Ch. 4 Tissues: The Living Fabric Flashcards
What are tissues?
Groups of cells that are similar in structure and perform a common or related function
Which tissue type covers body surfaces and lines cavities?
Epithelial tissue
What is the primary function of connective tissue?
Supports, protects, and binds other tissues together
What is the role of nervous tissue?
Provides internal communication throughout the body
Which tissue type is responsible for movement?
Muscle tissue
Where is epithelial tissue found?
Lining of digestive tract organs, glands, and epidermis
What is the primary function of muscle tissue?
Contracts to cause movement
Which tissue type is found in bones, tendons, and fat?
Connective tissue
What are the four primary tissue types in the human body?
Epithelial, connective, muscle, and nervous tissue.
Epithelial tissue
Tissue that covers body surfaces, lines cavities, and forms glands.
Where is nervous tissue found in the body?
In the brain, spinal cord, and nerves.
What are the three types of muscle tissue?
Skeletal muscle, cardiac muscle, and smooth muscle.
What is the role of epithelial tissue in the lining of digestive tract organs?
To protect, secrete, absorb, and/or filter.
What does the term ‘tissu’ mean?
Woven.
What is the first step in preparing animal tissue for microscopic viewing?
Fixing (preserving) the tissue
Why is staining important in light microscopy?
To enhance contrast between structures
What type of stains are used in light microscopy?
Colored synthetic dyes
What type of microscopy uses heavy metal salts for staining?
Transmission Electron Microscopy (TEM)
What is the purpose of using heavy metal salts in TEM?
To provide contrast by deflecting electrons
Which type of microscopy provides three-dimensional images of unsectioned tissue surfaces?
Scanning Electron Microscopy (SEM)
Why are electron-microscope images in shades of gray?
Because color is a property of light, not electron waves
What are artifacts in the context of microscopy?
Minor distortions introduced by tissue preparation procedures
What are the steps involved in preparing animal tissue for microscopic viewing?
Fixing, slicing into thin sections, and staining.
What type of stains are used in transmission electron microscopy (TEM)?
Heavy metal salts.
What is the main difference between transmission electron microscopy (TEM) and scanning electron microscopy (SEM)?
TEM provides two-dimensional images of thin sections, while SEM provides three-dimensional images of unsectioned tissue surfaces.
Fixing
The process of preserving tissue samples for microscopic viewing.
Staining
The process of applying dyes to tissue sections to enhance contrast between structures.
Artifacts
Minor distortions introduced to tissue samples during preparation for microscopic viewing.
Scanning Electron Microscopy (SEM)
A type of electron microscopy that provides three-dimensional images of unsectioned tissue surfaces.
Transmission Electron Microscopy (TEM)
A type of electron microscopy that provides two-dimensional images of thin tissue sections stained with heavy metal salts.
What are the two main forms of epithelial tissue?
Covering and lining epithelium, Glandular epithelium
Which surface of epithelial tissue is exposed to the outside of the body or an internal organ cavity?
Apical surface
What structure supports epithelial tissue and helps it resist stretching and tearing?
Basement membrane
Which type of epithelial tissue is most concerned with absorption, secretion, and filtration?
Simple epithelia
What type of epithelial cells are flattened and scale-like?
Squamous cells
Which epithelial tissue type forms the outer layer of the skin?
Stratified squamous epithelium
What is the primary function of simple squamous epithelium?
Allows materials to pass by diffusion and filtration
Which type of gland loses its ducts during development and secretes hormones?
Endocrine glands
Which type of epithelial tissue lines the urinary bladder?
Transitional epithelium
What is the main function of microvilli on epithelial cells?
Increase surface area for absorption
What are the six functions of epithelial tissue?
Protection, absorption, filtration, excretion, secretion, and sensory reception
Polarity in epithelial tissue
Characteristic where epithelial cells have an apical surface exposed to the body exterior or cavity, and a basal surface attached to underlying connective tissue
Basal lamina
A noncellular, adhesive sheet consisting of glycoproteins and collagen fibers that acts as a selective filter and scaffolding for epithelial cells
How are epithelial cells nourished if they are avascular?
By substances diffusing from blood vessels in the underlying connective tissue
Simple squamous epithelium
A single layer of flattened cells that allows materials to pass by diffusion and filtration
Where can simple cuboidal epithelium be found?
In kidney tubules, ducts and secretory portions of small glands, and on the ovary surface
What is the function of pseudostratified columnar epithelium?
Secretion, particularly of mucus, and propulsion of mucus by ciliary action
Stratified squamous epithelium
A thick epithelium composed of several cell layers that protects underlying tissues in areas subjected to abrasion
What is the main function of transitional epithelium?
To stretch readily and permit stored urine to distend urinary organs
Endocrine glands
Ductless glands that secrete hormones directly into the extracellular space, which then enter the blood or lymphatic fluid
What is the difference between exocrine and endocrine glands?
Exocrine glands secrete their products onto body surfaces or into body cavities, while endocrine glands secrete hormones directly into the extracellular space
Goblet cell
A unicellular exocrine gland that produces mucin, which dissolves in water to form mucus
What are the three modes of secretion for multicellular exocrine glands?
Merocrine, holocrine, and apocrine
What are the two main characteristics that set connective tissue apart from other primary tissues?
Extracellular matrix and common origin from mesenchyme
Which type of connective tissue is avascular?
Cartilage
What is the primary function of adipose tissue?
Storing reserve fuel
Which connective tissue type contains the least abundance of collagen fibers?
Areolar
What is the main function of blood as a connective tissue?
Transporting substances within the body
Which type of connective tissue forms the fibrous tissue of ligaments?
Dense regular connective tissue
What is the primary cell type found in bone tissue?
Osteocytes
Which component of connective tissue acts as a molecular sieve for nutrients and other substances?
Ground substance
What type of connective tissue is found in the walls of large arteries?
Elastic connective tissue
Which connective tissue type is known for its ability to resist both compression and tension?
Bone
What are the four main classes of connective tissue?
Connective tissue proper, cartilage, bone, and blood
What are the three main components of connective tissue?
Ground substance, fibers, and cells
Which type of connective tissue is known for its high tensile strength due to collagen fibers?
Dense regular connective tissue
What is the role of fibroblasts in connective tissue?
To secrete the ground substance and fibers characteristic of their particular matrix
Extracellular matrix
A nonliving material that separates the living cells in connective tissue, allowing it to bear weight and withstand tension
Mesenchyme
An embryonic tissue from which all connective tissues arise
Chondroblasts
Cells that produce the matrix in growing cartilage
Osteoblasts
Cells that produce the organic portion of the bone matrix
Hyaline cartilage
The most abundant type of cartilage, providing firm support with some pliability
Elastic fibers
Long, thin fibers that allow connective tissue to stretch and recoil
Reticular fibers
Short, fine fibers that form delicate networks to support the soft tissue of organs
Which type of muscle tissue is responsible for voluntary movements?
Skeletal muscle
What is a unique structural feature of cardiac muscle cells?
Intercalated discs
Where is smooth muscle primarily found?
Walls of hollow organs
What is the main function of skeletal muscle tissue?
Causing body movements
Which muscle tissue type has cells that are spindle-shaped and contain a single central nucleus?
Smooth muscle
What type of muscle tissue is injured when you pull a muscle while exercising?
Skeletal muscle
Which characteristic is true for skeletal muscle cells?
Long, cylindrical cells with many nuclei
Which muscle tissue type is found only in the walls of the heart?
Cardiac muscle
What are the three types of muscle tissue?
Skeletal, cardiac, and smooth muscle.
Where is cardiac muscle found?
In the walls of the heart.
What is the primary function of smooth muscle?
Propels substances or objects along internal passageways.
Skeletal Muscle
Muscle tissue attached to bones, responsible for voluntary movements, with long, cylindrical cells that are striated and multinucleated.
Cardiac Muscle
Muscle tissue found only in the heart, responsible for pumping blood, with branching, striated cells that are generally uninucleate and connected by intercalated discs.
Smooth Muscle
Muscle tissue found in the walls of hollow organs, responsible for involuntary movements, with spindle-shaped cells that lack striations and have a single central nucleus.
What unique junctions are found in cardiac muscle cells?
Intercalated discs.
What is the appearance of smooth muscle cells?
Spindle-shaped with central nuclei and no striations.
What is the primary function of neurons in nervous tissue?
Generate and conduct nerve impulses
Which part of the neuron is responsible for transmitting electrical impulses over long distances?
Axons
What is the role of dendrites in a neuron?
Respond to stimuli
What are neuroglia also known as?
Glial cells
Which cells in nervous tissue are nonconducting and support neurons?
Neuroglia
Where is nervous tissue primarily located in the body?
Brain, spinal cord, and nerves
What are the two major cell types found in nervous tissue?
Neurons and supporting cells (glial cells or neuroglia)
What are the processes called that allow neurons to respond to stimuli?
Dendrites
What are the processes called that transmit electrical impulses over long distances?
Axons
What is the function of supporting cells in nervous tissue?
To support, insulate, and protect neurons
Neurons
Highly specialized nerve cells that generate and conduct nerve impulses
Neuroglia (Glial cells)
Nonconducting cells that support, insulate, and protect neurons
Axons
Long processes of neurons that transmit electrical impulses over long distances
Dendrites
Short processes of neurons that allow for response to stimuli
Which membrane is known as the skin and is a dry membrane?
Cutaneous membrane
What type of epithelium is found in the cutaneous membrane?
Keratinized stratified squamous epithelium
Which type of membrane lines body cavities that open to the outside?
Mucous membrane
What is the primary function of mucous membranes?
Absorption and secretion
Which membrane is found in closed ventral body cavities?
Serous membrane
What type of fluid is found between the visceral and parietal layers of serous membranes?
Serous fluid
Which membrane contains an abundance of the protein keratin?
Cutaneous membrane
What is the layer of areolar connective tissue found in mucous membranes called?
Lamina propria
Which serous membrane encloses the heart?
Pericardium
Which membrane is dry and exposed to air?
Cutaneous membrane
What are the two layers of serous membranes called?
Visceral layer and parietal layer
Cutaneous membrane
A dry membrane that forms the skin, consisting of keratinized stratified squamous epithelium attached to a thick layer of connective tissue
Mucous membrane
Membranes that line body cavities open to the exterior, such as the digestive, respiratory, and urogenital tracts, and are typically moist
Serous membrane
Moist membranes found in closed ventral body cavities, consisting of simple squamous epithelium resting on areolar connective tissue
What are the two major ways tissue repair occurs?
Regeneration and fibrosis
What triggers the inflammatory response during tissue repair?
Release of inflammatory chemicals by injured tissue cells and mast cells
What is the role of fibroblasts during the organization stage of tissue repair?
Produce growth factors and collagen fibers
What type of tissue is formed initially during wound healing?
Granulation tissue
Which tissues have virtually no functional regenerative capacity?
Cardiac muscle and nervous tissue in the brain and spinal cord
What happens during the inflammation stage of tissue repair?
Clotting seals off the injured area and prevents the spread of harmful substances
What is the primary function of granulation tissue?
Restore the vascular supply
What is the outcome of regeneration and fibrosis in tissue repair?
A fully regenerated epithelium with underlying scar tissue
What is the role of macrophages during the organization stage of tissue repair?
Phagocytize dead and dying cells and other debris
Which stage of tissue repair involves the formation of a scab?
Inflammation
What are the three main stages of tissue repair?
Inflammation, organization, and regeneration
During which stage of tissue repair does granulation tissue form?
Organization
Which tissues have a high regenerative capacity?
Epithelial tissues, bone, areolar connective tissue, dense irregular connective tissue, and blood-forming tissue
Granulation tissue
A delicate pink tissue that contains capillaries growing in from nearby areas, forming a new capillary bed
Fibrosis
The replacement of destroyed tissue with scar tissue, which is dense connective tissue
Regeneration
The process of replacing destroyed tissue with the same kind of tissue
What is the main function of histamine released by mast cells during inflammation?
It makes blood vessels leaky, allowing white blood cells and clotting factors to seep into the injured area
What is a neoplasm?
An abnormal mass of proliferating cells
What distinguishes malignant neoplasms from benign neoplasms?
Malignant neoplasms are nonencapsulated and invade surrounding tissues
What is metastasis?
The capability of cancer cells to travel to other parts of the body
What are oncogenes?
Cancer-causing genes
What role do tumor suppressor genes play?
They inhibit cell growth and division
What is the function of the TP53 gene?
It codes for a protein that stops cell division in cells with damaged DNA
What is the first sign of colorectal cancer?
A polyp
Which cancers are most common in the U.S. and Canada?
Skin, colon, lung, breast, and prostate
What is the purpose of screening tests in cancer detection?
To detect cancer early before symptoms appear
What is a common problem with chemotherapy?
Cancer cells can develop resistance to the drugs
What is a promising new approach in cancer treatment?
Personalized medicine based on DNA sequencing
What is cancer immunotherapy?
Therapies that activate the immune system to attack cancer cells
What is a neoplasm?
An abnormal mass of proliferating cells resulting from excessive cell division.
Benign neoplasm
A non-cancerous growth that remains localized, grows slowly, and is often encapsulated.
Metastasis
The process by which cancer cells spread from the primary tumor to other parts of the body.
Proto-oncogenes
Normal genes that code for proteins essential for cell division, growth, and cellular adhesion, which can become oncogenes when mutated.
TP53
A tumor suppressor gene that codes for a protein stopping cell division in cells with damaged DNA, and can trigger apoptosis if the damage is irreparable.
Chemotherapy
A cancer treatment using drugs to kill rapidly dividing cells, but can also affect normal cells, causing side effects.
Cancer immunotherapy
Treatments that activate the immune system to attack and kill cancer cells, or block specific receptors on cancer cells.
What are the three primary germ layers formed during embryonic development?
Ectoderm, Mesoderm, Endoderm
Which primary germ layer is the most superficial?
Ectoderm
From which germ layer does nervous tissue develop?
Ectoderm
Which tissues develop mostly from the mesoderm?
Muscle and connective tissue
What is the primary tissue type that develops from all three germ layers?
Epithelium
By the end of which month of development have the primary tissues appeared and all major organs are in place?
Second month
Which cells stop or nearly stop dividing during the fetal period?
Nerve cells
Which tissues are highly mitotic in adults?
Epithelia and blood-forming tissues
What is a common problem of aging tissues?
Increased risk of cancer due to DNA mutations
Which germ layer is the most superficial?
Ectoderm
Which primary tissues develop mostly from the mesoderm?
Muscle and connective tissue
Ectoderm
The most superficial germ layer in embryonic development
Mesoderm
The middle germ layer in embryonic development
Endoderm
The deepest germ layer in embryonic development
Stem cells
Relatively undifferentiated cells that divide as necessary to produce new cells
Atrophy
The wasting away or decrease in size of an organ or tissue
What is an adenoma?
A neoplasm of glandular epithelium
What is another term for an autopsy?
Postmortem examination
What type of cancer arises in an epithelium?
Carcinoma
What is healing by first intention?
Healing when wound edges are brought together by sutures or staples
What characterizes healing by second intention?
Wound edges remain separated and large amounts of granulation tissue bridge the gap
What is a keloid?
An abnormal proliferation of connective tissue during healing
What is Marfan’s syndrome?
A genetic disease resulting in abnormalities of connective tissues
What is osteogenesis imperfecta also known as?
Brittle bone disease
What is the scientific study of changes in organs and tissues produced by disease called?
Pathology
What is pus composed of?
Tissue fluid, bacteria, dead and dying tissue cells, white blood cells, and macrophages
What type of cancer arises in mesenchyme-derived tissues?
Sarcoma
What causes scurvy?
Lack of adequate vitamin C
What is the purpose of vacuum-assisted closure (VAC) in wound healing?
To induce healing by applying suction through a special sponge
What is the term for the examination of the body after death to determine the cause of death?
Autopsy
Carcinoma
Cancer arising in an epithelium; accounts for 90% of human cancers.
What is healing by first intention?
The simplest type of healing where wound edges are brought together by sutures, staples, or other means.
What results from abnormal proliferation of connective tissue during healing of skin wounds?
Keloid
Lesion
Any injury, wound, or infection that affects tissue over an area of a definite size.
What genetic disease results in abnormalities of connective tissues due to a defect in fibrillin?
Marfan’s syndrome
Osteogenesis imperfecta
An inherited condition causing defective collagen production, resulting in weak bones that break easily.
What is the scientific study of changes in organs and tissues produced by disease?
Pathology
Sarcoma
Cancer arising in mesenchyme-derived tissues, such as connective tissues and muscle.
What nutritional deficiency is caused by a lack of adequate vitamin C?
Scurvy
What are the four primary types of tissues in the human body?
Epithelial, connective, muscle, and nervous tissues
What is the main function of simple squamous epithelium?
Filtration and exchange of substances
Which type of epithelial tissue lines most of the digestive tract?
Simple columnar epithelium
What type of connective tissue forms tendons and ligaments?
Dense regular connective tissue
Which type of muscle tissue is found in the walls of hollow organs?
Smooth muscle
What is the primary cell type in cartilage?
Chondroblast
Which type of epithelial tissue is adapted to resist abrasion and is found lining the esophagus and vagina?
Stratified squamous epithelium
What is the main function of nervous tissue?
Receiving and transmitting electrical impulses
Which type of connective tissue is known for its high tensile strength and forms structures such as tendons and ligaments?
Dense regular connective tissue
What type of epithelial tissue is found in the upper respiratory passages and is rich in mucus-secreting cells?
Pseudostratified columnar epithelium
What is the main function of epithelial tissue?
Protection, absorption, excretion, filtration, secretion, and sensory reception
Where is simple cuboidal epithelium commonly found?
In glands and kidney tubules
Pseudostratified columnar epithelium
A type of epithelium that appears stratified but is actually a single layer of cells, often ciliated and found in the upper respiratory passages
Transitional epithelium
A type of stratified epithelium adapted for stretching, found lining hollow urinary system organs
What are the two main classifications of glands based on the site of product release?
Exocrine and endocrine
Connective tissue
The most abundant and widely distributed tissue in the body, with functions including binding, support, protection, insulation, fat storage, and transportation
What are the three types of fibers found in the extracellular matrix of connective tissues?
Collagen, elastic, and reticular fibers
Hyaline cartilage
A type of cartilage with a firm ground substance containing collagen fibers, found in the embryonic skeleton, articulating surfaces of bones, and trachea
What type of muscle tissue is responsible for pumping blood through the heart?
Cardiac muscle
Neurons
Branching cells that receive and transmit electrical impulses, involved in body regulation
Cutaneous membrane
A dry membrane consisting of an epithelium bound to an underlying connective tissue layer
Histology
Branch of anatomy dealing with the microscopic structure of tissues.
Sections
A cut through the body (or an organ) that is made along a particular plane; a thin slice of tissue prepared for microscopic study.
Metastasis
The spread of cancer from one body part or organ into another not directly connected to it.
Reticular lamina
A layer of extracellular material containing a fine network of collagen fibers; together with the basal lamina it is a major component of the basement membrane.
Fibrocytes
Mature fibroblast; maintains the matrix of fibrous types of connective tissue.
Osteocytes
Mature bone cell.
Stroma
The basic internal structural framework of an organ.
Serosa membranes
The moist membrane found in closed ventral body cavities.
Areolar connective tissue
A type of loose connective tissue.
Holocrine glands
Glands that accumulate their secretions within their cells; secretions are discharged only upon rupture and death of the cell.
Malignant
Life threatening; pertains to neoplasms that spread and lead to death, such as cancer.
Intervertebral discs
Discs of fibrocartilage between vertebrae.
Hyaline cartilage
The most abundant cartilage type in the body; provides firm support with some pliability.
Pleurae
Two layers of serous membrane that line the thoracic cavity and cover the external surface of the lung.
Osteoblasts
Bone-forming cells.
Adipose tissue
Areolar connective tissue modified to store fat; a connective tissue consisting chiefly of adipocytes.
Intercalated discs
Specialized connections between myocardial cells containing gap junctions and desmosomes.
Cutaneous membrane
Pertaining to the skin.
Skeletal muscle
Muscle composed of cylindrical multinucleate cells with obvious striations; the muscle(s) attached to the body’s skeleton; voluntary muscle.
Endocrine glands
Ductless glands that empty their hormonal products directly into the blood.
Fibrocartilage
The cartilage most resistant to compression and stretch. Forms vertebral discs and knee joint cartilages.
Involuntary muscle
Muscle that cannot ordinarily be controlled voluntarily (e.g., smooth and cardiac muscle).
Basal surface
The surface near the base or interior of a structure; nearest the lower side or bottom of a structure.
Mast cells
Immune cells that function to detect foreign substances in the tissue spaces and initiate local inflammatory responses against them; typically found clustered deep to an epithelium or along blood vessels.
Alveolus
(1) One of the microscopic air sacs of the lungs; (2) tiny milk-producing glandular sac in the breast; (3) tooth socket.
Endoderm
Embryonic germ layer; forms the lining of the digestive tube and its associated structures.
Myofilaments
Filament that constitutes myofibrils. Of two types: actin and myosin.
Reticular connective tissue
Connective tissue with a fine network of reticular fibers that form the internal supporting framework of lymphoid organs.
Chondroblasts
Actively mitotic cell of cartilage.
Fibrosis
Proliferation of fibrous connective tissue called scar tissue.
Connective tissue
A primary tissue; form and function vary extensively. Functions include support, storage, and protection.
Voluntary muscle
Muscle under strict nervous control; skeletal muscle.
Neurons
Cell of the nervous system specialized to generate and transmit electrical signals (action potentials and graded potentials).
Pericardium
Double-layered sac enclosing the heart and forming its superficial layer; has fibrous and serous layers.
Benign
Not malignant.
Mesoderm
Primary germ layer that forms the skeleton and muscles of the body
Goblet cells
Individual cells (unicellular glands) that produce mucus.
Elastic cartilage
Cartilage with abundant elastic fibers; more flexible than hyaline cartilage.
Elastic fibers
Fiber formed from the protein elastin, which gives a rubbery and resilient quality to the matrix of connective tissue.
Microvilli
Tiny projections on the free surfaces of some epithelial cells; increase surface area for absorption.
Secretion
(1) The passage of material formed by a cell to its exterior; (2) cell product that is transported to the exterior of a cell.
Peritoneum
Serous membrane lining the interior of the abdominal cavity and covering the surfaces of abdominal organs.
Macrophages
Immune cell type common in connective tissue, lymphoid tissue, and many body organs; phagocytizes tissue cells, bacteria, and other foreign debris; presents antigens to T cells in the immune response.
Fibroblasts
Young, actively mitotic cell that forms the fibers of connective tissue.
Gland
Organ specialized to secrete substances for further use in the body or excrete substances for elimination.
Endothelium
Single layer of simple squamous cells that line the walls of the heart, blood vessels, and lymphatic vessels.
Extracellular matrix
Nonliving material in connective tissue consisting of ground substance and fibers; separates the living cells.
Mucous membranes
Membranes that form the linings of body cavities open to the exterior (digestive, respiratory, urinary, and reproductive tracts).
Alveolar (al-ve′o-lar)
A gland whose secretory cells form small, flasklike sacs.
Cardiac muscle
Specialized muscle of the heart.
Stem cells
Unspecialized cells that can divide to produce various kinds of more specialized cell types.
Duct
A canal or passageway; a tubular structure that provides an exit for the secretions of a gland, or for conducting any fluid.
Basal lamina
Noncellular, adhesive supporting sheet consisting largely of glycoproteins secreted by epithelial cells.
Tissues
A group of similar cells and their intercellular substance specialized to perform a specific function; primary tissue types of the body are epithelial, connective, muscle, and nervous tissue.
Hormones
Steroidal or amino acid–based molecules released to the blood that act as chemical messengers to regulate specific body functions.
Adipocytes
An adipose, or fat, cell.
Chondrocytes
Mature cell of cartilage.
Basement membrane
Extracellular material consisting of a basal lamina secreted by epithelial cells and a reticular lamina secreted by underlying connective tissue cells.
Ectoderm
Embryonic germ layer; forms the epidermis of the skin and its derivatives, and nervous tissues.
Smooth muscle
Spindle-shaped cells with one centrally located nucleus and no externally visible striations (bands). Found mainly in the walls of hollow organs.
Exocrine glands
Glands that have ducts through which their secretions are carried to a particular site.
Cartilage
One of four types of connective tissue—avascular and not innervated.
Pus
Fluid product of inflammation composed of white blood cells, the debris of dead cells, and a thin fluid.
Osseous tissue
A connective tissue that forms the bony skeleton.
Regeneration
Replacement of destroyed tissue with the same kind of tissue.
Neoplasm
An abnormal mass of proliferating cells. Benign neoplasms remain localized; malignant neoplasms are cancers, which can spread to other organs.
Unicellular
Individual cells (unicellular glands) that produce mucus.
Mesothelium
The epithelium found in serous membranes lining the ventral body cavity and covering its organs.
Epithelium
Pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands.
Cilia
Tiny, hairlike projections of a cell; may move in a wavelike manner to propel substances across the exposed cell surface.
Lamina propria
Loose connective tissue supporting an epithelium; part of a mucous membrane (mucosa).
Filtration
Passage of a solvent and dissolved substances through a membrane or filter.
Merocrine glands
Glands that produce secretions intermittently; secretions do not accumulate in the gland.
Mesenchyme
Common embryonic tissue from which all connective tissues arise.
Muscle fibers
A muscle cell.
Bone
A connective tissue that forms the bony skeleton.
