Ch.4 Tissue Flashcards
Tissues
groups of cells similar in structure and function
4 primary tissue types
- epithelium
- connective
- muscle
- nervous
Nervous tissue
- internal communication
- brain, spinal cord, nerves
Muscle tissue
- contracts to cause movement
1. skeletal: muscles attached to bone
2. cardiac: muscles of heart
3. smooth: muscles of walls of hollow organs
epithelial tissue
- forms boundries between different environments, protects, secretes, absorbs, filters
- skin surface (epidermis)
- lining of Gi tract organs and other hollow organs
- two types: lining & covering + glandular
lining & covering epithelium function
type of epithelial tissue
- protection
- absorption
- filtration
- excretion
- secretion
- sensory reception
lining & covering epithelium characteristics
type of epithelial tissue
- close packed cells
- Polarity
apical – free surface (no tissue attached)
basal – attached to underlying basement membrane - basement membrane - connective tissue that anchors and supports the epithelium
Two layers:
basal lamina - noncellular, adhesive sheet of glycoproteins reticular lamina - between basal lamina & underlying tissue made of thin collagen fibers - avascular ( no capillaries…..nutrients diffuse through underlying connective tissue)
- fast regeneration (short life span due to stress, high rate of mitosis)
lining & covering epithelium nomenclature
first name = how many layers of cells
- simple: diffusion, absorption, filtration
- stratified: protection
second name = shape of apical cells
- squamaous
- cubodial
- columnar
stratified cubodial
epithelium
- quite rare in body
- found in some sweat and mammary glands, secretory function
- typically two cell layers thick
Stratified Columnar
- Limited distribution in body
- Small amounts in pharynx, male urethra, and lining some glandular ducts
- occurs at transition areas between two other types of epithelia
- structural integrity, seen where tissue types meet
Glandular epithelium
Type of epithelial tissue
- Glands are organs that make and secrete a product (usually a water based fluid with proteins)
Glandular epithelium classification
- endocrine (ductless glands)
- Product = hormones
- Secretion is into the blood - exocrine (ducted glands)
- Products vary
- Secretion is through a duct onto a body surface
- Unicellular = single cells mixed among epithelial cells example = goblet cells
- Multicellular = consist of a secretory unit and a duct
- - merocrine = secretes product by exocytosis (pancreas, sweat, saliva)
Exocrine gland multicellular types
Glandular epithelium –> exocrine glands –> 2 multicellular types
- merocrine: secretes product by exocytosis (pancreas, sweat, salvia)
- holocrine: product accumulates and cell ruptures to release product (oil glands)
connective tissue types
- Fibrous connective tissue (connective tissue proper) – fat and fibrous tissue of ligaments
- Supporting connective tissue – cartilage and bone
- Fluid connective tissue – blood and lymph
connective tissue function
- Binding of organs
- Support
- Physical protection
- Immune protection
- Movement
- Storage
- Insulation
-Transport
connective tissues charcteristics
- Varying degrees of vascularity
- Cells separated by nonliving extracellular matrix (ground substance and fibers)
connective tissue structure
- Ground substance - Medium through which solutes diffuse between blood capillaries and cells
- Mitotically active and secretory cells = “blasts”
- Mature cells = “cytes”
Components:
- Mature cells = “cytes”
- Interstitial fluid
- Adhesion proteins (“glue”) - fibers that link cells
– ex. Fibronectin – attaches collagen to other substances - Proteoglycans (protein + sugar)
– ex. Hyaluronic acid – viscous, slippery, holds water
Three fibers of connective tissue
- Collagen (white fibers)
- Strongest and most abundant type
- Provides high tensile strength - Elastic: Networks of long, thin, elastin fibers that allow for stretch
- Reticular: Short, fine, highly branched collagenous fibers
Connective Tissue cell types
- Fibroblasts in connective tissue proper
- Chondroblasts and chondrocytes in cartilage
- Osteoblasts and osteocytes in bone
- Hematopoietic stem cells in bone marrow
- Fat cells, white blood cells, mast cells, and macrophages
Fibrous connective tissue (connective tissue proper) types
- Loose – areolar, reticular and adipose
- Dense – regular, irregular and elastic
Supporting Connective Tissue Types
- cartilage: hyaline, elastic and fibrocartilage
- bone
Cartilage Tissue Structure Characteristics
Connective Tissue –> Supporting Connective Tissue –> Cartilage Tissue
- Composition = avascular and not innervated
- ground substance = can be up to 80% water
- fibers = mostly fine collagen and some elastin
- cells = chondrocytes in lacunae
- Function = strong, yet f lexible, supportive
Hyaline cartilage
Description:
- Amorphous and firm matrix
- collagen fibers form an imperceptible network;
- chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae
Function:
- Supports and reinforces
- has resilient cushioning properties
- resists compressive stress.
Location:
- Forms embryonic skeleton
- covers the ends of long bones in joint cavities
- forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx
Elastic cartilage
Description:
- Similar to hyaline cartilage, but more elastic fibers in matrix
Function:
- Maintains the shape of a structure while allowing great flexibility
Location:
- Supports the external ear (pinna) + epiglottis
Fibrocartilage
Description:
- Matrix similar to but less firm than that in hyaline cartilage
- thick collagen fibers predominate
Function:
- Tensile strength with the ability to absorb compressive shock.
Location:
- Intervertebral discs
Bone Tissue characteristics
Connective Tissue –> Supporting Connective Tissue –> Bone Tissue
- well vascularized & innervated
- ground substance = contains calcium salts
- fibers = layers of collagen adjacent layers run in opposite direction
- cells = osteocytes, adipocytes, hemocytoblasts
Bone Tissue
Connective Tissue –> Supporting Connective Tissue –> Bone Tissue
Description:
- Hard, calcified matrix containing many collagen fibers
- osteocytes lie in lacunae
- well vascularized.
Function:
- Bone supports and protects (by enclosing)
- provides levers for the muscles to act on
- stores calcium, minerals and fat
- marrow inside bones is the site for blood cell formation (hematopoiesis)
Fluid Connective Tissues
Type of Connective Tissue
Structure:
- Liquid Tissue:
– Plasma and blood clotting fibers
- Cells:
– Rbc’s
– Wbc’s
– platelets
- Types: Blood and Lymph
Blood
Connective Tissue –> Fluid Connective Tissue –> Blood
Description: Red and white blood cells in a fluid matrix (plasma).
Function: Transport of respiratory gases, nutrients, wastes, and other substances.
Location: Contained within blood vessels.
Nervous tissue
- Cells: Neurons(branching cells) + neuroglia
- Function: Transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity.
Location: Brain, spinal cord, and nerves
Muscle tissue
Structural Elements:
3 types of cells:
- Myocytes
- Cardiocytes
- Visible nuclei
Striations (skeletal and cardiac)
Intercalated discs (cardiac)
3 types:
- Skeletal
- Cardiac
- Smooth
Skeletal Muscle
Type of Muscle Tissue
Description:
- Long + cylindrical
- multinucleated cells
- striated
Function:
- Voluntary movement/ control
- locomotion
- manipulation of the environment
- facial expression
Location:
- In skeletal muscles attached to bones or skin
Cardiac muscle
Type of Muscle Tissue
Description:
- Branching
- striated
- uninucleate cells that interdigitate at specialized junctions (intercalated discs)
Function:
- contracts –> propels blood into the circulation
- involuntary control
Location:
- The walls of the heart.
Smooth Muscle
Type of Muscle Tissue
Description:
- Spindle-shaped cells with 1 central nuclei
- not striated
- cells arranged closely to form sheets
Function:
- Propels substances or objects (foodstuffs, urine along internal passage ways
- involuntary control
Location:
- Mostly in the walls of hollow organs
Types of Membranes
- Cutaneous
- Mucous
- Serous
Cutaneous Membranes
- skin
- stratified squamous epithelium + dense irregular connective tissue
Mucous Membranes
- Structure = epithelium varies (stratified
squamous, simple columnar, or pseudostratified) + areolar loose
connective tissue (this is called lamina propria) - Location = lines cavities that are open to the external environment (digestive, respiratory, urogenitalia)
Serous Membranes
- Structure = simple squamous epithelium (mesothelium) + areolar connective tissue
- Location = lines cavities not open to external environment (pleura, pericardium, peritoneum)
