa - the 2 laminae clostest to the epithelium which contain collagen fibers, specific proteins and carbohydrates (some of which are secreted by epithelial cells) reticular lamina - secreted by the connective tissue and contains protein fibers and carbohydrates
ciliated simple columnar epithelium
lines the larger bronchioles of the lungs and uterine tubes; wavelike motion of cilia propels materials through the lumen
Where would you find simple columnar epithelium?
lining of the digestive tract
where would you find transitional epithelium?
lining of the urinary bladder
Pseudostratified ciliated columnar epithelium is found
lining the larynx, trachea, and upper respiratory tract like nasal passages
Simple Ciliated Columnar Epithelium is found
lining the uterine tubes
hematopoietic stem cells
located in bone and produce blood cells
connective tissue proper
loose connective tissue and dense connective tissue
name an example of an apocrine gland?
mammary glands and ceruminous glands
Osteocytes
mature bone cells
Chondrocytes
mature cartilage cells
merocrine glands
package their secretions into secretory vesicles and release the secretions by exocytosis
extracellular matrix of CT
protein fibers and ground substance
Gap junctions (communicating junctions)
provide cytoplasmic channels between adjacent cells. this gap is bridged by structures called connexons that consist of 6 transmembrane proteins arranged to form a tiny fluid filled tunnel or pore.
Erythrocytes
red blood cells, aspect of formed elements in blood
Cells of connective tissue proper
resident cells and wandering cells
merocrine secretion (what and where)
secretions released by vesicle exocytosis; eg sweat, lacrimal (tear), salivary, pancreatic and gastric exocrine glands
Cancellous bone is also called ______.
spongy bone
Resident cells of CT (function and types)
stationary cells that help support, maintain, and repair the extracellular matrix -fibroblasts, adipocytes, fixed macrophages, mesenchymal cells
Mucous Connective Tissue (Wharton's Jelly)
structure mesenchymal cells scattered within ground substance with immature protein fibers present function provide support to umbilical cord structure location found exclusively in the umbilical cord of the fetus
Mesenchyme Connective Tissue
structure viscous gel ground substance with some immature protein fibers; cells are stellate/spindle shape function origin of all connective tissue types location throughout embryo, fetus, and adult
Histology
study of tissues
columnar cells
tall and column shaped cells
Define polarity of epithelial tissue and name the surfaces of an epithelial cell.
the cell is not uniform on all sides but different from the topside to the bottom. - Apical surface (free or top surface) exposed to the external environment or internal body space. - Basal surface (fixed or bottom surface) where the epithelium is attached to the underlying connective tissue - Lateral surface (sides) have intercellular junctions
Stem cells of the epithelium
the deepest epithelial cells that are constantly undergoing mitotic division to provide a high regeneration capacity. these are found near the basement membrane
skeletal muscle
voluntary muscles found connected to bones and sometimes ski that moves skeleton. also functions in heat production -fibers are striated, long, cylindrical, parallel, and unbranched. fibers are multinucleated with nuclei along periphery.
elastic connective tissue location
walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes
Leukocytes
white blood cells, aspect of formed elements in blood
