Tissues Flashcards
List the 6 functions of Epithelial tissue
- Protection - covering + lining
- Filtration - biochemical substances
- Absorption - nutrients
- Sensation - sensory input
- Secretion
- Excretion
List 6 characteristics of of Epithelial Tissue
- Are polar
- Have cell junctions
- Are avascular
- Are innervated
- Have a basal lamina
- Have surface specialization
epithelial cells have a sense of direction relative to surrounding structures
Polarity
epithelial cell surface that faces the lumen
Apical Surface
Body cavity
Lumen
epithelial cell surface that faces the underlying connective tissue
Basal Surface
the attachments between the plasma membranes on the lateral surfaces of neighboring epithelial cells
Cell Junctions
cellular attachments that prevent substances from leaking across the tissue
Tight Junctions
cellular attachments that consist of a strong plaque that cements neighboring cells together
Desmosomes
intermediate filaments that extend from the plaque into the cytoplasm of each cell like anchors to stabilize a desmosome junction
Tonofilaments
junctions that link epithelial cells to the basement membrane
Hemidesmosomes
cellular attachments that link the cytoplasm of neighboring cells together via connexons in order to allow the exchange of ions, electrical signals, and nutrients
Gap Junctions
Transmembrane channel proteins that extend between the cytoplasm of neighboring cells
Connexons
the non-living meshwork of fibers that cements epithelial cells to the underlying connective tissue and allows for the exchange of molecules and substances between the epithelial cells and the connective tissue
Basement Membrane (Basal Lamina)
What is the difference between microvilli and cilia?
Microvilli - fingerlike projections that increase the surface area of the cell and enhance the cell’s ability to absorb or secrete
Cilia - hairlike projections that serve to aid in the transport of materials
What are 4 actions taken by vet staff to treat patients with parvovirus?
- Combat the dehydration
- IV fluid therapy with electrolyte supplements
- Antibiotics
- Anti-vomiting meds
What are the 3 ways epithelia can be classified?
- Number of layers of cells
- Shape of cells in the luminal tissue surface
- Presence of surface specializations
Explain the difference between simple and stratified epithelia
Simple = a single layer of cells
Stratified = multiple layers of cells
Explain the characteristics and structural differences in squamous, cuboidal and columnar epithelial cells
- Squamous - flat + hexagonal cells, central disc shaped nuclei, fragile
- Cuboidal - cubic cells, central round nuclei, fragile, ciliated or smooth
- Columnar - elongated cells, nuclei aligned toward the basement membrane, protective, ciliated or smooth
What is special about pseudostratified columnar epithelial tissue? Give 3 reasons
- Appear stratified > due to not all cells reaching the luminal surface
- Nuclei at different levels across the tissue
- Simple tissue
What is special about transitional epithelial tissue? Give 1 reason
Layer cell shapes are based on the level of tissue distension > relaxed (cuboidal) or stretched (squamous)
the accumulation of a protective, waterproof substance within some epithelial cells
Keratinization
cells that manufacture and store lubricating mucus that is secreted onto the luminal epithelial surfaces in the GI tract
Goblet Cells
specialized protein molecules that remain within the body
Secretions
substances that ultimately leave the body
Excretions
Explain the 6 classifications of glands
- Presence or absence of ducts - endocrine or exocrine
- Number of cells - unicellular or multicellular
- Shape of secreting ducts - simple or compound
- Structure of secretory portion - tubular, alveolar, or tubuloalveolar
- Type of secretion - mucoid or serous
- Manner of secretion storage and discharge - merocrine, apocrine, or holocrine
glands that produce and secrete hormones directly into the bloodstream and lymphatic system
Endocrine Glands
Glands that:
- Have no ducts or tubules
- Don’t have to act locally
- Products enter circulation
Endocrine Glands
glands that discharge secretions directly into nearby areas where they may cover cell surfaces or empty into lumen
Exocrine Glands
Glands that:
- Have ducts
- Act locally
- Products do not enter circulation
Exocrine Glands
a thick, sticky mixture of glycoproteins and proteoglycans that become mucus when mixed with water
Mucin
What is the only unicellular exocrine gland?
Goblet Cells
Multicellular Exocrine Glands are made of what 2 things?
- Secretory Unit
- Duct
produce secretions in secretory cells and is surrounded by connective tissues
Secretory Unit
carries out the secretion to the deposition site
Duct
classification if the main duct is unbranched
Simple
classification if the main duct is branched
Compound
glands with secretory units that form long channels of even width
Tubular Gland
glands with secretory units that form rounded sacs
Alveolar (Acinar) Glands
glands with secretory units that possess both tubular and alveolar qualities
Tubuloalveolar Glands
thick, viscous secretions that are composed of glycoproteins
Mucoid Secretions
watery secretions that contain a high concentration of enzymes
Serous Secretions
glands that contain both mucous and serous components
Mixed Exocrine Glands
glands that package their secretions into granular units and release them as they are made via exocytosis
Merocrine Glands
glands that store granules until the apex of the cell is full, pinch in two, release the apex into the duct system, repair the damage and then repeat the process
Apocrine Glands
glands that store granules until they are needed and release their secretory product via the degeneration of the cell
Holocrine Glands
Match the gland to the result of secretory process:
- Apocrine/Holocrine/ Merocrine
- Remains intact during process / cells are damaged and repaired during process / cells are destroyed during process
Apocrine - damaged + repaired
Merocrine - remain intact
Holocrine - destroyed
What are the 2 functions of connective tissue?
Bind and Support the organism and the body systems
What are 5 characteristics of connective tissue?
- Consist of cells embedded in a nonliving matrix
- Vascularized
- Ground Substance
- Extracellular Fibers
- Various types of cells
a medium through which nutrients and waste are exchanged with the bloodstream and can act as a barrier against invading microorganisms
Ground Substance (matrix)
strong, thick, white strands composed of collagen that are organized into bundles of long, parallel fibrils
Collagenous (White) Fibers
What are the most common types of fibers in connective tissue?
Collagenous Fibers
thin, delicate strands composed of collagen that branch into complicated networks
Reticular Fibers
delicate strands composed of elastin that branch into complex networks
Elastic (Yellow) Fibers
What are collagen and elastin and what is the difference between them?
- Both are proteins
- Collagen allows for firmer support. Elastin allows for flexible support.
What areas are the following extracellular fibers found in? Give an example of each
1. Collagenous Fibers
2. Reticular Fibers
3. Elastic Fibers
- Collagenous > areas of high stretching and contracting force > tendons/ligaments
- Reticular > highly cellular organs > lymph nodes
- Elastic > tissues that stretch constantly > blood vessel walls
connective tissue cells that remain in the tissue and are involved in the production and maintenance of the matrix
Fixed Cells
large, irregularly shaped cells that manufacture and secrete both the fibers and the ground substance characteristic of their particular matrix
Fibroblasts
Explain the life cycle of fibroblasts
- Initially > metabolically very active + reproducing
- Maturation > less active > names adopt suffix -cyte
- Cells convert back to -blast form if more matrix is needed later
fat cells
Adipocytes
Where are 4 places adipose tissue can be found?
- Under the skin
- Behind the eyeballs
- Around the kidneys
- In the omentum of the abdominal cavity
flat, star-shaped cells with long, outreaching arms that form net-like connections throughout the tissue they compose in order to facilitate immune responses and manufacture their associated fibers
Reticular Cells
connective tissue cells that pass in and out of the tissue as needed and are involved in the repair and protection of the tissue
Transient Cells
cells found in blood that move into connective tissue in large numbers during infections
Leukocytes
oval shaped cells that contain large amount of dark-staining granules in the cytoplasm which contain histamine or heparin
Mast Cells
a biochemical that, when released into a tissue, increase blood flow to an area by making the capillaries leaky in order to initiate an inflammatory response
Histamine
a biochemical that, when released into a tissue, prevents blood from clotting and ensures the pathways for increased blood flow remain open in order to initiate an inflammatory response
Heparin
massive, irregularly shaped phagocytizing cells that are drawn to sites of infection or inflammation in order to engulf the microinvaders
Macrophages
the mixture of fibers and ground substance
Extracellular Matrix
What are the 2 categories of connective tissue?
- Connective Tissue Proper
- Specialized Connective Tissue
connective tissue that is embedded in a matrix of elastin and collagen
Connective Tissue Proper
What is the largest category of connective tissue?
Connective Tissue Proper
What are the 2 types of Connective Tissue Proper?
- Loose Connective Tissue
- Dense Fibrous Connective Tissue
What is the most common type of loose connective tissue?
Areolar Tissue
List the 3 types of Loose Connective Tissue
- Areolar
- Adipose
- Reticular
adipose tissue found throughout the body, particularly deep skin layers
White Adipose Tissue
adipose tissue found only in newborn animals + hibernating animals
Brown Adipose Tissue
List the 3 types of Dense Connective Tissue
- Dense Regular
- Dense Irregular
- Elastic Connective
How does dense fibrous connective tissue tightly packed structure affect its ground substance and cells?
- There is little room for ground substance and cells
- These tissues are found in smaller quantities than LCT
What are the 3 specialized connective tissues?
- Cartilage
- Bone (Osseous)
- Blood
List the 3 types of cartilage
- Hyaline
- Elastic
- Fibrocartilage
List the 3 components of Osseous Connective Tissue matrix
- Collagen fibers
- Calcium phosphate
- Calcium bicarbonate
List the 2 types of osseous connective tissue
- Compact
- Cancellous
What are the fibers and ground substance of blood as a specialized connective tissue?
“Fibers” > leukocytes, erythrocytes, thrombocytes
Ground Substance > plasma
a condition when the interstitial spaces fill with an excessive amount of body fluid due to trauma or pathogens
Edema
a condition in which an edema remains compressed in an area after pressing into it with a finger
Pitting Edema
a connective tissue that surrounds muscles, organs, and bones that can withstand forces from more than one direction due to the alternating direction of fibers in each layer
Fascia
a type of fascia that bind muscle to bone and to the fascia of other muscles
Aponeuroses
cartilage cells embedded in a matrix of collagen
Chondrocytes
hollowed-out pockets in a matrix that house connective tissue cells
Lacunae
a vascular membrane that surrounds and provides nutrition to cartilage
Perichondrium
hyaline cartilage at the ends of long bones in joints and connects the ribs to the sternum
Articular Cartilage
bone cells embedded in a matrix of collagen and minerals that form the skeleton of an organism
Osteocytes
a central channel that contains both a vascular and nerve supply within a bone
Haversian Canal
tiny threadlike channels that radiate away from the lacunae
Canaliculi
thin, protective layers that line lumen, separate organs, and cover surfaces
Membrane
membranes that line the organs of the reproductive, urinary, and respiratory tracts
Mucous Membranes (Mucosae)
Animals may show signs of illness through changes in appearance in what type of membranes?
Mucous Membranes
What are 4 colors of mucous membranes that may indicate illness?
- Yellow
- Blue
- Bright Red
- White
a condition in which bilirubin is elevated in the blood and causes a jaundiced appearance
Icterus
yellowing of the skin and mucous membranes
Jaundice
a condition that occurs when an animal cannot provide their tissues with adequate amounts of oxygen and causes blue mucous membranes
Hypoxia
a condition in which the mucous membranes of an animal turn bright red
Hyperemia
a state in which blood flow to peripheral tissues is increased
Hyperperfused
Shock, anemia and hypothermia cause what color mucous membranes?
Pale or White
Examining the mucous membranes of animals can tell you what 3 things?
- Signs of illness - color
- Hydration - tacky vs wet gums
- State of Circulatory System - examine CRT
Name 3 things that can cause prolonged CRT
- Compromised cardiac output
- Low BP
- Severe peripheral vasoconstriction
Name 2 things that can cause shortened CRT
- High BP
- Hypercompensatory States
What is normal, prolonged, and shortened CRT?
Normal = 2 seconds
Prolonged = > 2 seconds
Shortened = < 2 seconds
highly permeable membranes that line the walls and cover the organs that fill those cavities
Serous Membranes (Serosae)
Serous membranes are composed of what 3 things?
- Visceral Layer
- Parietal Layer
- Serous Fluid
a thin and watery transudate that reduces friction between the cavities and organs
Serous Fluid
a condition in which an abnormally large amount of fluid enters a body cavity or joint
Effusion
when an injury causes blood cells to leak into and build up in the pleural space due to broken capillaries
Hemothorax
an effusion in the peritoneal space of the abdominopelvic cavity
Ascites
an extracellular fluid that is able to pass through membranes into narrow spaces between tissue and has different names based on location
Transudate
Name the transudates in:
1. serous membranes
2. the thorax
3. the abdomen
4. the region around the heart
- Serous Fluid
- Pleural Fluid
- Peritoneal Fluid
- Pericardial Fluid
an extracellular fluid made of cells, protein and other solid material that is denser than a transudate
Exudate
abnormal connections that form between the parietal and visceral layers when serous membranes are damaged and the production of serous fluid is impeded
Adhesions
supportive ligaments in the abdominopelvic cavities that secure organs to the body wall and are made from merged layers of visceral serous membranes
Mesenteries
the mesentery that connects the stomach to the abdominal wall
Omentum
the mesentery that connects the uterus to the pelvic wall
Broad Ligament
List the 4 types of membranes found in the animal body
- Mucous Membranes
- Serous Membranes
- Cutaneous Membranes
- Synovial Membranes
an organ that is perpetually exposed to the outside environment and possesses unique features that distinguish it from other membrane types
Integument (Cutaneous Membrane)
What are the 2 layers of the Integument?
- Epidermis - superficial layer
- Dermis - deep layer
membranes that line the joint cavities and produce their associated fluid
Synovial Membranes
fluid that works with hyaline cartilage to reduce friction in joint spaces
Synovial Fluid
the removal of a small piece of tissue from an organ or mass that is used to find a definitive disease diagnosis
Biopsy
Give 5 methods of obtaining a biopsy specimen
- Inserting a special biopsy needle into the tissue
- Excising a piece of tissue with a scalpel
- Grasping attachments on the exploratory end of endoscopes
- Biopsy Punch
- Tissue Forceps (NOT dressing forceps)
a cookie-cutter type instrument used to get biopsy samples
Biopsy Punch
Why is it important to use sharp instruments when obtaining biopsies?
To prevent the microanatomy from being crushed
Biopsy samples are placed in a fixative solution of _____ buffered formalin
10%
The ratio of formative solution volume to tissue volume is _______.
10:1
Sliced samples of biopsies should be no thicker than _____.
1 cm
______ & ______ are fibers composed of specialized proteins arranged into microfilaments
Myosin & Actin
How many types of muscle tissue are there and what are they?
Three
1. Skeletal
2. Smooth
3. Cardiac
tissue that contains specialized cells that can conduct electrical and chemical impulses throughout the body
Nervous Tissue
Nervous tissue is located in what 2 major systems?
- Central Nervous System
- Peripheral Nervous System
the longest cells in the body (up to 1 meter) that form connections with other tissues in order to regulate body functions
Neurons
Nervous Tissue has 2 components. What are they?
- Neurons
- Neuroglial Cells
supporting neural cells that do not transmit impulses
Neuroglial Cells
List the 3 parts of a neuron
- Cell body
- Axon
- Dendrites
contains the nucleus and controls the metabolism of the cell
Cell Body
a long single extension that conducts impulses away from the cell body
Axon
short cytoplasmic extensions that receive impulses from other cells
Dendrites
What are the 3 stages of tissue repair?
- Inflammation
- Organization
- Regeneration
the first stage after injury in the body’s attempt to limit further damage to injured tissue and eliminate harmful pathogens
Inflammation
inflammation caused by viruses, bacteria, and fungi
Infection
The extent of inflammation depends on what 2 things?
- Type of tissue involved
- Severity of illness or injury
How long is the vasoconstriction period during inflammation?
5-10 min
the accumulation of dead and degenerated neutrophils and macrophages that may collect in an injured area
Pus
forms under the overlying blood clot and over the injured area to protect the injured tissue from further damage and inhibits infectious agents from entering the area
Granulation Tissue
when granulation tissue becomes too thick and stands out above the epithelial layer
Proud Flesh
Proud Flesh is commonly seen in what species with what injuries?
Horses with skin wounds
when particular cells around the wound edges actively divide to lay down a new layer of tissue over the granulation tissue
Epithelialization
scar tissue common in abdominal and thoracic cavities that covers organs and forms connections between multiple structures
Fibrous Adhesions
Classification of tissue healing depends on _______ & _______.
- Mechanism of healing
- Proximity of wound edges
healing that occurs in wounds in which the edges are held in close apposition, the skin forms a primary union without the formation of granulation tissue, and doesn’t result in significant scarring
First-Intention Healing
healing that occurs in wounds in which the edges are separated from one another, granulation tissue forms to close the gap and results in scarring
Second-Intention Healing
Surgery sites typically demonstrate what type of healing?
First-Intention Healing
List the 3 factors that affect healing rate and healing extent
- Age
- Overall health
- Nutrition
With unhealthy or critically ill animals, ________ is avoided and ________ is often used.
- Elective surgery is avoided
- IV nutrition is used
