Tissues Flashcards
1
Q
Define the term tissue.
A
A tissue is a group of similar cells that usually have a similar embryological origin and are specialized for a particular function.
2
Q
Name the four primary adult tissue types, and give a brief description of each.
A
Depending on their function and structure, the various tissues of the body are classified as the following four principal types:
- Epithelial tissue covers body surfaces; lines hollow organs, body cavities, and ducts; and forms glands. Epithelial tissue provides external protection for underlying tissue.
- Connective tissue protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity.
- Muscle tissue is responsible for movement and generation of force.
- Nervous tissue initiates and transmits action potentials (nerve impulses) that help coordinate body activities, monitors the external environment, and contribute to homeostasis.
3
Q
What is the function of Epithelial Tissue?
A
- Epithelial tissue covers body surfaces;
- lines hollow organs, body cavities, and ducts
- forms glands.
- Epithelial tissue provides external protection for underlying tissue.
4
Q
What is the function of Connective Tissue?
A
Connective tissue protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity.
5
Q
What is the function of Nervous tissue?
A
Nervous tissue initiates and transmits action potentials (nerve impulses) that help coordinate body activities, monitors the external environment, and contribute to homeostasis.
6
Q
Describe the features of epithelial tissue.
A
- arranged in sheets, in either single or multiple layers.
- consists mostly of packed cells with little extracellular material. In epithelial tissues, many cell junctions are present, providing secure attachments among cells.
- has an apical surface and a basal surface attached to a base membrane.
- Epithelia adhere firmly to nearby connective tissue through a thin extracellular layer called the basement membrane. Epithelia have a nerve supply and a high capacity for renewal (a high mitotic rate).
- The basement membrane is made up of a cellular layer of collagen and glycoproteins called the basal lamina; often, it is underlain with a layer of reticular fibres and glycoproteins called the reticular lamina.
- Epithelial tissue is avascular; the exchange of materials between epithelium and adjacent connective tissue is by diffusion.
- Functions of epithelia include protection, filtration, lubrication, secretion, digestion, absorption, transportation, excretion, sensory reception, and reproduction.
7
Q
What are the different types of simple epithelial tissues?
A
Simple Squamous Epithelium Simple Cuboidal Epithelium Simple Columnar Epithelium (non-ciliated and ciliated) Pseudostratified columnar Epithelium (non-ciliated and ciliated)
8
Q
What are the different types of stratified epithelium?
A
Stratified squamous Epithelium Stratified cuboidal Epithelium Stratified columnar Epithelium Transitional Epithelium
9
Q
Discuss the classification scheme for epithelia.
A
The covering and lining of the epithelia can be classified as a combination of layers and shapes of cells. The name of the specific type of stratified epithelium depends on the shape of the surface cells.
Layers are arranged as simple (one layer), stratified (several layers), or pseudostratified (one layer that appears as several).
Cell shapes include squamous (flat), cuboidal (cube-like), columnar (rectangular), and transitional (variable).
10
Q
Provide a structural description of simple squamous epithelium
A
The simple squamous epithelium consists of a single layer of flat, scale-like cells.
11
Q
Provide a structural description of the Simple Cuboidal Epithelium.
A
- consists of a single layer of cube-shaped cells,
- round
- centrally located nucleus.
12
Q
Provide the structural description of Nonciliated simple columnar epithelium.
A
- single layer of non-ciliated column-shaped cells
- nuclei near the base of the cell
- contains cells with microvilli
- Contains goblet cells..
13
Q
Provide a structural description of Ciliated Simple Columnar Epithelium.
A
- single layer of ciliated column-like cells with nuclei near bases
- contains cilia
- contains goblet cells in some locations.
14
Q
what are microvilli?
A
microscopic finger-like projections, which increase the surface area of the plasma membrane increasing the absorption rate.
15
Q
What are goblet cells?
A
modified columnar cells that secrete mucus at their apical surface.
16
Q
Provide a structural description of Nonciliated Pseudostratified Columnar Epithelium.
A
- Appear to have several layers due to the nuclei being at different levels
- All cells attach to the basement cell
- not all cells extend to the apical level of the cell.
- It does not have goblet cells
- does not have cilia or mircovilli.
17
Q
Provide a structural description of Ciliated Pseudostratified columnar epithelium.
A
- Appear to have several layers because the nuclei are at different levels.
- All cells attach to the basement cell
- not all cells extend to the apical level of the cell.
- It contains cells that extend to the surface and either contain cilia or secrete mucus (goblet cells)
18
Q
Provide a structural description of stratified squamous epithelium
A
- Consists of several layers.
- The apical and several deeper layers are squamous.
- The deeper layers beyond that vary from cuboidal or columnar.
- Basal (deepest) cells continually undergo cell division.
- New cells push the old cells closer to the top.
- Skin closer to the top keratinizes
19
Q
what is keratinization of the cell?
A
when a tough layer of skin develops in the apical layer of skin. Helps protect skin and underlying tissues from microbes, heat and chemicals.
20
Q
Provide a structural description of Stratified cuboidal epithelium
A
- 2 or more layers of cells
- the apical layer are cube-shaped
- fairly rare type.
21
Q
Provide a structural description of stratified columnar epithelium
A
- basal layer consists of shortened
- irregularly shaped cells
- the apical layer has columnar cells.
22
Q
Provide a structural description of Transitional Epithelium.
A
- Appearance is variable.
- An unstretched or relaxed state looks like a stratified cuboidal epithelium.
- The apical layer tend to be large and rounded.
- A stretched state the cells become flatter, look like stratified squamous epithelium.
23
Q
Define gland, and differentiate between exocrine and endocrine.
A
Is a single cell or a group of epithelial cells adapted for secretion.
Endocrine glands secrete hormones into interstitial fluid then the blood
Exocrine glands (mucous, sweat, oil, and digestive glands), secrete into ducts or directly onto a free surface.
24
Q
Describe the general characteristics of connective tissues (CTs), and discuss their major structural differences from epithelial tissue.
A
- consists of 2 basic elements: cells and extracellular matrix. (material between widely spaced cells)
- extracellular matrix consists of protein fibres and ground substance (material between cells and fibres)
- The extracellular matrix is secreted by the cells of the connective tissue and determines the tissue’s qualities.
- for example, in bone, the extracellular matrix is firm and not pliable, in cartilage, it’s firm but pliable.
- Unlike epithelial tissue, connective tissues do not occur on free surfaces.
- Unlike epithelium, connective tissue is highly vascular (except for cartilage and tendons).
- like epithelium, has a nerve supply (cartilage does not)
25
Describe matrix and ground substance; list the three CT fibre types, and name the types of cells of which CT can be composed
**Extracellular matrix**
* The properties of the connective tissue is based on the extracellular materials between the cells. This matrix consists of a fluid, gel, or solid ground substance + protein fibres.
* Ground substance can take the form many forms; fluid, semifluid, gelatinous, fibrous or calcified. This usually secreted by the connective tissue cells and adjacent cells. They determine the qualities of tissues.
* Cells found in connective tissue include;
* fibroblasts (which secrete fibres and matrix),
* macrophages (perform phagocytosis)
* plasma cells (secrete antibodies)
* mast cells (produce histamines)
* adipocytes or fat cells (which store energy in the form of fat).
* The three types of fibres embedded in the matrix between the cells of connective tissues are the following:
* **Collagen fibres**, composed of the protein collagen, are very tough and resistant to stretching, yet allow some flexibility in the tissue; they are found in bone, cartilage, tendons, and ligaments.
* **Elastic fibres**, composed of the protein elastin, fibrillin and other glycoproteins. Provide strength and stretching capacity and are found in the skin, blood vessels, and lungs.
* **Reticular fibres**, consisting of collagen and glycoprotein, provide support in the walls of the blood vessels and form a strong, supporting network around fat cells, nerve fibres, and skeletal and smooth muscle fibres.
26
What is the function of ground Substance?
* supports cells
* binds cells together
* provides a medium through which substances are exchanged between the blood and cells.
* Influences tissue development, migrate, proliferate, change shape, and perform metabolic function.
27
List the different classifications of connective tissue.
Five types of CT include:
* Loose connective tissues
* areolar
* adipose
* reticular
* Dense connective tissues
* dense regular
* dense irregular
* elastic
* Supporting Connective Tissues
* Cartilage
* Hyaline Cartilage
* Fibrocartilage
* Elastic Cartilage
* Bone
* Liquid
* blood
* lymph
28
Describe the structure of areolar Connective Tissue
* Consists of randomly arranged fibres (collagen, reticular, elastic)
* several kinds of cells, (fibroblasts, macrophages, plasma cells, adipocytes, mast cells)
* has a few white blood cells
* forms the subcutaneous layer of skin along with adipose tissue.
29
What are the subclassifications of loose connection tissue?
* Areolar Connective Tissue
* Adipose Connective Tissue
* Reticular Connective Tissue
30
What are the subclassifications of Dense Connective Tissue
* Dense Regular
* Dense Irregular
* Elastic
31
What are the subclassifications of Supporting Connective Tissue?
* Cartilage
* -hyaline -fibrocartilage -elastic
* Bone Tissue
* Liquid Connective Tissue
* -blood -lymph
32
Describe the structure of Adipose Tissue
Structure:
* It has cells called Adipocytes (specialized for fat storage)
* When the cell fills up with a single, large triglyceride droplet, the cytoplasm and nucleus are pushed to the periphery of the cell.
* The more adipose tissue a person has the more blood vesicles that form
33
Describe the structure of Reticular Connective Tissue.
Structure:
* fine interlacing network of reticular fibres (thin form of collagen fibre)
* reticular cells.
34
Describe the structure of Dense Regular Connective Tissue.
Structure:
* The extracellular matrix looks shiny white
* Composed of mainly collagen fibres regularly arranged in bundles
* fibroblasts present in rows btw the bundles.
35
Describe the structure Dense Irregular Connective Tissue
Structure:
* mostly collagen fibres randomly arranged
* have a few fibroblasts
36
Describe the structure of Elastic Connective Tissue.
Structure:
* Mostly elastic fibres
* fibroblasts presents in spaces btw fibres
* unstained tissue is yellowish
37
Describe the structure of Hyaline Cartilage
Structure:
* contains a resilient gel as ground substance which appears bluish-white.
* fine collagen fibres are not visible
* Chondrocytes are found in lacunae surrounded by perichondrium.
* most abundant cartilage in the body
38
Describe the structure of Fibrocartilage
* contains chondrocytes scattered among clearly visible thick bundles of collagen fibres within the extracellular matrix
* it lacks perichondrium.
39
Describe the structure of elastic cartilage
Structure:
* contains chondrocytes located in a threadlike network of elastic fibres within the extracellular matrix
* the perichondrium is present.
Locations:
* lid on top of larynx (epiglottis)
* part of external ear (auricle)
* auditory tubes
Function:
* provides strength and elasticity
* maintains the shape of certain structures
40
Describe its structure, name a key body location, and identify its function(s): Bone
* Composed of several different types of connective tissue
Function:
* supports soft tissue
* protect delicate structures
* works with skeletal muscles to produce movement
* stores calcium and phosphorous
* stores red bone marrow
* houses yellow bone marrow
41
Describe its structure, name a key body location, and identify its function(s): Blood Tissue
Structure:
* this is a liquified extracellular matrix called blood plasma.
* Has a pale yellow fluid that consists mostly of water with a wide variety of dissolved substances; nutrients, wastes, enzymes, hormones, respiratory gases, and ions.
* suspended in the plasma membrane are; red blood cells, white blood cells, and platelets.
Function:
* red blood cells transport oxygen to body cells and removes carbon dioxide from them
* white blood cells perform phagocytosis, immunity, and allergic reactions
* platelets participate in blood clotting
42
What is the epithelial membrane? What are the different types of membranes and what is their general function?
The epithelial Membrane is the combination of an epithelial layer and an underlying connective tissue layer.
* Mucous Membranes: line entire digestive tract, respiratory, the reproductive and urinary systems
* Serous Membrane (lines body cavities)
* cutaneous membrane (skin)
* Synovial membrane (lines joints)
43
Compare and contrast the three types of muscle tissue in terms of their structure, control, location in the human body, and function.
**Skeletal Muscle Tissue**
* attached to the bones of the skeleton
* voluntary contraction
**Cardiac Muscle Tissue**
* forms the bulk of the wall of the heart
* involuntary contractions.
**Smooth Muscle Tissue**
* located in the walls of hollow internal structures such as blood vessels, airways to the lungs, the stomach, intestines, gallbladder and urinary bladder.
* involuntary contractions.
44
Identify the major cell of nervous tissue; denote the location of nervous tissue in the body, and discuss its function.
consists of neurons and neuroglia
Neurons: sensitive to stimuli converting them into nerve impulses and conduct them to other neurons, muscle fibres, or to glands
Neuroglia: do not transmit nerve impulses they have other protective and supportive functions
45
Define the term mucous membrane, and discuss the structure, location, and function of mucous membrane
* Lines the body cavities that open to the outside of a cell. It secretes mucus from goblet cells
* found lining the digestive tract, respiratory, reproductive, and urinary systems.
* prevents cavities from drying out, traps particles in the respiratory tract, lubricates and absorbs food, secretes digestive enzymes.
46
Define the term serous membrane, and discuss the structure, location, and function of serous membrane
* lines body cavities that do not open directly to the exterior. covers organs that lie within the cavity.
* Composed of a visceral layer (attaches to organs inside the cavity) and Parietal layer (attached to the cavity wall)
* each layer consists of areolar connective tissue covered by mesothelium.
* the mesothelium secretes serous fluid which lubricates the organs to glide over one another or slide against the walls.
47
Define the term Synovial membranes, and discuss the structure, location, and function of Synovial membranes
line the cavities of some joints.
composed of a areolar connective tissue and adipose tissue with collagen fibres. they do not have an epithelial layer.
synoviocytes secrete synovial fluid
lubricates the ends of bones as they move at joints. nourishes cartilage covering the bones and removes microbes and debris from the joint cavity.
48
Describe the role of tissue repair in restoring homeostasis.
* This is the process that replaces worn-out, damaged, or dead cells. New cells originate by cell division from the stroma, supporting connective tissue, or from the parenchyma (cells the make up the functioning part of the tissue or cell)
* Each cell has a different rate for replenishing parenchyma cells lost by damage, disease, or other processes.
* Epithelial tissue and some connective tissue like bone have the highest renewal rate
* Muscle tissue has a poor renewal rate
* smooth muscle is better than cardiac or skeletal however it is still slower than connective or epithelial
* Nervous tissue has the poorest renewal capacity of all the tissues.
49
Define what an endocrine gland is and its function.
Endocrine glands enter the interstitial fluid and then diffuse into the bloodstream without flowing through a duct. (these secretions are called hormones.) Include the pituitary, thyroid, and adrenal.
50
Define what an exocrine gland is and what it does.
Exocrine Glands secrete their products into ducts that empty at surface epithelium such as the skin or the lumen of a hollow organ. include; mucus, perspiration, oil, earwax, milk, saliva, and digestive enzymes.
51
Name the key body locations of the Nonciliated Pseudostratified Columnar Epithelium.
* lines the epididymis
* larger ducts of many glands
* part of the male urethra.
52
What is the function of the of Non-ciliated Pseudostratified Columnar Epithelium.
* Secretion
* Absorbtion
53
Identify the function(s) of Ciliated Simple Columnar Epithelium.
* cilia move foreign particles trapped in muscous out of the respiratory tract
* moves oocytes through fillopian tubes
54
What are the body location of Ciliated Simple Columnar Epithelium.
* found in a few portions of the upper respiratory tract
* Uterine tubes.
55
What are the key body locations of the simple squamous epithelium.
* lines the heart
* blood vessels
* lymphatic vessels called endothelium
* mesothelium forms the serous membrane such as the peritoneum, pleura, or pericardium.
56
identify the function(s) of Simple Squamous Epithelium
* diffusion
* filtration
* osmosis
* secretion in serous membranes.
57
Whare are the key body location of the Simple Cuboidal Epithelium.
* covers the ovaries
* in the kidneys and eyes
* Lines some glandular ducts
58
What are the key body locations of Nonciliated simple columnar epithelium.
* lines most of the gastrointestinal tract
* ducts of many glands
* gallbladder.
59
Identify the function(s) of the Simple Cuboidal Epithelium.
* secretion
* absorption
60
Identify the function(s) of Nonciliated simple columnar epithelium.
* microvilli perform absorption
* goblet cells secrete mucus
61
What are the key body locations of Ciliated Pseudostratified columnar epithelium.
* lines the airways of most upper respiratory tract. (ex. Trachea)
62
Identify the function(s) of Ciliated Pseudostratified columnar epithelium.
* Secretes mucus that traps particles
* Cilia sweep away mucus for eventual elimination from the body
63
What are the key body locations of stratified squamous epithelium
* Keratinized variety forms a superficial layer of skin (epidermis)
* nonkeratinized variety line wet surfaces like the mouth
64
Identify the function(s) of stratified squamous epithelium
Protection, first line of defence against microbes.
65
What are the key body locations of Stratified cuboidal epithelium
* found in adult sweat glands
* esophageal glands
* part of male urethra.
66
Identify the function(s) of Stratified cuboidal epithelium
* protection
* limited secretion
* limited absorption
67
What are the key body locations of stratified columnar epithelium
* part of urethra
* large excretory ducts of some glands (esophageal glands)
68
Identify the function(s) of stratified columnar epithelium
* protection
* secretion.
69
What are the key body locations of Transitional Epithelium.
* Lines urinary bladder
* portions of the ureters
* portions of the urethra
70
Identify the functions of Transitional Epithelium.
* allows urinary organs to stretch and hold a variable amount of fluid without rupturing
* while still serving to protect the lining
71
Name the key body locations of areolar Connective Tissue
* Found in and around almost every body structure
* subcutaneous layers of deep skin
* around blood vessels, nerves, and body organ
72
Identify the function(s) of areolar Connective Tissue.
* Provides Strength
* Elasticity
* Support
73
Name the key body locations of Adipose Tissue
Key body Locations:
* wherever areolar connective tissue is located
* around heart and kidneys
* subcutaneous layer of deep skin
* yellow bone marrow
* behind eye
* around joints
74
Identify its function(s) of Adipose Tissue
Function:
* insulates
* serves as an energy reserve
* supports and protects organs.
75
Name the key body location of Reticular Connective Tissue.
Locations:
* Stroma (supporting framework) of
* liver
* spleen
* lymph nodes
* red bone marrow
* part of basement membrane
* around blood vessels and muscles.
76
Identify its function(s) of Reticular Connective Tissue.
Functions:
* forms stroma of organs
* binds smooth muscle tissue cells together
* removes worn-out blood cells in spleen
* removes microbes in lymph nodes
77
Name a key body location of Dense Regular Connective Tissue
Locations:
* Forms tendons (muscle to bone)
* most ligaments (bone to bone)
* aponeuroses (sheetlike tendons which attach muscle to muscle or muscle to bone)
78
Identify its function(s): Dense Regular Connective Tissue
Functions:
* provides strong attachment btw various structures
* resists pulling along long axis of fibres.
79
Name a key body location: Dense Irregular Connective Tissue
Locations:
* occur in sheets, such as fasciae (tissue beneath the skin and around muscle and other organs)
* deeper regions of dermis of skin
* periosteum of bone
* joint capsules
* membrane capsules around various organs (kidneys, liver, testes, lymph nodes
* heart valves
* pericardium of the heart
80
Identify its function(s): Dense Irregular Connective Tissue
* provides tensile strength in many directions.
81
Name the key body locations: Elastic Connective Tissue.
* Lunge tissue
* walls of elastic arteries
* trachea
* bronchial tubes
* true vocal cords
* suspensory ligaments of the penis
* some ligaments btw vertebrae.
82
Identify its function(s): Elastic Connective Tissue.
* Allows organs to stretch
* strong enough to recoil to original shape when stretched
* Important for heartbeat in vesicles and lunges when breathing.
83
Name a key body location of Hyaline Cartilage
Location:
* ends of long bones
* anterior ends of ribs
* nose
* part of larynx
* trachea
* bronchi
* bronchial tubes
* embryonic and fetal skeleton
84
Identify the function(s) of Hyaline Cartilage
* provide smooth surface for movement at joints
* provide flexibility
* provide support
* weakest type of cartilage.
85
Name the key body locations of Fibrocartilage
* pubic symphysis (where hip bone joins anteriorly)
* intervertebral discs
* menisci of knee.
* portions of tendons that insert into cartilage.
86
Identify its function(s): Fibrocartilage
* supports
* joins structures together
* strength and rigidity make this the strongest type of cartilage.
87
Name the key body location of elastic cartilage
* lid on top of larynx (epiglottis)
* part of external ear (auricle)
* auditory tubes (eustachian)
88
Identify its function(s) of elastic cartilage
* provides strength and elasticity
* maintains the shape of certain structures
