musculoskeletal system

Question 1

What is the axial skeleton?

Answer 1

Consists of the bones along the axis of the body.

Question 2

What is the appendicular skeleton?

Answer 2

Consists of the bones of the appendages and girdles.

Question 3

How many bones are in the adult human body?

Answer 3

206

Question 4

What is an articulation?

Answer 4

A joint

Question 5

What functions does the skeleton have?

Answer 5

> Mineral and fat storage
Production of blood cells
Provides protection for internal organs
Provides us with a frame.shape.

Question 6

Name 5 different types of bones and give examples of where they might be located on the body

Answer 6

1. Long bones - greater in length than width. For example, the humerus.
2. Short bones - cube shaped. For example, trapezoid wrist bones.
3. Flat bones - made of thin layers of parallel plates. For example the sternum.
4. Irregular bones - complex shapes. For example the vertebra.
5. Sesamoid bones - shaped like a sesame seed. For example, the patella.

Question 7

Describe at least one unique characteristic of vertebrae in each vertebral column.

Answer 7

The thoracic vertebrae support the ribs and have special structures for rib health and tubercle attachment.

The lumbar vertebrae are the strongest and largest of the vertebral column. They support the body’s weight.

Question 8

Describe the function of the atlas.

Answer 8

Supports the skull.

Question 9

Describe the function of the axis

Answer 9

Enables to pivot motion of the head.

Question 10

How do red and yellow bone marrow differ in composition and function?

Answer 10

Red marrow:
>Largely composed of haematopoietic tissue.
>Found within the trabecular cavities of spongy bones and long bones.

Yellow marrow:
>In adults, predominantly composed of adipose tissue.
>Found in a medullary cavity of long bones.

Question 11

Under what circumstances are bone marrow samples taken for testing?

Answer 11

AKA a b one marrow biopsy.

Usually taken to diagnose disorders of blood cell formulation, leukaemia, marrow infections and anaemia resulting from damage to or failure of the bone marrow.

Question 12

Which bones are bone marrow samples usually taken?

Answer 12

Samples are usually taken from the anterior or posterior iliac crest (lower back).

Question 13

During intramembranous ossification, which types of tissue are replaced by bone?

Answer 13

Mesenchymal tissue.

Question 14

How do bone growth and bone remodelling differ?

Answer 14

Bone growth is a process where in which your bones lengthen by interstitial growth of the epiphyseal plate cartilage.

Remodelling is the process by which bone is deposited and reabsorbed at the surface of the periosteum and the surface of the endosteum. Remodelling is carried out by osteoblasts (builders) and osteoclasts (breakers).

Question 15

In endochondral ossification (bone formation, what is the original source of osteoblasts?

Answer 15

The cells of the inner layer of the perichondrium in this region.

Question 16

How could X-Rays of the femur help to determine whether a person has reached their full height?

Answer 16

In a grown adult, the epiphyseal plates (growth plates) which originally are cartilage become ossified and turn to bone. this would show on an X-Ray.

Question 17

What would happen to a synovial joint if there was no synovial fluid?

Answer 17

Synovial fluid reduces friction and without it, joint surfaces would rub away as a result of the friction.

Question 18

What is a graded contraction? How does it work?

Answer 18

Graded contractions are contractions of whole muscles which can vary in terms of their strength and degree of contraction.

When you want to exert a greater force, you send a series of nerve impulses at higher frequency to the muscle. Then, more axon brush nerve endings would be involved in the transmission of impulses. Each axon brush nerve ending is responsible for a fixed number of muscle fibres.

Question 19

What are troponin and tropomyosin and what role do they play in muscle contraction?

Answer 19

Tropomyosin is a protein that covers the myosin binding sites. Troponin is attached to tropomyosin.

When the body sees an intracellular rise in calcium ion levels, troponin binds to the calcium and because troponin is attached to tropomyosin, it causes both to move away from the myosin binding sites on actin allowing a cross-bridge to form.

Question 20

What is muscle tone?

Answer 20

Muscle tone is the maintenance of partial contraction of a muscle. Muscle tone does not produce movement.

Question 21

What is muscle tone?

Answer 21

Muscle tone is the maintenance of partial contraction of a muscle. Muscle tone does not produce movement.

Question 22

What role does calcium play in muscle contraction?

Answer 22

Calcium ions are released into the intracellular space, eventually binding to troponin so that tropomyosin can move away from the myosin binding sites on actin, allowing for cross-bridges to form and contraction to occur.

Question 23

What would happen in a patient with low calcium levels?

Answer 23

Low calcium levels lead to increased permeability of the neuronal membranes to sodium ions, causing a progressive depolarisation which increases the possibility for action potentials.

This can cause muscle cramps, spasms, tremors or tetany from prolonged contraction.

Question 24

What is a plane/gliding joint?

Answer 24

Formed between bones that meet at flat or nearly flat articular surfaces.

Eg. Wrist joint

Question 25

What is a ball and socket joint?

Answer 25

Possess a rounded, ball-like end of one bone fitting into a cup-like socket of another bone.

Eg. The shoulder joint.

Question 26

What are condyloid joints?

Answer 26

Consist of an oval-shaped end of one bone fitting into a similarly oval-shaped hollow of another bone.

Eg. The joint between your carpal and phalange.

Question 27

What are saddle joints?

Answer 27

Ends of each bone resemble a saddle, with concave and convex portions that fit together.

Eg. The thumb joint.