chapter 4 - tissues Flashcards
A tissue is a ….
A tissue is a group of similar cells and extracellular products that perform a common function
The _____ of different tissues varies in structure and function
Generally composed of ___, ___, & ___
__, __, and ___is different across tissues
he extracellular matrix of different tissues varies in structure and function
Generally composed of water, protein fibers, dissolved molecules
Composition, volume and consistency is different across tissues
Four types of tissue in the body:
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
muscle tissue
general characteristics
contractile
receives stimulation from nervous system and/or endocrine system
Muscle tissue
general functions
facilitates movement of skeletal or organ walls
muscle tissue
primary germ layer derivative
mesoderm
muscle tissue
subtypes
skeletal muscle: attached to bones
cardiac muscle: heart
smooth muscle: digestive tract
nervous tissue
two components and brief descriptions
neurons: excitable, high metabolic rate, extreme longevity, non mitotic
glial cells: non excitable and mitotic
nervous tissue
functions
neurons: control activities and process info
glial cells: support and protect neurons
primary germ layer of nervous tissue
ectoderm
epithelial tissue
general characteristics
cellular. polar, attached, avascular, innervated, high regeneration capacity
Epithelial tissue
functions
covers surfaces
lines insides of organs and body cavities
epithelial primary germ layer
ectoderm
mesoderm
endoderm
epithelial tissue
subtypes
simple columnar (lining of digestive) stratified squamous (epidermis of skin) transitional (lining of bladder)
connective tissue
general characteristics
diverse types
all contain cells
protein fibers
connective tissue
functions
protects
binds together
supports organs
connective tissue
primary germ layer
mesoderm
connective tissue
subtypes
adipose - fat dense regular -ligament and tendons dense irregular - dermis of skin hyaline cartilage - some joints fluid - blood and lymph
Muscle is comprised of cells called ___
When cells are active, internal changes cause them to ___
The result of shortening is ___
Examples: Movement of bones, blood, food, semen, urine
Muscle is comprised of cells called fibers
When cells are active, internal changes cause them to shorten
The result of shortening is movement
Examples: Movement of bones, blood, food, semen, urine
skeletal muscles
Skeletal muscle fibers are:
___&___ (some as long as whole muscle)
_____
_____ and _____
Attached to ____ and sometimes skin
Skeletal muscle fibers are:
Cylindrical and long (some as long as whole muscle)
Multinucleated
Striated (striped internal appearance) and voluntary
Attached to bones of skeleton and sometimes skin
skeletal muscle
___, ___, & ____fibers
Multiple ___ in periphery of each fiber
Moves ____
Attaches to ____
Long, cylindrical, striated fibers
Multiple nuclei in periphery of each fiber
Moves body (voluntary control)
Attaches to bone and/or skin
cardiac muscle
Found in ___
Cells are: 1. 2. 3. 4.
Contraction causes ____
Found in wall of the heart (myocardium)
Cells are:
- Branched and shorter than skeletal fiber cells
- Striated
- Involuntary
- Attached end-to-end by strong gap junctions at intercalated discs that allow rapid passage of electrical current from one cell to the next during each heartbeat
Contraction causes movement of blood
cardiac muscle
___, bifurcated, & ___ fibers
One or two ___ in center of each fiber
____ between cells
Pumping action moves ___
Located in ____
Short, bifurcated, striated fibers
One or two nuclei in center of each fiber
Intercalated discs between cells
Pumping action moves blood
Located in heart wall
smooth muscle
Found in walls of ___
Examples:
Cells are:
Relatively __, ___ in the middle, and ___ at the ends (fusiform)
Not ___
Contraction causes…
Found in walls of most internal organs
Examples: Stomach, intestines, urinary bladder
Cells are:
Relatively short, wide in the middle, and tapered at the ends (fusiform)
Not striated
Contraction causes involuntary movement of food, blood, sperm
smooth muscle
___, ___, ____ cells
One ___ in center of each cell
Moves material through ____ (involuntary)
Located in walls of many hollow organs including ____
Nonstriated, short, fusiform cells
One nucleus in center of each cell
Moves material through internal organs (involuntary)
Located in walls of many hollow organs including intestines
nervous tissue
Two types of cells in nervous tissue:
Two types of cells in nervous tissue:
Neurons
Glial cells
Neurons:
Each cell has a prominent cell body, branches of ___ that receive signals, and a long ___ that carries signals toward other cells
Neurons: Nerve cells capable of initiating and conducting electrical activity throughout the body
Each cell has a prominent cell body, branches of dendrites that receive signals, and a long axon that carries signals toward other cells
Glial cells:
___ and ___
Found in… (3)
Glial cells: Cells that support and protect neurons
Communication and control of body functions
Found in brain, spinal cord, and nerves
nervous tissue
Contains neurons with fibrous processes called ___ and ___ and glial cells
3 functions:
Located in….
Contains neurons with fibrous processes (dendrites and axons) and glial cells
Process and store information, control body systems
Located in central (brain, spinal cord) and peripheral nervous systems
epithelial tissue
Epithelial tissue lines every ____ and all ____
Organs are lined on the __ & ___ by epithelial tissue
The majority of ___ are derived from epithelial tissue
Epithelial tissue possesses little to no ____
Epithelial tissue lines every body surface and all body cavities
Organs are lined on the outside and inside by epithelial tissue
The majority of glands are derived from epithelial tissue
Epithelial tissue possesses little to no extracellular matrix
All epithelia are:
All epithelia are: cellular, polar, attached to a basement membrane, avascular, richly innervated, and regenerative
Characteristics of Epithelial Tissue
cellularity polarity attachment avascularity innervation high regeneration capacity physical protection selective permeability secretion sensation
Cellularity: Composed almost entirely of __ - little ______
—-Cells are bound together by several types of ______
Cellularity: Composed almost entirely of cells - little extracellular matrix
—Cells are bound together by several types of intercellular junctions
Polarity: Epithelial cells have an ___ & a ___
Apical surface is ____
Basal surface is attached to _____ underneath it
Polarity: Epithelial cells have an apical surface and a basal surface
Apical surface is exposed
Basal surface is attached to connective tissue underneath it
epithelial tissue
Attachment:
Attachment: Basal surface attaches to basemement membrane - molecules produced by both epithelial and neighboring connective tissues
epithelial tissue
avascularity
Epithelial tissues lack blood vessels
epithelial tissue
innervation
Epithelia are richly innervated to detect changes in environment (externally or internally)
epithelial tissue
high regeneration
Because exposed apical surface is frequently damaged, epithelial cells are quickly replaced
epithelial tissue
physical protection
Defend against dehydration and abrasion, as well as physical, chemical, and biological agents
epithelial tissue
selective permeability
Regulate passage of molecules in or out of certain regions of the body
epithelial tissue
secretion
Secrete substances for use in the body (e.g., hormone) or for elimination from the body (e.g., sweat)
epithelial tissue
sensation
Possess nerve endings that can detect light, taste, sound, smell, and hearing
Specialized Structures of Epithelial Tissue
The _____ is a specialized structure of epithelium
Found between ___ & _____
Provides __ ____ and anchoring of epithelial tissue
Acts as a barrier regulating passage of large molecules between ___ & ____
The basement membrane is a specialized structure of epithelium
Found between epithelium and underlying connective tissue
Provides physical support and anchoring of epithelial tissue
Acts as a barrier regulating passage of large molecules between epithelium and connective tissue
Specialized Structures of Epithelial Tissue
Epithelial cells are strongly bound to each other on their ___ surfaces by membrane specializations called ___
There are several types of these junctions:
(4)
Epithelial cells are strongly bound to each other on their lateral surfaces by membrane specializations called intercellular junctions
There are several types of these junctions: Tight junctions Adhering junctions Desmosomes Gap junctions
tight junctions
Encircle cells near…
Prevent molecules from ….
So that molecules must go through epithelial cells rather than in between them
“Gatekeepers” between an ….
Encircle cells near their apical surface
Prevent molecules from traveling between epithelial cells
So that molecules must go through epithelial cells rather than in between them
“Gatekeepers” between an external and internal environment
adhering junctions
Formed completely around the cell deep to the ____
___ act like a purse string to stabilize the apical surface of the epithelial cell
Formed completely around the cell deep to the tight junction
Microfilaments act like a purse string to stabilize the apical surface of the epithelial cell
desmosomes
-Like a ___ between adjacent cells
Appear at locations of …
Consist of a ____ on each of the apposed cell membranes with a fine network of proteins spanning the intercellular space between the plaques
On the cytoplasmic side, intermediate filaments attach to the plaques and provide ___ & ____
Some basal epithelial cells have _____ anchoring them to basement membrane
Like a button or snap between adjacent cells
Appear at locations of mechanical stress between cells sharing this type of junction
Consist of a thickened protein plaque on each of the apposed cell membranes with a fine network of proteins spanning the intercellular space between the plaques’
On the cytoplasmic side, intermediate filaments attach to the plaques and provide support and stability
Some basal epithelial cells have hemidesmosomes anchoring them to basement membrane
Gap junctions span the intercellular space between…
A Connexon is a group of membrane proteins…
The ____ connects the cytoplasms of the two cells
Allow adjacent cells to _____ by the flow of ions and small molecules
Gap junctions span the intercellular space between neighboring cells
A Connexon is a group of membrane proteins that forms a pore
The fluid filled pore connects the cytoplasms of the two cells
Allow adjacent cells to communicate with each other by the flow of ions and small molecules
Classification of Epithelial Tissue
Many different types of epithelial tissue
Classified according to two criteria:
1.
2.
Classification of Epithelial Tissue
Many different types of epithelial tissue
Classified according to two criteria:
Number of layers of cells
Shape of the cells
classification by number of cell layers
simple epithelium
stratified epithelium
pseudostratified epithelium
Simple epithelium:
Consists of …
All cells have ….
Simple epithelium: Consists of a single layer of cells
All cells have an apical surface and attach to the basement membrane
Stratified epithelium:
Consist of …
Not all cells have _____ nor do all cells attach to____
Stratified epithelium: Consist of two or more layers of cells
Not all cells have an apical surface nor do all cells attach to the basement membrane
Pseudostratified epithelium:
Appears to have____, but all cells attach to _____
A subtype of _____
Pseudostratified epithelium:
Appears to have multiple layers, but all cells attach to the basement membrane
A subtype of simple epithelium
classification by cell shape
Squamous
Cuboidal
Columnar
Squamous:
Cuboidal:
Columnar:
Squamous: Flat, wide, and somewhat irregular in shape
Cuboidal: About the same size on all sides; nucleus is usually centrally located
Columnar: Taller than they are wide; nucleus is oval and located in basal region of the cell
simple squamous epithelium
what is it?
allows for?
Single layer of flat cells
Allows for rapid exchange
simple cuboidal epithelium
what is it?
allows for?
Single layer of boxy cells
Allows for absorption, secretion
Nonciliated Simple Columnar Epithelium
- what is it?
- No ____
- Allow ___ & ____
- Especially secretion of ____
-Example: lining of intestine
Single layer of tall, narrow cells
No cilia present
Allow absorption and secretion
Especially secretion of mucin
Example: lining of intestine
Ciliated Simple Columnar Epithelium
- Single layer of …
- Allow for…
- Example: uterine tube
- Single layer of tall, narrow, ciliated cells
- Allow for secretion, movement of material across free surface
- Example: uterine tube
Pseudostratified Columnar Epithelium
Single layer of …
- Some examples are ____
what is the function?
- Single layer of narrow cells with varying heights
- Some examples are ciliated
Protection; ciliated form secretes mucin, moves mucus
Stratified Squamous Epithelium
Multiple ____, apical cells are ____
Apical cells may or may not be _____
Multiple layers, apical cells are flat
Apical cells may or may not be keratinized
Keratinized Stratified Squamous Epithelium
Multiple ... Apical cells are \_\_\_\_\_ Superficial layers of cells contain ... Function: \_\_\_ Example: epidermis of skin
Multiple layers of cells Apical cells are dead, flat Superficial layers of cells contain tough, protective keratin Function: protection Example: epidermis of skin
nonkeratinized stratified squamous epithelium
Multiple….
Flat, apical cells are …
Function: _____
Example: lining of vagina
Multiple layers of cells
Flat, apical cells are alive and moist
Function: protection
Example: lining of vagina
Stratified Cuboidal Epithelium
Multiple….
apical cells are ____
___ and _____
Example: lining of sweat gland duct
Multiple layers of cells,
apical cells are boxy
Protection and secretion
Example: lining of sweat gland duct
stratified columnar epithelium
Multiple….
apical cells are _____
___ and _____
Example: part of male urethra
Multiple layers of cells, apical cells are elongated
Protection and secretion
Example: part of male urethra
transitional epithelium
Multiple…
apical cell shape ….
Can __ or ____depending on how ____it is
Lining of urinary tract
Multiple layers
apical cell shape varies depending on degree of stretch
Can distend or recoil depending on how stretched it is
Lining of urinary tract
two types of glands
endocrine
exocrine
glands
___ or ____
Perform a ____ fxn
Produce …..
Individual cells or multicellular organs
Perform a secretory function
Produce mucin, hormones, enzymes, waste products
endocrine
do not?
secrete directly into?
exocrine
possess?
secrete products into?
Endocrine glands do not possess ducts; secrete directly into interstitial fluid or bloodstream
Exocrine glands possess ducts and their cells secrete products into their ducts
Structure of Exocrine Glands
__ ___ are unicellular exocrine glands
Multicellular exocrine glands are often enclosed in a ___
–Inside the capsule, the gland is divided into ____
–A connective tissue ___ does what?
–Microscopic lobules contain …
Goblet cells are unicellular exocrine glands
Multicellular exocrine glands are often enclosed in a fibrous capsule
–Inside the capsule, the gland is divided into lobes
–A connective tissue stroma supports and organizes the gland
–Microscopic lobules contain secretory acini and ducts
Classification of Exocrine Glands
- Gland structural categorization depends on the ___ of the duct and the ____of the secretory portion
- -Ducts type distinguishes ___ from ___
- -Secretory portion can be ___, ___ or ____
- Gland structural categorization depends on the complexity of the duct and the shape of the secretory portion
- –Ducts type distinguishes simple from compound glands
- —Secretory portion can be tubular, acinar or tubuloacinar
Classification of Exocrine Glands
Types of secretion mechanisms
3 of them
Types of secretion mechanisms
- –Merocrine: secrete products from vesicles via exocytosis
- —Holocrine: cell accumulates product, then disintegrates
- —Apocrine: product stored in apical part of cell that pinches off
secretion mech of exocrine
Merocrine:
Holocrine:
Apocrine:
Merocrine: secrete products from vesicles via exocytosis
Holocrine: cell accumulates product, then disintegrates
Apocrine: product stored in apical part of cell that pinches off
Classification of Exocrine Glands
- Gland secretion types are ___, ___ or ____
- -Serous glands produce …
- -Mucous glands secrete ____
- -Mixed glands produce a mixture of ___ and ____ seretions (e.g. salivary glands under oral cavity)
Gland secretion types are serous, mucous, or mixed
- –Serous glands produce watery fluids (such as sweat)
- –Mucous glands secrete mucin
- –Mixed glands produce a mixture of watery and mucoid secretions (e.g. salivary glands under oral cavity)
Connective tissue is the most ….
It is the ___of the body
Includes …
Connective tissue is the most diverse, abundant, widely distributed, and structurally varied of the four main tissue types
It is the “glue” of the body
Includes blood, tendons, ligaments, fat, bones, cartilage
characteristics of connective tissue
cells
protein fibers
ground substance
connective tissue
Cells: Different ___ in different types of ____
Examples include ___ ___ ___
Protein fibers: ___ ___ ___
Ground substance: A mixture of ___ & ____with variable amounts of ___ & ____
-Protein fibers and ground substance comprise the _____
Cells: Different cells in different types of connective tissue
Examples include fibroblasts, osteocytes, and adipocytes
Protein fibers: Elastic fibers, collagen, reticular fibers
Ground substance: A mixture of proteins and carbohydrates with variable amounts of salts and water
-Protein fibers and ground substance comprise the extracellular matrix
Functions of connective tissue
6
Physical protection Support and structural framework Binding of structures Storage Transport Immune protection
development of connective tissue
Arises from ___
Two types of embryonic CT:
1.
2.
Arises from mesoderm
Two types of embryonic CT:
- Mesenchyme: The source of all adult connective tissue
- Mucous connective tissue: Found in umbilical cord
classification of connective tissue
Types present after birth can be classified into three broad categories:
Types present after birth can be classified into three broad categories:
- Connective tissue proper
- Supporting connective tissue
- Fluid connective tissue
Connective tissue proper includes multiple subtypes
Subtypes vary in ___ & ____ and in properties of ____
Connective tissue proper includes multiple subtypes
Subtypes vary in number and types of cell and in properties of extracellular matrix
There are two groups of cells in connective tissue proper:
- ____ cells
- ____cells
There are two groups of cells in connective tissue proper:
Resident cells: Include fibroblasts, adipocytes, fixed macrophages, and mesenchymal cells
Wandering cells: Include mast cells, plasma cells, free macrophages, and other leukocytes
protein fibers of connective tissue proper
Three types of fibers produced by cells and secreted into the extracellular matrix:
collagen fibers, elastic fibers, reticular fibers
Collagen fibers: ___, ___ & ___ cables
- -Collagen is the most …
- -Called “__ ___” (e.g. in tendons and ligaments)
Collagen fibers: long, strong, flexible cables
- -Collagen is the most abundant protein in human body
- -Called “white fibers” (e.g. in tendons and ligaments)
Elastic fibers: ___ than collagen, ___ easily, ___and ___
Allow structures such as blood vessels to __ ___
Elastic fibers: Thinner than collagen, stretch easily, branch, and rejoin
Allow structures such as blood vessels to stretch and relax
Reticular fibers: ___ than collagen fibers; form a ___/___ framework
Found in the stroma of organs with ___ ____ such as liver, lymph nodes, and spleen
Reticular fibers: Thinner than collagen fibers; form a branching, woven framework
Found in the stroma of organs with abundant spaces such as liver, lymph nodes, and spleen
Ground Substance of Connective Tissue Proper
A combination of ___ & ___
Texture is usually ___
Additional content such as ___ & ___ can result in a texture anywhere from ___ to ___
A combination of proteins and carbohydrates
Texture is usually gelatinous
Additional content such as water and salts can result in a texture anywhere from semi-fluid (adipose) to hard (bone)
categories of connective tissue
Connective tissue proper is classified into two categories:
Loose connective tissue
Dense connective tissue
Loose connective tissue: Serves as the body’s ____, found in spaces around ___
Types include
Loose connective tissue: Serves as the body’s packing material, found in spaces around organs
Types include areolar, adipose, and reticular
Dense connective tissue:
___, has …
Types include…
Dense connective tissue: Strong, has fibers (mostly collagen) packed tightly together
Types include dense regular, dense irregular, and elastic
Areolar Connective Tissue
describe it
___ and ____; connects ____ to deeper tissues
Example: papillary layer of dermis
Scattered fibroblasts, abundant ground substance, web of fibers
Surrounds and protects; connects epithelia to deeper tissues
Example: papillary layer of dermis
Adipose Connective Tissue
what is it?
Stores ___, cushions ___, and ___
Example: subcutaneous fat
Tightly packed adipocytes
Stores energy, cushions organs, insulates
Example: subcutaneous fat
Reticular Connective Tissue
Scattered ____, _____, reticular fibers; ___/___ substance
Provides __ ___
Example: stroma of spleen
Scattered fibroblasts, white blood cells, reticular fibers; gel-like ground substance
Provides supportive framework
Example: stroma of spleen
Dense Regular Connective Tissue
Densely packed ____, fibroblasts, scarce _____
Resists ___ in ____
Example: tendons
Densely packed parallel collagen fibers, fibroblasts, scarce ground substance
Resists stress in one direction
Example: tendons
Dense Irregular Connective Tissue
____ collagen fibers, fibroblasts, ___ substance
Resists ___ in ____
Example: dermis
Randomly arranged collagen fibers, fibroblasts, ground substance
Resists stress in all directions
Example: dermis
Elastic Connective Tissue
Many ____, fibroblasts, ____ substance
Allows ____
Example: walls of large, elastic arteries
Many branching elastic fibers, fibroblasts, ground substance
Allows stretching
Example: walls of large, elastic arteries
Two types of supporting connective tissue:
Two types of supporting connective tissue:
Cartilage
Bone
cartilage
Firm, gel-like extracellular matrix composed of…
Cells are called ____
and they occupy small spaces enclosed by their extracellular matrix called lacunae
___ and ____ to provide ___ and withstand deformation
Usually covered by ____
—Dense irregular connective tissue and stem cells for cartilage growth
Firm, gel-like extracellular matrix composed of protein and ground substance
Cells are called chondrocytes
Chondrocytes occupy small spaces enclosed by their extracellular matrix called lacunae
Strong and resilient to provide support and withstand deformation
Usually covered by perichondrium
—Dense irregular connective tissue and stem cells for cartilage growth
There are three types of cartilage:
There are three types of cartilage:
Hyaline cartilage
Fibrocartilage
Elastic cartilage
hyaline cartilage
__ ___; chondrocytes in lacunae
_____ type of cartilage, but also the ____
Smooths ___ ___, model for ____
Example: articular cartilage of long bones
Glassy matrix; chondrocytes in lacunae
Most common type of cartilage, but also the weakest
Smooths joint surfaces, model for bone growth
Example: articular cartilage of long bones
Fibrocartilage
____ in matrix; chondrocytes in lacunae
Absorbs ____
Example: intervertebral discs
Parallel collagen fibers in matrix; chondrocytes in lacunae
Absorbs shock
Example: intervertebral discs
Bone
Two-thirds of bone’s weight is ___; one-third is ___
Organic parts provide ___
Inorganic parts provide ____
Two-thirds of bone’s weight is inorganic (mostly calcium salts); one-third is organic (collagen and other proteins)
Organic parts provide flexibility
Inorganic parts provide compressional strength
bone
Periosteum:
Mature bone cells are called ___
Periosteum: dense irregular connective tissue covering
Mature bone cells are called osteocytes
Two forms of bone:
Compact bone is arranged in cylindrical osteons of concentric lamellae
Spaces within spongy bone house hemopoietic cells that generate blood cells
Compact bone
Calcified matrix organized in ___
Protects ___, provides ___ for ___, stores ___
Example: bones of body
Calcified matrix organized in osteons
Protects organs, provides levers for movement, stores calcium
Example: bones of body
Fluid Connective Tissue
Fluid connective tissue refers to…
Fluid connective tissue refers to blood and lymph
Blood consists of:
Blood consists of:
Plasma: A watery ground substance containing protein fibers
Erythrocytes: Red blood cells
Leukocytes: White blood cells
Platelets: Fragments of blood cells involved in blood clotting
Lymph is derived from ____—has no formed elements
Lymph is derived from plasma—has no formed elements
Blood
Contains __, ___, & ___
Transports …
governs…
Found in…
Contains blood cells, platelets, and plasma
Transports respiratory gases, nutrients, wastes, hormones;
governs immune response
Found in heart and in blood vessels throughout body
body membranes do what?
Membranes line the major body cavities and cover organ surfaces
body membranes
- Mucous membranes line passages that open to external environment
- Serous membranes (e.g., pericardium) have two layers (parietal and visceral) and secrete friction-reducing fluid between them
- Cutaneous membrane is the skin (epidermis and dermis)
- Synovial membranes line the cavities of some joints and secrete friction reducing fluid there
Tissue change and aging
Tissues often undergo changes in— & ___with aging
Epithelia thin, connective tissues lose ___
Repair processes lose ___
Tissues often undergo changes in structure and chemical composition with aging
Epithelia thin, connective tissues lose pliability
Repair processes lose efficiency
aging tissue
Metaplasia: Epithelia lining respiratory airways of people who smoke change from ___ to ___
Hypertrophy: An increase in the ____of existing cells
Hyperplasia: An increase in ____ in a tissue
Neoplasia: _____, which forms a tumor
Atrophy: _____ of tissue by cell size or number
Metaplasia: Epithelia lining respiratory airways of people who smoke change from pseudostratified ciliated to stratified squamous
Hypertrophy: An increase in the size of existing cells
Hyperplasia: An increase in number of cells in a tissue
Neoplasia: Out-of-control growth, which forms a tumor
Atrophy: Shrinkage of tissue by cell size or number
