Tissues Flashcards
Define tissue
A group of one or more cell types which carries out specialized function/ functions
What are the four major types of animal tissue
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
What is the location of epithelial tissue
Covers the external or internal surfaces and organs.
How does the epithelial tissue get its nutrients and oxygen
From the underneath connective tissue
What are the characteristics of epithelial tissues ?
1) covers the external and internal free surfaces and organs
2) cells are closely packed
3) cells have both apical and basal surfaces where the apical surface is free and the basal surface is attached to the basement membrane
4) no blood vessel
5) gets nutrients and oxygen from connective tissue underneath
Functions of epithelial tissue
Protection
Secretion
Absorption
Epithelial tissue provided protection against
Mechanical injury
Fluid loss
Pathogens
Epithelial tissues secrete
Enzymes
Hormones
Mucus
Sweat
Epithelial tissues absorb
Nutrients
What are the two general types of epithelial tissues based on the number of cell layers on the basement membrane ?
- Simple epithelia
- Compound epithelia
What are the examples for simple epithelia
- Simple squamous
- Simple cuboidal
- Simple columnar
- Pseudostratified
Examples for compound epithelia
Stratified squamous
Transitional
Features of simple squamous epithelium
- Single cell layer with plate like cells
- Thin and leaky
- Found in places where material exchange by diffusion
What are the examples for two places with simple squamous epithelia
Blood capillary
Alveoli
What are the features of simple cuboidal epithelium
- Single cell layer with dice shaped cells
- Specialized for secretion
- Found in glands
Places where simple cuboidal epithelium are found
Kidney tubules
Thyroid glands
Salivary glands
Features of simple columnar epithelia
- Single cell layer with large brick shaped cells
- Often Found in places where secretion and absorption are important
Example for a place that has simple columnar epithelium
Intestinal lining
What are the features of pseudostratified columnar epithelium
- Single cell layer
- Cells are not equal height
- Nuclei of cells are located at different levels.
- Cells appear to be as several layers
- In many vertebrates has ciliated cells that form a mucous membrane
Places where pseudostratified columnar epithelium is found
Nasal passage
Trachea
Features of stratified columnar epithelium
- Composed of number of cell layers
- Regenerate rapidly
- Cell division produces new cells at the basement membrane
- Old cells are sloughed off
- Found on surfaces where they are subjected to abrasion
Where are stratified squamous epithelium found
Outer skin
Lining of mouth
Anus
Vagina
What is the most abundant type of animal tissue
Connective tissue
What is the primary function of connective tissue?
Connect organs and tissues together structurally and functionally
General structure of connective tissues
Consists of different types of cells scattered in a large amount of extracellular matrix containing different types of fibres.
What are the states the matrix can be in
Semi-solid (jelly like)
Liquid
Solid (dense and rigid)
What are the different types of cells found in matrix
- Fibroblasts
- Macrophages
- Mast cells
Additionally - Fat cells
- Leukocytes
What secretes fibre proteins
Fibronectin
Function of macrophages
Engulf foreign particles or any cell debris by phagocytosis
Function of mast cells
Secrete heparin histamine
Function of fat cells
Storage
Insulation
Function of leukocytes
Protection
What are the three types of fibres found in connective tussues
- Collagen fibres - strength and flexibility
- Reticular fibres - join connective tissue to adjacent tissue
- Elastic fibres - make tissue elastic
What are the functions for connective tissues
Binding and structural support
Protection
Transport of material
Insulation
What are the different types of connective tissues
Loose connective tissue - areolar tissue
Fibrous connective tissue - dense connective tissue
Adipose tissue
Blood
Cartilage
Bone
What is the mostly widespread connective tissue in the vertebrate body
Areolar connective tissue
Loose connective tissue
What is the generalized type of connective tissue
Areolar connective tissue
What are the types of cells in loose connective tissue
Fibroblasts
Mast cells
Macrophages
Leukocytes
Fat cells
Arrangement of the three fibres in areolar connective tissue
Loosely arranged and wavy in nature
Functions of areolar tissue
Binds epithelia and underlying tissue
Holds organs in place
Found under the skin throughout the body
Arrangement if fibres and cells and matrix in fibrous Cn. Tissue
Densely packed with collagen fibres
Matrix is relatively reduced
Fewer fibrocyte cells are found
Where are fibrous connective tissues found
Tendons (attach muscle to bone)
Ligaments (attach bones at joints)
Where tensile strength is required
What is the specialized type of loose connective tissue that pads and insulated the body will
Adipose tissue
What are the functions of adipose tissue
Pads and insulates the body
Store fuel as fat molecules
Act as thermal insulator and energy store under skin
What type of cell are found abundantly in adipose tissue
Adipose cells that contain a large fat droplet .
What is the specialized connective tissue where the matrix is not secreted by the cells
Blood tissue
Among the connective tissues why is the blood tissue different than the others
Matrix is not secreted by the blood cells
Fibres are formed only during blood clotting process
What is the liquid extracellular matrix of blood called
Plasma
What are the constituent of blood plasma
Salts
Water
Dissolved proteins
What are the cells suspended within blood plasma
Red blood cells - transport respiratory gases
White blood cells - involve in defense
Platelets - involve in blood clotting
Main functions of blood tissue
Transport of materials
Defense
Osmoregulation
What is the matrix of cartilage composed of?
Chondroitin sulphate
A rubbery protein carbohydrate complex
What are embedded in the matrix of cartilage
Collagen fibres and chondrocytes
What secretes chondroitin sulphate and collagen fibres
Chondrocytes
Function of cartilage
Provide support and flexibility in places like trachea and inter-vertebral discs
What is the mineralised connective tissue
Bone
What are the constituents of bones
Collagen and inorganic salts
What are the inorganic components found in plants
Calcium
Magnesium
Phosphate ions
What are the types of cells found in bones
Osteoblast : bone forming cells
Osteocytes : mature bone cells
What encloses the osteocytes
Lacunae
What is the repeating unit of mammalian hard bone
Osteons
Composition of osteons
Concentric layers of mineralised materials
Centre of the osteon
Is a central canal containing blood vessels and nerves
Functions of bones
Forms the endoskeleton of most vertebrates
Provide support and strength to body
What tissue is responsible for movement
Muscle tissue
What proteins are present in the muscle tissue cells
Actin
Myosin
What are the three types of muscle tissues
Smooth muscle
Skeletal muscle
Cardiac muscle
What abilities of muscle tissues help it with movement
Ability to contract relax
Features of smooth muscle tissue
Spindle shaped
Uni nucleated
Cells lack striations
Function of smooth muscle tissue
Involuntary body functions like
Churning if stomach
Constriction of arteries
Locations of smooth muscle tissues
Digestives tract
Urinary bladder
Arteries
Other internal organs
Features of skeletal muscle tissue
Composed of bundle of long cells
Multi nucleated
Cells are striated
What is the contractile unit of skeletal muscle tissue
Sarcomers
What gives the striated appearance to the skeletal muscle tissue
The arrangement of sarcomers along the muscle cells
What is the location of skeletal muscle tissue
Generally attached to the skeletal system
What is the function of skeletal muscle tissue
Helps mainly in voluntary body movements
What are the features of cardiac muscle tissue
Uni nucleated cells
cells are interconnected via intercalated disc
cells are striated with sarcomers
Where is the cardiac muscle tissue found
Only found in the wall of the heart
Where is the cardiac muscle tissue found
Only found in the wall of the heart
What is the main function of cardiac muscle tissue
In voluntary heart contractions
What is the use of intercalated disc
They help relay signals from cell to cells and synchronise heart contractions
What are the cells found in nervous tissue
Neurons
Glial cells
What are the functions of neurons
Receive process and transmit nerve impulses
What is the function of neuroglia
Glial cells
Support the neurons
What are the parts of a neuron
Cell body
dendrites
Axon
What is the basic structural unit of the nervous system
Neuron
What are the parts of the neuron that receive nerve impulses from other neurons
Dendrites
cell body
What is the function of axon
Transmit impulses to other neurons cells or muscles
What is a bundle of axon called
Nerves
What are the functions of neuroglia
Nourishment of nerve cells
insulation of nerve cells
replenishing neurons
sometimes modulate neuron functions
