Chp4 tissue level Flashcards
What are tissues?
•collection of specialized cells and cell products that perform a limited number of functions
What is the study of cells?
•histology
How many types of tissue is there? And name them
•4
- Epithelial Tissue
- Connective Tissue
- Muscular Tissue
- Nervous Tissue
Where can you find Epithelial Tissue?
• Covering exposed surfaces, lining internal passageway and chambers, and forming glands
Where can you find connective tissue?
- filling internal spaces,
- provides structural support for other tissues
- transports material w/in the body
- storing energy (triglycerides)
Where can you find Muscle Tissue?
- specializes in contraction
- skeletal muscle
- muscle of the heart
- muscular walls of hollow organs
What does Neural Tissue do?
•carry information in form of electrical impulses
What does Epithelial tissue include?
- epithelia
* glands
What is Epithelia?
- Layers of cells that cover internal or external organs
- Skin, blood vessels
- Lining digestive, respiratory, reproductive and urinary tracts
- ALL PASSAGEWAY TO THE OUTSIDE WORLD
What are glands?
- Structures that produce fluid secretions
* either attached to or derived from epithelia
What is cellularity of the epithelia?
- Cells bound closely together by interconnections known as cell junction.
- in other tissue type, the cells are often widely separated by extracellular material
What is Polarity of the Epithelia?
- epithelium has an expose surface called APICAL and an attached one named BASAL.
- polarity refers to their difference in membrane structure & function
What is the attachment of the epithelia?
•the bounding of the base of the epithelia to a thin Basement Membrane or Basal Lamina (produced by the basal surface)
What is Avascularity of the Epithelia?
- lacks blood vessels
* Epithelial cells obtain nutrients by diffusion or absorption either the exposed or attached epithelial surface
What is regeneration of the epithelia?
- the exposed layer of the epithelia is constantly being replaced by stem cell division.
- this can be found in other tissues, but at a much slower rate
How many and what essential functions does epithelial perform?
•4
- Provide Physical Protection
- Control permeability
- Provide sensation
- Produce specialized Secretion
What does Celia in an epithelia m?
- moves substances in or out of the exposed surfaces
* example: mucus from lungs to throat to be expelled
What factors maintain the integrity of epithelia?
- Intercellular connections
- Attachment to the basement membrane
- Epithelial maintenance and repair
What is the transmembrane protein that interconnects areas of opposing plasma membranes?
•Cell Adhesive Molecules (CAMs)
What are the 3 most common type of cell junctions?
- Right junctions
- Gap junctions
- Desmosomes
What is lumen?
•A central space w/in a duct or other internal passageway
What are the types of desmosomes?
- Spot desmosomes- small discs connected to bands of intermediate filament (stabilize shape of cell)
- Hemidesmosomes- attaches a cell to extracellular filaments in basement membrane (stabilizes the position of the epithelial cell)
5 important characteristics of epithelia?
- Cellularity
- Polarity
- Attachment
- Avascularity
- Regeneration
How is epithelia classified?
1. By number of layers
•simple
•stratified
2. By cell shape
•squamous
•cuboidal
•columnarSimple squamous epithelium that lines ventral body cavity?
• Mesothelium (middle)
Simple squamous epithelium lining the inner surface of the heart and all blood vessels?
• Endothelium (inside)
What is Keratinized epithelium important for?
• for tough and water resistant layers
What happens to nonkeratinized epithelial?
• are resistant to abrasion, but will dry out unless kept moist
Where is dimple cuboidal epithelium found?
•where absorption takes places, like kidney tubules
Where does stratified cuboidal epithelial found?
•rare tissue, located in ducts of sweat glands and larger ducts of mammary glands
What is rare about transitional epithelium?
.•it is an unlike stratified epithelium because it can stretch and recoil w/o damage
•example: the bladder when it’s full (cuboidal like) or empty (stratified squamous) of urine.
Where can you find simple columnar epithelium?
- where absorption and secretion occur such as the small intestine
- in the stomach and large intestines it protects against chemical stresses
What is pseudo stratified columnar epithelium?
- found in portions of the respiratory tract
- contains cilia and it is found in the trachea, nasal, & parts of make reproductive system
- are not truly stratified, cells are different shapes and sizes
Where can stratified columnar epithelium be found?
- a rare type of tissue
* found along portions of the pharynx, epiglottis, anus and urethra
What are the types of glandular epithelia?
- Endocrine glands -release their secretion INTO the interstitial fluid
•no ducts - Exocrine glands- release their secretion into passageways called “ducts” that open onto epithelial surface
•through ducts
Modes of secretion in glandular epithelium
- Merocrine secretion -most common
- Apocrine secretion -loss of cytoplasm
- Holocene secretion - cell bursts
Types of secretion in glandular epithelium
- Serous glands - watery solution that contains enzymes (salivary)
- Mucous glands - secretes mucins to form mucus and mucous
- Mixed exocrine glands - serous and mucous
What does connective tissue do?
- connects epithelia to the rest of the body
- bone, fat and blood provide structure, store energy and transports materials through the body
- never exposed to the outside world
What are the 3 basic components of connective tissue?
- Specialized cells
- Extracellular protein fibers
- Ground substance
•extracellular protein and ground substance constitute the MATRIX (volume)
What are the 3 major classification of connective tissue?
- Connective tissue proper - Loose (fat) dense (tendon)
- Fluid connective tissue -blood and lymph
- supporting connective tissue - cartilage and bone - matrix of bone is calcified
Connective tissue proper permanent population
- Fibroblasts -always present most abundant
- Fibrocytes - 2nd most abundant
- Adipocytes- fat cells
- Mesenchymal-embryonic tissue, stem cells, divide rapidly in case of injury
Connective tissue proper NON resident cells
- Macrophages-big eater, activate immune system
- Mast cells-small, near blood vessels (histamine)
- Lymphocytes- may develop into plasma cells which produce antibodies
- Microphages - phagocytic blood cells
What is melanocytes?
•store the brown pigment names Melanin which gives tissue it’s dark color.
What are the 3 types of fiber in connective tissue?
- Collagen fibers
- Reticular fibers
- Elastic fibers
What are collagen fibers?
- most common fibers in connective tissue
- long, straight and unbranched
- tendons
What are reticular fibers?
•thinner than collagen, form branching, interwoven framework (Stroma) that is rough, yet flexible
What are elastic fibers?
- contain the protein elastin
- are branches and wavy
- after stretching, they go back to original length
What is Elastic Ligaments important for?
- Rare type of ligaments
* interconnects vertebrae
What does histamine do?
• Stimulates local inflammation after an injury
What is the Matrix?
- Composed of Extracellular protein fibers and Ground Substance
- Majority of tissue Volume
- Determines specialized function
What is Mesenchyme?
- Embryonic connective Tissue
- First CT that appears in a developing embryo
- Gives rise to all other connective tissues
How do we classify glandular epithelia?
- By gland structure
* unicellular and multicellular (secretory sheet)
Only unicellular exocrine gland?
•mucous (goblet) cells
What are the 2 categories of connective tissue proper?
•loose and dense connective tissue
What is loose connective tissue?
- called the “packing material”
* more ground substance fewer fibers
What is loose connective tissue composed of?
•consists of
Areolar- open framework
Adipose- fat
Reticular- 3D Stroma found in lymph nodes and bone marrow
What is Dense connective tissue?
- often called collagenous tissue
* More fibers less ground substance
What is dense connective tissue composed of?
- Dense regular CT - parallel to each other, packed tightly
- Dense irregular CT- interwoven meshwork
- Elastic Tissue- composed of elastic fibers
What is fluid connective tissue?
•blood and lymphs with distinctive collection cells
What is the watery matrix in blood called?
- plasma
* contains blood cells and fragments of cells called- formed elements
What are formed elements composed of?
- White blood cells
- Red blood cells
- Platelets
What does the extracellular fluid contain?
- Plasma
- Interstitial fluid
- Lymph
What is supporting connective tissue?
- cartilage and bone
* contains numerous of fibers and insoluble calcium salts
What is cartilage in supporting connective tissue?
- AVASCULAR
- covered by a calcified matrix called chondroitin sulfate
- set apart from surrounding tissues by a fibrous perichondrium
What is the only cell type in cartilage?
- chondrocyte cells
* which occupy smells chambers called lacunae
How does cartilage grow?
By two mechanism
• interstitial growth- most important during development
• apposition all growth- new layers of cartilage added to the surface
•neither occur in adults
What are the types of cartilage?
- Hyaline cartilage- most common, tough yet flexible
- Elastic cartilage- resilient and flexible, yellowish
- Fibrocartilage- matrix dominated by interwoven collagen fibers
Where can you find hyaline cartilage and what does it do?
- between tips of ribs and sternum , supporting larynx, forming nasal septum
- stuff by flexible support and reduces friction
- lacunae are bubbly, matrix clear
Where can you find Elastic cartilage and what is its function?
- auricle of external ear, epiglottis, auditory canal
- provides supper but tolerates distortion w/o damage
- lacunae is round, elastic fiber in matrix looks like strings
Where can you find Fibrocartilage and what does is its function?
- pads between knee joint, Pubic bones of pelvis, intervertebral discs
- resists compression, prevents bone to bone contact, limits movement
- lacunae is round, fibrous matrix has soft strokes
What is bone is supporting tissue?
- Extensively VASCULAR
- high oxygen demands
- appositional growth only
- high repair capability
- Collagen fibers are predominant
What does lacunae in matrix of bone contain?
- Osteocytes - bone cells
- arranged around central canals
- canaliculi allow access to blood supply
What are tissue membranes?
- a physical barrier
- line or cover portions of the body
- consist of epithelium supported by connective tissue
How many types of membrane is there and what are they?
•4
- Mucous membrane
- Serous membrane
- Cutaneous membrane
- Synovial membrane
What covers bone surfaces?
- periosteum
* outer fibrous layer and I bet cellular layer
What does mucous membrane do?
- line passageways and chambers that communicate with the exterior.
- epithelial surfaces are moist to reduce friction
What is the areolar connective tissue in mucous membrane called?
• Lamina propria
What does serous membrane do?
- lines cavities NOT open to the outside (thin but strong)
- includes pleura (covering Lung) peritoneum (covers abd. Organs) pericardium (covering heart)
- parietal portion and visceral portion (serosa)
What is the fluid to reduce friction in serous membrane called?
• transudate
What does cutaneous membrane do?
- Skin
- Thick, water proof and dry.
- Keratinized
What does synovial Membrane do?
- articulates joint cavity
- produce lubricant called synovial fluid
- protects ends of bones
- lacks true epithelium
What is fasciae?
- body’s framework of connective tissue
* Layers and wrappings that support or surround organs
What are the three types of fasciae?
- Superficial fascia-
- Deep fascia-
- Subserous fascia
What is superficial fascia?
- Layers of areolar and adipose tissue
* Separates skin from underlying tissue
What is deep fascia?
- Dense irregular CT
* connects to capsules surrounding organs, perichondrium, periosteum, muscle tendons
What is Subserous fascia?
• Areolar layer between deep fascia and serous membrane
What does Muscle tissue do?
- specializes in contraction
* produces all body movements
How many types of muscle tissue are there and what are they?
•3
- Skeletal
- Cardiac
- Smooth
What is skeletal muscle tissue?
- voluntary
- striated
- multicleated
- can be up to a foot long
- long cylindrical
What is cardiac muscle tissue?
- involuntary
- striated
- intercalated discs
- branched
- short
- has cardiac “walls”
What is smooth muscle tissue?
- found in walls of hollow organs
- involuntary
- Non striated
- uninucleated
What is neural tissue?
- also know as nervous tissue
- specializes in conducting electrical Impulses
- 98% in brain and spinal chord
What are the two basic cells in neural tissue?
- neurons- longest cells in body
* neuroglia
What does neurons do?
- receives and sends information
- has dendrites (ears)
- has axons (tail like- conducts information)
What does neuroglia do?
- maintain physical structure of tissues
- Repair tissue framework
- provides nutrients to neurons
- regulate composition of surrounding neurons
What are the responses to tissue injury?
- inflammation
* regeneration
Germative cells?
• divide continually to produce new epithelia
Neuroglia
• Support, Protect and nourish nerve cell
