A group of cell joined together to carry out specialized activities
Name 4 main tissues
Define Epithelial tissues
Cells that are arranged in continuous sheets in either single or multiple layers and are held together by cell junctions and are avascular
Where are epithelial tissues found?
They are found on body surfaces, hollow organs, and body cavities
A physician who examines cells and tissues to help other physicians make accurate diagnoses in resulting changes in the tissues
What is a cell junction?
Filament microfibers that hold cells together to form tissues
What do epithelial cell cover?
They cover surfaces, line organs and body cavities or secrete substances.
Define basement membrane
A thin extracellular layer that attaches the epithelial tissue to the underlying connective tissues
Define a apical surface?
Superficial surface epithelial cells that faces a body cavity, lumen and may contain cilia or microvilli.
Define a basal surface?
A thin opposing the deep surface of the epithelial cells and adheres to an extracellular matrix.
If an epithelial cell is avascular, where does it get its nutrients and dispose of its waste?
They diffuse between epithelium and blood vessels of the underlying connective tissues.
What are two types of epithelial tissues?
Covering and lining epithelium and Glandular epithelium.
Summarize the different functions of an epithelial tissue.
Epithelial tissue is avascular and therefore relies on receiving nutrients and expelling waste from the underlying connective tissues and blood vessels. Other functions include; protection, filtration, absorption, and excretion
What are the two names of the arranging covering and lining epithelium?
the arrangements of cells in layers and cell shapes
What are the names of the arranging covering and lining epithelium?
- Simple--a single layer of cells
- Stratisfied---tow or more layers of cells arranged in a wave pattern.
- Pseudostratisfied--a single layer that appears to have multiple layers and an arrangement of wave patterns
What are the names of the covering and lining epithelial cell shapes?
- Squamous- flat cells with round or oval nuclei
- Cubodial- cells that look cubed
- Columnar- cells that appear to be set in columns
- transitional- cells that change shape from cubodial to flat squamous in response to pressure
Describe a simple squamous epithelium and its function
A single layer of flat cells with one nuclei that functions in the filtration and diffusion of substances.
* small intestines
Describe a simple cuboidal epithelium and its function
A single layer of cube-shaped cells that are round with a centrally located nuclei. Its function is secretion and absorption of substances
Describe a simple columnar epithelium and its function.
A single layer of tall, column shaped cells with oval nuclei at the base of the cells.
Serves in secretion of mucus by the goblet cells, microvilli increases surface area for absorption of substances.
* small intestines
Describe pseudostratified columnar epithelium and its function
composed of a single layer of cells that are attached to the basement membrane and appears to be stratified because of the nuclei are arranged at different depths.
Its functions is secretion of mucus by the goblet cells and the movement of mucus by the cilia on the columnar cells. It also can serve as protection.
Describe Stratified squamous epithelium and its functions.
Flat apical layer cells with more cuboidal basal cells that continually divide.
It functions as;
- protection against abrasion
- water loss
- ultraviolet rays
- foreign invaders
Describe Transitional epithelium and its functions.
Has a variable appearance to stratified cuboidal epithelium when in a relaxed state, except apical layer cells tend to be large and round.
Its function is; allows organ to stretch and hold large amounts of fluids without rupturing
What is the function of Glandular epithelium?
They are tissues that secrete substances into ducts, surfaces, and blood.
Endocrine and exocrine glands
Compare covering and lining epithelia with Glandular epithelia
Epithelial tissues have many cells that are tightly packaged together with little or nor extracellular matrix; they cover and line organs, body cavities, and form gland substances.
Glandualr epithelium tissues may have a single or multiple group of cells that secrete substances into ducts, onto a surface, or into blood.
What is secretion?
The production and release of substances such as mucus, sweat and enzymes.
What is absorption?
It is the intake of substances, such as digested food from the intestinal tract.
A single layer of cells
Multiple layers of cells who's nuclei lie at different level and cells rest on the basal level and have cilia
Two or more layer of cells that are in a wave motion.
What is the shape and arrangement of a simple squamous epithelial tissue and it's function?
It is a single layer of flat cells that are oval or spherical shaped, with a centrally located nucleus. Its function is to diffuse, filtrate and secrete in serous membranes.
found in the peritoneum of the abdomen
What is the shape and arrangement layer of a pseudostratisfied columnar epithelium and its function?
It has multiple layer of cells with different levels of nuclei that do not reach the apical level, but it does rest on the basement level in a single layer/It may contain cilia or goblet cells and look multi-layered.
Its function is to secrete mucus that traps foreign particles and then cilia sweeps the mucus away
Non-ciliated epithelium tissue functions in absorption and protection. found in the trachea
What is the shape and arrangement of a stratisfied squamous epithelium and its function?
It consists of tow or more layers of cells; cells with nuclei on the apical and several layer deep that vary from cuboidal to columnar.
Its function os to protect against abrasion, water loss, ultraviolet radiation.
found in vaginas and skin
What are the shapes and arrangement layers of a simple cubodial epithelium and its function?
A single layer of cubed-shaped cells that are round and have a central nucleus.
Found in the kidneys, its function is secretion and absorption.
What are the shapes and arrangement of a non-ciliated columnar epithelium and its function?
A single layer of non-ciliated column like cells with oval nuclear near the basal cell with microvilli at the apical surface.
Found in the intestines, its function is to secrete and absorb mucus to lubricate.
What is the shape and arrangement of ciliated columnar epithelial tissues and its functions?
A single layer of ciliated columnar like cells with nuclei (near) the base of the cells and usually have goblet cells.
Found in the utering tubes, cilia functions in moving mucus and ovum.
What are the shapes and arrangements of a transitional epithelium tissue and its function?
Having the appearance of stratisfied cubodial or stratisfied squamous epithelium, but their appearances varies. It has cells that are large and rounded at the apical level.
Found in the urinary bladder, transitional tissues function is to allow the urinary organ to stretch and hold variable amounts of fluids without rupturing.
simple squamous epithelium cells
a single layer of flat cells that are oval and spherical shaped with a central located nucleus.
Cells that are wide and shaped like cubes, have microvilli
tall cells that protect the underlying surface of tissue and contain cilia or microvilli.
they are shaped between squamous and cubodial cells and can change their sizes when stretched or collapsed.
Describe the basic structures and functions of Glands.
Glandular epithelium function is secretion of hormones. they consist of a single cell or a group of cells that secretes substances into ducts, onto a surface, or into the blood.
classified into exocrine and endocrine glands
are glands that secrete hormones that enter into the blood stream and regulate metabolic and physical activities by maintaining homeostasis
Substances that are secreted into ducts that empty onto a surface of a covering and lining epithelium.
Ex. skin surface, lumen, or a hollow organ
List 4 classes of connective tissues
- loose connective tissue
- dense connective tissue
- osseous connective tissue
- liquid connective tissue (blood and lympth)
Material located between the spares of cells that consists of ground substances and fibers
Describe the general features of connective tissues, cells, and matrix
(ground substance and fibers)
connective tissues extracellular matrix is composed of protein fibers embedded in a ground substance. The ground substance supports cell by binding them together, stores water, and provides an exchange of substances between the blood of cells and tissues. The 3 different fibers consists of materials that are able to stretch and recoil back to shape. These fibers function in the strength, support of the cells that make up the connective tissues.
A component of extracellular matrix within a connective tissue that are located between cells and fibers. Can be fluid, gelatinous, calcified, or semi-fluid.
Its function is to exchange substances between blood and cells
Binds organs together, stores energy reserves as fat, and helps provide immunity
List and describe all the classes of connective tissues.
Loose connective tissues--are loosley arranged between cells and has more matrix.
Dense connective tissue---contains more fibers that are thicker, less cells, and almost has no matrix (formed by fibroblasts).
Cartilage connective---consists of a dense network of collagen and elastic fibers in its matrix (chondrocytes).
Osseous connective-- cartilage, joints and bones. Matrix is maintained by (osteocytes).
Liquid connective----cells are suspended in a liquid medium of blood or lymph. Matrix is (plasma).
What are the different connective tissue fibers and their functions?
they are collagen fibers, elastic fibers, and reticular fibers.
Their functions are: to strengthen and support connective tissues.
Describe the collagen, elastic , and reticular fibers and where they can be found.
Collagen fibers-- are tightly packaged thick and very strong fibers. Can be found in bone, cartilage and tendons
Elastic fibers ---A fiberous network that is provides strength and elasticity. can be found in skin and blood vessels.
Reticular fibers-- are fine branching interwoven fibers that provide support and strength. can be found in areolar, adipose, smooth muscle tissues
Describe loose connective tissues and what are its subclasses?
Loose connective tissue are loosley arranged between cells and maintains extracellular matrix.
- areolar connective tissue
- Adipose connective tissue
- reticular connective tissue
Describe Areloar connective tissues and list its function.
- Areolar consists of the fibers (collagen, elastic, and reticular) and
- are arranged randomly with several kinds of cells embedded in a
- semi-fluid ground substance. Its function is strength, elasticity, and
* found under all epithelial tissues.
Describe Adipose connective tissue and its functions.
Adipose tissue contains adipocytes specialized to store fats. Its function is to reduce heat loss through the skin, energy reserves, and supports cushions organs.
*found under the skin and surrounding organs
Describe reticular connective tissues and its functions
A subclass of loose connective tissue. Reticular consists of a fine interlacing web like form of fibers and cells in the stroma. Its function is to form support for:
*the liver, spleen and lymph nodes.
Dense connective Tissue
Are more densely packaged and contains more fibers and less cells the loose connective tissues
dense regular, dense irregular, and elastic connective tissues
Describe dense regular connective tissues and its functions
consists of many tightly packaged collagen, fiberblasts that are arranged in parallel and secretes an extracellular matrix. Its function as a strong attachment between various structures.
Describe irregular dense connective tissues and its functions
Consists of few randomly arranged collagen fibroblasts in and secretes extracellular matrix. Its function is to provide strength and easy stretching in many directions around muscles and organs.
Elastic connective tissue
Mostly elastic fibers that are dark and very thin fibroblasts between fibers that secrete extracellular matrix. Its function is to allow stretching and recoiling of various organs such as; the heart and lungs to help maintain blood flow.
A dense network of collagen fibers an elastic fibers that are in a gel matrix and contain chondrocytes in the lacunae. Its function is to reduce friction and absorb shock at joints, provide flexibility and support in long bones, trachea and others
Describe Fibrocartilage and give its function.
Chondrocytes scattered among thick clearly bundled of collagen fibers within a gelatenous extracellular matrix.
Its function so to support and join structures together. Strength and rigidity makes it the strongest type of cartilage.
*cartilage in the knee pads
Describe Elastic Cartilage and give its function.
Chondrocytes in threadlike network of elastic fibers within a gelatenous extracellular matrix.
Its function is to provide strength and elasticity; maintains the shape of structures.
*auricle of the ear.
Describe osseous tissue and give its function.
Osseuos tissue are mature connective tissues that are stored in bones, with an extracellular matrix consisting of mineral salts and mostly calcium and phosphorus and collagen fibers.
Functions is to protect, support, storage and house blood forming tissues in bones
Describe liquid connective tissues and its functions.
Cells are suspended in a liquid extracellular matrix of blood plasma in blood vessels and in lymph connective tissues that flows in a lymphatic vessel and has a clear liquid matrix.
includes: red blood cells, white cells, and platelets.
functions in rbc transports oxygen and some co2. wbc carry out phagocytosis and immune responses, platelets are essential for blood clotting
Compare connective tissue with epithelial tissues in terms of vascularity, and the amount of matrix.
Epithelial tissues have many tightly packaged together cells with little or no extracellular matrix and is avascular.
connective tissues have few cells with lots of extracellular matrix and has has many blood vessels (vascular)
What tissue is found under Simple squamous epithelia?
Lung or alveoli
what tissue is found under simple cuboidal?
Kidney or Thyroid
What tissue is found under simple columnar?
- Small intestines
- Uterine tube
- spinal cord
what tissue is found under stratified squamous epithelium?
Skin or esophogus
What tissues are found under Transitional?
What tissue are found under Pseudostratified?
Trachea or bronchi
What is a serous membrane?
A watery membrane that lines body cavities that do not open directly to the exterior and covers the organs that re within the cavity.
Where are serous membranes found?
thoracic or abdominal cavities
Compare visceral and parietal layers.
both are part of the serous membranes. The layer that lines the cavity wall is partietal layer (outer).
The layer that covers the organs (inside) the cavity is the visceral.
Describe the basic function of a mucus membrane, cutaneous membrane, and serous membrane.
Mucus consists of both lining and underlining layer of the connective tissues. Its function is to line body cavities that do open to the exterior (gastro tract, respiratory tract, urinary tract).
Serous membranes consists of areolar connective tissues and functions in the lining of body cavities that do not open directly to the exterior (thoracic cavity and abdominal cavity).
cutaneous membranes consists of superficial portion call epidermis and deeper portion called dermis. Its function is to cover the surface of the body (skin).
Three types of muscle tissues and their functions.
Skeletal muscle is a voluntary muscle that functions in the motion, posture, heat production, and protection. It consists of long cell striations with multiple nuclei per cell.
Cardiac muscle is involuntary muscle that functions in pumping blood to tall body parts. It consists of striations, intercalated disks and a single nuclei per cells.
Smooth muscle is also involuntary and it function is the motion of foods through the gastrointestinal tract, contraction of stomach and urinary bladder. It does not contain striations and include only a single nuclei in its cells.
What are the two main types of cells in the nervous system?
Neurons and neuroglia
Neurons function in the conversion of stimuli into electrical signals and conduct these impulses to other neurons, muscles, or glands.
Neuroglia do not function in generating or conduction impulses but do support the cells.
Tissue repair of the 4 main tissue cells
Epithelial cells have the capacity for continuous renewal.
Connective cells have different capacities for renewal from complete to minimal.
Muscle and nervous cells have poor capacity for repair.
- Stem cells in some tissues are immature.
- Undifferentiated cells can divide and repair.
Good nutrition and blood circulation are vital to tissue repair.