Tissues And Cells Flashcards
What is the definition of tissues?
Groups of cells of the same type and function working together
What are the 4 types of tissues?
Epithelial
Connective
Muscle
Nerve
Definition of Epithelial tissue
Covers tissue for all of the ducts and body cavities in the body including mouth, blood vessels, thorax and bladder
What are the 6 main functions of Epithelial tissues?
Protects, covers and lines
Filters biochemical substances
Absorbs nutrients
Provides sensory output
Manufacturers secretion
Manufactures excretion
What are the characteristics of Epithelia?
Each Epithelia cell has an apical surface and a basal surface
Definition of Apical surface?
Faces the lumen or outside of the organ
Definition of Basal Surface
Faces the basal lamina and blood vessels
Remember: Basal Surface=Basement, attaches the cell to the interior mechanisms of the body
How are lateral surfaces connected to neighboring cells
Junctional complexes
Epithelial Cells are…
Avascular
Most Epithelial cells are…
Innervated
Matrix filled channels provide cells with
Nutrients
The plasma membranes are connected via ____ to create a strong network of communication
Junctions
Three major types of cellular junctions
Tight Junctions
Desmosomes
Gap Junctions
What are tight junctions formed by
The fusion of the outermost layers of the plasma membranes of adjoining cells
What tissues are tight junctions found in
Found in tissues in which there can be no leaks, such as, urinary bladder and digestive tract
How are Desmosomes formed
Mechanical coupling formed by filaments that interlock with one another
Tonafilaments exted from the ____ into the ____ (Desmosomes)
Plaque and Cytoplasm
What type of tissues are Desmosomes found in
Tissues that undergo repeated episodes of tension and stretching (skin, heart, uterus)
Meshwork of fibers that cements the epithelial cells to the underlying connective tissues
Basement Membrane
Also called Basal Lamina
Basement Membrane
Basement Membrane helps prevent the ____ from being torn off by intraluminal pressures (pressures against the cell)
Cell
Basement Membrane acts as a partial barrier between the ____ cells and the underlying ____ tissue
Epithelial and Connective
Surface Specializations (4 types)
Smooth
Microvilli (Smooth border)
Cilia
Keratin
Found in the gut. They increase surface area and allow for greater surface for absorption of nutrients and secretions
Microvilli
Found in the respiratory tract and the oviduct to help move objects along because ____ are an aspect of locomotion.
Cilia
Tissue that increase the surface area and the Microvilli are these tiny little finger like projections from the Epithelial cells that increase surface area for the cell itself (like a brush border)
Villi
The Epithelial cells of the outermost layer of the skin get impregnated with _____ in order to become waterproof and create a barrier.
Keratin
What characteristics are Epithelial tissues classified based on
Number of layers of cells
Shape of the cells
Prescience if surface specializations
Names for the amount of layers epithelial tissues (cells) can have
Simple (one layer)
Stratified (more than one layer)
Names for the shapes of the cells
Squamous-Flat
Cubodial-Cube shaped
Columnar-Tall
Large, flat, cornflake shaped epithelium cells that are found in areas of gas exchange (alveoli), pericardial, peritoneal and pleural cavity lining
Simple Squamous Epithelium
Single layer, round or cuboidal, has a large central nucleus and is commonly found in salivary glands, thyroid glands and the pancreas along with anywhere that secretion is occurring all of the time
Simple Cuboidal Epithelium
Tall and slender and has a oval nucleus. Ciliated found in the bronchi of the respiratory tract and oviduct, also found in areas of absorption and secretion
Simple columnar epithelium
Which epithelium is in the GI Tract as Microvilli or goblet cells and in mucus as fluid that comes out of the nose when congested
Simple Columnar Epithelium
Mucus producing cells that are often seen next to the collated columnar epithelium cells in the respiratory tract because along with deferring foreign materials out of the respiratory tract we also produce mucus continuously
Goblet Cells
Serious virus that puppies and older dogs can get (offers other animals but primarily dogs) the virus attacks the Epithelial lining in the GI tract. Causes sudden attack of the GI Epithelium which causes the cells to not work properly, not secrete, absorb nutrients which causes their epithelial tissue to lose its attachment
Parvovirus (Dogs)
Panleukopenia (Cats)
Cell nuclei are found at different levels across the length of the tissue, some cells don’t reach the liminal surface, found in respiratory tract and in portions of the male reproductive tract
Pseudostratified Columnar Epithelium
They are pretend stratified meaning they’re not technically in two layers, they’re in one layer but look like they’re in two layers because the lengths of the cells differ
Pseudostratified
Multi layer tissue lining the mouth, esophagus, and vagina
Tends to form a thick membrane
Protects the underlying tissue
Stratified squamous epithelium
___is most often the layer that’s closest to the lumen, lumen is the tallest, most tube like layer
Found only in select parts of the respiratory, digestive and reproductive systems and along some excretory ducts (sweat, salivary, and mammary glands) function in secretion, absorption and protection
Stratified Columnar Epithelium
Usually two layers of __cells
Primarily found along large excretory ducts
Protects underlying tissues
Secretion and protection
Stratified cuboidal epithelium
Looked at in urine samples
Found in areas of the body required to expand and contract as part of their normal functions
Leak proof connections
Transitional Epithelium
Specialized protein molecules that are produced in the rough endoplasmic reticulum, packaged into granules by the Golgi Apparatus, and discharged from the cell
Secretions
Releases it’s secretions directly into the bloodstream
Endocrine
Examples of endocrine gland
Adrenal gland
Thyroid gland
Pituitary gland
Discharges secretions via ducts directly into local areas or systems
Exocrine
Examples of exocrine gland
Liver
Pancreas
Sweat
Salivary glands
What animal does hyperthyroidism affect
Cats
What animal does Hypothyroidism affect
Dogs
Either a lack of feedback loop happening in the ___gland or the gland is malfunctioning and is producing too much of the hormone. Causes animal to lose weight and muscle, really high heart rate and owners describe them as hyperactive. It is treatable.
Hyperthyroidism
Their ___is not producing enough hormone which causes their metabolism to suffer and become slow which causes decreased immune function, changes in skin, start to lose hair, weight gain, no energy, lethargic and overtime their face can take on a specific shape
Hypothyroidism
Affects both cats and dogs and is when the pancreas is not responding to the high blood glucose by producing insulin
Diabetes Mellitus
Affects mostly dogs and affects the adrenal gland, it stops producing cortisol which causes the body to not respond well to stress and the body gives up which looks like losing blood pressure, lethargic and electrolyte imbalance when left untreated
Addisons Disease
Common in young German Shepherd’s. Hello bile colored diarrhea, smells terrible and causes them to get really skinny, caused by the pancreas not producing the needed enzymes to break down food product so the food gets shifted through the intestines without being fully broken down, digested and absorbed
Exocrine Pancreatic Insufficiency
Inflammation of the ___ and is most common in Shnauzers. Caused by change in the animals diet from increasing the level of fat in the diet. Symptoms include diarrhea and vomiting because their ___ stops secreting the enzymes that are needed for digestion
Pancreatitis
Involved in Exocrine and endocrine function
Pancreas
Most abundant tissue in the body
Connective tissue
Functions of connective tissue…
-Forms metabolic and structural connections between other tissues
-Forms a protective sheath around organs and helps insulate the body
-acts as a reserve for energy
Provides the frame that supports the body
Connective tissue
Background outside the cells, includes ___fibers and ground substances
Extracellular Matrix
The medium through which cells exchange nutrients & waste with the bloodstream, it acts as a shock absorbing cushion & it helped to protect the more delicate cells that it envelopes
Ground Substance
The 3 Types of Extracellular fibers
Collagenous Fibers
Reticular Fibers
Elastic Fibers
-Strong, thick strands of collagen
-Organized into bundles of long, parallel fibrils composed of bundled microfibers
-Found in tendons and ligaments
Collagenous Fibers
-Thin, delicate branches networks of collagen
-Provide support for highly cellular organs
-Also found around blood vessels, nerves, muscle fibers and capillaries
Reticular Fibers
-Branched networks composed primarily of the protein elastin
-Composed of Coiled bundles of microfibrils
-Occur in tissues commonly subjected to stretching
Elastic Fibers
Involved in production and maintenance of the matrix (Fibroblasts, Chondroblasts, Osteoblasts, adipocytes and Reticular cells)
Fixed Cells
Involved in the repair and protection of tissues (Leukocytes, Mast cells and macrophages)
Transient cells
The baseline connective tissue cell
Fibroblasts
When the cells get designated to a specific area of connective tissue (such as cartilage)
Chondroblasts
Associated with bone
Osteoblasts
Associated with fats
Adipocytes
Connective tissue with some possible immune response
Reticular Cels
As they become adult cells we drop the suffix ‘blasts’ and become ‘Cytes’
Fibrocytes
Chondrocytes
Osteocytes
Adipocytes
White blood cells that wander from blood into tissue during times of infection or clean up. They either physically eat foreign invaders so they can phagocytize or they produce an immune response to foreign invaders
Leukocytes
They circulate close to blood vessels and when they identify a foreign invader they burst open and release histamine into the bloodstream, this is the initiation of a systemic allergic reaction and inflammation
Mast Cells
Specialized cells that engage in phagocytosis, they can either be fixed or transient in connective tissue, if they are fixed than they are typically named for their locations such as Kupffer cells which are ___ only found in the liver
Macrophages
