The Skeletal System PAF3O PERSONAL FITNESS

Overview TODAY Anatomical Language Bones TOMORROW (Wed, April 8) Inert Tissues Joints THURSDAY, APRIL 9 QUIZ! Muscular System FRIDAY, APRIL 10 Muscular System Cont’d NEXT WEEK QUIZ! (Muscular System) UNIT TEST

Why Do We Have an Internal Skeleton?

Anatomical Language… GROUND ZERO – ANATOMICAL POSITION The body is assumed to be standing, the feet together, the arms to the side, and the head and eyes and palms of the hands facing forward. In the Anatomical Position, the thumb is a lateral structure, not an anterior one

Anatomical Language… PLANES Frontal/Coronal Plane Sagital/Median Plane Transverse Plane

Anatomical Language… Sagittal plane – Divides body into right and left halves Frontal plane – Divides body into front and back halves Transverse plane – Divides body into upper and lower halves Anterior– towards the front side of Posterior – towards the backside of Superior – above Inferior – below Medial – towards the midline Lateral – away from the midline Superficial – towards the surface Deep – away from the surface Proximal – towards the trunk Distal – away from the trunk Supine – lying on spine (back) Prone – face down

Anatomical Language… MOVEMENT!

Anatomical Language… MOVEMENT CONT’D

Anatomical Language… MOVEMENT CONT’D Flexion - where there is a reduction in the angle between bones or parts of the body. An example of arms flexing is a bicep curl. Extension - is the opposite of flexion, and there is an increase in the angle. ADduction –Movement of a limb towards the midline of the Body. ABduction - the exact opposite of ADduction, movement of a limb Away from the midline of the Body. Pronation - this is the rotation of the hand so that the palm faces down. Supination - the rotation of the hand so that the palm faces up. Dorsiflexion - movement which decreases the angle between the foot and the leg Plantar flexion - the movement which increases the angle between the foot and the leg, as when depressing an automobile pedal

BONES Why do we need bones?

BONES 5 Functions of the Skeleton… FRAMEWORK/SUPPORT – Bones give the body it’s shape and allow it to stand upright PROTECTION – Bones protect the body’s vital organs MOVEMENT – Bones provide attachments for muscles to produce movement RED BLOOD CELL PRODUCTION – Red bone marrow within bones produces red blood cells. STORAGE – Bones serve as a storage bank for minerals such as calcium and phosphorus.

Types of Bones 1. 5. Long Bones Short Flat Irregular Sesamoid 3. 4. 2.

BONES THE AXIAL SKELETON The axial skeleton’s main purpose is to protect the body’s most vital organs; The Brain Heart Lungs Also acts as attachment for muscles.

BONES THE APPENDICULAR SKELETON The appendicular skeleton allows for movement mainly due to greater joint mobility Also provides protection for the organ of digestion, excretion, and reproduction.

INERT TISSUES CARTILAGE The 3 main structural components of the human body are BONE, MUSCLE, and CARTILAGE Bones are rigid, while muscles stretch and bend. Cartilage is the perfect halfway point between muscle and bone. Therefore, we find cartilage in places where we need some support and structure, but a bit of flexibility as well. Main Functions of Cartilage: Acts as cushion between bones, holds bones together (i.e Ribs), shock absorber.

INERT TISSUES MENISCUS Lateral Meniscus Medial Meniscus

INERT TISSUES LIGAMENTS Ligaments are strong bands of connective tissue that connect BONE TO BONE Ligaments keep bones together while allowing for movement, but also prevent unwanted movement (i.e hyperextension)

INERT TISSUES ATFL – Anterior Talofibular Ligament CFL – Calcaneofibular Ligament COMMONLY INJURED LIGAMENTS ACL – Anterior Cruciate Ligament PCL – Posterior Cruciate Ligament MCL – Medial Collateral Ligament LCL – Lateral Collateral Ligament

Joints There are 3 Types of Joints: 1. Immovable (Fibrous) i.e Sutures in the skull. 2. Slightly Moveable (Cartilaginous) i.e Vertebral Joint, Tibiofibular Joint 3. Freely Moveable (Synovial Joint) i.e Elbow, Knee, Fingers, Shoulders, Hips The Synovial Joint contains synovial fluid which allows the joint to move freely and decreases friction

The Muscular System

Muscular System Overview Muscles pump blood through our bodies, move food through our digestive system, and control the movement or air in and out of our lungs Exercise is the key to health of the muscular system In mass, muscle is the most abundant tissue in the body Our muscles consist of 75% water Muscles work by CONTRACTING, they become shorter A muscles is composed of bundles of fibers

Types of Muscle Smooth Muscle (Involuntary Muscle) – Movement of internal organs (eg. Intestines, bladder, etc.). Smooth muscle is not under conscious control Skeletal Muscle (Voluntary Muscle) – Muscles attached to bones that aid in body movements. An average adult male is made up of 40–50% of skeletal muscle and an average adult female is made up of 30–40% Cardiac Muscle – Striated tissue that forms the walls of the heart. Striated means Marked by narrow lines or grooves, usually parallel.

Skeletal Muscle Type I – Slow Twitch Type I – “slow oxidative” or “slow twitch” muscle is dense with capillaries and is rich in mitochondria and myoglobin, giving the muscle tissue its characteristic Red color. The slow muscles are more efficient at using oxygen to generate more fuel (known as ATP) for continuous, extended muscle contractions over a long time. They fire more slowly than fast twitch fibers and can go for a long time before they fatigue. Therefore, slow twitch fibers are great at helping athletes run marathons and bicycle for hours.

Skeletal Muscle Type II – Fast Twitch Because fast twitch fibers use anaerobic metabolism to create fuel, they are much better at generating short bursts of strength or speed than slow muscles. However, they fatigue more quickly. Fast twitch fibers generally produce the same amount of force per contraction as slow muscles, but they get their name because they are able to fire more rapidly. Having more fast twitch fibers can be an asset to a sprinter since he/she needs to quickly generate a lot of force.

Name the fibre type mainly used. Type II Type I & II Type II Sport Fiber Type Used Baseball Basketball Cross Country Skiing  Type I Football   Gymnastics Golf Ice Hockey Lacrosse    Rugby Soccer Swimming - Sprint  Type II Synchonized Swimming Tennis Track & Field Volleyball Weight Training Name the fibre type mainly used. Type II Type I & II Type II Type I & II Type II Type I & II Type I & II Type I & II Type I & II Type I Type I & II Type I & II Type II Type I

Fiber Type and Performance Our muscle fiber type may influence what sports we are naturally good at or whether we are fast or strong. Olympic athletes tend to fall into sports that match their genetic makeup. Olympic sprinters have been shown to possess about 80 percent fast twitch fibers, while those who excel in marathons tend to have 80 percent slow twitch fibers.

Can Training Change Fiber Type? This is not entirely understood, and research is still looking at that question. There is some evidence showing that human skeletal muscle may switch fiber types from "fast" to "slow" due to training but not the other way around. Fiber type is part of a great athlete's success, but it alone is a poor predictor of performance. There are many other factors that go into determining athleticism, including mental preparedness, proper nutrition and hydration, getting enough rest, and having appropriate equipment and conditioning.

Muscle Development Hypertrophy – The growth and increase of the size of muscle cells Example? Bodybuilding

Atrophy – The decrease in the size of skeletal muscle cells Atrophy – The decrease in the size of skeletal muscle cells. When a muscle atrophies, it becomes weaker Example? Inactivity, when a cast is put on a limb.

Muscular Physiology Each muscle is made up of many Muscle Fibers Each muscle fibre is made up of Myofibrils Each myofibril is made up of a series of Sarcomeres The Sarcomere is made of 2 types of proteins, a thin filament (Actin) and a thick filament (Myosin)

How Does a Muscle Know When to Contract? Messages from the nervous system travel via nerves into the muscle telling it to contract. A motor nerve connects to a muscle and branches out into nerve endings. It is these endings which stimulate the muscle fibres.

Muscle Fatigue A muscle requires fuel and oxygen for energy. Muscles that are repeatedly contracted require a high amount of oxygen and energy. When the amount of oxygen coming in, does not meet the demands of the muscle, lactic acid is produced causing a burning sensation in the muscle.

QUIZ NEXT WEEK – TUESDAY APRIL 14 - MUSCLES UNIT TEST - THURSDAY