apk ch6 - the skeletal system

What are the 3 organs of the skeletal system?

Bones, cartilages, and joints

What are the three types of cartilages?

Hyaline, elastic, and fibrocartilages

Where can hyaline cartilage be found?

At the ends of bones forming articular cartilages

What do hyaline cartilages do?

Reduce friction during movement occurring at joints

Reducing friction between bones

What does articular mean?

A reference to joints

Where is elastic cartilage found?

External ear (pinna)

Epiglottis (flap in our throat)

Epiglottis

Flap in our throat

Where is fibrocartilage found?

Intervertebral disk/form intervertebral disk

Meniscus (in knee joints)

What does fibrocartilage do?

Shock absorber

What structures permit movement?

Joints (1)

What type of tissue is cartilage?

Connective tissue

How is cartilage’s extracellular matrix?

Abundant/Tons

Lot of ground substance (gel-like material)

Lots of fibers

Cartilage Gel-like extracellular matrix

Not liquid or fluid

Not solid or calcified

What is cartilages pre-dominant cell type?

Chondrocyte

Chondro-

Cartilages

Where are chondrocytes found?

In the lacunae

Lacunae

Translates to lakes

Cavities/pits

Houses chondrocytes

How does hyaline cartilage look?

Due to abundant gel-like matrix

Amorphous texture/substance

Opaque/frosted glass

Not transparent

What cartilage is found at ends of long bones (articular cartilage)?

Hyaline

What cartilage is found at growth plates within bones?

Hyaline

What cartilage is found in costal cartilages?

Hyaline

Where are costal cartilages found?

Ends of ribs connecting to breastbone or sternum

What cartilage forms key respiratory structures

Hyaline

What cartilage forms the embryonic skeleton during fetal development?

Hyaline

How does elastic cartilage look?

Has lacunae (cavities)

Extracellular matrix is not frosted glass

Abundance of elastic fibers

What is the function of the epiglottis?

Covers the larynx when swallowing to prevent food down respiratory tract

Ensures food travels down esophagus

What is the pinna?

The upper portion of the ear

Flexible

What is the elastic cartilage not part of?

The ear lobe

What does the fibrocartilage look like/made up of?

Whole lot of collagen fibers

What cartilage is found in pubic symphysis?

Fibrocartilage

Where is in the pubic symphysis is fibrocartilage found?

In between your hip bones/pelvis in the front

What cartilage is found in the menisci in the knee joint?

Fibrocartilage

What cartilage is found in between the vertebrae forming the intervertebral disks?

Fibrocartilage

Peri-

Around

What is the perichondrium?

Piece of tissue around cartilage

What is this a picture of?

Epiglottis

Perichondrium of elastic cartilage in epiglottis

What is the perichondrium made up of?

Dense, irregular, connective tissue

What does the connective tissue in the perichondrium allow for?

Strength, flexibility as epiglottis is bending forward to cover larynx and opening back up

What is superficial to the perichondrium?

Thin sheet of epithelium

What are the functions of bones?

Support

Protection

Movement

Mineral storage

Hemopoiesis

Energy storage

Metabolism

What does the bone function of support do?

Provides framework/scaffolding

Keeps you upright

What provides protection of internal organs?

Bones

Protection is function

What protects the brain and what function of bone is this?

Skull

Protection

What protects the internal organs (heart, lungs, etc.) and what function of bone is this?

Thoracic cage

Protection

What protects the spinal cord and what function of bones is this?

Vertebral bone

Protection

What does the bone function of protection do?

Protects internal organs

What does the bone function of movement do/mean?

Muscles attach to bones

Muscles contracting and shortening, pull on bone attached for movement

What does the bone function of mineral storage do?

Storage facility/reservoir for minerals

Liberate needed minerals from the bone and into blood

Main minerals: Calcium and phosphate

What are the two main minerals from bone?

Calcium

Phosphate

What does bone function hematopoiesis do?

Formation of red blood cells

What does bone function energy storage and metabolism do?

Regulate blood glucose levels

There is a specific type of bone cells that signals for release of hormone regulating blood glucose levels

How many classifications of bones and in respect to what?

4 classifications

In respect to shape NOT size

What are the four bone classifications?

Long bone

Short bone

Flat bone

Irregular bone

What is a long bone (classification)?

Elongated shape/shaft

Two distinct ends

What is an example of a long bone?

Humerus

Femur

Tibia

Metacarpals

What is a short bone (classification)?

Cube-like

Short

No distinct ends

What is an example of a short bone?

Talus

What is a sesamoid bone?

A sub classification of a short bone

Sesame seed type shape

What is an example of a sesamoid bone?

Patella (knee cap)

Where is the sesamoid bone derived from?

The tendon

What is the function of the sesamoid bone?

Alters direction when we have movement at certain joints

Acts as “pulley”

What is a flat bone (classification)?

Relatively flat

Can be curved

What is an example of a flat bone?

Sternum

Scapula (shoulder blade)

What is an irregular bone (classification)?

Does not fit into other classifications

Bony protrusions and processes coming off of it

What is an example of an irregular bone?

Vertebra

What are the two types of bone tissue?

Compact and spongy

What is compact bone tissue?

Dense

Outer layer

What is spongy bone tissue?

Found internally

Network of spaces (holey)

AKA trabecular bone

What is another word for spongy bone tissue?

Trabecular bone

What do compact and spongy bone refer to?

Microscopic structure and texture

Proximal epiphysis

Proximal end of long bone (Closer to origin point)

Epiphysis = end

Distal epiphysis

Distal end of long bone

Diaphysis

Shaft of long bone

Metaphysis

Junction between epiphysis and diaphysis in long bone

Epiphyseal line

Part of metaphysis of long bone

Calcified area of bone where growth place used to be

How does the epiphyseal line form?

After growing, growth plate calcified and turns into bone

Bony scarred line

Indicates that we are looking at adult bone

Where is the articular cartilage in long bones?

At the edges of the epiphysis

(Made up of hyaline cartilage to reduce friction)

What can you have within spongy bone?

Red bone marrow responsible for hematopoiesis

Where is the periosteum found?

Thick membrane around the bone

Covers external bone surface

Not present at sites covered by articular cartilage

What are the two layers of the periosteum?

Superficial layer = dense irregular CT proper

Deep layer = osteogenic layer (on top of bone surface)

What is part of the osteogenic layer (deep layer of periosteum)

Two types of bone cells

• Osteoblasts = early immature bone cells secreting matrix calcified into bone tissue

• Osteoclasts = breaking/degrading down bone

Medullary cavity

Along the diaphysis of long bone

Yellow bone marrow found in here

What is yellow bone marrow

Fatty bone marrow

What are the parts of the epiphysis?

Compact and spongy bone

Articular cartilage

Endosteum

Veins and arteries in the bone (blood vessels traveling through spongy bone carry nutrients)

What are the holes in the spongy bone marrow filled with?

Red bone marrow

Some have blood vessels going through them

Endosteum

Type of membrane lining interior (and structures) of bone

Thin osteogenic membrane covering internal bone surfaces

Osteoblasts and osteoclasts present

Endosteum locations

Central canal (hollow area) of osteons (compact bone)

Lines all spongy bone trabeculae (pillars forming network of spongy bone)

• Medullary cavity

• Epiphyses of long bones

• Inside short, irregular, and flat bones

What are the parts of the diaphysis (+ medullary cavity) in long bone?

Yellow bone marrow (in medullary cavity)

Endosteum

Compact bone (NO spongy) forming walls around medullary cavity

Periosteum

Veins and arteries

Perforating collagen fiber bundles

What are perforating collagen fiber bundles

Found in the diaphysis and medullary cavity (long bone)

Collagen fiber bundles attaching the periosteum to most outer surface of bone (glue)

AKA Sharpey’s fibers

What does the anatomy of short, flat, and irregular bones lack?

Medullary cavities

Only have spongy bone and compact bone

What is the anatomy of short, flat, and irregular bones like?

Compact bone continuous all the way around

Only have spongy bone and compact bone

Periosteum on outside of compact bone

Endosteum (covers little trabeculae of spongy bone)

Different types of bone markings

Projections, joint surfaces, and depression & openings

Projections (bone marking)

Bump

Attachment site for muscles

Joint surfaces (bone marking)

Can be rough or smooth

Foramen (foramina)

Openings allowing for blood vessels or nerves to run through

Spinal cord can run through

What does the surface of the bone reflect?

Stresses applied to that particular bone (compact bone takes pressure)

Osteon (compact bone)

AKA Haversion system

Has a central (haversion) canal in middle runs longitudinally along bone where blood vessels, nerves, etc. found here that nourish osteon

Concentric lamellae

Calcified extracellular matrix part of osteon

Circular rings around central canal forming an osteon