- Created by: luluirmiger
- Created on: 18-11-18 16:03
BONES AND THE SKELETON
Functions of the skeleton:
- Support - of the muscles and vital organs
- Protection - mainly by flat bones
- Movement - different joints and bones allow different movement
- Shape - structure
- Mineral storage - such as calcium, for bone formation
- Blood cell production - red blood cells formed in bone marrow
Types of bones:
- Short bones (enable finer, controlled movements): Carpals, tarsals
- Long bones (enable gross movement): Humerus, radius, ulna, phlanges, metacarpals, femur, tibia, fibula
- Flat bones (protect vital organs): Cranium, jaw, clavicle, ribs, pelvis, sacrum, talus
- Irregular bones (shaped to protect): Vertebrae, patella
Synovial joints: Ball & socket (where adduction + abduction can occur), Hinge (where flexion + extension can occur).
THE STRUCTURE OF A SYNOVIAL JOINT
THE MUSCULAR AND SKELETAL SYSTEM
The main joints & muscles:
- Shoulder - deltoid, trapezius, pectorials, latissimus dorsi, biceps, triceps, rotator cuff
- Elbow - biceps, triceps
- Hip - gluteals, hip flexors
- Knee - quadriceps group, hamstring group
- Ankle - tibialis anterior, gastrocnemius
Ligaments = bands of fibres attatced to bones, linking joints together
Tendons = strong cords joining muscle to bone
Muscles come in pairs (e.g. biceps + triceps) as they cannot push, only pull:
- Agonist - muscle which contracts to start movement
- Antagonist - muslcle which relaxes to allow movement to take place
Isotonic contractions = where the muscle changes length, resulting in limb movement (concentric - muscle shortens, eccentric - muscle lengthens)
Isometric contractions = where the length does not change - no limb movement.
THE CARDIO-RESPIRATORY SYSTEM
- 1 - Oxygen gets breathed in, passes through alveoli and into red blood cells in the capillaries
- 2 - The oxygen combines woth the haemoglobin to form oxyhaemoglobin
- 3 - At the same time, haemoglobin carries CO2 from the body to the capillaries
- 4 - The CO2 in the capillaries passes through alveoli and is breathed out
Diffusion pathway = the distance travelled during diffusion, it is short in gaseous exchange.
Mechanics of breathing:
- Inhalation/inspiration - (resting) The diaphram moves down, intercostal muscles contract, rib cage muves up & out. This reduces the air pressure inside the chest cavity so air rushes in.
- Exhalation/expiration - (resting) The diaphram moves up, intercostal muscles relax, rib cage moves down & in. This increases the pressure in the chest cavity so air rushes out.
- Tidal volume - normal amount of air between inspiration and expiration per breath
- Inspiratory reserve volume - maximal amount of air that could be inhaled after tidal volume
- Expiratory reserve volume - maximal amount of air that could be exhaled after tidal volume
- Residual volume - volume of air remaining in the lungs after expiratory reserve volume
- Vital capacity - largestvolume of air that can be forcibly expired after the deepest possible inspiration
THE CARDIOVASCULAR SYSTEM
The pathway of the blood:
- Deoxygented blood enters the right atrium through the superior + inferior vena cava.
- It then passes through the right ventricle
- The pulmonary artery transports the blood to the lungs
- Gaseous exchange occurs, resulting in oxygenated blood
- The pulmonary vein transports oxygenated blood from the lungs to the left atrium
- It then passes through a valve to the left ventricle
- Oxygenated blood is ejected from the heart and is transported to the body via the aorta
Diastole = the phase of the heartbeat when the chambers relax + fill with blood.
Systole = the phase of the heartbeat when the chambers empty of blood.
Stroke volume = amount of blood pumped out of the heart be each ventricle during one contraction.
Cardiac output = stroke volume X heart rate
ANAEROBIC AND AEROBIC EXERCISE
Anaerobic - respiration in the absence of oxygen. Glucose = energy + lactic acid. Only for a short time as energy isn't being generated. (e.g 100m sprint)
Aerobic - respiration in the presence of oxygen. Glucose + oxygen = energy + CO2 + water. (e.g marathon runner)
Excess post-exercise oxygen consumption/EPOC/oxygen debt = The additional oxygen consumption during recovery above what is usually required at rest.
The recovery process:
- Cool-down - allows lactic acid to disperse safely, helps to maintain elevated breathing/heart rate and therefore blood flow.
- Manipulation of diet - rehydrating, eating carbs as an additional energy source, eating protein to repair muscles
- Ice baths/massage - to prevent delayed onset muscle soreness (DOMS), causes vasoconstriction, removes lactic acid (ice bath), causes vasodilation which speeds up healing process and reduces pain.
THE EFFECTS OF EXERCISE
- temperature increase
- heart rate increase (heart is working harder to deliver oxygen to muscles)
- increased levels of sweating
- increase in depth & frequency of breathing
- aching and cramp (a sudden contraction of muscles)
- change in body shape such as more toned muscles
- improved components of fitness
- building of muscle strength
- increased heart size (hypertrophy) + decreased resting heart rate (bradycardia)