Anatomy 6.1: Muscoskeletal System 1

What does the skeletal system consist of?

Bones and cartilage

What is the main function of the skeletal system?

It provides shape and support for the body

Which system acts on the skeletal system to produce movement?

The muscular system

Name two vital organs protected by the skeletal system

The heart and lungs. (Also protects pelvic organs.)

What does the articular system consist of?

Joints and their associated ligaments

What is the function of the articular system?

It connects bones and provides sites where movement occurs

What does the muscular system consist of?

Skeletal muscles, smooth muscle, and cardiac muscle

What is the function of skeletal muscles?

To contract and move or position parts of the body

What do smooth and cardiac muscles do?

They propel, expel, or control the flow of fluids and substances in the body

Parts of the skeletal system

- bones (skeleton)

- joints

- cartilages

- ligaments (bone to bone)

2 divisions of the skeletal system

1. Axial

2. Appendicular

axial skeleton components

- skull, vertebral column, rib cage, sternum

- forms vertical axis of the body by supporting head, neck, back and chest

appendicular skeleton

- Bones of the limbs and limb girdles that are attached to the axial skeleton

- all bones of the upper and lower limbs

Functions of Bones and Muscles

- support the body

- protection of soft organs

- movement due to attached skeletal muscles

- storage of minerals and fats

- hematopoesis (blood cell formation)

How many bones does the human body have?

206 bones

2 types of bone tissue

compact bone and spongy bone

compact bone

- Hard, dense bone tissue that is beneath the outer membrane of a bone

- homogenous

4 types of bone classificstion based on shape

- long bone

- short bone

- flat bone

- irregular bone

example to long bone

femur, humerus

example of short bone

carpals of the wrist

example of flat bone

parietal bone of skull

Example of an irregular bone

vertebrae

What is a joint (articulation)?

The place where two bones come together

How are joints structurally classified?

Fibrous, cartilaginous, and synovial

What type of joint is fibrous?

Immovable joints

What do fibrous joints connect?

Bones with no movement

Give examples of fibrous joints.

Skull and pelvis

What type of movement do cartilaginous joints allow?

Slight movement

How are bones connected in cartilaginous joints?

By cartilage (e.g. hyaline or fibrocartilage)

Give examples of cartilaginous joints

Spine or ribs

What type of movement do synovial joints allow?

Free movement

What fills the cavity between bones in synovial joints?

Synovial fluid

What is the function of synovial fluid?

It lubricates and protects the bones

Which type of joint is the most movable?

Synovial joints

structural classification of joints

1. Fibrous

2. Cartilaginous

3. Synovial

suture (fibrous joint)

interlocking line of union between bones made with dense fibrous connective tissue; skull

Periosteum

A dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.

joint capsule

The fibrous sac that encloses a joint.

components of joint capsule

fibrous capsule and synovial membrane

synovial membrane

The lining of a joint that secretes synovial fluid into the joint space.

joint cavity

contains synovial fluid

articular cartilage

covers the surfaces of bones where they come together to form joints

Meniscus

Curved surface of liquid

Diploe (spongy bone)

spongy bone in flat bones

Syndesmosis (fibrous joint)

Joint held together by a ligament. Fibrous tissue can vary in length, but is longer than in sutures.

Gomphosis (fibrous joint)

attachment of a tooth to its socket

Periodontium

Structures that surround, support, and are attached to the teeth

What is another name for primary cartilaginous joints?

Synchondroses

What type of cartilage connects the bones in primary cartilaginous joints?

Hyaline cartilage

Are primary cartilaginous joints permanent or temporary?

Usually temporary

What is the main function of primary cartilaginous joints?

Allow bone growth

What is another name for secondary cartilaginous joints?

Symphyses

What type of cartilage connects bones in secondary cartilaginous joints?

Fibrocartilage

Are secondary cartilaginous joints temporary or permanent?

Permanent

What type of movement do secondary cartilaginous joints allow?

Slight movement.

Give examples of secondary cartilaginous joints.

Intervertebral discs and pubic symphysis.

Label the schematic model of the synovial joint

1. periosteum

2. ligament

3. fibrous capsule

4. synovial membrane

5. compact bone

6. joint cavity (contains synovial fluid)

7. articular cartilage

What is the functional classification of joints based on?

The degree of movement between bones

What are the three functional types of joints?

Synarthrosis, amphiarthrosis, and diarthrosis

What is a synarthrosis?

An immobile or nearly immobile joint

What is the main function of synarthrosis joints?

To provide strong, stable connections and protect internal organs

Give two examples of synarthrosis joints

Skull sutures and epiphyseal plates

epiphyseal plates

growth plates

What is an amphiarthrosis?

A slightly movable joint.

What structures usually connect bones in amphiarthrosis joints?

Cartilage or ligaments

Give two examples of amphiarthrosis joints

Pubic symphysis and intervertebral discs

What is a diarthrosis?

A freely movable joint

Which structural joint type corresponds to diarthrosis?

Synovial joints

what structures allow smooth movement in diarthrosis joints?

Synovial fluid, a joint capsule, and articular cartilage

Where are diarthrosis joints commonly found?

In the limbs (e.g., shoulder, hip, knee, elbow)

What is a uniaxial diarthrosis?

A joint that moves in one anatomical plane

Give an example of a uniaxial diarthrosis.

The elbow joint

What is a biaxial joint?

a joint that allows movement in two planes

Give an example of a biaxial joint.

The metacarpophalangeal joint (knuckle joint) of the hand.

What is a multiaxial joint?

A joint that allows movement in three planes

Give two examples of multiaxial joints

Shoulder and hip joints

What are cartilaginous joints functionally classified as?

synarthrosis or amphiarthrosis

What are fibrous joints functionally categorised as?

synarthrosis or amphiarthrosis

The suture joints in the skull are what type of functional joint? (structurally a type of fibrous joint)

synarthrosis

What type of functional joint is the hip joint?

- diarthrosis: multiaxial joint

What type of functional joint is the intervertebral disc? (structurally secondary cartilogenous)

amphiarthrosis

Name the six synovial joints

- Ball-and-socket

- hinge

- pivot

- condyloid (ellipsoid)

- saddle

- plane (gliding)

Which synovial joint allows the greatest range of movement?

Ball-and-socket joint

What movements are possible at ball-and-socket joints?

Rotation, flexion, extension, abduction, and adduction

Give two examples of ball-and-socket joints

Shoulder and hip joints

What type of movement occurs at hinge joints?

Flexion and extension in one plane

Name two examples of hinge joints

Elbow and knee.

What movement occurs at pivot joints?

Rotation around a central axis

Give examples of pivot joints

Atlanto-axial joint

What movements occur at condyloid joints?

Angular movements in two planes (flexion, extension, abduction, adduction)

Give an example of a condyloid joint.

- Radiocarpal (wrist) joint

- metacarpophalangeal joint

What is the main feature of a saddle joint?

Opposing concave and convex bone surfaces that permit movement on two different planes

Where is the main example of a saddle joint found?

Carpometacarpal joint of the thumb

What movement occurs in plane joints?

Small gliding or sliding movements

Give three examples of plane joints.

Intercarpal joints (wrist)

intertarsal joints (ankle)

acromioclavicular joint (between clavicle and scapula)

About how many muscles are in the human body?

Over 600

What are the main functions of muscles?

Movement, maintaining posture, and generating body heat

What are the three types of muscle tissue?

Skeletal, cardiac, and smooth muscle

Skeletal muscle

Voluntary muscle attached to bones.

cardiac muscle

Involuntary muscle tissue found only in the heart.