Tissues Flashcards
True or false: The process by which a less specialized cell ,a Rude’s into a more specialized cell is called maturation
False. This process is differentiation
What is a group of similar cells that work together to perform a specific function?
A tissue
Which of the following stem cells have the potential to differentiate into any type of human tissue, but cannot support the full development of an organism?
A) Pluripotent
B) Multipotent
C) Totipotent
D) Uniopotent
A) Pluripotent
Consider the levels of living things to complete the following: Tissues are made from ________ and tissues form ________.
A) organs; cells
B) cells; molecules
C) molecules; cells
D) organs; organ systems
E) cells; organs
E) cells; organs
Define histology
It is the microscopic study of tissue appearance, organization, and function.
Define epithelial tissue
Epithelial tissue, also referred to as epithelium, refers to the sheets of cells that cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands.
Define connective tissue
Connective tissue, as its name implies, binds the cells and organs of the body together and functions in the protection, support, and integration of all parts of the body.
Define muscle tissue
Muscle tissue is excitable, responding to stimulation and contracting to provide movement, and occurs as three major types: skeletal (voluntary) muscle, smooth muscle, and cardiac muscle in the heart.
Define nervous tissue
Nervous tissue is also excitable, allowing the propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body
Nervous tissue involves?
The brain, spinal cord, and nerves
Muscle tissue involves?
Cardiac, smooth, and skeletal muscles
Epithelial tissue involves?
Lining of GI tract organs and other hollow organs, and skin surface (epidermis)
Connective tissue involves?
Fat and other soft padding tissue, bone, and tendons
Define totipotent
totipotent, meaning each has the capacity to divide, differentiate, and develop into a new organism.
What does ectoderm mean?
The outer germ layer. Ecto means outer
What does mesoderm mean?
The middle germ layer. Meso means middle
What does endoderm mean?
The inner germ layer. Endo means inner
Epidermis, glands on the skin, some cranial bones, pituitary and adrenal medulla, the nervous system, the mouth between the cheek and gums, the anus
What does the mesoderm germ layer give rise to?
Connective tissues proper, bone, cartilage, blood, endothelium of blood vessels, muscle, synovial membranes, serous membranes lining body cavities, kidneys, lining of the gonads
What does the endoderm germ layer give rise to?
Lining of airways and digestive system except the mouth and distal part of the digestive system (rectum and anal canal), glands (digestive glands, endocrine glands, adrenal cortex)
Define tissue membrane
A tissue membrane is a thin layer or sheet of cells that covers the outside of the body (for example, skin), the organs (for example, pericardium), internal passageways that lead to the exterior of the body (for example, mucosa of stomach), and the lining of the moveable joint cavities.
What are the two basic types of tissue membranes?
Connective tissue and epithelial membranes
What do the mucous membranes line?
They line the digestive, respiratory, urinary, and reproductive tracts.
They are coated with the secretions of mucous glands
What do the serous membranes line?
The body cavities flossed to the exterior of the body: the peritoneal, pleural, and pericardial cavities
What does the cutaneous membrane do?
It covers the body surface. This is skin
What do the synovial membrane line?
Joint cavities and produce the fluid within the joint
Define connective tissue membrane
The connective tissue membrane is formed solely from connective tissue. These membranes encapsulate organs, such as the kidneys, and line our movable joints.
What is a synovial membrane?
A synovial membrane is a type of connective tissue membrane that lines the cavity of a freely movable joint. For
Define epithelial membrane
The epithelial membrane is composed of epithelium attached to a layer of connective tissue, for example, your skin.
Define mucous membrane
The mucous membrane is also a composite of connective and epithelial tissues.
What is the lamina propria?
The underlying connective tissue, called the lamina propria (literally “own layer”), help support the fragile epithelial layer.
Define serous membrane
A serous membrane is an epithelial membrane composed of mesodermally derived epithelium called the mesothelium that is supported by connective tissue.
Define merocrine secretion
Merocrine secretion is the most common type of exocrine secretion. The secretions are enclosed in vesicles that move to the apical surface of the cell where the contents are released by exocytosis
What are two uncommon epithelium that can be found in certain glands and ducts, but are uncommon throughout the body?
Stratified cuboidal epithelium and stratified columnar epithelium
What is the most common type of stratified epithelium in the body?
Stratified squamous epithelium
What is a goblet cell?
A goblet cell is a mucous-secreting unicellular “gland” interspersed between the columnar epithelial cells of mucous membranes
Define pseudostratified columnar epithelium
Pseudostratified columnar epithelium is a type of epithelium that appears to be stratified but instead consists of a single layer of irregularly shaped and differently sized columnar cells.
What is a tight junction?
The tight junction separates the cells into apical and basal compartments. When two adjacent epithelial cells form a tight junction, there is no extracellular space between them and the movement of substances through the extracellular space between the cells is blocked. This enables the epithelia to act as selective barriers.
What is atrophy?
It is when many tissues, including those in muscles, lose mass
Define cutaneous membrane
The skin is an epithelial membrane also called the cutaneous membrane. It is a stratified squamous epithelial membrane resting on top of connective tissue.
What is a primary union?
Aprimary uniondescribes the healing of a wound where the edges are close together. When there is a gaping wound, it takes longer to refill the area with cells and collagen.
What is a secondary union?
The process calledsecondary unionoccurs as the edges of the wound are pulled together by what is calledwound contraction. When a wound is more than one quarter of an inch deep, sutures (stitches) are recommended to promote a primary union and avoid the formation of a disfiguring scar.
Define clotting
Clotting(coagulation) reduces blood loss from damaged blood vessels and forms a network of fibrin proteins that trap blood cells and bind the edges of the wound together.
Define necrosis
Necrosis, or accidental cell death, causes inflammation.
Define inflammation
Inflammationis the standard, initial response of the body to injury. Whether biological, chemical, physical, or radiation burns, all injuries lead to the same sequence of physiological events.
Define apoptosis
Apoptosisis programmed cell death, a normal step-by-step process that destroys cells no longer needed by the body. By mechanisms still under investigation, apoptosis does not initiate the inflammatory response.
What are the four cardinal signs of inflammation?
The four cardinal signs of inflammation are redness, swelling, pain, and local heat.
Define Vasodilation
Vasodilation is the widening of the blood vessels.
In response to injury, what is released?
In response to injury, mast cells present in tissue degranulate, releasing the potent vasodilatorhistamine
What do Schwann cells produce?
Schwann cellproduces myelin in the peripheral nervous system
What do Oligodendrocytecells produce?
Oligodendrocytecells produce myelin in the central nervous system (brain and spinal cord)
Define astrocyte
Astrocytecells, named for their distinctive star shape, are abundant in the central nervous system. The astrocytes have many functions, including regulation of ion concentration in the intercellular space, uptake and/or breakdown of some neurotransmitters, and formation of the blood-brain barrier, the membrane that separates the circulatory system from the brain.
Define myelin
A long “tail,” the axon, extends from the neuron body and can be wrapped in an insulating layer known asmyelin, which is formed by accessory cells.
What 2 main classes of cells make up nervous tissue?
Two main classes of cells make up nervous tissue: theneuronandneuroglia
What do neurons do?
Neurons propagate information via electrochemical impulses, called action potentials, which are biochemically linked to the release of chemical signals.
What do neuroglia do?
Neuroglia play an essential role in supporting neurons and modulating their information propagation.
What does cardiac muscle do?
Cardiac muscleforms the contractile walls of the heart. The cells of cardiac muscle, known as cardiomyocytes, also appear striated under the microscope.
What does smooth muscle do?
Smooth muscletissue contraction is responsible for involuntary movements in the internal organs. It forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and arteries.
When does striation happen?
Thestriationis due to the regular alternation of the contractile proteins actin and myosin, along with the structural proteins that couple the contractile proteins to connective tissues.
Define myocyte
The muscle cell, ormyocyte, develops from myoblasts derived from the mesoderm. Myocytes and their numbers remain relatively constant throughout life.
Define fibrocartilage
Fibrocartilage is tough because it has thick bundles of collagen fibers dispersed through its matrix. Menisci in the knee joint and the intervertebral discs are examples of fibrocartilage
Define hyaline cartilage
Hyaline cartilage, the most common type of cartilage in the body, consists of short and dispersed collagen fibers and contains large amounts of proteoglycans. Under the microscope, tissue samples appear clear. The surface of hyaline cartilage is smooth. Both strong and flexible, it is found in the rib cage and nose and covers bones where they meet to form moveable joints. It makes up a template of the embryonic skeleton before bone formation.
Define elastic cartilage
Elastic cartilage contains elastic fibers as well as collagen and proteoglycans. This tissue gives rigid support as well as elasticity. Tug gently at your ear lobes, and notice that the lobes return to their initial shape. The external ear contains elastic cartilage.
Define skeletal muscle
Skeletal muscleis attached to bones and its contraction makes possible locomotion, facial expressions, posture, and other voluntary movements of the body. Forty percent of your body mass is made up of skeletal muscle.
What is embedded within the cartilage matrix?
Embedded within the cartilage matrix are chondrocytes, or cartilage cells, and the space they occupy are called lacunae (singular = lacuna).
Define adipose tissue
Adipose tissue consists mostly of fat storage cells, with little extracellular matrix
What is elastic fiber?
Elastic fiber contains the protein elastin along with lesser amounts of other proteins and glycoproteins. The main property of elastin is that after being stretched or compressed, it will return to its original shape. Elastic fibers are prominent in elastic tissues found in skin and the elastic ligaments of the vertebral column.
What is collagen fiber?
Collagen fiber is made from fibrous protein subunits linked together to form a long and straight fiber. Collagen fibers, while flexible, have great tensile strength, resist stretching, and give ligaments and tendons their characteristic resilience and strength. These fibers hold connective tissues together, even during the movement of the body
What is the mesenchymal cell?
The mesenchymal cell is a multipotent adult stem cell. These cells can differentiate into any type of connective tissue cells needed for repair and healing of damaged tissue.
Define adipocytes
Adipocytes are cells that store lipids as droplets that fill most of the cytoplasm.
Define fibrocyte
A fibrocyte, a less active form of fibroblast, is the second most common cell type in connective tissue proper.
What are the three main types of fibers that are secreted by fibroblasts?
Three main types of fibers are secreted by fibroblasts: collagen fibers, elastic fibers, and reticular fibers.
What is the most abundant cell in connective tissue proper?
The most abundant cell in connective tissue proper is the fibroblast.
What does supportive connective tissue do?
Supportive connective tissue—bone and cartilage—provide structure and strength to the body and protect soft tissues.
What is fluid connective tissue?
In fluid connective tissue, in other words, lymph and blood, various specialized cells circulate in a watery fluid containing salts, nutrients, and dissolved proteins.
What does embryonic connective tissue do?
A second type of embryonic connective tissue forms in the umbilical cord, called mucous connective tissue or Wharton’s jelly.
What is a cell junction?
Adjoining cells form a specialized intercellular connection between their cell membranes called a cell junction
Define basal lamina
The basal lamina, a mixture of glycoproteins and collagen, provides an attachment site for the epithelium, separating it from underlying connective tissue.
Define anchoring junction
An anchoring junction includes several types of cell junctions that help stabilize epithelial tissues. Anchoring junctions are common on the lateral and basal surfaces of cells where they provide strong and flexible connections.
What does a gap junction do?
A gap junction forms an intercellular passageway between the membranes of adjacent cells to facilitate the movement of small molecules and ions between the cytoplasm of adjacent cells.
What do the cells in simple squamous epithelium do?
The cells in simple squamous epithelium have the appearance of thin scales. Squamous cell nuclei tend to be flat, horizontal, and elliptical, mirroring the form of the cell.
Define endothelium
The endothelium is the epithelial tissue that lines vessels of the lymphatic and cardiovascular system, and it is made up of a single layer of squamous cells.
Define mesothelium
The mesothelium is a simple squamous epithelium that forms the surface layer of the serous membrane that lines body cavities and internal organs.
What is simple cuboidal epithelium?
In simple cuboidal epithelium, the nucleus of the box-like cells appears round and is generally located near the center of the cell.
What is simple columnar epithelium?
In simple columnar epithelium, the nucleus of the tall column-like cells tends to be elongated and located in the basal end of the cells.
Define transitional epithelium
Another kind of stratified epithelium is transitional epithelium, so-called because of the gradual changes in the shapes of the apical cells as the bladder fills with urine. It is found only in the urinary system, specifically the ureters and urinary bladder.
What is an endocrine gland?
An endocrine gland, a ductless gland that releases secretions directly into surrounding tissues and fluids (endo- = “inside”)
What is an exocrine gland?
Exocrine gland whose secretions leave through a duct that opens directly, or indirectly, to the external environment (exo- = “outside”).
What is an apocrine secretion?
Apocrine secretion accumulates near the apical portion of the cell. That portion of the cell and its secretory contents pinch off from the cell and are released.
What is the process of holocrine secretion?
The process of holocrine secretion involves the rupture and destruction of the entire gland cell. The cell accumulates its secretory products and releases them only when it bursts.
What does the serous gland do?
The serous gland produces watery, blood-plasma-like secretions rich in enzymes such as alpha amylase
What does the mucous gland do?
The mucous gland releases watery to viscous products rich in the glycoprotein mucin.
Define matrix
The matrix usually includes a large amount of extracellular material produced by the connective tissue cells that are embedded within it. The matrix plays a major role in the functioning of this tissue.
What is the mesenchyme?
The first connective tissue to develop in the embryo is mesenchyme, the stem cell line from which all connective tissues are later derived.
Connective tissue proper includes what?
Connective tissue proper includes loose connective tissue and dense connective tissue
Both tissues have a variety of cell types and protein fibers suspended in a viscous ground substance. Dense connective tissue is reinforced by bundles of fibers that provide tensile strength, elasticity, and protection. In loose connective tissue, the fibers are loosely organized, leaving large spaces in between.
What is Reticular fiber?
Reticular fiber is also formed from the same protein subunits as collagen fibers; however, these fibers remain narrow and are arrayed in a branching network. They are found throughout the body, but are most abundant in the reticular tissue of soft organs, such as liver and spleen, where they anchor and provide structural support to the parenchyma (the functional cells, blood vessels, and nerves of the organ).
What is Areolar tissue?
Areolar tissue shows little specialization. It contains all the cell types and fibers previously described and is distributed in a random, web-like fashion. It fills the spaces between muscle fibers, surrounds blood and lymph vessels, and supports organs in the abdominal cavity. Areolar tissue underlies most epithelia and represents the connective tissue component of epithelial membranes, which are described further in a later section.
What is reticular tissue?
Reticular tissue is a mesh-like, supportive framework for soft organs such as lymphatic tissue, the spleen, and the liver (Figure 4.14). Reticular cells produce the reticular fibers that form the network onto which other cells attach. It derives its name from the Latin reticulus, which means “little net.”
True or false: The epithelial cells exhibit polarity with differences in structure and function between the exposed or apical facing surface of the cell and the basal surface close to the underlying body structures.
True
True or false: The basal lamina attaches to a basement membrane, which is secreted by the underlying connective tissue, forming a reticular lamina that helps hold it all together.
False. The basal lamina attaches to a reticular lamina, which is secreted by the underlying connective tissue, forming a basement membrane that helps hold it all together.
What is not one of the four major types of tissue found in the human body?
A) Contractile tissue
B) Connective tissue
C) Nervous tissue
D) Epithelial tissue
A) Contractile tissue
This is not a real tissue type
Sheets of cells lining the organs of the GI track from what tissue?
Epithelial tissue covers external surfaces of the body and lines internal organs
Which of the following connective tissues normally lacks extracellular fibers?
A) Hyaline cartilage
B) Adipose CT
C) Blood
D) Areolar CT
C) Blood
As long as blood is circulating normally, it has no fibers. Blood has a protein in its ground substance that can become fibrous, it only does that after an injury. When blood breaks out of its vessel, like when we are cut, this protein assembles into fibers that help with clotting
Hyaline cartilage fits into what category of connective tissue?
Supportive connective tissue
In adults, new connective tissue cells originate from what?
The mesenchyme
Which of these is not one of the many functions of connective tissue?
A) Defense against microorganisms
B) Protection of other tissues and organs
C) Contracting to enable movement of organs or bones
D) Attachment of muscle to bone
C) Contracting to enable movement of organs or bones
This is the role of muscular tissue
What forms of connective tissue contain mostly fibroblasts and fibrocytes along with the protein fibers they produce?
Connective tissue proper
Examples would be regular and elastic and loose areolar tissue
The basement membrane is what?
What sticks epithelial tissue to connective tissue
All epithelial tissue sits on a basement membrane, but only some epithelium originates from the ectoderm
What tissue membrane is made up entirely of connective tissue?
Synovial
What junction makes a seal between two cells so that nothing can slip through from the lumen to the basal edge between the cells?
The tight junction
True or false: Mineral storage is a function of epithelial tissue
False. Mineral storage is NOT a function of epithelial tissue
What gland stores its secretion until the glandular cell ruptures?
The holocrine
What gland releases its apical region and reforms?
Apocrine
What epithelial tissue lines the interior of blood vessels?
Simple squamous
True or false: Epithelial tissue has a large amount of extracellular material between cells
False. Epithelial tissue has very little extracellular matrix
What is a function of epithelial tissue?
A) To contract and provide movement
B) To cover external surfaces of the body
C) To protect, support, and bind other tissues and organs together
D) To allow communication in the form of electrochemical impulses
B) To cover external surfaces of the body
The skin and lining of the mouth are examples
When a colonoscopy is performed, the gastroenterologist views the lining of a patient’s colon. The tissue being viewed is what?
Epithelial tissue
What lines the body cavities exposed to the external environment?
Mucosa
Differentiated cells in a developing embryo derive from what?
Ectoderm, mesoderm, and endoderm
True or false: Embryonic tissue is a type of primary tissue
False
Where are serous membranes most likely to be found in the body?
They are found within the lining of body cavities closed to the external environment
Serous membranes line the coelomic cavities of the body, and cover the organs located within those cavities
Connective tissue proper involves what?
Loose connective tissue (Areolar, adipose, and reticular) and dense connective tissue (dense regular, elastic, dense irregular)
Supportive connective tissue involves what?
Cartilage (Hyaline, fibrocartilage, elastic) and bone
Fluid connective tissue involves what?
Blood and lymph
True or false: The mesoderm gives rise to bone, cartilage, blood, blood vessels, and muscle
True, each of these tissues arise from the mesoderm
What cell type is likely to contain the most mitochondria?
Muscle cell
Most cells within the body only contain one nucleus. Some exceptions to this rule are ______ cells which are multinucleate, and _______ cells which are anucleate
A) Liver, white blood
B) Bone, sperm
C) Muscle, red blood
D) Nerve, skin
C) Muscle, red blood
Some electrically-active cells, like smooth and cardiac muscle cells, are able to spread their electrical activity to cell-to-cell through what junctions?
Gap junctions
What best describes the histology of skeletal msucle?
Long fibers, striated, and multinucleated
How does skeletal muscle enable motion?
Contracting and pulling attached bones closer together
Skeletal muscle is directly attached to the skeleton and manipulates it through contractions
What muscle type is striated and involuntary?
Cardiac muscle
The striations visible in muscle tissues reflect what?
A very ordered cytoskeleton that enables movement
Which muscle tissue type is electrically excitable?
A) Skeletal muscle
B) Cardiac muscle
C) Smooth muscle
D) All of the above
D) All of the above
The spinal cord is an organ of which system?
The nervous system
Reflexes that maintain homeostasis in the body respond to what?
Stimuli. Stimuli will be sensed up and responded to in order to maintain homeostasis
After you eat lunch, nerve cells in your stomach respond to the distension (the stimulus) resulting from the food. They relay this information to ______
A control center
When an atom donates an electron to another atom, it becomes what?
An ion
Which of these best describes how a neuron generates a response in the body?
A) An action potential is generated, which travels down the axon towards the synapse, releasing a neurotransmitter
B) A neurotransmitter is generated within the neuron, which is then released by the dendrite
C) An action potential is generated, which travels down the dendrite
D) A neurotransmitter is released and generates an action potential
A) An action potential is generated, which travels down the axon towards the synapse, releasing a neurotransmitter
This is the sequence followed during all nerve signals
The cells responsible for the transmission of the nerve impulse are what?
Neurons
Which of the following central nervous system cells regulate ions, regulate the uptake and/or breakdown of some neurotransmitters, and contribute to the formation of the blood-brain barrier?
A) Microglia
B) Neuroglia
C) Oligodendrocytes
D) Astrocytes
D) Astrocytes
Which part of the neuron is an informational input region and can be present in high numbers in one neuron?
Dendrite
An action potential is what?
An electrical impulse
Why are epithelial cells polarized?
They have an apical and a basal edge
Which cell type is responsible for making collagen fibers?
Fibroblasts
These fiber makers make all the different CT fibers
Someone who develops tendinitis has inflammation of what type of connective tissue?
Dense regular connective tissue
Which of these is true regarding the primary union versus secondary union healing processes?
A) Primary unions occur in large, gaping wounds
B) Primary unions require stitches to minimize scarring
C) Primary unions are pulled together by the tissue that fills in the wound
D) Primary unions are much less likely to produce scar tissue
D) Primary unions are much less likely to produce scar tissue
Primary unions occur when the edges of the wound are close together
What is responsible for the appearance of wrinkles?
Reduced elasticity caused by the thinning and drying of tissue
These effects are specifically due to changes on skin and blood vessels due to aging
What is degranulation of mast cells?
It is the exocytosis (secretion) of their previously synthesized chemicals like histamine
What is the histology of skeletal tissue?
Long cylindrical fibers, striated, many peripherally located nuclei
What is the function of skeletal tissue?
Voluntary movement, produces heat, protects organs
What is the location of skeletal tissue?
Attached to bones and around entrance points to the body (examples are the mouth and anus)
What is the histology of cardiac tissue?
Short, branched, striated, single central nucleus
What is the function of cardiac tissue?
Contracts to pump blood
What is the location of cardiac tissue?
The heart
What is the histology of smooth tissue?
Short, spindle-shaped, no evident striation, single nucleus in each fiber
What is the function of smooth tissue?
Involuntary movement, moves, food, involuntary control of respiration, moves secretions, regulates flow of blood in arteries by contraction
What is the location of smooth tissue?
Walls of major organs and passageways
