Test Two Module 5 Flashcards
What are tissues?
Organized groupings of cells and secreted materials that are connected or intertwined with each other and which perform specific, limited functions within a larger system (such as within an organ or larger grouping.)
In animals, all tissue can be grouped into one of the four major categories:
Epithelial tissue, Connective tissue, Muscle tissue, and Nervous tissue
_____ tissue lines surfaces that are subject to a lot of wear and tear?
Epithelial tissue
_____ tissue forms glands to create secretions?
Epithelial tissue
Epithelial tissue lines surfaces subject to a lot of wear and tear because they either: (2)
- cover surfaces that face the outside world (skin) or connect to the outside world (digestive tract)
- Line internal passageways for blood, lymph, and secretions
Connective tissues main functions are: (6)
- fills internal spaces
- supports other tissues
- covers and wraps internal organs
- transports materials
- stores energy
- provides insulation
What is the most versatile and diverse tissue type?
Connective tissue
_____ tissue are specialized for contraction
Muscle tissue
What are the three types of muscle tissue?
- skeletal muscle(move bones)
- cardiac muscle(contracts heart
- smooth muscle(in the walls of hollow organs)
What type of muscle is found in the walls of organs?
smooth muscle
What type of muscle contracts heart?
cardiac muscle
What type of muscle moves bones?
Skeletal muscle
_____ tissue carries electrical signals from one part of the body to another?
Nervous tissue
_____ tissue supports the cells that deliver the electrical signals?
Nervous tissue
Nervous tissue two functions? (2)
- carries electrical signals from one part of the body to another
- supports the cells that deliver the electrical signals
In animal cells, cell division is by _____?
Mitosis
What is cell differentiation?
When a cell has developed a set of structures and functions that are unique to the specific tissue it is part of; usually, but not always accompanied by a loss of the ability to undergo mitosis.
Most of the cells in a non-embryonic individual are _____ and cannot divide to produce new copies of themselves?
specialized
New cells in tissues are produced by ______?
stem cells
What are stem cells?
Undifferentiated cells able to undergo mitosis to produce two daughter cells, one of which will remain a stem cell and one of which will differentiate into a specific specialised cell within a specialised tissue.
For a short while after the fertilized egg starts dividing and forms an embryo, all the embryonic cells are _____?
stem cells
The _____ have the ability to form any cell type from any tissue type, but only for a short while.
embryonic stem cells
Somatic stem cells are basically?
Adult stem cells
After a baby is born, all tissues are present and most of the cells in the body can no longer _____ and there are also no more embryonic cells?
divide
What are somatic stem cells?
An undifferentiated cell (found in a tissue of otherwise differentiated cells) that can replicate itself and differentiate into a limited repertoire of differentiated cells.
The different types of somatic stem cells are often named for either:
The location they are found of the cells they differentiate into
Neural stem cell are found where?
in the brain
Dental pulp stem cells are found where?
Interior of teeth
Most somatic stem cells can only differentiate into:
One or at most a few different cell types
Neural stem cells in the brain can only differentiate into _____?
Neurons
Liver stem cells can only differentiate into _____?
Liver cells
One epithelial (singular) tissue is known as an _____?
epithelium
What is an epithelium?
A layer of epithelial cells covering an internal or external surface
Epithelial are always _____ of some sort?
Linings
Some but not all epithelial linings _____ onto their surface?
Secrete fluids
What is a glad?
A single epithelial cell that has differentiated/specialised into a cell that produces secretions.
Or
A group of epithelial cells that form a structure where some of the epithelial cells produce secretions that travel through a duct to the surface of the rest of the epithelial tissue.
Is a gland one cell or many cells working together?
Both
Epithelial cells (both glandular and non-glandular epithelia) usually have a straightforward appearance of?
boxy and tightly packed together
All cells in epithelia have five important characteristics:
- polarity
- attachment
- regeneration
- association
- avascularity
Describe the what the polarity of epithelial tissue means:
The two “ends” of the epithelial cells are not the same.
One end of an epithelial cell is closer to the exterior surface it lines = apical surface of the cell.
The other end is closer to the base of the tissue where it connects to other tissues = basolateral surface of the cell.
What is the apical surface of the cell?
The one end of an epithelial cell that is closer to the exterior surface it line (the top of the cell)
What is the basolateral surface of the cell?
The other end of the cell tissue where it connects to other tissues (the bottom of the cell that attaches to the basement membrane)
The cytoplasm of epithelial cells has its organelles distributed _____ between the apical and basolateral surfaces?
unequally
Describe what attachment of epithelial tissue means?
Epithelial cells are tightly bound to one another via cell-to-cell interactions, and they are also tightly attached to the material below/basolateral to them. (they are attached through junctions and the basement membrane)
Describe what regeneration means for epithelial tissue?
Because epithelial cells are at surfaces, they are worn away at a fast pace.
Some of the cells within any epithelial layer are able to act as somatic stem cells that divide and replace any lost epithelial cells all throughout the tissue. These stem cells can only specialize into epithelial cells, no other types.
Describe what association mans for epithelial tissue?
Epithelial tissue always sits on top on and is tightly associated with a different underlying tissue.
(The underlying tissue is almost always connective tissue.)
What is almost always the underlying tissue of epithelial tissue ?
connective tissue
What does avascularity mean for epithelial tissue?
Epithelial cells lack blood vessels running through or between them.
Blood vessels only run below epithelia through the connective tissue that underlies it.
Blood vessels travel through underlying connective tissue but not through epithelial tissues, so transfer of material to epithelial tissue has to travel through _____?
Many cells to get to or from blood
What are the four main function of epithelial tissue?
- provide physical protection
- control permeability
- provide sensation
- produce specialized secretions
How does epithelial tissue provide physical protection?
As the outside-world-facing layer of most surfaces, they prevent undesired material from getting in and desirable material from getting out.
How does epithelial tissue control permeability?
As the outside-world-facing layer of most surfaces, they are the gateway to the interior tissues; so the membrane transporter proteins on epithelial cells will determine what gets in or out of the body.
Most materials allowed into the body have to cross into and out of epithelial cells.
Some materials can squeeze between epithelial cells.
The cells and how tightly they are packed control what gets in on one side and out the other.
Most materials allowed into the body have to cross into and out of _____ cells?
epithelial
How do epithelial cells control permeability in the body?
By controlling what travels through them and between them
How do epithelial tissue provide sensation?
While epithelia lack blood vessels, epithelia are well-supplied with nerves;
this allows them to provide information about their external and internal environments
The _____ of the digestive tract (like that of the skin) is constantly sending sensory information to the brain via nerves that attach to or between epithelial cells.
epithelia
How do epithelial tissue produce specialized secretions?
Glands can be either single cells, or multicellular structures, but both are specialized epithelial cells that produce and release secretions that coat the exterior of the epithelial layer.
What do cell biologists call a membrane?
The lipid bilayer around the cell
What is sandwiched between the epithelial tissue and connective tissue?
The basement membrane
What is the basement membrane?
A thin layer of extracellular protein fibers that is found beneath epithelial tissues and which is attached to both the epithelial cells above it and to the connective tissue below it.
What is the basement membrane made of?
Protein fibers
What is the first portion of the basement membrane called?
Basal lamina
What is the second portion of the basement membrane?
Reticular fibers
What is the basal lamina?
The first part of the basement membrane that is made up of protein fibers secreted by the epithelial cells above the basement membrane
What are the reticular fibers?
the second portion of the basement membrane that is made up of protein fibers secreted by the connective tissue cells below the basement membrane
What is he function of the basement membrane?
to ensure epithelial layers cannot be easily separated from the lower layers of tissue
What is the basement membrane made of?
The basal lamina and the reticular fibers
The epithelial layer surrounding an organ can either be?
Tight or leaky depending on how tightly the epithelial cells are sealed together
_____ epithelia does not allow extracellular fluid to pass freely through them?
tight
_____ epithellia do allow extracellular fluid to pass freely through them?
leaky
What happens with leaky epithelia?
Extracellular fluid and other materials can easily move from one side of the epithelial layer to the other
What are three main specialized structures made up of protein fibers serve as cell-to-cell junctions, sealing epithelial cells to one another either tightly, or more loosely?
- Tight junctions (occluding junctions)
- Desmosomes (macula adherens)
- Gap junctions
An epithelium with many tight junctions between its cells will _____?
not be leaky
What are the tightest junctions?
Tight junctions
_____ junction consist of a branching network of interlocking proteins that cross between two adjacent cells, sealing them tightly together.
tight junctions
What is also known as occluding junctions?
tight junctions
_____ junction is a large complex of densely packed interlocking protein fibers that start in the cell, cross the membrane, then lock up with equivalent protein fibers from the adjacent cell.
Desmosomes (macula adherens)
_____ are distinguished by the disc of proteins on each side of the attached membranes, with protein fibers extending into the cytoplasm before they lock up
Desmosomes
What is also known as macula adherens?
Desmosomes
______ are among the leakiest of junctions, they hold cells together, but not all that closely?
Desmosomes
_____ are secure but not particularly tight junctions?
Desmosomes
_____ junctions is a ring of proteins that cross both membranes of adjacent cells, both sealing them, and creating a pore connecting their cytoplasm?
gap junctions
____ junctions allows cells to adhere adjacent to one another but also allow them to share cytoplasmic contents?
Jap junctions
What are CAMs?
Cell adhesion molecules
_____ are the proteins that collectively make up the junctions?
CAMs (cell adhesion molecules)
Individual specific CAMs have names like:
Cadherins, integrins, connexins
The cells in epithelial tissues always attach to the _____ a fibrous matrix of proteins secreted by both the epithelial cells and also by connective tissue below it?
Basement membrane
Epithelial cells attach to the basement membrane via?
hemidesmosomes
What are hemidesmosomes?
They are similar to desmosomes, but instead of attaching one cell to another, it attaches one cell to the basement membrane
_____ are distinguished by one disc of proteins (inside the cell) and protein fibers that extend and attach to the basement membrane protein fibers below it?
hemidesmosomes
What are the two main ways we categorize epithelia?
Shape and layers
What is the types of shape epithelia can have?
Squamous= thin and flat cubiodal= square shaped Columnar= tall columns or rectangular shapes
What is the types of layers epithelia can have?
Simple= one single layer Stratified= several layers pseudostratified= appears to have many layers
When trying to identify the shape of a cell you always refer to what part?
The apical or top row is used for determining shape
In multilayered epithelia which row is used to determine the shape name for epithelium?
The top row
Some layers of simple squamous epithelia have been given special names, but they are still just types of simple squamous epithelia, what are they?
Mesothelium
endothelium
endocardium
What is the mesothelium?
The simple squamous epithelia that forms the epithelial layer of serous membranes found in the ventral body cavities
What is some example of mesothelium?
The epithelial layer of the pleural membrane (lungs, of the pericardium (heart), and of the peritoneum (abdominal organs
What is he endothelium?
The simple squamous epithelium lining blood vessels
What does endothelium always line?
blood vessels
What is the endocardium?
The simple squamous epithelia lining the interior of the heart (facing blood in heart chambers)
What is pseudo-stratified columnar epithelia?
Epithelia that at first glance appear to have multiple layers, but really they do not
What is transitional stratified epithelia?
Several layers of epithelial cells that cant be classified by shape because they change shaped.
Why can’t transitional stratified epithelia be classified by shape?
Because they change shape
______ epithelia are found lining organs or structures that have to stretch, like the bladder, ureters, and urethra.
Transitional epithelia
What are the two categories glands can be?
endocrine glands and exocrine glands
What is a endocrine glad?
Specialised epithelial cells that release signal molecules (hormones) directly into the extracellular fluid and have no ducts for delivery of the secretion.
_____ gland is just a specialized epithelial cell that releases a secretion just by dumping it outside the cell, where it quickly crosses blood vessel walls and enters the blood.
Endocrine gland
What is a exocrine gland?
Specialised epithelial cells that release secretions onto non-specialized epithelial cells that form a duct, or passageway to the tissue surface.
Which gland can be further sub categorized by mode of secretion?
exocrine glands
What are the 3 other sub categories exocrine glands can be further categorized into?
- merocrine
- apocrine
- holocrine
What is merocrine secretion?
The secreted material is produced in the Golgi apparatus and then packaged into vesicles (membrane-bound delivery sacs).
The vesicles travel from the Golgi to the plasma membrane, where the vesicles fuse with the membrane and release the vesicle contents (secreted material
What is some examples of merocrine secretion?
salvitory glands and most sweat glands
_____ is membrane bound secretion?
merocrine
What is appocrine secretion?
The secreted material is produced in the Golgi apparatus and then packaged into vesicles (membrane-bound delivery sacs).
The vesicles travel from the Golgi to the plasma membrane, where the secreted material is released en masse with the surrounding cytoplasm by shedding an entire section of the cell, although remainder of cell remains intact.
What is some examples of appocrine secretion?
mammary glands and some sweat glands
_____ a part of the cell releases during secretion?
appocrine
What is holocrine secretion?
Secreted material is produced inside the cells.
Secreted material is released by cells bursting, killing the entire gland cells but also releasing all its contents, including the newly-synthesized material.
Gland cells are replaced by stem cells so gland is never depleted
What is some examples of holocrine secretion?
sebaceous glands in skin
_____ whole cell bursts during secretion and releases all contents?
holocrine
What is always under the basemment membrane to which epithelial tissue is attached?
Connective tissue
The epithelial cells that make up both exocrine and endocrine glands are surrounded by ______?
connective tissue
_____ tissue is the most diverse group of tissue?
Connective tissue
Connective tissue is defined by its _____?
characteristics
Connective tissue includes: (9)
- Coverings that do not have to be as tough as epithelial coverings
- cushioning
- supporting epithelial layers
- bones
- blood
- ligaments
- tendons
- fat
- cartilage
Connective tissues are subdivided into what three main categories?
Connective tissue proper
Fluid connective tissue
Supporting connective tissue
Connective tissue of all categories is characterized by at least two of the following three features?
- It is made up of more extracellular material than cells (except adipose, which has more cells than extracellular material
- Are disconnected and lack attachment to another (expect osteocyte cells in bone, which do contact one another with thin cellular extensions)
- Develop from mesenchymal stem cells (except blood cells, which develop from their own specialized stem cells called hematopoietic stem cells)
The specialized cells of connective tissue are specific to the type of _____?
connective tissue they are found in
What is extracellular matrix?
A better term for the material surrounding connective tissue cells than extracellular fluid because it is not fluid
The extreacellular matrix (ECM) of connective tissue consists of:
- extracellular protein fibers
2. ground substance
Which connective tissue are cells that are attached too each other?
bone cells or osteocytes
What are three kinds of extracellular protein fibers used in the extracellular matrices of connective tissues?
- collagen protein fibers
- reticular protein fibers
- Elastic protein fibers
_____ fibers is the most common fibers found in connective tissue?
collagen protein fibers
_____ are long, straight, and unbranched, they consist of many triply-coiled proteins attached in overlapping bundles to create a long straight fiber? also are strong and flexible?
collagen protein fibers
_____ fibers resist force when stretched in direction of fiber?
collagen protein fibers
Collagen fibers resist stretching in which directions?
stretching in the direction of the fiber
The extracellular matrix of tendons and ligaments is mostly _____?
collagen fibers
_____ is a network of interwoven branched fibers forming a mesh rather then bundles, also are strong and flexible?
Reticular protein fibers
_____ fibers resists force in many directions since interwoven?
Reticular protein fibers
_____ fibers stabilizes non-connective tissue cells and structures in mesh like organs?
reticular protein fibers
_____ fibers hold together the cells in lymph nodes, spleen, kidneys?
reticular protein fibers
_____ fibers are coiled and wavy fibers made up of many cross linked elastin proteins?
elastic protein fibers
_____ fibers can be stretched but then return to original length after stretching?
elastic protein fibers
_____ fibers only relist force once they are stretched to their maximum capacity?
Elastic protein fibers
_____ are much thinner than collagen or reticular fibers and are often branched?
Elastic protein fibers
_____ fibers are in the connective tissue that surrounds the innermost epithelial layer of blood vessels?
Elastic protein fibers
All the components of the extracellular matrix that aren’t fibrous proteins are collectively called the _____?
Ground substance
What do you call large carbohydrates with proteins attached?
Proteoglycans
The _____ of connective tissue is filled with both small, soluble components and non-fibrous but viscous molecules?
ground substance
The viscous molecules include:
- Glycoproteins (proteins with carbohydrate attached.)
- Proteoglycans (large carbohydrates with proteins attached.)
- Polysaccharides such as hyaluronan (long branched chains of sugars.)
But most often, the ground substance of connective tissues is _____ and _____, due to the glycoproteins, proteoglycans, and polysaccharides?
thick and viscous
What does viscous mean?
Thick
The ground substance in bone connective tissue is?
solid
The ground substance in blood connective tissue
very liquid
What is hyaluronan?
An extremely large polysaccharide molecule synthesised from the same two sugars linked together over and over in a long chain that twists and folds into a tangled (non-fibrous) tangle.
One of the main constituents of connective tissue ground substance that contributes to is thick & viscous nature is the polysaccharide _____?
Hyaluronan
The hyaluronan is one reason connective tissue ground substance tends to be very _____? And the more _____ present, the more viscous it is?
viscous
_____ and _____ are also present in connective tissue ground substance? They bind up water and thicken the ground substance like hyaluronan does.
Proteoglycans and glycoproteins
Once an animal is adult, most of the _____ cells are lost?
Mesenchymal stem cells
Where are mesenchymal stem cells found after embroyonic development is finished? (3)
fat, bone marrow, and dental pulp
Connective tissue proper is considered “proper” because it always (with one exception) has all the stereotypical characteristics of connective tissue: (4)
- Dispersed, non-connected cells
- More extracellular material than cells
- Gelatinous, semi-fluid ground substance
- Large protein fibers in the extracellular matrix
What is on exception to connective tissue proper that does not have all the stereotypical characteristic of connective tissue?
adipose tissue
Connective tissue proper is sub-categorized into _____ and _____?
dense connective tissue proper and loose connective tissue proper
What distinguishes dense and loose connective tissue proper apart ?
by the density of the extracellular protein fiber mesh
_____ has a dense matting of extracellular protein fibers?
dense connective tissue proper
What is an example of dense connective tissue?
tendons. they are are very tough and durable due to tight weaving of type 1 collagen fibers in the extracellular matrix
_____ (with the exception of adipose tissue) has a looser (less dense) matting of extracellular protein fibers?
Loose connective tissue proper
The main cells in connective tissue proper (except for adipose tissue) are called _____?
fibroblasts
What are fibroblasts?
generic-looking cells found interspersed (and unconnected to each other) throughout the extracellular protein fibers (usually type I collagen.)
_____ are the cells that synthesise and secrete the extracellular proteins and materials of the extracellular matrix of connective tissue proper – collagen proteins, proteoglycans, hyaluronan, and whatever other protein fibers or ground substance materials is in the extracellular matrix?
Fibroblasts
_____ also maintain and repair the molecular components of the extracellular matrix?
fibroblasts
How many different types of cells are found in connective tissue proper?
6
Most of the cells in connective tissue proper are _____ cells?
immune
_____ leave the blood and travel through the extensive extracellular space of connective tissue proper to survey the body for foreign invaders or cellular debris that needs removing?
immune cells in connective tissue proper
The _____ in connective tissue proper aren’t involved in whatever the overall function of the tissue is – wrapping, cushioning, etc?
immune cells
What are the 6 types of cells in connective tissue proper?
fibroblasts, mesenchymal cells, macrophages, neutrophils, mast cells, and lymphocytes
What is the most abundant cell type and is most responsible for the functioning of a particular layer of connective tissue proper?
fibroblasts
_____ synthesize and secrete the molecule components of connective tissue proper extracellular matrix in connective tissue proper?
fibroblasts
_____ are also responsible for maintaining and repairing the extracellular matrix that gives each type of connective tissue proper its specific properties?
fibroblasts
What are the connective tissue proper stem cells?
mesenchymal cells
When there is growth need in connective tissue proper what cell will divide?
mesenchymal cells
There are pools of _____ cells present in most layers of connective tissue proper?
mesenchymal cells
What cells in connective tissue proper receive signals if there is damage detected to divide?
mesenchymal cells
When _____ divide in connective tissue proper, they produce two daughter cells, one of which stays a stem cell, the other specializes into a fibroblast if the site of growth or damage is connective tissue proper?
mesenchymal cells
______ cells can also specialize into other connective tissue cell types if those cell types are needed?
mesenchymal cells
_____ are a type of immune cell in connective tissue proper hat starts out a white blood cell, but then moves out of blood and into connective tissue (and into other tissue types as well)?
macrophages
Some macrophags are called _____ and reside for long periods in the same location in connective tissue?
fixed macrophages
Other macrophages are called_____ and are mobile, so they move about the same location in connective tissue to different locations and to different tissues?
free macrophages
_____ cells in connective tissue proper engulf and digest pathogens and cell debris to remove them? The process of engulfing is called phagocytosis.
Macrophages
What is phagocytosis?
The process that brings materials into cells by invaginating the plasma membrane and engulfing the material.
Macrophages are not the only cells that can carry out _____?
phagocytosis
Macrophages specifically phagocytose (engulf) what in the body?
foreign invaders and cells debris
_____ cells are another immune cell in connective tissue proper that is a type of white blood cell also found in blood, but that can squeeze out of blood vessels and travel to connective tissue during infections? they also travel to other tissue types if there is an infection there? they also are mobile and can move to an infection anywhere in connective tissue?
neutrophils
_____ will engulf and digest foreign material or debris by phagocytosis, similar to macrophages, but they respond faster to infections than macrophages and often get their first?
Neutrophils
What is the cell in connective tissue proper that responds fastest and will arrive to infections first to engulf and digest foreign material by phagocytosis?
neutrophils
_____ cells are another type of immune cell in connective tissue proper that starts out a white blood cell, but then moves out of blood and into connective tissue (and into other tissue types as well) they are also mobile and can constantly move around the connective tissues to new locations?
mast cells
When _____ cells in connective tissue encounter an injury or infection or allergen, they release the molecule histamine, which causes inflammation (swelling, heat, pain.)
mast cells
_____ is another type of immune cells that is also found as white blood cell in blood vessels. Some are constantly squeezing out of blood vessels and traveling to connective tissue then returning to blood vessels later.
They are mobile, so they move around in connective tissue (and other tissues too) and then return to blood or lymph?
Lymphocytes
What is a plasmocyte?
A type of lymphocyte that is responsible for secreting antibodies in response to foreign materials
_____ connective tissue proper has less fibers (more ground substance) in its extracellular matrix than dense connective tissue proper?
loose
In ______ connective tissue the cells a loosely packed and tissue is soft?
loose
What is a example of loose connective tissue?
the upper portion of the dermis under the ski’s epidermis
What are three functions of loose connective tissue?
- fills space
- cushioning, stabilizing cells of other tissue layers
- supporting epithelial tissues
Loose connective tissue is generally used as _____ within the body?
packing material
What are the three main types of loose connective tissue?
- Areolar loose connective tissue
- Adipose loose connective tissue
- Reticular loose connective tissue
_____ loose connective tissue proper contains a type of connective tissue cell only found in adipose tissue, the adipocyte?
adipose loose connective tissue proper or adipose tissue
_____ are cells which mostly contain a droplet of fat, with everything else (nucleus, cytoplasm, organelles) crammed into the outer edges of the cell?
adipocytes
In adipocytes, all the lipid molecules in the fat droplet are _____, so no hydrophilic cytoplasm can intermingle with the fat?
hydrophobic
What is unique about adipose as a connective tissue?
It has more cells than extraceullar matrix.
Adipose loose connective tissue proper is mostly _____, plus a few fibroblasts to synthesise the extracellular matrix, plus a few mesenchymal stem cells, macrophages, etc?
adipocytes
_____ cells are more crowded than most other connective tissue cells & their crowdedness leaves less room for extracellular matrix protein fibers?
adipocytes
_____ is the one connective tissue with more cells than extracellular matrix?
adipocytes
_____ connective tissue proper has the protein fibers of its extracellular matrix (mostly collagen) more tightly (densely) packed than loose connective tissue proper?
dense
What are the three types of dense connective tissue?
- Regular dense connective tissue proper
- Irregular dense connective tissue proper
- Elastic dense connective tissue proper
_____ dense connective tissue proper has mainly collagen protein fibers in its extracellular matrix, and its collagen fibers run in parallel?
regular
_____ dense connective tissue proper is mainly used to attach different tissues?
regular
Regular dense connective tissue proper makes up tissue connectors like:
Ligaments, tendons, aponeuroses
What shape is an aponeurosis?
A broad sheet
_____ connect bone to bone & hold organs in place?
ligaments
_____ connect muscles to bones?
Tendons
_____ are sheets of dense connective tissue that connect broad, flat muscles to other muscles or to bones (e.g., skull, lower back, abdomen muscles)?
Aponeuroses
What are some functions of dense regular connective tissue proper? (4)
- provides firm attachment
- conducts pull of muscles
- reduces friction between muscles
- stabilizes relative positions of bones
_____ dense connective tissue proper has a dense mesh of mainly collagen protein fibers in its extracellular matrix, but they are not arranged in parallel?
irregular
_____ dense connective tissue proper is mainly used to give strength and support to tissues subject to twisting and bending?
irregular
_____ dense connective tissue proper is found in lower layers of skin and gives skin its strength?
irregular
_____ dense connective tissue proper is found as coverings on bones, muscles, nerves, and cartilages?
irregular
What are some functions of irregular dense connective tissue proper? (2)
- provides strength to resist forces applied from many directions
- helps prevent over expansion of organs such as the urinary bladder
_____ dense connective tissue proper has a dense mesh of all elastic protein fibers (not collagen protein fibers) in its extracellular matrix, arranged in parallel?
elastic
_____ dense connective tissue proper makes up elastic ligaments, holding up vertebrae in spine, in blood vessel walls, in other places?
elastic
What are some functions of elastic dense connective tissue proper? (3)
- stabilize positions of vertebrae and penis
- cushions shocks
- permits expansion and contraction of organs
What are the two groups of fluid connective tissue proper?
Blood and lymph
Blood and lymph have a ______ extracellular matrix of water and dissolved materials?
all fluid
_____ fluid connective tissue proper consists of cells and plasma?
blood
_____ is what remains after all the cells are removed (liquid + dissolved molecules)?
plasm
Blood fluid connective tissue is grouped into what 3 main categories?
Erythrocytes, leukocytes, and thrombocytes
What is a typical life span of a red blood cell (erythrocytes)?
100 days
What type of blood cells pick up oxygen and from the lungs and deliver oxygen to tissues?
red blood cells or erythrocytes
Which blood cell type does not have nuclei?
red blood cells (erythrocytes)
How many red bloods cells do at one time?
26 million
What percent of all cells in the blood are red blood cells?
95%
_____ blood cells do not leave blood vessels unless there is damage or inflammation?
red
_____ blood cells are components of the immune system, fighting pathogens?
white blood cells or leukocytes
_____ blood cells have nuclei ?
white blood cells or leukocytes
Most _____ blood cells can squeeze out of blood vessels and travel through tissues like different types of connective tissue proper, and then return to blood?
white blood cells or leukocytes
_____ are not full cells, but rather membrane-enclosed packets of cytoplasm?
Platelets or thrombocytes
_____ form from the breakdown of larger precursor cells?
Thrombocytes or platelets
_____ like leukocytes, do not have a nuclei?
thrombocytes or platelets
_____ are involved in forming blood clots (thrombi) when damage occurs to endothelium of blood vessels?
thrombocytes or platelets
How long to thrombocytes/platelets last on average?
7 days
What is lymph?
The interstitial fluid and white blood cells that have been collected into lymph vessels for transport back to the blood.
Lymph contains both cells and extracellular material, but it is more _____ than _____?
Extracellular material / cells
_____ does contain cells because many white blood cells (immune cells) enter and circulate in the lymph?
lymph
The extracellular matrix of lymph is mostly _____?
lymph fluid
Where do all lymphatic vessels drain?
Into blood veins near the heart
What are lymph’s two main functions?
- Return fluid that leaks out of blood vessels back to the blood circulatory system (via lymph vessels that collect interstitial fluid and drain it into the heart)
- Bring interstitial fluid to lymph nodes so it can be surveyed for foreign material.
What are the two types of supporting connective tissue proper?
cartilage and bone
_____ is a very tough and strong tissue. It can serve as a substitute for bone?
cartilage
_____ is also smooth, flexible, and can provide a low-friction surface for things to rub against. So it can also serve as a surface when parts articulate
cartilage
_____ evolved before bones, and initially animals with internal skeletons had cartilage skeletons?
cartilage
What type of cartilaginous fish still have cartilage skeletons and not bone?
sharks
In cartilage what is the only cell present?
Chondrocytes
Cartilage’s ground substance is extra rich in viscous _____?
proteogylcans
What do chondrocytes do in cartilage:(2)
- secrete the cartilage extracellular matrix
- within the cartilage the chondrocytes sit in empty spaces/chambers called lacunae
The _____ in the collagen extracellular matrix contribute the most to collagen’s strength and hardness.
protein fibers
About 2/3’s of the mass of cartilage is its ____?
protein fibers
Most of the cartilage in the body uses only _____ protein fibers?
collagen
_____ protein fibers are densely and tightly meshed to provide the durability and toughness that characterizes cartilage?
collagen
In _____ cartilage, elastic fibers are used instead of collagen fibers in the extracellular matrix and make it more bendable and flexible. Ex. the outer ear and epiglottis of the throat
elastic cartilage
How vascular is cartilage?
Not at all. there are no blood vessels that travel into cartilage
All nutrient and wastes for cartilage must diffuse into, through, and out of the extracellular matrix to _____ outside cartilage?
blood vessels
As a result of the lack of blood vessels in cartilage itself, _____ deep in cartilage are slow in getting materials to and from blood?
chondrocytes
_____ in cartilage are unconnected to each other and are in chambers/lacunae surrounded by a very dense extracellular matrix?
chondrocytes
Because all three types of cartilage do not have blood vessels going through it, damaged cartilage is?
hard to repair
_____ is among the slowest of tissues to heal after injury and in some cases wont ever heal if damaged?
cartilage
_____ in cartilage can not migrate to site of damage to secrete new fibers
chondrocytes
Cartilage in the body is always covered by a layer of connective tissue called the _____?
Perichondrium
What is the perichondrium?
A layer of irregular dense connective tissue proper
_____ is not different from any other irregular dense connective tissue proper. It is given a separate name because of its location on top of cartilage?
Perichondrium
So, the supporting connective tissue cartilage is always associated with what 2nd type of connective tissue?
Irregular dense connective tissue proper
The _____ will have blood vessels traveling through it to deliver nutrients and pick up wastes?
perichondrium
What are the three different types of cartilage?
- Hyaline cartilage
- Elastic cartilage
- Fibrous cartilage
____ cartilage is stiff and flexible and is used to reduce friction between bony surfaces and is found in nose and trachea?
Hyaline cartilage
_____ cartilage is very flexible and is used in the ear?
Elastic cartilage
_____ cartilage resists compression and is used in knee (inter-vertebral disc)
Elastic
_____ is also known as osseous tissue.
Bone
In bone there is more _____ than _____, just like most other connective tissues?
Extracellular matrix than cells
What are the 4 types of cells in bone?
- osteocytes
- osteoblasts
- osteoclasts
- osteoprogenitoe cells (osteogenic cells)
_____ are the main cells of bone tissue?
osteocytes
_____ are found in empty
spaces/chamber called lacunae (same term as used for spaces holding chondrocytes in cartilage) that prevent the solid extracellular matrix from crushing them.
_____ have many long thin extensions outward and are surrounded by tiny channels out of the lacunae space to allow osteocyte extensions to project – these channels are called canaliculi?
osteocytes
_____ are connected to one another via their projections, which form gap junctions, joining them and connecting their cytoplasm?
osteocytes
Unlike other types of connective tissue cells, _____ are connected to each other through these extensions?
osteocytes
_____ bone cells form new bone and convert to osteocytes?
osteoblast
_____ bone cells dissolve existing bone to allow repair, remodeling?
osteoclast
_____ bone cells are the adult stem cells that can form new osteoblasts and osteocytes, but not new osteoclasts?
osteoprogenitor
_____ bone cells are involved in the maintenance of the cell?
osteocyte
The bone extracellular matrix has very little fluid and consists of mainly :
solid Ca2+ mineral deposits and collagen protein fibers.
The _____ of bone is what gives bone its useful properties – flexible, but very strong and firm?
extracellular matrix
The _____ of bone consists of mineral calcium – mostly a form of calcium phosphate known as hydroxyapatite) but also calcium carbonate – which provides the strength?
extracellular matrix
In the _____ of bone, mineral surrounds collagen protein fibers – which provides the flexibility?
extracellular matrix
The calcium phosphate, ______, mineral of bone is very hard, but without the collagen fibers throughout it, it would be brittle?
hydroxyapatite
Just like the outside of cartilage is always covered by perichondrium connective tissue, the outside of bone is covered by a layer of irregular dense connective tissue proper called (in this location) the _____?
Periosteum
So the supporting connective tissue bone is always associated with what 2nd connective tissue?
Irregular dense connective tissue proper
Bone repair is a lot more efficient and speedy than cartilage repair for two main reasons:
- The osteocytes in bone are connected to each other in the canaliculi spaces. The chondrocytes in cartilage are isolated in their unconnected lacunae.
- Blood vessels travel throughout bone providing access to fresh materials via osteocyte projections which reach to and connect with the blood supply.Cartilage has no blood vessels and relies on slow diffusion of materials through the cartilage extracellular matrix to the chondrocytes.
_____ can share and transfer materials to speed repair, chondrocytes cannot?
osteocytes
_____ repair is a lot more efficient and speedy than cartilage repair?
Bone
