Connective Tissue Fibers

Collagen fibers

Relatively thick, thread like, composed of collagen and occuring in long parallel bunders which withstand force when pulled along axis.

Elastic fibers

Thinner and form complex networks. Return to original length after stretching.

Reticular fibers

Highly branched and delicate supporting networks. Able to resist forces applied from many branches.

Areolar connective tissue

Located in papillary layer of dermis and epidermis and around organs

Functions are movement and stretching, support

Reticular connective tissue

Located in bone marrow, spleen, and liver.

Function is removes worn out RBCs in spleen and support.

Hint: looks like chicken wire.

Adipose connective tissue

Has modified fibroblasts which store fat and thus become swollen, pushing nucleus to edge of cell.

Located: throughout body

Function: supports/protects organs, energy reserve, reduces heat loss through skin.

Dense regular connective tissue

Fibers are all parallel. Function is to pull force in one direction, strength.

Located: tendons, ligaments, covers skeletal muscle.

Dense irregular connective tissue

Located in nerve and muscle sheaths and perichondria of cartilage, organs/joints.

Function: Strength, tensile strength in all directions.

Elastic connective tissue

Located: Lung tissue, aorta, vocal cords, respiratory passages.

Function: Stretch, ability to go back to original shape.

Cartilage

A supporting connective tissue made up of chondrocytes(cartilage cells) surrounded by a semisolid gel like matrix. Avascular.

Lacunae

hole that holds chondrocytes.

Hyaline cartilage

Matrix of closely packed collagen fibers. Found in costal cartilages of bronchi, ribs, tracheal rings. Function: support, flexibility.

Fibrocartilage

Matrix is suppored by collagenous fibers which are densly packed and regularly arranged.

Located: menisci of knees, intervertabrel discs. Function: Prevent bone=bone contact, support.

Elastic cartilage

Located: pinna of ear, auditory canal, tip of nose.

Function: Strength and elasticity. Matrix is supported by elastic fibers which make it resilient and flexible and are less densly packed and arranged irregularly.

Bone

A supporting connective tissue, one third of its matrix is collagenous fibers.

blood

Fluid connective tissue.

Lymph

Fluid connective tissue

Epidermis layers

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.

Dermis

Divided into papillary and reticular regions.

Papillary layer of dermis

Areolar connective tissue and makes up 1/5 of dermis.

Reticular layer of dermis

Deep to papillary and is dense irregular tissue. 4/5 of dermis

Sebaceous glands

Found around hair follicle, secrete sebum, oil.

Sudoriferous apocrine glands

None in thick skin. Not present til puberty. Located in axilla, groin, nipples. Larger in size. FUnction is body odor, sweat

sudoriferous eccrine glands

MOst common, thermoregulation

Vellous hair

Peach fuzz

Terminal hair

Thick and coarse. Found on head, groin, axilla, eyebrows.

Intermediate hair

Finer than terminal. Located on limbs.

Arrector pili muscle.

Smooth muscle on hair follicle. Function to create goosebumps and push sebum up through hair follicle.

Merkel cells

Fine touch and only found in the stratum basale of epidermis.

Meissner's corpuscles

Light touch receptors in dermis

Ruffini corpuscle

Touch receptors in dermis for stretch and torsion.

Pacinian corpuscle

Deep pressure/vibration receptors found deepest in dermis. Think Pac Man

Burn

Tissue damage from heat, chemicals, radiation, electricity. Protein in skin cells denature and no longer can function to prevent infection, regulate temperature, and hydration.

Rule of 9

TO assess burns by percentages in ER. 9% for Head/neck, 36% for trunk, 36% for lower limbs 18% for upper lims, and 1% for perineum.

1st Degree burn

Sunburn. Epidermis is damaged and is characterized by mild pain, redness but have normal skin fucntion.

2nd Degree burn

Epidermis and partial dermis damage. Lose skin function, but sweat and hair not damaged. Characterized by pain, edema, and takes 3-4 weeks to heal.

3rd degree burn

Damages epidermis, dermis and other structures. Total skin function loss. Characterized by numbness, edema. Systemic effects include infections, dehydration, decreased urine production, reduced circulation of blood, and decreased immune response. Skin graft necesary.