Anatomical Terms and Body Planes

• The notes below discuss the structure and function of the skeletal system, including major bones, synovial joints, joint actions, muscular system, respiratory and circulatory systems, and the endocrine system.

Anatomical Position

• The anatomical position is a standard reference for describing the body, where movements are defined.

Body Planes

• Sagittal Plane: Divides the body into left and right sides, movements in this plane are forward or backward (e.g., lunges, walking).
• Frontal Plane: Divides the body into front (anterior) and back (posterior) sections, lateral movements occur in this plane (e.g., star jumps, lateral raises).
• Transverse Plane: Divides the body into top and bottom halves, rotation occurs in this plane (e.g., rotation, pronation, supination).

Directional Terms

• Superior (cranial): Toward the head end (e.g., shoulders are part of the superior extremity).
• Inferior (caudal): Away from the head (e.g., the foot is part of the inferior extremity).
• Anterior (ventral): Front of the body (e.g., the knee is located on the anterior side of the body).
• Posterior (dorsal): Back of the body (e.g., the shoulder blades are on the posterior side).
• Medial: Toward the midline of the body (e.g., the nose is located at the medial side of the face).
• Lateral: Away from the midline of the body (e.g., the ear is located at the lateral side of the head).
• Proximal: Nearest the point of origin (e.g., the proximal end of the tibia joins with the femur).
• Distal: Farthest from the origin (e.g., the foot is located at the distal end of the leg).

Axial and Appendicular Skeleton

• Axial Skeleton: Supports the body's central structure, including the skull, vertebral column, and thorax.
• Appendicular Skeleton: Aids movement, includes the shoulder girdle, arm, wrist, hand, pelvic girdle, leg, ankle, and foot.

Skeletal System Functions

• Provides structure and shape, allows movement, and protects vital organs.
• Produces red and white blood cells in the bone marrow and stores minerals like calcium and phosphorus.
• Regulates endocrine functions.

Bones

• The human body has 206 bones that enable movement with the help of over 600 muscles.
• Bones are classified into five main categories based on shape and size.
• Short bones: Cube-shaped, provide stability (e.g., carpals), mostly in the appendicular skeleton, contain cancellous bone.
• Long bones: Support weight and facilitate movement (e.g., femur), have a shaft (diaphysis) and two ends.
• Flat bones: Thin and curved, protect internal organs (e.g., skull, pelvic organs), found in the axial skeleton.
• Irregular bones: Complex shapes that protect internal organs (e.g., pelvis).
• Sesamoid bones: Small bones embedded in tendons near joints, reduce stress on the tendon (e.g., patella).

Joints

• A joint is where two or more bones meet and are also called articulations.
• Fibrous joints: Immovable, provide protection (e.g., skull and sternum bones).
• Cartilaginous joints: Slightly movable, allow limited movement (e.g., vertebrae of the spine).
• Synovial joints: Freely movable, allow maximum movement (e.g., hip, shoulder, elbow), contain tendons, ligaments, cartilage, and synovial fluid.

Synovial Joint Structures

• Ligaments: Bands of tough, elastic tissue that connect bone to bone, support joint stability by restricting excessive movement and guiding controlled motion.
• Tendons: Fibrous connective tissues that attach muscles to bones, transmit muscle generated force to bones, and stabilize the joint.
• Synovial Fluid: A thick, slippery fluid in joint cavities that lubricates cartilage surfaces, minimizes friction, acts as a shock absorber, and supplies oxygen and nutrients to the cartilage.
• Articular Cartilage: Firm, flexible connective tissue at the ends of bones in synovial joints that allows bones to move freely over each other, receives nourishment from synovial fluid, and helps weight bearing.

Types of Synovial Joints

• Ball and Socket: Freely moving in all axes (e.g., hip and shoulder), allowing flexion, extension, adduction, abduction, and rotation.
• Hinge: Move on one axis (e.g., elbow and knee), allowing flexion and extension.
• Gliding: Move against each other on a single plane (e.g., intervertebral joints, wrists, and ankles), allowing gliding movements.
• Pivot: Allow rotation of one bone around another (e.g., at the top of the spine), rotation of the head occurs here.
• Condyloid: Allow circumduction, abduction, adduction, flexion, and extension (e.g., wrist joint).
• Saddle: Allow flexion, extension, adduction, abduction, and circumduction (NOT rotation).

Major Bones

• Clavicle (Collarbone): A long bone connecting the shoulder girdle and vertebral column; forms part of the shoulder joint.
• Scapula (Shoulder Blade): A triangular flat bone that is part of the ball and socket shoulder joint; muscles attach to this bone for movement.
• Humerus: Main long bone in the upper arm joining the shoulder joint to the elbow joint, allows movement in many directions and rotation.
• Radius: Long bone on the thumb side of the forearm, works with the ulna to rotate the forearm and palm.
• Ulna: Long bone on the little finger side, part of the hinge joint in the elbow and used for palm rotation.
• Carpals, Metacarpals, Phalanges: Bones of the wrists and fingers; carpals are short, while metacarpals and phalanges are long.
• Pelvic Girdle: Supports the upper body's weight, attaches lower limbs, and allows less movement than the shoulder girdle due to strong ligaments.

Major Bones Continued

• Femur (Thigh Bone): Largest, supporting up to 30x an adult's weight, forms hip and knee joints, covered by large muscles for movement.
• Patella (Kneecap): Provides protection to the knee's hinge joint.
• Tibia (Shinbone): Larger lower leg bone, forms knee and ankle joints, supports most of the bodyweight.
• Fibula: Parallel lower leg bone outside of the tibia; supports and stabilizes the lower leg, allows slight rotation.
• Tarsals, Metatarsals, Phalanges: Bones in the foot; tarsals are short, metatarsals and phalanges are long, enables balance.

Joint Actions

• Flexion: Decreases the angle of a joint (e.g., bicep curl).
• Extension: Increases the angle of a joint (e.g., bottom phase of a chin-up).
• Supination: Rotates the forearm with the palm facing upward (e.g., chin-ups).
• Pronation: Rotates the forearm with the palm facing downwards (e.g., bouncing a basketball).
• Inversion: Moves the foot towards the median plane (e.g., side-to-side direction changes).
• Eversion: Moves the foot away from the middle of the body (e.g., ballet plies).
• Adduction: Moves the limb toward the body's midline (e.g., jumping jacks [arms down]).
• Abduction: Moves the limb away from the body's midline (e.g., lateral raises [upwards]).
• Plantar-Flexion: Bends the sole of the foot down (e.g., pointing toes).
• Dorsi-Flexion: Moves a body part backwards (e.g., swinging arm back when walking).
• Rotation: Twisting movement produced by summation of small rotational movements (e.g., Russian twists).
• Circumduction: Combines flexion, adduction, extension, and abduction (e.g., freestyle swimming).

Types of Muscles

• Cardiac Muscle: Found in the heart; involuntary; responsible for heartbeats.
• Skeletal Muscle: Produces movement; voluntary; controlled contractions.
• Smooth Muscle: Lines the walls of hollow organs; involuntary.

Importance of Musculoskeletal Interrelationship

• Provides shape and stability, protects vital organs, and produces voluntary movement.
• Muscle contraction enables movement via bones acting as levers. Stabilizing tissue is ensured via ligaments and tendons within the joints.

Muscle Attachment Points

• Origin is the attachment point to the bone that doesn't move during muscle contraction at the proximal end.
• Insertion is the attachment to the base that moves during contraction, further from the body's midline.

Major Muscles, Bones, and Movements

• Upper Limb: Deltoid (scapula, clavicle, humerus) in the shoulder enables the arm action in a star jump.
• Upper Limb: Biceps (humerus, scapula, and radius) in the shoulder and elbow allows a bicep curl.
• Upper Limb: Triceps (scapula, humerus, and ulna) in the shoulder and elbow facilitates shooting in netball.
• Trunk: Latissimus (vertebrae, ribs, humerus, and scapula) in the shoulder enables an underarm throw.
• Trunk: Trapezius (skull, vertebrae, scapula, and clavicle) in the shoulder facilitates shoulder shrugs.
• Trunk: Pectorals (sternum, clavicle, and humerus) in the shoulder performs an underhand serve in volleyball.
• Trunk: External Obliques (ribs and ilium) in the hip completes a golf shot.
• Trunk: Erector Spinae (skull, vertebrae, and sacrum) in the hip maintains upright posture when running.
• Trunk: Rectus Abdominis (pubis, ribs, and sternum) in the hip bends the body forward to dive into a pool.

Major Muscles, Bones, and Movements Continued

• Lower Limb: Gluteus Maximus (pelvis, sacrum, and femur) in the hip lifts the leg for a side kick.
• Lower Limb: Hamstrings (ischium, femur, tibia, and fibula) in the hip and knee aids flexion in the knee for running.
• Lower Limb: Quadriceps (ilium, femur, tibia, and patella) in the hip and knee pushes off the blocks in a 100m sprint.
• Lower Limb: Gastrocnemius (femur and heel bone) in the knee and ankle enables the standing on the toes in ballet.
• Lower Limb: Soleus (tibia, fibula, and heel bone) in the knee and ankle aids in pointing your toes.
• Lower Limb: Tibialis Anterior (tibia, tarsals, and metatarsals) in the knee and ankle assists with kicking a soccer ball.

Skeletal Muscle Fiber Characteristics

• Skeletal muscle contains thousands of muscle fibers bundled together with a connective tissue called Fascia, including long cylindrical myofibrils with sarcomere sections containing actin and myosin filaments, allowing muscle contraction (striated).

Muscle Fiber Types

• Slow twitch muscle fibers (ST, red fibers) contract slowly over time for endurance.
• Fast twitch muscle fibers (FT, white fibers) reach peak tension rapidly for power.

Muscle Fiber Function

• A nerve impulse triggers its action to contract from the spinal cord for the skeletal muscles resulting in movement. Fibers react to produce movement based on fiber usage.

Slow Twitch Muscle Fibers

• Suited for long endurance aerobic activity; require oxygen (oxidative).
• Contract slowly; gradually release energy for jogging; rich in blood for oxygen.
• Increased mitochondria (ATP) and myoglobin, also have smaller diameters.

Fast Twitch Muscle Fibers

• Contract quickly but tire fast due to anaerobic metabolism used for providing their energy.
• There is less oxygenated blood, resulting in their pale appearance. Type IIA fibers combine type 1 and type 2B.
• Uses glycogen or oxygen in either aerobic or anaerobic metabolism for contraction.
• Fibers are multi tasked making and are useful in activities employing aerobic and anaerobic elements.
• The body preferentially uses FTa fibers for strength and sprints.
• The fibers have intermediate diameters and are stimulated by a small neuron.
• Fast Twitch IIB Fibres are called glycolitic fibers and use glycogen as their primary source to contract
• FtB fibers create fast contractions but fatigue rapidly.
• They perform in strength and power activities and need a large neuron for stimulus.

Types of Muscle Contractions

• Isotonic Concentric: Muscle shortens (e.g., flexing during a bicep curl against gravity).
• Isotonic Eccentric: Muscle lengthens (e.g., extending during a bicep curl with gravity).
• Isometric: Muscle length remains the same despite the tension application (e.g., plank hold).
• Isokinetic: Constant speed with the muscle length changing against resistance (requires special equipment).

Muscle Relationships

• Agonist: Prime mover muscle causing the major action
• Antagonist: Opposing muscle that has to relax and lengthen for its parter, the agonist to contract, assisting the action.
• Stabilizer: Muscle that stabilizes a joint and allows more effective movements.

Respiratory System Structure

• Nasal Cavity & Mouth: Air enters, is warmed, and moistened.
• Pharynx: Throat part that divides into the oesophagus and larynx.
• Larynx: Voice box containing vocal cords.
• Trachea: Windpipe with smooth muscle and cartilage rings.
• Bronchi: Tree-like structures branching into the lungs.
• Bronchioles: Smaller air passages branching off from the bronchi.
• Alveoli: Small, cup shaped air sacs surrounded by capillaries for gas exchange.
• Lungs: Located within the thoracic cavity, protected, with bronchioles and alveoli.
• Diaphragm: Controls involuntary breathing.

Lung Function

• The diaphragm contracts and relaxes to facilitate breathing.
• Diffusion (high to low concentration): Gas exchange occurs in the lungs and at the muscle.
• Lungs (alveolar/capillary interface): Oxygen moves into the blood and carbon dioxide into the alveoli due to concentration differences for gas exchange.
• Muscles (capillary/muscle interface): Capillaries transport oxygen to muscle tissue.
• The brain monitors carbon dioxide/oxygen trigger to breathe via levels in the blood.

Mechanisms of Breathing

• Ventilation: Tidal Volume multiplied by Respiratory rate of air per breath.
• Inspiration: The diaphragm contracts, external intercostals lift the rib cage, increases lung volume.
• Expiration: The diaphragm relaxes, external intercostals relax, decreases lung volume. Air is expelled from the lungs in both instances to offset pressure.

Circulatory/Respiratory Systems

• Breathing controlled by a respiratory center in the brain stem monitors oxygen levels via arterial sensors for balance.
• Carbon dioxide buildup prompts brain to increase rates of repsiration - known as respiratory rate.
• If oxygen demands increase, the body responds and adjusts respiratory and heart performance so demands can be met faster.

Arteriovenous Oxygen

• Measured via oxygen levels taken by muscles from blood in arteries compared to veins - the difference in levels (a-vO2 diff).

The Circulatory System

• Consists of cardiovascular (blood movement) and lymphatic (collection of fluids to blood) systems. Blood transports nutrients, energy, hormones, waste, and gases.

Circulatory System Functions

• Circulates blood, transports nutrients, gases, wastes, and maintains body temperature.
• Hypothermia: Body constricts vessels reducing blood flow in the skin slowing heat loss.
• The body is warmed due to muscular contractions. Hyperthermia involves vasodilation for heat, and if there´s no more loss body decreases fluid loss to avoid fluid evaporation and retain heat.

The Heart

• The heart pumps the blood and its beats are generated by muscular contractions. There is a 4 way valve and left / right pumps with separated segments. The right side pumps deoxygenated blood to lungs in 2 chambers and the left side (with 2 chambers) pumps oxygenized blood.
• Each segment has chambers that are upper, thin walled chambers (atria) which have 2 valves between the atrium and ventricles known as atrioventricular to stop backflow.

Blood Vessels

• Arteries carry blood away from the heart (oxygenated except pulmonary arteries). They have strong thick and elastic walls.
• These vessels branch into many tiny arteries/arterioles including capillaries and microscopic vessels to allow oxygen and nutrients.
• Veins carry used blood back to the heart; the venules collect used blood.
• They may or may not contain valves with thinner walls than its counterpart, the artery.

Blood Composition

• Plasma: Fluid that transports water, salts, waste, and enzymes.
• Red blood cells contain protein for oxygen and come from the bone.
• White blood cells are part of the body´s immune system.
• Platelets are small cell portions for clotting.

Circulation of Blood to the Body

• The main redistribution of fluid during exercise means vasodilation or constriction of arteries or bloodflow will ensue, but if a non active area is selected, the process is called vasoconstriction.
• Right atrium receives blood which comes from the body and the body eventually has oxygenated blood again (via pulmonary artery) , where it has a system to push everything with force.

Circulatory System Types

• Both sides have overlapping heart pumps - meaning that the right will give depleted to the lungs while the left will take back oxygenized contents again.
• All the information also occurs in artery form which is called systemic.

Circulatory System Terminology

• Stroke Volume: The amount of blood produced via the left ventricle
• Cardiac output: Stroke volume * HR, in L/min. To increase, and provide the necessary nutrients and work the exercise needs and levels.
• Exercise level varies because intensity goes up, levels may be jogging (rest, SV and HR occur, and it steady states until oxygen matches supply) to sprinting (HR increases linearly to max), and stroke plateaus to increase cardiac output by 40%.

Gaseous Exchange

• The getting down to body sales, of O2 but up from waste and CO2, that occurs mainly from inside alveoli. Gas exchange occurs (as they´re high concentration CO2 is released but O2 diffuses) both internally and outside, lungs, in capillaries and the process for the latter, the inside lungs (external for the outside process) is called external exchange.
• The process for exercise needs more 02 for energy, to eliminate fat from cells the gaseous exchange, heart, cardiac output and bloodvessel control go up to work the machine.

Factors Affecting Circulatory System

• Altitude (above sea level): The change makes the ability to extract needed oxygen harder, because increased levels may also result in acute hypoxia or shortness of breath. If the person acclimates to these issues through careful management such as Epo from the body´s side may ensue.
• Levels of hemoglobin should have high levels to perform in athletes. Lower levels increase the work the body should perform- the body also needs oxygen to be delivered and the heart rate should also increase to facilitate its usage.
• Diseases may lower and increase bloodflow and thus should be managed.

Endocrine System

• Endocrine glands secrete hormones.
• Different hormones are distributed through the blood via the circulatory system.
• Controls hormones via stimulus. Types include nervous stimuli, levels or balance and hormonal ones

Endocrine System Hormones

• Hypothalamus: Wide range of releasing and inhibiting hormones; its target pituitary gland. It has the following affects: nerves, hunger, sleep, etc.
• Thyroid Gland: secretes Thyroxine (T4) and Triiodothyronine (T3), target most body tissues: increases energy
• Pituitary gland has a function with Growth hormones and targets bones to Stimulate muscle growth
• Endorphins releases, muscles in the body are targets and controls size and pain.
• Adrenal glands secrete adrenalin and cortisol to target and effect body metabolism and blood sugar.
• Glucagon release which affects the pancreas and its effect with glucose. All these levels and bodily processes make sure it's all running and meeting its required levels.

Macronutrients

• Includes fats, proteins and carbohydrates that are found in large portions, as well. These promote support, and are all stored and provided in order of usage such as atp.

Micronutrients

• These are in small amounts and usually come as vitamins and minerals to supplement and develop bodily processes As hormones go, and processes or stimulus levels of any kind increase, bodily forces should increase also with such help. If there´s too little of some kind can be promoted to work on better balances.

Stress

• Stress promotes adrenalin due to external actions that may exist, resulting also (cortisol level also increases). There is blood and energy also provided. This should be done in small portions because elevated results cause levels decrease via blood pressures or sugar with decreased ability, and the disease also promotes a change in levels.