Tissues Flashcards
What are the two different types of epithelium?
Covering/lining and glandular
What is the basal lamina composed of?
Glycoproteins secreted by epithelia cells
What is the purpose of the basal lamina?
It acts as a selective filter for molecules entering the epithelium from the connective tissue and acts as a scaffolding for migrating epithelial cells during wound repair
What are the two components of the basement membrane and where do they originate?
The basal lamina originating from the epithelial cells and the reticular lamina originating from the connective tissue
What is the reticular lamina composed of?
A fine network of collagen fibers
What keeps epithelium as continuous sheets of cells?
Tight junctions and desmosomes
Where would you find simple cuboidal epithelium?
The ducts and secretory portions of small glands, kidney tubules, ovary surface
Where would you find simple squamous epithelium?
Kidney glomeruli, air sacs of lungs, lining of the heart, serosae, blood vessels, and lymphatic vessels
What are the main functions of simple squamous epithelium?
Passage of materials in areas of low abrasion and high diffusion, secretes lubricating substances in the serosae
What epithelial tissue type would you find in the endothelium and mesothelium?
Simple squamous
What two epithelial tissue types share the chief functions of secretion and absorption?
Simple columnar and simple cuboidal
Where would you find simple columnar epithelium in the body?
Lining the digestive tract from stomach to rectum, gallbladder, excretory ducts of some glands, small bronchi, uterine tubes, some regions of the uterus
Where would you find pseudostratified columnar epithelium?
Lining the trachea and most of the upper respiratory tract (ciliated), and in sperm-carrying ducts and the ducts of large glands (nonciliated)
Where would you find non-keratinized stratified squamous epithelium?
Forming the linings of the mouth, esophagus, and vagina
Where would you find keratinized stratified squamous epithelium?
Epidermis of the skin
What two modifications of the digestive tract epithelium make it ideal for secretion and absorption?
Microvilli, goblet cells
Besides the digestive tract, where can goblet cells commonly be found?
Within ciliated pseudostratified epithelia of the respiratory tract
What epithelial tissue type is found in the pharynx, male urethra, the lining of some glandular ducts, and occurs at transition areas between two other types of epithelia?
Stratified columnar
Which layer of stratified columnar tissue is actually columnar?
The apical layer
What type of epithelial tissue is found in the mammary, salivary, and sweat glands and enhances their durability and structure?
Stratified cuboidal
How many layers does stratified cuboidal epithelia typically have?
Two
What is a gland?
Epithelia that consists of one or more cells that make and secrete an aqueous fluid
Where does an endocrine gland secrete its product?
Into the blood
Where does an exocrine gland excrete its product?
Into a body cavity or onto the skin
What is a type of unicellular gland?
Goblet cells
What types of products do endocrine glands typically secrete?
Hormones
Which type of gland has ducts?
Exocrine
Where would you find individual hormone-producing cells (unicellular endocrine glands)? What is another name for them?
In the digestive tract and brain; the diffuse endocrine system
What two organs are also exocrine glands?
Liver and pancreas
What do all unicellular exocrine glands produce? What is it made of?
Mucin, a complex glycoprotein
What are the two basic parts of multicellular exocrine glands?
An epithelium-lined duct and a secretory unit
What is a merocrine gland? What are some examples?
A gland whose cells secrete products by exocytosis and are not altered by secretion in any way; pancreas, most sweat glands, salivary glands
What is a holocrine gland? What is the only true example?
A gland that accumulates products within it until it ruptures; sebaceous gland
What is an apocrine gland?
A gland that accumulates products just beneath its apical surface, then releases secretory granules and a small amount of cytoplasm.
What are the five major functions of connective tissue?
- Binding and support, 2. Protection, 3. Insulation, 4. Energy storage, 5. Transport
What are the two subclasses of the connective tissue proper?
Loose and dense connective tissue
Which class of connective tissue contains all three fiber types?
Connective tissue proper
Which of the five major functions is the connective tissue proper responsible for?
Binding/support, protection, insulation, and energy storage
What kind of cells would you find in the connective tissue proper?
Fibroblasts, fibrocytes, defense cells, and adipocytes
Which of the five major functions is cartilage responsible for?
Binding/support, protection
What are the three types of cartilage?
Hyaline, elastic, and fibrocartilage
What kinds of fibers can be found in cartilage?
Mostly collagen, some elastic
What class of connective tissue resists compression and functions to cushion and support body structures?
Cartilage
What class of connective tissue resists both compression and tension, functions in support, and provides protection and energy storage?
Bone
What type of fiber is found in osseous tissue?
Collagen
What component of connective tissue is instrumental in allowing it to bear weight, withstand great tension, and endure trauma?
The extracellular matrix
What are components of ground substance?
Interstitial fluid, cell adhesion proteins, and proteoglycans
What ground substance component is responsible for the substance’s viscosity?
Glycosaminoglycans of the proteoglycans; chondroitin sulfate and hyaluronic acid
What ground substance component serves mainly to allow cells to attach to the extracellular matrix?
Cell adhesion proteins
What ground substance component consists of large amounts of fluid through which nutrients and other dissolved substances can diffuse between cells and capillaries?
Interstitial fluid
What type of fiber provides high tensile strength due to cross-linking?
Collagen
What type of fiber allows stretching and recoiling and is found where great flexibility is needed?
Elastic
What type of fiber branches extensively, surrounds blood vessels and soft tissue organs, and is abundant in basement membranes?
Reticular
What connective tissue type is most widely distributed in the body?
Areolar connective tissue
Where is areolar connective tissue found?
In all mucous membranes as the lamina propria
What are the functions of areolar connective tissue?
Supporting and binding other tissues, holding body fluids and provided a reservoir of water and salts, defending against infection, and storing nutrients as fat
What cell types are found in areolar connective tissue?
Fibroblasts, macrophages, adipocytes, and mast cells
What molecule is present in high concentration in the ground substance of areolar connective tissue, making it highly viscous?
Hyaluronic acid
Although areolar connective tissue contains all three fiber types, which is the least abundant?
Collagen
Which loose connective tissue is highly vascular, has great nutrient storing ability, and accounts for 18% of an average person’s body weight?
Adipose tissue
What are the functions of adipose tissue?
Shock absorption, insulation, and energy storage
Where is adipose tissue found?
In the subcutaneous tissue, around the kidneys, behind the eyeballs, in genetically-determined locations such as abdomen and hips, and around the heart and lymph nodes
What does white adipose tissue do?
Stores nutrients
What does brown adipose tissue do?
Generate heat from lipids
What type of loose connective tissue has only one type of fiber, which forms a stroma that can support many free blood cells?
Reticular
Where is reticular connective tissue found?
Only in the lymph nodes, spleen, and bone marrow.
What type of dense connective tissue has closely-packed bundles of collagen fibers running in the same direction, parallel to the direction of pull?
Dense regular connective tissue
What types of cells are found in dense regular connective tissue?
Fibroblasts
What does dense regular connective tissue typically form?
Tendons, aponeuroses, and ligaments
What is the difference between tendons and ligaments?
Tendons attach muscle to bone while ligaments bind bones together at joints and contain more elastic fibers.
What are the flats sheetlike tendons that attach muscles to other muscles or to bones called?
Aponeuroses
What type of dense connective tissue has bundles of collagen arranged in multiple directions and forms sheets in body areas where tension is exerted in different directions?
Dense irregular connective tissue
Where is dense irregular connective tissue found?
In the skin as the dermis, in fibrous joint capsules, and as fibrous coverings that surround some organs
What type of dense connective tissue is found in both ligaments and in the walls of large arteries?
Elastic
What connective tissue class possesses qualities of both dense connective tissue and bone?
Cartilage
What two notable things does cartilage lack?
Blood vessels and nerve fibers
Where does cartilage get its nutrients from?
Blood vessels in the perichondrium
What does the ground substance of collagen contain?
Large amounts of glycosaminoglycans and collagen fibers
What allows cartilage to rebound after being compressed?
It is 80% water
What type of cartilage is most abundant?
Hyaline
Where is hyaline cartilage found?
The ends of long bones, the tip of the nose, connecting the rib to the sternum, supporting respiratory passages, and making up most of the embryonic skeleton
What type of cartilage is found where strength and flexibility are needed?
Elastic
Where is elastic cartilage found?
Epiglottis, external ear
What type of cartilage is similar to dense regular connective tissue?
Fibrocartilage
Where is fibrocartilage found?
Intervertebral discs; where strong support and ability to withstand heavy pressure is needed
What makes osseus tissue harder and more rigid than cartilage?
Its matrix contains inorganic calcium salts
What is the function of osteoblasts?
To form the organic portion of the extracellular matrix of bone tissue
Where would you find osteocytes?
In the lacunae of bone tissue
What are osteons?
Concentric rings of bony matrix surrounding central canals of blood vessels and nerves
Why is blood classified as a connective tissue?
It develops from mesenchyme and consists of cells surrounded by nonliving fluid matrix.
What are the elaborate networks of actin and myosin, responsible for movement and contraction, called?
Myofilaments
What are the special junctions between myocardial cells called?
Intercalated discs
How are myocardial cells linked together?
Via gap junctions and desmosomes at the intercalated discs
What are the two major cell types of nervous tissue?
Neurons and supporting cells (neuroglia)
Which neuron component receives a stimulus?
The dendrite
Which neuron component transmits electrical impulses?
Axons
What do the glial cells do?
Support, insulate, and protect neurons
What are the two most common epithelia types in mucous membranes?
Stratified squamous and simple columnar
What is the lamina propria?
A layer of areolar connective tissue that lies beneath all of the mucous membrane’s epithelial sheets.
What are the moist membranes found in the closed ventral body cavities called?
Serous membranes
What do serous membranes consist of?
Simple squamous epithelium (the mesothelium) resting on a thin layer of areolar connective tissue
How do mesothelial cells lubricate the facing surfaces of the parietal and visceral layers?
The add hyaluronic acid to the fluid being filtered from the capillaries into their associated connective tissue
What type of cartilage is a precursor to bone and is found in adult synovial joints?
Hyaline
What is the central cavity of an osteon called?
The Haversian canal
What two types of cells exhibit electrical excitability?
Neurons and muscle fibers
What is the soma of a neuron?
The cell body, containing the organelles and having an afferent and efferent side
What is the afferent side of a neuron?
The dendrites
What is the efferent side of a neuron?
The axon
Which part of the neuron conducts information to other cells?
The axon
What is the axon made of?
Microfibrils and microtubules
