Calcium Is Very Important In Building Biology Essay

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A patient with a T-score between +1 and −1 is considered normal or healthy. A T-score between −1 and −2.5 indicates that they have low bone mass known as osteopenia, which is a bone mineral density (BMD) that is lower than normal peak BMD but not low enough to be diagnosed with osteoporosis. A T-score of −2.5 or lower indicates that the patient has osteoporosis. The greater the negative number, the more severe the osteoporosis (Boyle, & Senior, 2008).

(max 100 words)

A 50 year old, post-menopausal woman who has osteoporosis has been referred to you.

b) What nutritional supplements (including dosage) would you recommend and why?

(max 200 words)

Calcium is very important in building and maintaining strong bones, doctors recommend women above 50 with osteoporosis to take 1,000-1,500 milligrams of calcium daily, eating plenty of calcium-rich foods, such as nonfat milk, low-fat yogurt, broccoli, cauliflower, salmon, tofu, and leafy green vegetables provide a good source of calcium. Calcium can also be obtained from calcium supplement tablets if the correct levels of calcium could not be obtained from a food diet alone (NHS, 2012). In addition to calcium, vitamin D is also important to take daily as is it allows the body to absorb calcium. The recommended daily amount for women over 50 is 800-1000 IU daily. Vitamin D can also be produced in the body from exposure to sunlight, or, alternatively may be taken as vitamin D supplements (Johnson, 2012).

http://www.webmd.com/osteoporosis/guide/osteoporosis-treatments

Drugs such as Actonel, Boniva, and Fosamax work by inhibiting cells that break down bone and slowing bone loss. Actonel, Binosto, and Fosamax are usually taken once a week, while Boniva is taken once a month (Johnson, 2012). Another medication is Reclast, which is given as a once-yearly via a 15-minute infusion in a vein. Reclast is said to increase bone strength and reduce fractures in the hip, spine and wrist, arm, leg, or rib (Johnson, 2012).

c) What types of exercises (including frequency) would you recommend for this patient to undertake as part of their treatment and why? You can presume the patient has no broken bones and is not pregnant

1) Posture exercises. These exercises improve your posture and reduce rounded or "sloping" shoulders. They can help you decrease the risk of breaking a bone, especially in the spine (NHS, 2012).

Corner stretch shoulders, flattens upper back. Improves rounded shoulders. for 20-30 seconds. Do 2 on each side, 3 times per week (National Osteoporosis Foundation, 2011).

2) Hip and back (spine) strengthening exercises. These exercises can help you to strengthen the muscles in your back and hips. (and improve balance) repeat 10 times. Do this 2-3 times per week (National Osteoporosis Foundation, 2011).

Prone leg lifts: Lower and repeat 10 times.Then do 10 on the other side. Do this 2-3 times per week (National Osteoporosis Foundation, 2011).

Benefit: Strengthens lower back and buttocks. Stretches hip flexors and the front of the thighs (National Osteoporosis Foundation, 2011).

3) Balance Exercise Example These exercises strengthen your legs and challenge your balance. They can decrease your chance of falling (NHS, 2012).

Toe raises/heel raises Repeat 10 times. Do this once each day. Benefit: Strengthens lower legs. Helps balance (NHS, 2012).

Wall slide Do this 10 times, 2-3 times per week. Benefit: Strengthens thighs, abdomen and back. Decreases rounded upper back and forward head posture. Improves leg alignment (NHS, 2012).

(max 150 words)

d) What key hormones are involved in the formation of healthy bones in women?

(max 200 words)

Calcitonin a hormone secreted by the thyroid gland, stimulates osteoblast activity (important in bone formation). It functions mainly in children and pregnant women; it seems to be of little significance in nonpregnant adults (Saladin, 2004).

Growth hormone promotes intestinal absorption of calcium, the proliferation of cartilage at the epiphyseal plates, and the elongation of bones (Saladin, 2004).

Sex steroids (estrogen and testosterone) stimulate osteoblasts and promote the growth of long bones, especially in adolescence. Bone deposition is also promoted by thyroid hormone, insulin, and local growth factors produced within the bone itself (Saladin, 2004).

Parathyroid hormone (PTH) is produced by four small parathyroid glands, which adhere to the back of the thyroid gland in the neck. The parathyroid glands secrete PTH in response to a drop in blood calcium level. PTH stimulates osteoblasts, which then secrete an osteoclast-stimulating factor

that promotes bone resorption by the osteoclasts. The principal purpose of this response is not to maintain bone composition but to maintain an appropriate level of blood calcium, without which a person can suffer fatal muscle spasms. PTH also reduces urinary calcium losses and promotes calcitriol synthesis (Mader, 2003).

e) How could a female do to reduce the risk of osteoporosis? Include discussion of childhood, food and exercise/lifestyle.

(max 150 words)

The amount of bone mass you obtain while you are young determines your skeletal health for the rest of your life. It is therefore imperative in to start in childhood and throughout life to maintain a healthy diet containing calcium-rich foods. One should also avoid phosphorus-rich food, which can promote bone loss. High-phosphorus foods include red meats, soft drinks, and those with phosphate food additives (NHS, 2012). Excessive amounts of alcohol and caffeine are also thought to reduce the amount of calcium absorbed by the body and should be avoided. To help keep estrogen levels from dropping sharply after menopause it is advisable to consume more foods containing plant estrogens, especially tofu, soybean milk, and other soy products (NHS, 2012).

Not only must you get enough calcium in your diet, you must also exercise to maintain strong bones. Exercise which put stress on bones, such as running, walking and weightlifting -- reduce bone loss and help prevent osteoporosis. To benefit from the exercise, one must do it at least three times per week for 30 to 45 minutes (National Osteoporosis Foundation, 2011).

Criterion 1, 1.1, 1.2

A) All bones in the skull (except for the mandible) are attached by interlocking joints called sutures.  The mandible is attached to the skull by paired temporomandibular joints, allowing it to move up and down. The hyoid bone is not part of the skull but is attached to the skull and larynx by muscles and ligaments.

The Vertebral Column holds up the head as well as allowing the "yes" motion of the head. It also allows the head to tilt from side to side. The vertebrae are joined by an intervertibral disc joint (amphyatrthrasis).

The Ribs

There are twelve pairs of ribs. The upper seven pairs of ribs connect directly to the

sternum via costal cartilages. The next three pairs of ribs do not connect

directly to the sternum rather via cartilage. The last two pairs are called "floating ribs" because they do not attach to the sternum at all. The ribs allow little movement.

Appendicular Skeleton:

The Pectoral (Shoulder) Girdle.

The Pectoral girdle consists of two shoulder blades and two collar bones. The upper end of the shoulder blade forms a cavity into which fits the head of the upper arm bone, forming a ball and socket joint. Collar Bones (Clavicles) form a support for the shoulder blades in front and keep the shoulder blades back so that the arms can hang freely at the sides of the body.

The Upper Arm (Humerus)

The upper arm is a single long bone. The upper end consists of a spherical ball which fits into the socket of the shoulder blade to form a ball-and-socket joint. Ball-and-socket joints allow flexion, extension, adduction, abduction and medial rotation. The lower end of the humerus forms a small ball and socket joint with the radius and a hinge joint with the ulna in the elbow. The elbow joint allows Flexion, Extension, Pronation and Supination.

The Forearm (Radius and Ulna)

The wide, lower end of the radius forms most of the wrist joint (saddle joint). The radius also allows the forearm to be rotated. The radio-ulnar joints are pivot joints.

The Wrist

The wrist consists of eight carpal bones. They are able to slide over one another. The wrist joint has the following range of movement: Flexion, Extension, Adduction, Abduction and Circumduction.

. The Pelvic (Hip) Girdle.

The two pubic bones are attached in the middle, by a symphysis which consists of fibrocartilage and ligaments. On the outer side, there is a large hip socket into which the head of the femur fits, forming a ball and socket joint. The hip joint allows Flexion, Extension, Adduction, Abduction, Medial Rotation and Lateral Rotation. At its distal end, the femur widens to form the hinged knee joint with the main long bone (tibia) of the lower leg. The knee joint allows flexion and extension.

The Lower Leg

The two bones of the lower leg are the tibia and the fibula. The lower end of the tibia joins with one of the tarsals to form the ankle joint. The lower end of the fibia also forms part of the ankle joint. The joint is called a talocrural joint. This allows plantar flexion, dorsi flexion, inversion and eversion.

b) Identify and describe three abnormal spinal curvatures (200 - 500 words)

Criterion 2.1

Scoliosis:

Scoliosis is an abnormal curvature of the spine towards the left or the right. The curve can be similar to a C or S shape. The two most common forms of scoliosis are; 1) Thoracic scoliosis affecting the chest area.

2) Lumbar scoliosis, affecting the lower back area.

In 80% of scoliosis cases the cause is unknown. This is known as idiopathic scoliosis (NHS, 2012). Most cases of scoliosis are degenerative meaning it gradually becomes worse with time. Either due to damage to 1) Vertebrae - bones which support the spine and neck. 2) Disks - spongy tissue between the vertebrae helping to cushion the vertebrae. 3) Ligaments - tissue which holds the vertebrae and disks together. 4)Tendons - tissue which connects the bones in the spine to the muscle (Seenley, Stephens, & Tate, 2004). Damage to any one of these body parts could damage the spinal structure, causing it to curve. Other causes could be weakening of the bone through osteoporosis, damage from surgery, motor nurone disease, multiple sclerosis or Parkinson disease (Seenley, Stephens, & Tate, 2004).

Kyphosis:

Kyphosis is a condition where the top part of the back is excessively curved forward its generally diagnosed when the curve is more than 40 degrees. In most cases kyphosis doesn't cause any sympotons, however in some severe cases it may cause back pain, stiffness and tiredness. Kyphosis occurs when the middle section of the vertebrae, known as the thoracic vertebrae curve disproportionally out of position (NHS, 2012). A poor posture can cause the ligaments in the vertebrea to strecthc snd in some cases also the muscles that support the vertebrae to stretch. This in turn pull the thoracic vertebrae away from their normal position ,resulting in kyphosis.

Kyphosis can also be caused when the vertebrae fail to develop correctly they then adopt an irregular shape leading to the vertebrae being out of position. The medical term for this is known as Scheuermann's kyphosis (NHS, 2012).

Congenital kyphosis is also the vertebrae failing to develop correctly, however two or more vertebrae may fuse together leading to the abnormal curvature (NHS, 2012).

Lordosis:

Lordosis is when the lower back curves significantly inwards (a small amount of curvature is considered normal). Sitting for extended periods could cause lordosis, as the body adapts to the sitting position by shortening and stiffening certain muscles, and also stretching and weakening other muscles Lordosis could also be due to, neuromuscular problems, osteoporosis, or, may even be present at birth (Health Line, 2009).

Structu

Structural Characteristics

Types

Type of Mobility

Fibrous joints

Fibrous Joints

Fibrous joints consist of two bones that are united by fibrous connective tissue, have no joint cavity, and exhibit little or no movement.

Sutures are seams between the bones of the skull. The tissue between the two bones is dense, regular collagenous connective tissue.

Syndesmoses

A syndesmosis is a fibrous joint in which the bones are farther apart than in a suture and are joined by ligaments.

Gomphoses

Gomphoses are specialized joints consisting of pegs that fit into sockets and that are held in place by fine bundles of regular collagenous connective tissue. The joints between the teeth and the sockets (alveoli) of the mandible and maxillae are gomphoses

Sutures

Sutures allow no movement.

Syndesmoses

Some movement may occur at syndesmoses because of flexibility of the ligaments, such as in the radioulnar syndesmosis, which binds the radius and ulna together.

Gomphoses

The connective tissue bundles between the teeth and their sockets are called periodontal ligaments and allow a slight amount of "give" to the teeth during mastication.

Cartilaginous joints

Cartilaginous joints unite two bones by means of either hyaline cartilage or fibrocartilage A synchondrosis consists of two bones joined by hyaline cartilage where little or no movement occurs. Most synchondroses are temporary,with bone eventually replacing them to form synostoses. On the other hand, some synchondroses persist throughout life. An example is the sternocostal synchondrosis between the first rib and the sternum by way of the first costal cartilage. A symphyses consists of fibrocartilage uniting two bones. Symphyses include the junction between the manubrium and body of the sternum, the symphysissymphysis pubis, and the intervertebral disks. Some of these joints are slightly movable because of the somewhat flexible nature of fibrocartilage.

Synchondrosis

The Epiphyseal plate and the Sphenooccipital have no movement capabilitys, however the Sternocostal may allow very slight movement.

Symphyses

The Manubriosternal and Xiphisternal allow no movement. The Intervertebral though allow slight movement. The Symphysis pubis allows no mevemnt except during childbirth.

Synovial joints

Synovial joints contain synovial fluid and allow

considerable movement between articulating bones.

The articular surfaces of bones within synovial joints are covered with a thin layer of hyaline cartilage called articular cartilage, which provides a smooth surface where the bones meet. The articular surfaces of the bones that meet at a synovial joint are enclosed within a synovial joint cavity, which is surrounded by a joint capsule. This capsule helps to hold the bones together while allowing for movement. The joint capsule consists of two layers: an outer fibrous capsule and an inner synovial membrane. Gliding joints consist of two opposed flat surfaces of about equal size in which a slight amount of gliding motion can occur between the bones. Saddle joints consist of two saddle-shaped articulating surfaces oriented at right angles to each other so that complementary surfaces articulate with each other. Saddle joints are biaxial joints. Hinge joints are monoaxial joints and consist of a convex cylinder in one bone applied to a corresponding concavity in the other bone.Ellipsoid joints (or condyloid joints) are modified ball-andsocket joints. The articular surfaces are ellipsoid in shape rather than spherical as in regular ball-and-socket joints A pivot joint consists of a relatively cylindrical bony process that rotates within a ring composed partly of bone and partly of ligament. Ball-and-socket joints consist of a ball (head) at the end of one bone and a socket in an adjacent bone into which a portion of the ball fits.

Hinge

Hinge joints allow one axes of movement (like a door hinge) i.e. forward and back but not sideways.

Gliding Joints allow a slight amount of gliding motion between the bones. They are considered monoaxial because some rotation is also possible but is limited by ligaments and adjacent bone.

Ellipsoid joints are biaxial, because the shape of the joint limits its range of movement almost to a hinge motion in two axes and restricts rotation.

Pivot joints are monoaxial joints that restrict movement to rotation around a single axis

Ball and socket joints are multiaxial, allowing a wide range of movement in almost any direction. Saddle joints allow movements in three planes of axis like an ellipsoidal joint, except rotation, as in a pivot joint.

Gliding

Ball-and-socket

Pivot

Saddle

Condyloid (ellipsoid)

You should include hand drawn colour diagrams of each structural class

Criteria 3.2

Task 4

a) Copy and complete the following table on the characteristics of muscles:

Characteristic

Skeletal

Cardiac

Smooth

Location

Attached to bones

Heart

Walls of hollow organs, blood vessels,

eyes, glands, and skin

Connective Tissue components

Regulation of contraction

Voluntary and involuntary (reflexes)

Involuntary

Involuntary

Speed of contraction

Rhythmic contraction

Criterion 4

Task 5

Define the term agonist, antagonist and synergist in relation to muscle movement. Say how they are related to limb movement and contribute to whole body locomotion (150 - 200 words)

The prime mover, agonist, is the muscle that produces most of the force during a particular joint action. In flexing the elbow, for example, the prime mover is the biceps brachii.

2. A synergist is a muscle that aids the prime mover. Several synergists acting on a joint can produce more power than a single larger muscle. The brachialis, for example, lies deep to the biceps brachii and works with it as a synergist to flex the elbow.

3. An antagonist is a muscle that opposes the prime mover. In some cases, it relaxes to give the prime mover almost complete control over an action.More often, however, the

antagonist maintains some tension on a joint and thus limits the speed or range of the agonist, preventing excessive movement and joint injury. If you extend your arm to reach

out and pick up a cup of tea, your triceps brachii on the posterior side of the humerus is the prime mover of elbow extension, while your biceps brachii acts as an antagonist to

slow the extension and stop it at the appropriate point. If you extend your arm rapidly to throw a dart, however, the biceps must be more relaxed.

b) Copy and complete the following table with the names of the muscles acting on the elbow:

Elbow Flexion

Elbow Extension

Pronation

Supination

Biceps brachii

Triceps brachii

Pronator teres

Supinator

Brachialis

Anconeus

Pronator quadratus

Biceps brachii

Brachiadialis

Pronator teres

Criterion 5.1, 5

Task 6

a. Explain the sliding filament theory of contraction including hand-drawn colour labelled diagrams of:

i. Bundle of fibres

ii. Muscle fibre

iii. Myofibril

iv. Actin & myosin filaments

v. Relaxed and contracted sarcomeres.

vi. The contraction cycle

(250 - 400 words)

Criterion 6.1

Muscles are made up of Muscle Fibers ( as well as a smaller amounts of connective tissues and blood vessels). The nuclei of each muscle fiber are located inside the sarcolemma. Most of the interior of the fiber is filled with myofibrils. Other organelles, such as the mitochondria and glycogen granules, are packed between the myofibrils. Each myofibril is a threadlike structure approximately 1-3 um in diameter that extends from one end of the muscle fiber to the other.Myofibrils are composed of two kinds of protein filaments called actin myofilaments & myosin myofilaments.

Actin myofilaments consist of two strands twisted around one another. Myosin myofilaments are rod shaped and have bulbous heads projecting to the side The actin and myosin myofilaments are organized into units called sarcomeres, which are joined end to end to form the myofibrils.

The sliding filament theory of contraction can be explained in three stages,

1)Muscle Stimulation:

An action potential reaches many neuromuscular junctions simultaneously, causing calcium ion channels to open and calcium ions to move into the synaptic knob. The calcium ions cause the synaptic vesicles to fuse with the presynaptic membrane and release their acetylcholine into the synaptic cleft. Acetylcholine diffuses across the synaptic cleft and binds with receptors on the postsynaptic membrane, causing it to depolarise.

2)Muscle contraction:

The action potential travels deep into the fibre through a system of tubules (T-tubules) that branch throughout the cytoplasm of the muscle (sarcoplasm). The tubules are in contact with the endoplasmic reticulum of the muscle (sarcoplasmic reticulum) which has actively absorbed calcium ions from the cytoplasm of the muscle.

The action potential opens the calcium ion channels on the endoplasmic reticulum and calcium ions flood into the muscle cytoplasm down a diffusion gradient. The calcium ions cause the tropomyosin molecules that where blocking the binding sites on the actin filament to move away. The ADP molecule attached to the myosin heads means they are now in a state to bind to the actin filament and form a cross bridge. Once attached to the actin filament, the myosin heads change their angle, pulling the actin filament along as they do so and releasing a molecule of ADP. An ATP molecule attaches to each myosin head, causing it to become detached from the actin filament. The calcium ions then activate the enzyme ATPase, which hydrolyses the ATP to ADP. The hydrolosis of ATP to ADP provides the energy for the myosin heads to return to their original position. The myosin head, once more with an attached ADP molecule then reattaches itself further along the actin filament and the cycle is repeated.

3)Muscle Relaxation:

When the nervous signals stop, calcium ions are actively transported into the endoplasmic reticulum using energy from the hydrolosis of ATP. The reabsoption of the calcium ions allows tropomyosin the block the actin filaments once again. Myosin heads are now unable to bind to the actin filament and the muscle contraction stops.

b. Describe the energy pathways involved in muscle contraction including hand-drawn colour labelled diagrams.

(250 - 400 words)

Criterion 6.2

The energy which is used in muscle contraction is adenosine triphosphate (ATP).

The energy required to produce ATP comes from three sources: (1) creatine phosphate, (2) anaerobic respiration, and (3) aerobic respiration. Initially the muscles use stored ATP for energy, this is called a direct energy source however this is only able to supply around 3 seconds worth of energy to the muscles. After this time creatine phosphate is used. Creatine phosphate reacts with ADP to produce ATP and creatine.

ADP + Creatine phosphate → Creatine + ATP

The reaction occurs very rapidly and is able to maintain ATP levels as long as creatine phosphate is available in the cell. During intense muscular contraction, however, creatine phosphate levels are quickly used up. ATP and creatine phosphate present in the cell provide enough energy to sustain maximum contractions for about 8-10 seconds. Anaerobic respiration requires no oxygen and results in the breakdown of glucose to produce ATP and lactic acid. For each molecule of glucose metabolized, two ATP molecules and two molecules of lactic acid are produced. Each glucose molecule is broken down into two molecules of pyruvic acid. Two molecules of ATP are used in this process, but four molecules of

ATP are produced, resulting in a net gain of two ATP molecules for each glucose molecule metabolized. The pyruvic acid is then converted to lactic acid.

During short periods of intense exercise, such as sprinting, anaerobic respiration

combined with the breakdown of creatine phosphate providesenough ATP to support intense muscle contraction for up to 3 minutes.

Aerobic Respiration

Aerobic respiration requires oxygen and breaks down glucose to produce ATP, carbon dioxide, and water. Compared to

anaerobic respiration, aerobic respiration is much more efficient.

In aerobic respiration each glucose molecule can produce up to 38 ATP

molecules. In addition, aerobic respiration can use other energy sources, such as

fatty acids and amino acids. In aerobic respiration, pyruvic acid is metabolized by chemical reactions within mitochondria. Two closely coupled sequences

of reactions in mitochondria, called the citric acid cycle and the

electron-transport chain, produce many ATP molecules. The following equation represents aerobic respiration of one molecule of glucose:

Glucose + 6 O2 + 38 ADP + 38 Phosphate → 6 CO2 + 6 H2O + About 38 ATP

Resting muscles or muscles undergoing long-term exercise, such as long-distance running, depend on aerobic respiration for ATP synthesis

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