Tissues Flashcards
Collections of specialized cells and the extracellular substances surrounding them
Tissues (note: hindi lang cells, kasama ang extracellular substances)
Body tissues are classified based on 3 characteristics. What are these?
- ) Structure of the cells
- ) Composition of the noncellular substances surrounding the cells (aka: extracellular matrix or ECM)
- ) Functions of the cells
Note: Struc(k) Comp-E Fun
What do you call the noncellular substances surrounding the cells?
Extracellular matrix or ECM
What are the four types of tissues?
- ) Epithelial Tissue
- ) Connective Tissue
- ) Muscle Tissue
- ) Nervous Tissue
What are the basic functions of epithelial tissues?
- ) Protecting underlying structures
- ) Acting as a barrier
- ) Permitting the passage of substances
- ) Secreting substances
- ) Absorbing substances
Note: Pro Acting Permits Secret(e) Abs
Epithelial tissue can be further classified according to 2 characteristics. What are these?
Number of layers & Shape of cells
List down all classifications of epithelium.
- ) Simple squamous
- ) Simple cuboidal
- ) Simple columnar
- ) Stratified squamous
- ) Stratified cuboidal
- ) Stratified columnar
- ) Pseudostratified columnar
- ) Transitional
Which classification of epithelium can be even further divided into nonkeratinized (moist) and keratinized?
Stratified squamous
Single layer of flat, often hexagonal cells; the nuclei appear as bumps when viewed across a cross section because the cells are so flat
Diffusion, filtration, some secretion, and some protection against friction
(( Note: “some” protection lang ))
Located in the alveoli of the lungs, portions of the kidney tubules, lining of the blood vessels of the heart, lymphatic vessels (endothelium) and small ducts, lining of serous membranes (mesothelium) of the body cavities (pleural, pericardial, peritoneal) and inner surface of the lymphatic membranes.
Simple squamous
Note: One flat layer lang ito, thus, it only provides ‘some’ protection against friction. Key structures are alveoli of the lungs and portions of the kidney tubules
Bakit kailangang simple squamous ang nasa alveoli of the lungs?
Because we need oxygen and other gasses to penetrate right away. Simple squamous allows the most diffusion of substances among all of the epithelial tissue classifications.
Hindi pwedeng makapal, kailangan manipis.
Single layer of cube-shaped cells; some cells have microvilli (kidney tubules) or cilia (terminal bronchioles of the lungs)
Secretion and absorption by cells of the kidney tubules; secretion by cells of glands and choroid plexuses; movement of particles embedded in mucus out of the terminal bronchioles by ciliated cells
Located in the kidney tubules, glands and their ducts, choroid plexuses of the brain, lining of terminal bronchioles of the lungs, surfaces of the ovaries
Simple cuboidal
Apparently, simple squamous and simple cuboidal can both be located in the kidney tubules. Expound.
Some portions of the kidney tubules are simple squamous epithelium. Meanwhile, kidney tubules are lined with simple cuboidal epithelium. Though they are different in shape, their single-layeredness still allows for good diffusion of substances, a vital function of the kidney as an organ.
Single later of tall, narrow cells; some cells have cilia (bronchioles of lungs, auditory tubes, uterine tubes, and uterus) or microvilli (intestines)
Movement of particles out of the bronchioles of the lungs by ciliated cells; partially responsible for the movement of oocytes through the uterine tubules by ciliated cells; secretion by cells if the glands, the stomach, and the intestines; absorption by cells of the small and large intestines
(( Keyword: Movement, secretion, and absorption ))
Glands and some ducts, bronchioles of the lungs, auditory tubes, uterus, uterine tubes, stomach, intestines, gallbladder, bile ducts, ventricles of the brain
Lining of stomach and intestines
(( Keyword: Parts of the GI tract ))
Simple columnar
Multiple layers of cells that are cube-shaped in the basal layer and progressively flattened toward the surface; the epithelium can be nonkeratinized (moist) or keratinized
Protection against abrasion, a barrier against infection, reduction of water loss from the body
Located:
Keratinized - primarily in skin
Nonkeratinized - mouth, throat, larynx, esophagus, anus, vagina, inferior urethra, cornea
Stratified squamous
Note: Don’t be confused by the word “cube-shaped” in the definition. Focus on “progressively flattened toward the surface”
When stratified squamous epithelium is ____, the surface cells retain a nucleus and cytoplasm.
nonkeratinized
When stratified squamous epithelium is ____, the cytoplasm of cells at the surface is replaced by a protein called keratin, and the cells are dead.
keratinized
When the stratified squamous epithelium is said to be “keratinized” is it moist or dry?
Dry
Note: Think of “keratin” as Mighty Bond™
When the stratified squamous epithelium is said to be “nonkeratinized” is it moist or dry?
Moist
Note: Think of “keratin” as Mighty Bond™
Multiple layers of somewhat cube-shaped cells
Secretion, absorption, protection against infection
Located in sweat gland ducts, ovarian follicular cells, salivary gland ducts (parotid, sublingual, submandibular)
Stratified cuboidal
Multiple layers of cells with tall, thin cells resting on layers of more cube-shaped cells; the cells are ciliated in the larynx
Protection, secretion
Mammary gland ducts, larynx, a portion of the male urethra
Stratified columnar
Note: Don’t be confused by the word “cube-shaped” in the definition. Focus on “thin cells resting on layers”
Single layer of cells but some are tall, thin, and reach the free surface while others do not; the nuclei of these cells are at different levels and appear stratified; the cells are almost always ciliated and are associated with goblet cells that secrete mucus onto the free surface
Synthesize and secrete mucus onto the free surface; move mucus (or fluid) that contains foreign particles over the surface of the free surface and from passages
Lining of the nasal cavity, nasal sinuses, auditory tubes, pharynx, trachea, bronchi of the lungs
Pseudostratified columnar
Note: Single layer; nuclei at different levels; appear stratified
Note: Mucus
Note: Almost all respiratory tract organs are lined with pseudostratified columnar
Stratified cells that appear cube-shaped when the organ or tube is not stretched and squamous when the organ or tube is stretched by fluid; the number of layers also decreases on stretch
Accommodate fluctuations in the volume of fluid in organs or tubes; protect against the caustic effects of urine
Located in the lining of the urinary bladder, ureters, superior urethra
Transitional
Note: Cube when not-stretched; Squamous when stretched
Note: Holds urine
Note: Located in renal tract except inferior urethra
Connective Tissue is divided into 2 categories. What are these?
Proper & Specialized
Proper connective tissue is further divided into 2 categories. What are these?
Loose & Dense
Specialized connective tissue is further divided into 3 categories. What are these?
Bone, Blood, & Cartilage
Note: Specialized = BBC
What are the basic functions of connective tissues?
- ) Enclosing and separating other tissues
- ) Connecting tissues to one another (tendon & ligament)
- ) Supporting and moving parts of the body
- ) Storing compounds (adipose and bone)
- ) Cushioning and insulating (adipose)
- ) Transporting (blood)
- ) Protecting (bone)
Note: ECon SupStor CuTP
Specialized cells of various connective tissues that produce the extracellular matrix
Connective Tissue Cells
Note: ECM can be imagined as a “gel”.
The three suffixes of connective tissue cells are:
-blast, -cyte, & -clast
(Type of Connective Tissue Cell)
Creates or forms the ECM
Blasts (-blast)
(Type of Connective Tissue Cell)
Maintains the ECM
Cytes (-cyte)
(Type of Connective Tissue Cell)
Breaks down the ECM for remodeling
Clasts (-clast)
Name the three connective tissue cells that forms, maintains, and breaks down the [[[bone]]], respectively.
- ) Osteoblast (forms)
- ) Osteocyte (maintains)
- ) Osteoclast (breaks down)
It is made up of protein fibers, ground substance, and fluid.
Extracellular Matrix
Note: ECM can be imagined as a “gel”.
Most abundant protein in the body.
Collagen
Collagen accounts for ____ of total body protein, or ____ of total body weight.
(fraction, percentage)
- ) one-fourth to one-third
2. ) 6%
Collagen is synthesized within ____ and secreted into the ____.
- ) fibroblasts
2. ) extracellular space
Expound on the process of creating collagen fibers.
- ) Collagen is synthesized by fibroblasts and secreted into the extracellular space.
- ) They are then linked together to make long collagen fibrils.
- ) The fibrils are joined together in bundles to form collagen fibers.
Very strong and flexible, like microscopic ropes, but quite inelastic.
Collagen fibers