Tissues
Epithelial Tissue  Tissue that always faces a free surface
Examples: Skin; lining of mouth
Cells are layered on top of one another
Part of cells opposite the free surface attaches to a basement
membrane
Basement membrane  membrane packed with proteins and
carbohydrates
Basement Membrane
Types of Epithelial Tissue
Simple  single layer of cells
Used for absorption, diffusion, and excretion
Stratified  2 or more cell layers
Used for protection
Pseudostratified single, staggered layer of cells
Usually ciliated; cilia sweep mucus across cell surface
Shapes of Epithelial Cells
Squamous epithelial --> Flattened cells
Cuboidal epithelial  Cube shaped cells
Columnar epithelial  Column shaped
Putting it All Together
Simple Squamous cells  lining of blood vessels; lungs
Simple Cuboidal Cells ducts and glands
Simple Columnar Cells  stomach and intestines
Stratified Squamous Cells  skin
Stratified Cuboidal Cells  ducts of sweat glands
Stratified Columnar Cells  ducts of salivary glands
Pseudostratified Columnar Cells  throat, nasal passages
Epithelial Tissue Types
The following pix are NOT in your Notes!
I just want you to SEE what these tissues types look like
I also want you to see SOME of their functions & locations
Function: to
protect
Location: outer layers
of skin
Description: single
layer of columnar
cells with cilia
Location: lines uterus,
central canal of spinal
cord, and some upper
respiratory tract
Function: moves particles
and fluids along
Description: two or more layers of
cubed shape cells
Location:
sweat glands
Function: to protect
Description: several
layers of
polyhedral cells
Location: excretory ducts in some
glands
Function: secretion
and protection
Glands
Glands  cells that secrete substances; made from epithelial cells
Exocrine Glands  secrete substances to the free surface of epithelial
cells through ducts
Example: Goblet Cells  secrete mucus into trachea
Saliva, earwax, and oil
Endocrine Glands  secrete substances directly into fluid
Example: Hormones are released directly into bloodstream
Thyroid, adrenal, and pituitary gland
Glands
Endocrine gland
Exocrine gland
Membranes
Membranes  sheet-like coverings over organs
Mucous Membranes  line the cavity of digestive, respiratory systems;
have ducts that release mucous
Serous Membranes  enclose organs
Cell to Cell Contact &
Connective Tissue
How do cells stick together?
Tight Junctions  rows of proteins that seal cells together
Prevents molecules from getting stuck in between cells
Important in epithelial cells of the intestines
Adhering Junctions  Mass of proteins (called desmosomes) that spot
weld the cell together at a very specific point
Important in areas where stretching occurs
Found in skin cells, lining of stomach
Gap Junctions  protein channels that connect cells
Promotes cell-to-cell communication; allows ions to move through cells
Found in heart & and other organs
Connective Tissues
Connective Tissue  Most abundant tissue in the body
Small numbers of cells embedded with connective fibers such as collagen
and elastin
Collagen  structural protein fibers give mass and volume to structures
Fibroblasts  secrete jelly-like substance; gives structure to organs
Elastin stretchable fibers that allow for elasticity
All connective tissue has the same ingredients,
just in different proportions
Loose Connective Tissue
Many Cells; few fibers
Collagen & Elastin Fibers are loosely arranged
Macrophages & Fibroblasts are the most common cells
Surrounds blood vessels and nerves
Dense Irregular
Connective Tissue
Lots of collagen fibers and fibroblasts
Deep regions of the skin
Dense Regular
Connective Tissue
Collagen fibers run parallel to each other
Creates strong attachments between muscles and bones
Found in ligaments and tendons
Cartilage & Bone
Cartilage  type of connective tissue that cushions and maintains shape
of body parts
Structure of Cartilage  Stretchable fibers similar in texture to rubber.
Newly divided cells are called chondroblasts; mature into chondrocytes
Very few blood vessels penetrate cartilage; difficult to heal
Cartilage
Bone
Types of Cartilage
Hyaline Cartilage  Consists of collagen fibers. Found where bone
meets bone or at joints in the body
Reduces friction between moving bones
Found on either side of femur; end of nose, in between ribs
Chondrocytes 
Types of Cartilage
Fibrocartilage  Rigid and Resilient; can withstand large amounts of
pressure
Densely packed with collagen fibers
Found in kneecaps, in between vertebrae
Collagen Fiber 
Bone
•Weight bearing tissue of body
•Bones are joined with muscles to bring about movement
•Bones store calcium & produce some kinds of blood cells
•Bones made from densely packed collagen fibers and calcium salts
•Inside fibers are lacunae, cavities that contain the living bone cells,
osteocytes
•Bone is innervated by more blood vessels than cartilage
Types of Bone
Compact Bone
Found on the outside of larger bones, embedded with lots of blood
vessels and nerves
Types of Bone
Spongy Bone
Found at the ends of bones, loosely packed collagen and calcium
Muscles & Nerves
Muscles  tissues that contract and relax to move body parts
Fibers are arranged in parallel for increased resiliency
Types of Muscle
Skeletal Muscle  Muscle attached to bones
Individual cells are called muscle fibers
Each cell has multiple nuclei, caused from the fusion of juvenile muscle
cells
Proteins are embedded in the muscle fibers (called Actin & Myosin)
Actin & Myosin form bands in skeletal muscle that make it striated
Fibers are bundled together in fasicles & wrapped in connective tissue
Types of Muscle
Smooth Muscle  muscle of stomach, blood vessels, & internal organs
Fewer Actin & Myosin fibers, no banding; unstriated
Maintains constant tension, smaller contractions
Often called involuntary muscle
Types of Muscle
Cardiac Muscle
Striated like skeletal muscle
Involuntary like smooth muscle
Muscle fibers are tightly packed together by specialized fibers called
intercalated discs
Nerve Tissue
Nerve Tissue  exercises control over body’s activities
Individual cells called neurons
Structure of Neurons
Main Structure is cell body
Dendrites  branched “arms” that pick up incoming chemical information
Axons  “arms” that send out chemical information
Nerve  cluster of neurons
Nervous Tissue
Nervous Tissue
Nervous Tissue
Sensory Neurons  Used to detect chemical changes
Examples  Olfactory neurons
Retinal Neurons in the eye
Epithelial Neurons embedded in the skin
Blood & Adipose Tissue
Blood  specialized tissue that carries proteins, ions,
oxygen, fibrin (clots tissue)
Blood cells are made in bone marrow (center of bone)
Parts of Blood
Plasma  fluid portion of blood
Platelets  irregular cell fragments
Red Blood Cells  Carry Oxygen to muscles; adult
cells are non-nucleated
White Blood Cells  function in immunity, cell defense
Platelets  fragments of cells (called mekaryocytes) that aid in blood clotting
Blood carries nutrients and proteins to cells and carries waste away from cells
White Blood Cells & Red
Blood Cells
Adipose Tissue
Large clustered cells used for fat storage
Excess carbohydrates and proteins are converted to fat
Adipose tissue is connected with lots of blood vessels
Where does adipose tissue collect?
Hips, abdomen, thighs, under skin, around kidneys