Support

Leverage

Protection

Storage

BC Production

Bones form the foundation of entire body

Bones are sites of attachment to muscles, ligaments, and tendons

Bones can function as levers to

increase the force, or range of motion 

of the force generated by contracting muscles

Bones store:

calcium

phosphorous

minerals including sodium and potassium

Bone marrow stores yellow fat (lipids) as a tremendous energy source

Red bone marrow fills internal cavity of bones, and is the site of RBC production.

This is done through the process of hematopoiesis

The adult skeleton is composed of ___ (#) bones, divided into 2 major divisions:

the ____ skeleton consisting of ___(#) bones, and

the ____ skeleton consisting of ___(#) bones

adult skeleton --> 206 bones

appendicular skeleton -->126 bones

axial skeleton --> 80 bones

Appendicular skeleton: provides foundation of movement at shoulder and pelvis

Axial skeleton: core or key foundation of the body

The 206 bones of the adult skeleton are composed to 2 types of bone: 

____ bone and ____ bone

(describe each)

Spongy bone - appearance of network of spaces surrounded by bony pillars.

Spaces are filled with bone marrow

Compact bone - dense and relatively solid 

The basic functional unit of ____ bone is called an o___

Describe.

compact bone functional unit: osteon

An osteon is made of layers of hardened bone tissue surround a central canal that carries BVs for delivery of nutrients and removal of waste from metabolically active bone tissue

A layer of ____ bone covers all bones in the body.

Where is this type of bone found?

layer of compact bone covers all bones in the body

compact bone is found in regions of high stress (stress usually comes from the same direction)

____ bone does not have osteons but is rather a network of 'bony mesh'

filled with bone marrow

Spongy bone does not have osteons but is rather a network of 'bony mesh'

filled with bone marrow

How do nutrients reach the bone cells in spongy bone?

Where is spongy bone found?

They diffuse from nearby bone marrow

Spongy bone is found in regions of low stress such as the skull

Spongy bone and medullary cavitiy of compact bone contain red and yellow bone marrow

Yellow bone marrow: high concentration of adipocytes; is an energy reserve

Red bone marrow: mixture of red and white blood cells

What membrane covers the outer surface of bone?

Describe it

Periosteum.

This membrane consists of an outer, strong, protective fibrous layer and an inner layer which is the site of actively growing bone cells

Bone, like other connective tissue, contains specialized cells and matrix (cement of bone tissue) made of 

protein fibers (collagen and calcium)

Collagen --> supplies the flexibility to bend

Matrix --> with all it's calcium and minerals, provides the strength and hardness

The 3 main cells within the matrix of bone tissue are:

(describe)

Osteocytes (mature bone cells that make up most of active bone tissue)

Osteoblasts (cells that secrete matrix to build and repair bones)

Osteoclasts (cells that remove bone tissue in response to stress)

Growth of bone tissue happens in 2 ways:

________ and ________

Endochondral ossification

and

Intramembranous ossification

Cartilage forms at sites of new bones (as early as 6 weeks after fertilization)

bone formation begins in diaphysis (shaft; primary ossification center), continues in epiphyses (ends; secondary ossification centers)

Bone tissue is secreted by osteoblasts, which cluster together in a shoft membrane at the site of future bone

Osteoblasts secrete components of bone matrix and trap osteocytes

Appearance of bone in this process resembles spongy bone but as BVs and nutrients are delivered to osteocytes, compact bone develops

Long bones

Short bones

Flat bones

Irregular bones

Sesamoid bones

Have a long shaft (diaphysis) and two expanded ends (epiphysis) 

Example: femuar, radius

generally equal in all dimensions, high component of spongy bone (so low stress)

Example: wrist bone

Thin and flattened in appearance, typically curved and cover considerable area

Example: sternum, parietal bone of skull

Irregular in shape

Example: vertebra

Bones that develop in tendons where there is a high level of stress, tension, and friction

Purpose: to protect tendon from high stress that could result in high rates of wear and tear

Example: patella

Nutrition

Exercise

Weight-bearing

Level of circulating hormones in blood

Genetic or environmental factors

What is the stimulus for new bone growth?

(2 things)

Weight bearing activity

Muscle contraction that loads the bone beyond the normal minimal essential strain (MES)

MES = minimal essential strain

Bone growth occurs if this happens

Following maturity, actual length of bones no longer increases and the epiphyseal plates or growth plates have closed.

However, ___ and ___ continue to be active

Osteoblasts and osteoclasts.

Bones that undergo great stress will get thicker and stronger

Calcium is essential to bone growth and overall body function. Calcium, along with phosphate and other minerals, is a major component of...?

(name 3)

99% of calcium in the body is in bone tissue. 1% is found in...?

B___ t____ can act as a reservoir that can release or store calcium depending on circulating concentration

Blood, interstitial fluid, tissue such as cardiac and skeletal muscle

bone tissue can act as a calcium reservoir

What happens if there's too little calcium in the blood (hypocalcemia)?

What happens with hypercalcemia?

Hypocalcemia - NS gets overly excited which leads to muscle tremors, spasms, and tetanus

Hypercalcemia - Leads to depression of the NS, muscle weakness, delayed reflexes

Calcitrol - active form of vitamin D

It regulates (low levels of) calcium deposited in bone in 2 ways:

1) stimulates small intestine to absorb more calcium and reduce amount of calcium excreted by kidney

2) stimulates relase of calcium from bones into blood

Calcitonin - produced by parafollicular cells of the thyroid (opposite of PTH), produced when blood calcium is too high

Calcitonin reduces osteoclast activity, increases osteoblast activity. These 2 effects removes calcium from blood and deposits it into bone

PTH - secreted by parathyroid glands behind the thyroid gland when blood calcium levels are low

PTH increases osteoclast activity and decreases osteoblast activity. It also ensures that kidneys preserve calcium in the blood instead of letting it pass out in urine

Osteoporosis, or 'porous' bones. This is where bones lose mass and become brittle as the matrix loses calcium.

Most prevalant in post-menopausal, elderly white females

Inflammation of the bursa, or the sinovial membrane which secretes the fluid in the bursa

Caused by physical trauma or friction

Tendonitis is inflammation of the tendon sheath

Caused by overuse and repetitive activities

What is arthritis?

Describe osteoarthritis and rheumatoid arthritis.

An inflammatory or degenerative disease that affects joints.

Osteoarthritis is a degenerative disease commonly affects the elderly and athletes who have used/abused their joints

Rheumatoid arthritis is a chronic inflammatory inflamatory condition that initially affects the synovial membrane of joints, then progresses over time to affect the entire joint structure

Describe aging on bones (in terms of the matrix and collagen)

Describe aging on joints

Bones get thinner and weaker due to the matrix becoming less dense and collagen becoming harder and less flexible

Joints begin to deteriorate with age. Decreased synovial production, thinnning of articular cartilage, and loss of ligament length and flexibility are characteristic of this

The skull is composed of 22 bones which form the c___ and the f___.

The c___ is composed of 8 large flat bones joined by s___ (immovable joints). 

The 14 bones of the f___ hold the eyes in place and serve as the sites of attachment for many of the facial muscles that move the head, eyes, and jaw

Skull --> bones form cranium and face

Cranium bones are joined by sutures (immovable joints)

14 bones of face--> hold eyes in place, serve as attachment sites for facial muscles

Extends from skull to pelvis.

the vertebral column:

- supports weight of body

- protects spinal cord and spinal nerves

33 individual vertebrae

7 cervical

12 thoracic

5 lumbar

5 sacral (fused)

4 coccyx

What are the 4 spinal curves of an adult spine?

The curves of the ____ and ____ are called primary curves because they wer present at birth.

The ____ and ____ curves are secondary curves because they develop later when the  baby _____

Cervical, thoracic, lumbar, sacral

Thoracic and sacral --> primary

Cervical and lumbar --> secondary, develops when the baby learns to raise its head and walk

All vertebrae, except the ____ and ____, have a central body for weight-bearing, lateral extensions, or transverse processes and the posterior extension or spinous process.

These processes are sites of attachments for ____ and ____

All vertebrae except the atlas and axis

(C1 & C2) have the processes that are the sites of attachment for muscles and ligaments

The atlas and axis have a unique structure (____ joint) that allow nodding/rotation of the skull

______ process have holes or foramina to allow for passage of BVs to head

atlas and axis --> pivot joint

Transverse processes have holes (foramina) to allow for passage of BVs to head

The 12 thoracic vertebrae, have locations for attachment of the ___ on either side.

The ____ processes point down

12 thoracic vertebrae --> attach to ribs on either side

spinal processes of thoracic vertebrae point down

The chest, or t____, is composed of the thoracic vertebrae, r___, and s____

The r___ and s___ form the ____ cavitty

thorax is composed of th. vertebrae, ribs, and sternum

ribs + sternum = chest cavity. Major muscles of respiration (intercostal) attach to rib cage.

There are __ pairs of ribs divided into 3 categories:

Ribs __-__ are true ribs b/c they...

Ribs __-__ are false ribs b/c they...

Ribs __-__ are false ribs b/c they...

12 pairs of ribs

Ribs 1-7: true b/c they attach directly to sternum by cartilage

Ribs 8-10: false b/c they join into one common cartilage before attaching to sternum

Ribs 11-12: false, and also called floating ribs b/c they don't attach to sternum

Collar bone = _____, attaches to the ____ and _____ of sternum.

This is the ONLY location where the appendicular skeleton attaches directly to the axial skeleton

The shoulder blade = ____, attaches to ____ and ____.

The shoulder blade is NOT attached by ligaments/bone to spine, and so permits flexibility and movement of upper limb

The pectoral girdle consists of the ___ and ___ and attaches the ____ to the ____.

Pectoral girdle provides attachment sites for several muscles that move the upper limbs

Upper arm is formed by...?

Forearm is formed by...?

Hand is formed by...?

Upper arm - humerus, articulates with scapula proximally (at the glenoid cavity), and forearm distally

Forearm - radius and ulna (radius connects to the thumb side of wrist)

Hand - carpals, metacarpals, phalanges

Carpal bones are arranged in 2 rows and form the ___

Palm of hand is formed by ___

Fingers is formed by

Carpal bones --> wrist

Palm --> metacarpals (knuckles)

fingers --> phalanges

Pelvic girdle articulates with the ____ and ____

Each coxal (pelvic) bone, left and right, has three fused components: ____, ____, and _____

Why are pelvic girdle bones are massive?

Pelvic girdle articulates with femuar and sacrum.

Each coxal has 3 fused components: ilium, ischium, pubis

Pelvic girdle bones are massive b/c of high stresses of weight bearing

Pubis or pubic bones form at front of pelvis.

Bones of each pubis bone join anteriorly at the pubic symphysis

The bones of the lower limbs carry the entire weight of the body and include the ____, ____ and ____, and bones of the ____/____

Why are these bones the strongest?

Bones of lower limbs: Femur, tibia and fibula, and bones of the ankle/foot

The bones of the lower limbs are subjected to very high forces (running/jumping), so they are the strongest

The thigh bone, or ____, articulates with the ____ and ____ to form the knee joint. 

The thigh bone is the longest/strongest in the body

shin bone = femur, works together with the fibula to form the lower leg

tibia --> transmits weight to ankle

fibula --> muscle attachment site/some support to ankles

Foot includes ____, ____, and ____

The ankle bone = ____

Ankle bone articulates with ____ and ____

Together, the ____ and ____ transmits most of the weight of the body onto the ground

Foot: Tarsals, metatarsals, phalanges

Ankle bone is the talus

Ankle bone (talus) articulates with the tibia and calcaneus (heel bone)

Talus and calcaneus transmits body weight onto ground

the arches of the feet give them strength and flexibility. They assist in weight distribution to heel and toes. 

The bones are held in position by ligaments and tendons. Weak arches = fallen arches

Lateral curvature most commonly in the thoracic region.

Caused by poor posture/muscle imbalance, or genetics

Kyphosis (hunchback) is abnormal thoracic curvature.

Caused by osteoporosis and males who have over-developed their chest muscles

Lordosis (swayback) is excess lumbar curve 

It is caused by excessive weight gain in abdominal region, bad posture, or weak abdominal muscles

What is a joint?

Ligament?

Tendon?

Joint (articulations) exist whenever 2 or more bones of the body meet

A ligament is a fibrous tissue that connects bones to bones (at a joint)

A tendon is a fibrous tissue that connects bones to muscles (at a joint) or muscle to muscle

____ and ____ work together to allow body parts to move.

Joints and muscles work together

When you lift your leg up to the side (lateral leg lift), your abductor muscles are contracting to lift, and the hip joint is abducting 

Fibrous - Typically immovable/slightly moveable depending on location

- Held together by fibrous connective tissue. Don't have a joint cavity (e.g, sutures of skull lock together the irregular shaped bones of skull)

Slightly movable or immovable depending on location

- Ends of the bones are held together by cartilage and do not have a joint cavity (e.g, intervertebral joints of the spine [slightly moveable]. Also, cartilage which joins ribs to sternum [immovable])

Typically freely movable, but movement pattern is based on structure of joint

- Synovial joints are joints which articulating bones (usu. long bones) are separated by a cavity filled with synovial fluid (e.g, knee joint)

Gliding/plane

Pivot

Hinge

Ball and socket

Ellipsoid

Saddle

- Rounded portion of one bone fits into depression of another bone

- Flexion/extension movements

- E.g, elbows

- Round head of one bone fits into cup-like depression of another bone

- All types of movement

- E.g, shoulder and hip joints

- Round end of one bone extends into sleeve formed by another bone/ligament

- Only possible movement is rotation around long axis

- E.g, atlas and axis (C1 and C2) during rotation of head

- Articular surfaces are flat

- Gliding/slipping movements only (in 3 dimensions)

- E.g, most joints in wrists/ankles

- Oval surface of one bone fits into hollow/depression of another bone. Both surfaces are oval

- Angular movements only (no rotation)

- E.g, Wrist joint where radius articulates with carpal bones (wrist rotations). Also, condyloid joints exists in fingers (but not thumbs)

-Each of the articulating bones have both elevated and depressed (concave and convex) aspects that give the appearance of a saddle

- Greater moveability in angular movements (but no rotation)

- E.g, Carpometacarpal joint (base of thumb); basically thumb rotations

What is an articular cartilage?

Articular capsule?

Articular cartilage (hyaline) covers the end of articulating bones

The 2 bones forming a joint are enclosed by a capsule which has a tough outer fibrous connective tissue that holds the bones together, and an inner synovial membrane that secretes synovial fluid

What is a synovial cavity?

Synovial fluid?

Synovial cavity or joint cavity is the space b/w articulating bones within the articular capsule

Synovial fluid fills the joint cavity. It assists in lubrication, shock absorption, and supply of nourishment. Synovial membrane secretes this fluid

Bursae - bag filled with synovial fluid that lubricates, reduces friction, and cushions.

Not specifically part of synovial joints, but are commonly associated with them. 

These are found whereever tendons, ligaments, muscles or bones rub together or come in close proximity to each other

What is a cartilage?

What does it allow bones to do?

What does it 'act' like?

Cartilage is a connective tissue that covers the ends of the bones where two bones meet (called an articulation but more commonly known as a joint) 

This allows bones of the joint to move smoothly over each other.

Cartilage acts like a flexible and sometimes binding material

What are the sites that are called points of origin and insertion?

What are these sites?

Tendons.

Tendons attach muscles to bones at attachment sites; these sites are called points of origin and insertion.

Points of origin: non-moveable, anchors muscle so it has a strong place to hold itself when it contracts, shortens, and pulls on insertion point

Insertion point: moveable, attached to another bone.

Sagittal (medial/lateral); right/left

Frontal (anterior/posterior); front/back

Transverse (superior/inferior); upper/lower

Oblique: crosses through body at an oblique/diagonal angle