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The Skeletal SystemThe Four Functions of The Skeletal System It supports the organs and tissues of the body. Without this support, they would collapse under
their own weight. It provides protection for internal organs (e.g. lungs are protected by ribs, brain is protected by
the cranium) It provides a base for the attachment of muscles and allows movement with the bones. The bones are a source of supply of blood cells and store minerals required for the body to
function. Types of Joints Immovable/fibrous joints: these joints occur where the bones are fused together, so no
movement is possible (e.g. the joints on the cranium and pelvis) Slightly movable/cartilaginous joints: these joints allow slight movement only, and have a
tough layer of cartilage between the bones (e.g. joints between the vertebrae) Freely moveable/synovial joints: these allow for free movement in one or s number of
directions. The majority of joints in our body are synovial (e.g. hip, shoulder, knee, elbow) Types of Synovial Joints Gliding Joint: side to side or back and forth movements e.g. Between carpals and the tarsals Hinge joint: flexion/extension e.g. Knee joints Pivot joint: rotation e.g. Radius rotates over ions to move palm from up to down Condyloid joint: back and forth, side to side in two planes e.g. Joints between palm fingers Saddle joint: abduction/adduction, flexion/extension but rotation is limited e.g. Ankle joint Ball and Socket joint: maximum movement (rotation, flexion/extension, abduction/adduction) e.g.
Shoulder and hip joints
Bones to Remember
Ribs/thorax
Cervical (7), thoracic (12), lumbar (5), sacrum (5), coccyx (4)
Long bones: are longer than they are wide, function as levers Short bones: have a short axis and are found in small spaces such as the wrist, they serve to
transfer forces Flat bones: have a broad surface and serve as places of attachment for muscles and to protect
vital organs Sesamoid bones: these are bones found in the body where tendons pass over a joint. They aim
to protect the tendon and increase movement. Irregular bones: these are bones that do not fall into one of the above categories Anatomical Reference Terms Superior—towards the head
o for example, the chest is superior to the hips Inferior — towards the feet
o for example, the foot is inferior to the leg Anterior — towards the front
o for example, the breast is on the anterior chest wall Posterior — towards the back
o for example, the backbone is posterior to the heart Medial — towards the midline of the body
o for example, the big toe is on the medial side of the foot Lateral — towards the side of the body
o for example, the little toe is on the lateral side of the foot Proximal — towards the body’s mass
o for example, the shoulder is proximal to the elbow Distal — away from the body’s mass
o for example, the elbow is distal to the shoulder Ligaments:
o fibrous bands that connect the articulating bones o restraining excessive movement, but can also control the degree and direction of movement
that occurs o Bone to bone
Tendons:
o tough, inelastic cords of tissue that attach muscle to bone o Muscle to bone
Synovial fluid:
o acts as a lubricant, keeping the joint well oiled o provides nutrition for the cartilage and carries away waste products
Hyaline cartilage:
o layer of smooth, shiny cartilage that allows the bones to move freely over each other Joint Movements Flexion decreases the angle between the bones at the joint
Extension increases the angle between the bones at the joint
Abduction away from the midline of the body
Adduction body part towards the midline of the body
Inversion make the sole of the foot face inwards
Eversion make the sole of the foot face outwards
Rotation moving a body part such as the head or trunk around on its long axis
Circumduction circular movement of a body part
Pronation rotation of the hand and forearm that causes the hand to face palm downwards
Supination rotation of the hand and forearm that causes the hand to face palm upwards
Dorsiflexion movement that pulls the top of the foot towards the tibia
Plantar flexion pointing the toes
The Muscular SystemFunction of Muscles Produce movement to walk, run, jump, breathe, digest Provide stabilisation of posture and internal organs Generate heat to maintain body temperature To locate muscle, we need the origin and insertion of the muscle
o Origin of muscle is usually attached to bone (tendons)
Major Muscles Smooth and cardiac muscles are voluntary muscles that the human body has no control over (e.g.
The heart) Skeletal muscle is responsible for producing human movement; groups of muscles work together
to control movement patterns. Muscle Relationship Agonist: prime mover is the muscle causing the major action
o Biceps during flexion (contracting) Antagonist:
o antagonist cause an opposite action to that caused by the agonist
o Triceps during extension Stabiliser: fixated muscles that act at a joint to stabilise it Types of Muscle Contraction Isotonic: length of the muscle will change, becoming longer or shorter Concentric: muscles shorten to cause movement at the joint Eccentric: muscle lengthens while under tension, often happens with assistance of gravity Isometric: muscle fibres activate and develop force but muscle length does not change Diagram of Muscular System
Muscular System Guide Trapezius Upper back muscle
Deltoid Shoulder muscle
Pectoralis major Breast muscle
Latissimus dorsi Side of torso muscle/upper level
Biceps brachii Upperside/top part of upper arm/humerus
Triceps brachii Downside of top part of upper arm/humerus
Obliques Side of torso muscle/lower level
Rectus abdominis Abs
Gluteus maximus Butt
Erector spinae Spine
Quadriceps femoris Top part of thigh
Hamstrings Under part of thigh
Gastrocnemius Calf muscle
Tibialis anterior Shin muscle
Soleus Muscle under calf
Sartorius On the medial side of the thigh
Achilles' tendon Ankle muscle
The Respiratory System
Respiration: the process by which the body takes in oxygen and removes carbon dioxide Inspiration: inhaling, diaphragm contracts, chest cavity increases Expiration: exhaling, diaphragm relaxes Process of Breathing 1. Air enters body through nose or mouth. When entering through nose, passes through nasal
cavities and is warmed, moistened and filtered of any foreign material 2. The pharynx/throat is a common passage for air to the trachea/windpipe or food to oesophagus. It
leads from nasal cavity to larynx/voice box located at beginning of trachea 3. After entering the chest cavity or thorax, the trachea divides into right and left bronchus/bronchial
tube, which lead to the right and left lungs respectively 4. The inner lining of the air passages produces mucus that catches and holds dirt and germs. It is
also covered with microscopic hairs/cilia that remove dirt, irritants and mucus through steady, rhythmic movements
5. They are enclosed in the thoracic cavity by the ribs at the sides and the diaphragm (a dome-
shaped muscle) at the base. The light, soft, lung tissue is compressed and folded and, like a sponge, is composed of tiny air pockets
Diagrams
Effects of Physical Activity 1. The rate and depth of breathing increases moderately, even before exercise begins, as the body’s nervous activity is increased in anticipation of the exercise 2. Once exercise starts, the rate and depth of breathing increase rapidly. This is thought to be
related to stimulation of the sensory receptors in the body’s joints as a result of the movement. Further increases during the exercise result mainly from increased concentrations of carbon dioxide in the blood,
3. The increases in the rate/frequency and depth/tidal volume of breathing provide greater
ventilation and occur, generally, in proportion to increases in the exercise effort (workload on the body)
Parts of Respiratory System Oral and Nasal Cavity: air containing oxygen from the atmosphere enters the body either through
nose or throat, when passed through the nose, the nasal cavities warm and moisten the air and filter of any foreign material
Pharynx: the nose or throat is a passageway for both air and food Larynx: the larynx or voice box is a short passageway that connects the pharynx to the trachea. It
closes off the larynx ensuring food and liquids go to the oesophagus
Trachea: or the windpipe is a passageway for air Bronchi: the trachea divides into the right and left bronchus. These bronchi eventually branch into
bronchioles Lungs: paired organs within the thoracic cavity. Each lung is divided into lobes, which receives
the bronchi. These eventually divide into alveoli, which are tiny air sacs. The gas exchange takes place within the alveoli
The Circulatory System Circulatory/cardiovascular system is a network that distributes blood containing oxygen and
nutrients and collects wastes. It comprises the heart, arteries, blood and veins. Consists of blood, heart and blood vessels (arteries, capillaries and veins) Functions of Blood transportation of oxygen and nutrients to tissues and removal of carbon dioxide and wastes protection of body via immune system (white blood cells) and by clotting to prevent blood loss regulation of body’s temperature and fluid content of body’s tissues. Components of Blood Plasma
o a straw-coloured liquid mainly consisting of water o substances such as plasma proteins, nutrients, hormones, mineral salts and wastes are
dissolved in plasma Red Blood Cells
o red blood cells are formed in bone marrow o their main role is to carry oxygen and carbon dioxide around the body o they contain iron and a protein called haemoglobin. Haemoglobin readily combines with
oxygen and carries it from the lungs to the cells o on average, men have 16 grams of haemoglobin per 100 millilitres of blood (as a percentage
of blood volume), while women average 14 grams per 100 millilitres of blood White Blood Cells
o white blood cells are formed in the bone marrow and lymph nodes o they provide the body with a mobile protection system against disease o these cells can change shape and move against the blood flow to areas of infection or disease o most common types of white blood cells are phagocytes, which engulf foreign material and
harmful bacteria, and lymphocytes, which produce antibodies to fight disease Platelets
o platelets are fragments of cells found in blood and are responsible for clotting o prevents blood loss by clotting o bone marrow cells that have no nucleus o important in preventing blood loss when a blood vessel is damaged
Parts of The Heart
Pulmonary and Systemic Circulation Pulmonary circulation is the flow of blood from the heart to the lungs and back to the heart Systemic circulation is the flow of blood from the heart to body tissue and back to the heart Blood Pressure Blood pressure refers to the force exerted by the blood on the walls of the blood vessel Systolic pressure is the highest pressure recorded when blood is forced into the arteries during
contraction of the left ventricle (systole). Diastolic pressure is the lowest pressure recorded when the heart is relaxing and filling
(diastole).