lecture exam 2 (chapters 4-6)

3 cartilage types

hyaline, elastic, fibrocartilage

hyaline cartilage location

ends of bones, nose, and rings in walls of respiratory passages

elastic cartilage location

external ear, epiglottis

fibrocartilage location

intervertebral discs, pubic symphysis, discs of knee joint

periosteum function

covers outer surfaces of bones

Periosteum consists of

outer fibrous and inner cellular layers

interstitial growth

growth in length

appositional growth

growth in width

osteogenesis and ossification

bone formation
-the process of replacing other tissues with bone

Endochondral ossification

Process of transforming cartilage into bone.

intramembranous ossification

bone develops from a fibrous membrane
- (flat bone) (clavicle)

chondral

cartilage

two hormones in blood regulation of Ca++

-Parathyroid Hormone (PTH)
-Calcitonin

parathyroid hormone (main regulatory hormone)

-stimulation of osteoclast
-increase in bone formation, small intestine Ca++ absorption, and kidney Ca++ reabsorption

Calcitonin

- stimulation of osteoblast
-increase of bone formation, decrease in small intestine Ca++ absorption, decrease in kidney Ca++ reabsorption

bone healing (four stages)

1. hematoma
2. Fibrocartilaginous callus formation
3. Boney Callus formation
4. Bone Remodeling

hematoma

a solid swelling of clotted blood within the tissues.

fibrocartilaginous callus formation

- Phagocytic cells clear debris
- Osteoblasts begin forming spongy bone within 1 week
-Fibroblasts secrete collagen fibers to connect bone ends
-Mass of repair tissue now called fibrocartilaginous callus

Boney callus formation

cartilage is replaced with bone material and bone strengthens

bone remodeling

ongoing replacement of old bone tissue by new bone tissue

factors that affect bone healing

age, bone type, severity of break, bone health

compact bone

dense, hard layers of bone tissue that lie underneath the periosteum

spongy bone

The layer of bone tissue that has many small spaces and is found just inside the layer of compact bone.

Osteoporosis

low-density bone
-osteoclast > osteoblast
underlining causes
1. low calcium ion
2. low vitamin D

bone growth depends on

1. minerals (calcium ion, phosphate)
2. vitamins (A, C, D, B12, K)

vitamin A

stimulates osteoblast activity

vitamin C

needed for synthesis of collagen

vitamin D

helps absorb calcium

Vitamin B12 and K

required for synthesis of bone proteins

red bone marrow

(in spongy bone)
-blood vessels
-supplies nutrients to osteocyte

yellow bone marrow

(in spongy bone)
-stores fat

Osteocytes

mature bone cells, maintain the protein and mineral content of the matrix

osteoblast

bone building cell

osteoclasts

break down bone

osteoprogenitor cells

bone stem cells, divides to produce osteoblast
assist in fracture repair

Structure of Long Bone: Diaphysis

Tubular shaft that forms the axis of long bones

Composed of compact bone that surrounds the medullary cavity

Structure of Long Bone: Epiphysis

Wide part at each end
Articulation with other bones
Mostly spongy (cancellous) bone
Covered with compact bone (cortex)

Structure of Long Bone: Metaphysis

where diaphysis and epiphysis meet

Structure of Flat Bone

resembles a sandwich of spongy bone between two layers of compact bone

Bone Matrix

2/3 calcium phosphate, 1/3 collagen fibers

osteon

structural unit of compact bone

central canal (haversian canal)

canal that houses blood vessels located at the center of the osteon

lamellae

rings around the central canal, sites of lacunae

Lacunae

small cavities in bone that contain osteocytes

Function and components of skeletal system

Supports and protects tissues; stores minerals; forms blood cells

Bones, Cartilages, and Joints, Ligaments, Bone Marrow

primary ossification center

region, deep in the periosteal collar, where bone development starts during endochondral ossification

secondary ossification center

this develops in the epiphyses of bone during endochondral ossification

sutral bones

small, flat, oddly shaped bones found between the flat bones of the skull

irregular bones

vertebrae and facial bones

short bones

carpals and tarsals

long bones

bones of the arms and legs

flat bones

bones of the ribs, shoulder blades, pelvis, and skull

sesamoid bones

patella

thin skin vs thick skin

Thin Skin
-cover most of body
-has glands & hair follicles
- 4 layers in epidermis

Thick Skin
-only on palmar or plantar skin
-no hair follicles
-abundant eccrine sweat glands
-5 layers in epidermis(extra layer stratum lucidum)
-epidermal ridges

stratum basal

Cells undergo rapid mitosis; the Deepest layer of the epidermis.

stratum spinosum

(little bit of mitosis) some cell division

stratum granulosum

apoptosis (program cell death) becomes denucleated

Statum Lucidum

(luci=clear) only in palms, fingertips, soles, dead, flat, clear cells

stratum corneum

toughest layer (most superficial layer) least protected layer by melanin

1st degree burn

Only the epidermis (red, painful, and edema)

2nd degree burn

epidermis and part of dermis (blistered)

3rd degree burn

Full thickness damage through skin into nerves and muscles

function and components of skin

-resistance to trauma, infections, waterproofing, uv radiation
(keratin, acid mantle)
two principle parts:
-epidermis, and dermis

ceruminous glands

modified sweat glands, located in external ear canal, secretes cerumen (earwax)
-protects eardrum

sebaceous glands

secrete sebum (oil) into the hair follicles where the hair shafts pass through the dermis

eccrine sweat glands

-all over the body
-aid in temperature control (Vitamin C)
-secrets water, salt, wastes such as urea and uric acid

Appcrine sweat glands

-anywhere with hair growth
-produce an odor in response to stress
-groin, anal, axilla, areola regions

basal cell carcinoma

Most common and least severe type of skin cancer; stratum basal cells proliferate and invade the dermis and hypodermis

squamous cell carcinoma

(prolong sunlight exposure)
-arises from keratinocytes of um
-most common in ears, scalp, and lower lip
-rapid growth, metastasizes
-radiation therapy

melanoma

The most serious form of skin cancer
-highly metastatic
-resistant to chemotherapy

Carotene

the yellow pigment of the skin

Oxyhemoglobin

reddish pigment of the skin
(100% saturated by oxygen)

Melanin

a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight.

Keratinocytes

The most abundant epidermal cells, they function mainly to produce keratin.
(makes glycoprotein)

Macrophages

immune cells

Merkel cells

touch receptors in the skin
-located in the deepest layer of epidermis

Pacinian corpuscles

respond to deep pressure and vibration

Meissher's corpuscles

respond to light touch

Ruffini

respond to heat

Bulbs of Krause

respond to cold

keratinocyte, melanocyte, Langerhans cell, Merkel cell

four types of cells within epidermis

ground substance

unstructured material that fills the space between the cells and contains the fibers

epithelial tissue

Tissue that covers outside of the body and lines organs and cavities.
(GI tract, kidney, glands)

connective tissue

A body tissue that provides support for the body and connects all of its parts
(bones, tendons, flat and other soft padding tissue)

muscle tissue

A body tissue that contracts or shortens, making body parts move.
(skeletal, cardiac, smooth)

nervous tissue

A body tissue that carries electrical messages back and forth between the brain and every other part of the body.
(brain, spinal card, and nerves)

Pseudostratified Columnar Epithelium

number of layers: single layer
location: respiratory system

stratified squamous epithelium

number of layers: two or more layers
location: esophagus, mouth, and vagina

stratified columnar epithelium

number of layers: multiple
location: some sweat and mammary glands

stratified cuboidal epithelium

number of layers: 2-3
location: Largest ducts of sweat glands, mammary glands, and salivary glands.

transitional epithelium

number of layers: 3-4
location: lines the ureters, urinary bladder, and part of the urethra

simple columnar epithelium

number of layers: single (1)
Location: digestive tract (stomach to anal canal), gallbladder, small bronchi, uterine tubes, and some regions of the uterus.

simple cuboidal epithelium

number of layers: single (1)
location: Kidney tubules; ducts and secretory portions of small glands, ovary surface.

simple squamous epithelium

number of layers: single (1)

Location: Kidney glomeruli, air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity(serosae)

collagen fibers

cable like, resist to stretching

elastic fibers

Flexible and "stretchy" fibers that add elasticity to tissue

reticular fibers

tough but flexible
-lymph nodes, spleen, liver

ground substance of connective tissue

unstructured material that fills the space between cells

Ground substance + protein fibers = extracellular matrix

Fibroblast (connective tissue)

always present. Produce collagen, reticular and elastic fibers, in addition to ground substance

loose connective tissue

(adipose tissue)
-reduces heat loss
-loose areolar