Muscular and Skeletal Systems

Agonist vs Antagonists

*Agonist* - muscles that are primarily responsible for an action due to their contraction *Antagonist* - muscles that relax to smooth the action of the agonist

Fixed Joint

These joints do now allow any movmenet and are extremely strong *Example - joints of the skull*

Osteomyelitis

● Bone inflammation often resulting from bacterial infection from trauma or puncture wound (stepping on a nail) ● Staphylococcus aureus (Staph infection) is often introduced through wounds and is a common cause of osteomyelitis

Cartilage

● Smooth slippery surface covering the ends of bones. ● Contains mostly water ● Most bones start out as flexible cartilage but as you grow the cartilage is replaced by bone. ● Growth plates of cartilage remain in bones providing aplace for the bones to continue growing. ● Some cartilage never becomes bone (nose,ears)

Three types of Muscle

*Cardiac Muscle* - found only in the heart *Smooth Muscle* - throughout the body but extensively in the digestive tract. *Skeletal Muscle* - throughout the body and are responsible for movement.

Types of Joints

1. Ball and Socket 2. Hinge 3. Pivot 4. Sliding 5. Fixed

What are the two types of Bone Tissue?

1. Compact Bone 2. Spongy Bone

Function of Cartilage

1. Reduces friction at joints 2. Aids in movement between bones 3. Support 4. Growth - cartilage is responsible for the growth of the long bones.

What are the roles of bones in your body?

1. Support 2. Storage 3. Movement 4. Blood Cell Formation

Number of Bones in the Human Body

206

Tendons

Attach most skeletal muscles to bones. Strong sheets of connective tissue that are identical with ligaments

Osteoblast

Bone forming Cells

Are bones living or dead?

Bones are a living organ.

Number of muscles to frown? Number of muscles to smile?

Frown - 43 Smile - 13

Why does Arthritus occur

If the cartilage wears away in a joint and the bones rub together you can get arthritis

Myofilaments

Long cylindrical structures that make up muscle fibers Made up of two types of protein: 1. Actin - thin myofilaments 2. myosin - thick myofiliments

Arthritis

Most common joint problem 1 out of 7 people suffer from arthritis

Describe the "Movement" role of bones.

Muscles attach to the bones by tendons, pull on the bones to produce movement.

Involuntary Muscles

Muscles that you cannot consciously control. Example: blinking, digestion

How many muscle functions are used for body movement?

Over 600

Which bones make red & whie blood cells?

Ribs Sternum Vertebrae

Tendons vs. Ligaments

Tendons - attach muscle to bone Ligaments - attach bone to bone

Voluntary Muscles

Those that you can control - are attached to bones and are typically used for movement, facial expressions, posture and other body movements

Shivering

When the body is cold it shivers resulting in quick muscle contractions that generate heat

Joint

Where two or more bones come together - they make body movement possible

Osteoporosis

● A bone disease characterized by low bone mass and structural deterioration of the bone tissue. ● Results in bone fragility and increased suscptibility to fractures of the hip spine and wrist ● Risk factors: little calcium or vitamin D, cigarette smoking and lack of physical activity

Spinal Muscular Atrophy (SMA)

● A disease of the anterior horn cells located in the spinal cord. ● SMA is an autosomal recessive disease - both parents must be carriers.

Skeletal muscle

● Allows bones to move - attached to bones by tendons ● Voluntary and striated in appearance.

Hinge Joint

● Allows movement in a single plane ● Formed when a convex projection on one bone fits into a concave depression in another *Example: Knee* - allows you to flex and extend you lower leg

Ball and Socket Joing

● Ball shaped end of one bone fits into a cup shaped socket on the other. ● Allows the widest range of motion including rotation. (like a joystick) *Examples: Shoulder and Hip*

Spongy Bone

● Bone tissue that has many open spaces ● Red Marrow is found in spongy bones of the legs and arms

Describe the "Support" role of bones.

● Bones protect and support. ● Ribs shield the heart and lungs ● Vertebrae protect the spinal cord ● Skull protects the brain.

Describe the "Storage" role of bones

● Bones store minerals like calcium phosphorus. these compounds are later released into the surrounding tissues ●Cavities inside your arm and leg bones store fat that can be used for energy

What are bones made up of?

● Connective Tissue ● Minerals depostied by living cells called *osteoblasts*.

Compact Bone

● Does not have any visible open spaces ● Located towards the ends of long bones ● Provides most of the strength and support for bones such as the femur ● It has a framework containing deposits of phosphate and calcium

Sliding Joint

● Formed when flat or slightly flat surfaces move against each other allowing sliding or twisting without circular movement. *Example: carpals in the wrist, rarsals in the ankle and the vertebra in the back*

Pivot Joint

● Formed when round or conical surfaces of one bone fit into a ring of one or tendon allowing rotation. ● Movment is inbetween hinge and the ball and socket joint. *Example - wrists, ankle and neck*

Marrow

● Found in bones. ● Red marrow found in spongy bone makes red and white blood cells ● Yellow marrow found in the center of the long bones stores fat.

Cardiac Muscle

● Found only in the heart ● Makes up the atria, ventricles and heart walls ● Contains striated and smooth fibers ● Involuntary muscle

Smooth Muscle

● Found throughout the body but extensively in the digestive organs - ● causes *peristalsis* - the wave like contractions that aid in food digestion and transport ● Smooth muscle is involuntary ● Smooth muscle is nonstriated - non banded ● Except for the heart, any movement done without conscious thought is done by smooth muscle contractions: - constricting, closing the bronchioles, air passages of the lungs or pupils of the eye, or goose bumps.

Muscular Dystrophy

● Group of genetic diseases characterized by progressive weakness and degeneration of the skeletal or voluntary muscles controlling movement. ● They are inherited ● They are "progressive" - that is they get worse over time ● No specific treatment

Ligaments

● Hold bones together at joints. ● Stretched or strained ligaments can heall, but torn ligaments must be surgically repaired

Periosteum

● Membrane that covers a living bone's surface. ● Small blood vessels in the periosteum carry nutrients into the bone.

Movement

● Movement occurs when pairs of skeletal muscles work together. ● Skeletal muscle is a system of paris that relax and contract to move a joint. ● When one muscle contracts (gets shorter), the other of the pair relaxes (gets longer) ● Muscles always pull, never push.