Skeletal System

Question 1

The human skeletal system consists of what 4 parts?

Answer 1

206 bones, cartilage, bone marrow and the periosteum (the membrane around the bones).

Question 2

Bone is formed by a process called ?

Answer 2

Ossification.

Question 3

1. Ossification begins around when and continues to ?
2. The embryonic skeletal framework consists of ?
3. The ossification process ____(a)______ in this tissue and then ____(b)___ _______ and other mineral salts.

Answer 3

1. The 6th week of embryonic life and continues throughout adulthood.
2. Fibrous connective tissue.
3. a) creates spaces b) deposites Calcium

Question 4

Name the Blue and Red Skeleton Sections:

Answer 4

Blue is called the Axial Skeleton

​Red is called the Appendicular Skeleton

Question 5

What does the Axial skeleton consist of?

Answer 5

Axial skeleton consists of the Skull, Spine, Ribcage & Sturnum

Question 6

What does the Appendicular skeleton consist of?

Answer 6

The Appendicular skeleton consists of the Shoulders, Arms, Hands, Pelvis, Hips, Legs & Feet.

Question 7

The Skeleton has a number of functions: (6)

Answer 7

• It supports and shapes the body (we would be very floppy without it).
• It provides fixation points for the muscles and tendons to facilitate movement.
• It protects internal organs and delicate tissues.
• The red marrow in the bones produces new blood cells.
• The yellow marrow in the bones consists of fat, which is used as an energy store.
• The bones store minerals - especially calcium and phosphorous - that can be released when required.

Question 8

Anterior View

Answer 8

Anterior View

Question 9

Posterior View

Answer 9

Posterior View

Question 10

For the skeletal structure to be able to support the body and facilitate movement, the bones in the body have to be attached. The point at which two or more bones articulate (meet) is called a ___1___. ___2a____, ____b____ and ____c______ all have a part to play in enabling the joints to be strong and moveable.

Answer 10

1. joint
2. a) Muscles, b) Tendons & c) Ligaments

Question 11

1. The impetus for any movement is derived from the what?
2. How are muscles connected to the bone?
3. How are bones connected to bones?

Answer 11

1. The impetus for any movement is derived from the contraction of a muscle.
2. However muscles rarely connect directly to the bones – most muscles are connected to the bones by tendons. Tendons are comprised of strong, almost inelastic white fibrousconnective tissue and vary in length and thickness. When a muscle contracts it pulls on its tendon. The tendon then pulls on the bone to which it is attached to cause the bone to move at the joint.
3. Ligaments are also made of white fibrous connectivetissue and are silvery in appearance. They join bone to bone to strengthen, support and protect joints. They hold the bones together to prevent dislocation but stretch slightly to allow movement. Ligaments are thicker at the joints that require the most strength and support (e.g. the hip) but are thinner and less abundant in joints that require a lot of movement (e.g. the shoulder).

Question 12

Tendons are comprised of what?

Answer 12

Tendons are comprised of strong, almost inelastic white fibrousconnective tissue and vary in length and thickness. When a muscle contracts it pulls on its tendon. The tendon then pulls on the bone to which it is attached to cause the bone to move at the joint.

Question 13

Ligaments are comprised of what?

Answer 13

Ligaments are also made of white fibrous connectivetissue and are silvery in appearance. They join bone to bone to strengthen, support and protect joints. They hold the bones together to prevent dislocation but stretch slightly to allow movement. Ligaments are thicker at the joints that require the most strength and support (e.g. the hip) but are thinner and less abundant in joints that require a lot of movement (e.g. the shoulder).

Question 14

Bone Structure: name the main parts of this Long Bone:

(How is a long bone defined?)

(What does ‘physis’ mean?)

Answer 14

(Long bone is defined as such because its length is greater than its width)

‘physis’ means growth.

Epiphysis (‘Epi-’ = above)

Metaphysis (‘Meta-’ = behind)

Diaphysis (‘Dia-’ = through)

Metaphysis

Epiphysis

Question 15

The main shaft of the bone is the diaphysis (dia- = _______).

There is a tunnel that runs through the diaphysis called the ____a___ or _____ ______. This contains ____ _____ ____ _______.

The lining of the ___a____ cavity is called the ____________.

Answer 15

The main shaft of the bone is the diaphysis (dia- = through).

There is a tunnel that runs through the diaphysis called the medullary or marrow cavity. This contains fatty yellow bone marrow.

The lining of the medullary cavity is called the endosteum.

Question 16

The area at ____ ___ of the bone is called the epiphysis (epi- = _____).

The diaphysis and the epiphyses are joined by an area of bone called the ________ (meta- = ______). This is the _______ area of the bone.

Answer 16

The area at each end of the bone is called the epiphysis (epi- = above).

The diaphysis and the epiphyses are joined by an area of bone called the metaphysis (meta- = behind). This is the growing area of the bone.

Question 17

1. What are the epiphyses covered by?
2. What is the outer membrane of the bone called?

Answer 17

1. The epiphyses are covered by articular (hyaline) cartilage. Articular cartilage is a gristly connective tissue. It is composed of chondrocytes (cartilage cells) and a dense network of fibrous collagen and elastic fibres in a jelly-like substance. This cartilage reduces friction and acts as a shock absorber.​
2. The outer membrane of the bone is called the periosteum. The periosteum surrounds the outside surface of the bone that is not covered by cartilage. It is composed of fibrousconnective tissue and contains blood vessels, lymphatic vessels and nerves. The vessels and nerves pass into the bone through holes called Volkmann’s (or perforating) canals.

Question 18

1. Bone is a ___________ tissue. It consists of widely separated cells within a __a___. The ___a__ consists of approximatelly __% water, __% protein and __% mineral salts.
2. The mineral salts crystallize in the collagen (a protein) fibres of the matrix, hardening the tissue. This process is called ___________. The hardness of the bone depends on this, but the presence of the ________ ______ allows the bone to be ______ and prevents __ ____ ______ __ _______.

Answer 18

1. Bone is a connective tissue. It consists of widely separated cells within a matrix. The matrix consists of approximately 25% water, 25% protein and 50% mineral salts.
2. The mineral salts crystallize in the collagen (a protein) fibres of the matrix, hardening the tissue. This process is called calcification. The hardness of the bone depends on this, but the presence of the collagen fibres allows the bone to be pliable and prevents it from being too brittle.

Question 19

There are 4 types of bone cell within the matrix:

Answer 19

1. Osteoprogenitors (These cells are unspecialized. They can divide mitotically to develop into osteoblasts. Osteoprogenitor cells are found in the inner portion of the periosteum, endosteum and in the canals in the bone that contain blood vessels.)
2. Osteoblasts (These are the cells that form bone. They secrete collagen and other organic components needed to build it. They are located on the surface of bone. As they surround themselves with matrix materials they become osteocytes.)
3. Osteocytes (These are the principal bone cells, derived from osteoblasts. Osteocytes do not secrete matrix materials. They maintain the cellular activities of the bone tissue.)
4. Osteoclasts (It is believed that osteoclasts develop from monocytes, a type of white blood cell. Osteoclasts play a part in the re-absorption of bone. This is a necessary function for growth and repair.)

Question 20

Osteoprogenitors

Answer 20

• Osteoprogenitors are unspecialized.
• They can divide mitotically to develop into osteoblasts.
• Osteoprogenitor cells are found in the inner portion of the periosteum, endosteum and in the canals in the bone that contain blood vessels.)

Question 21

Osteoblasts

Answer 21

• Osteoblasts are the cells that form bone.
• They secrete collagen and other organic components needed to build it.
• They are located on the surface of bone.
• As they surround themselves with matrix materials they become osteocytes.

Question 22

Osteocytes

Answer 22

• Osteocytes are the principal bone cells, derived from osteoblasts.
• Osteocytes do not secrete matrix materials.
• They maintain the cellular activities of the bone tissue.

Question 23

Osteoclasts

Answer 23

• It is believed that osteoclasts develop from monocytes, a type of white blood cell.
• Osteoclasts play a part in the re-absorption of bone. This is a necessary function for growth and repair.

Question 24

Name the two types of Bone Tissue

Answer 24

Compact & Spongy.

Question 25

As the name suggests, compact bone tissue contains ___ spaces. It forms the _______ \_\_\_\_\_\_ of all bones in the body and the _________ (\_\_\_\_\_) of long bones. Compact bone tissue is \_\_\_\_\_\_, providing __________ and \_\_\_\_\_\_\_.

Answer 25

As the name suggests, compact bone tissue contains **few** spaces. It forms the **external layer** of all bones in the body and the **diaphysis (shaft)** of long bones. Compact bone tissue is **strong**, providing **protection** and **support**.

Question 26

In compact bone tissue, canals called **\_\_\_\_\_\_\_\_\_\_\_\_** (or central) canals run longitudinally through the bone. Blood vessels run through the Haversian canals, connecting with those that penetrate the bone laterally through the **\_\_\_\_\_\_\_\_\_\_\_\_** canals. Label the diagram:

Answer 26

In compact bone tissue, canals called **Haversian** (or central) canals run longitudinally through the bone. Blood vessels run through the Haversian canals, connecting with those that penetrate the bone laterally through the **Volkmann’s** canals.

Question 27

Hard, calcified matrix called \_\_\_\__\_(a)\__\_\_\_\_ form concentric circles around the Haversian canals. Between the \_\_\_\_(_a_)\_\_\_\_\_ there are spaces called \_\_\_\_(_b_)\_\_\_\_. These contain \_\_\_\_(_c_)\_\_\_\_. Minute canals called \_\_\_\_(_d_)\_\_\_\_\_, filled with extracellular fluid, radiate from the \_\_\_\_(_b_)\_\_. The \_\_\_\_(_d_)\_\_\_\_ contain finger-like projections from the \_\_\_\_\_(c)\_\_\_\_\_\_. Each Haversian canal with its \_\_\_(a)\_\_\_\_, \_\_\_(b)\_\_\_\_, \_\_\_\_\_(c)\_\_\_\_\_ and \_\_\_\_\_(d)\_\_\_\_ forms an \_\_(e)\_\_. \_\_\_\_(e)\_\_\_ are characteristic of adult compact bone. The vast network of longitudinal and lateral canals that runs through compact bone provides the vascular route for nutrients and oxygen to reach the \_\_\_\_(c)\_\_\_\_ and wastes to be removed.

Answer 27

Hard, calcified matrix called **lamellae** form concentric circles around the Haversian canals. Between the lamellae there are spaces called **lacunae**. These contain **osteocytes**. Minute canals called **canaliculi**, filled with extracellular fluid, radiate from the lacunae. The canaliculi contain finger-like projections from the osteocytes. Each Haversian canal with its lamellae, lacunae, osteocytes and canaliculi forms an **osteon**. Osteons are characteristic of adult compact bone. The vast network of longitudinal and lateral canals that runs through compact bone provides the vascular route for nutrients and oxygen to reach the osteocytes and wastes to be removed.

Question 28

Spongy bone is also called ________ bone. During the ossification process, spongy bone is the _________ of most ________ bone.

Answer 28

Spongy bone is also called **cancellous** bone. During the ossification process, spongy bone is the **forerunner** of most **compact** bone.

Question 29

In the long bones, spongy bone forms the __________ and \_\_\_\_\_\_\_\_\_\_. It is also the main component of ____ bones, ____ bones, **irregularly shaped** bones and **sesamoid** bones.

Answer 29

In the long bones, spongy bone forms the **epiphyses** and **metaphyses**. It is also the main component of **short** bones, **flat** bones, **irregularly shaped** bones and **sesamoid** bones.

Question 30

Spongy bone does not contain \_\_\_\_\_\_. Its structure is more \_\_\_\_\_\_\_\_. The bone tissue is arranged in an _________ \_\_\_\_\_\_\_\_. This network consists of ______ of lamellae, lacunae and canaliculi called \_\_\_\_\_\_\_\_\_\_. In some bones, ___ \_\_\_\_\_ _______ is located in the spaces formed by the meshwork.

Answer 30

Spongy bone does not contain **osteons**. Its structure is more **irregular**. The bone tissue is arranged in an **interlacing network**. This network consists of **plates** of lamellae, lacunae and canaliculi called **trabeculae**. In some bones, **red bone marrow** is located in the spaces formed by the meshwork.

Question 31

Spongy bone does not have the ________ \_\_\_\_\_\_\_ ________ present in compact bone. Like compact bone, the _________ are located in the lacunae. However, as they are not so ______ \_\_\_\_\_\_\_ in spongy bone, they receive their ________ directly from the blood circulating through the ________ cavities.

Answer 31

Spongy bone does not have the **extensive vascular network** present in compact bone. Like compact bone, the **osteocytes** are located in the lacunae. However, as they are not so **deeply buried** in spongy bone, they receive their **nutrients** directly from the blood circulating through the **medullary** (or marrow) cavities.

Question 32

Bone growth is vital to __________ and \_\_\_\_\_\_. Bone grows both in _______ and in ___________ but growth is usually complete by about the age of \_\_. _Longitudinal growth of bone:_ During times of bone growth ____ layers of tissue, collectively called the ___________ \_\_\_\_\_, run across the \_\_\_\_\_\_\_\_\_. The activities of the __________ \_\_\_\_\_\_\_ enable the bone to extend in length.

Answer 32

Bone growth is vital to **development** and **repair**. Bone grows both in **length** and in **diameter** but growth is usually complete by about the age of **25**. _Longitudinal growth of bone:_ During times of bone growth **four** layers of tissue, collectively called the **epiphyseal plate**, run across the **epiphysis**. The activities of the **epiphyseal plate** enable the bone to extend in length.

Question 33

The _________ cells on the ________ \_\_\_\_\_ of the epiphyseal plate divide \_\_\_\_\_\_\_\_\_. These chondrocytes ______ and \_\_\_\_\_\_\_. __________ cartilage forms the layer of the epiphyseal plate on the _________ side. Under the influence of __________ and \_\_\_\_\_\_\_\_\_\_, the calcified cartilage is replaced by bone in the \_\_\_\_\_\_\_\_\_\_. The __________ is therefore the ________ area of the bone. The bone produced is initially ________ but later the outer regions are ___________ into ________ bone. The ________ division of ________ cells, to ______ those that are forming bone, maintains the __________ of the epiphyseal plate. When the ________ cells stop \_\_\_\_\_\_\_\_\_\_, bone growth \_\_\_\_\_. All the _______ cells of the epiphyseal plate are replaced by ____ and the remaining structure is called the __________ \_\_\_\_.

Answer 33

The **cartilage** cells on the **epiphyseal side** of the epiphyseal plate divide **mitotically**. These chondrocytes **mature** and **calcify**. **Calcified** cartilage forms the layer of the epiphyseal plate on the **diaphysis** side. Under the influence of **osteoclasts** and **osteoblasts**, the calcified cartilage is replaced by bone in the **metaphysis**. The **metaphysis** is therefore the **growing** area of the bone. The bone produced is initially **spongy** but later the outer regions are **reorganized** into **compact** bone. The **mitotic** division of **cartilage** cells, to **replace** those that are forming bone, maintains the **thickness** of the epiphyseal plate. When the **cartilage** cells stop **dividing**, bone growth **stops**. All the **cartilage** cells of the epiphyseal plate are replaced by **bone** and the remaining structure is called the **epiphyseal line**.

Question 34

Bones increase in _________ as they extend in length. \_\_\_\_\_\_\_\_\_ destroy the bone on the inside of the _________ cavity. At the same time, _________ from the _________ add new bone to the ______ surface of the bone. Some skeletal characteristics are _________ but ____ plays a part in maintaining healthy bones. A balanced diet containing minerals such as _______ and __________ promotes strong bones, and _________ is required for _______ to be successfully absorbed from the ______ and stored in the \_\_\_\_\_\_. Growth and development are also affected by \_\_\_\_\_\_\_\_\_.

Answer 34

Bones increase in **diameter** as they extend in length. **Osteoclasts** destroy the bone on the inside of the **medullary** cavity. At the same time, **osteoblasts** from the **periosteum** add new bone to the **outer** surface of the bone. Some skeletal characteristics are **inherited** but **diet** plays a part in maintaining healthy bones. A balanced diet containing minerals such as **calcium** and **phosphorous** promotes strong bones, and **Vitamin D** is required for **calcium** to be successfully absorbed from the **blood** and stored in the **bones**. Growth and development are also affected by **hormones**.

Question 35

Bones are classified by shape; there are 5 main Bone types; name them:

Answer 35

Long Short Flat Irregular Sesamoid

Question 36

Describe Long Bones & give examples:

Answer 36

Long bones have a: * **greater length than width** and * have a **shaft**. * They are **slightly curved** and * consist mostly of **compact** bone. For example: * the **femur** (thigh bone), * **tibia** and **fibula** (bones in the lower leg), * **humerus** (bone in the upper arm), * **ulna** and **radius** (bones of the forearm) and * the **phalanges** (fingers and toes).

Question 37

Describe Short Bones and give examples:

Answer 37

Short bones are * nearly **equal in length and width**. * They consist of **spongy** bone except for the thin **outer layer** of **compact** bone. For example: * **carpals** (bones of the wrist) and * **tarsals** (bones of the ankle).

Question 38

Describe Flat Bones & give Examples:

Answer 38

As the name suggests, * these are flat. * They are composed of **2 layers** of **compact** bone sandwiching a layer of **spongy** bone. For example: ​ * **cranial bones** (bones that make up the skull), * **sternum** (breast bone), * **ribs** and * **scapula** (shoulder blade).

Question 39

Describe Irregular Bones and give examples:

Answer 39

Irregular bones have * **complex shapes** and * **vary in the quantities** of **compact** and **spongy** bone present. For example: * the **vertebrae** (bones of the vertebral column).

Question 40

Describe Sesamoid Bones and give examples:

Answer 40

Sesamoid bones are * **small rounded bones** found in some tendons as they cross the joint. * Enable the tendon to move smoothly over certain bones, so preventing damage. * Consist of **spongy bone except for the outer layer**. * They tend to be **tiny** and are **most common in the hands and the feet**. Example: * the **patella** (knee cap) keeps the tendon of the anterior thigh muscle in place when the knee is bent.

Question 41

The vertebral column (\_\_\_\_\_) runs from the ____ of the ________ (\_\_\_\_) down through the _______ of the skeleton. The vertebral column is ______ and yet it can bend \_\_\_\_\_\_\_\_, ________ and to either \_\_\_\_. It can also \_\_\_\_\_. This mobility is possible as the adult vertebral column is made up of a series of __ individual bones, or \_\_\_\_\_\_\_\_, separated by rings of cartilage called __________ \_\_\_\_\_.

Answer 41

The vertebral column (**spine**) runs from the **base** of the **cranium** (**skull**) down through the **centre** of the skeleton. The vertebral column is **strong** and yet it can bend **forwards**, **backwards** and to either **side**. It can also **rotate**. This mobility is possible as the adult vertebral column is made up of a series of **26** individual bones, or **vertebrae**, separated by rings of cartilage called **intervertebral discs**.

Question 42

The vertebral column has five main areas; name them:

Answer 42

The structure of the vertebrae in each area is slightly different but all have similar features. Cervical Vertebrae Thoracic Vertebrae Lumbar Vertebrae Sacrum Coccyx

Question 43

This is a superior view of a typical vertebra. The ____ of the vertebra is thick and disc shaped. The body is the _____ \_\_\_\_\_\_\_ part of the vertebra and it contacts on either side with the __________ \_\_\_\_\_. The _____ \_\_\_ runs through the gap in the center of the vertebra. This gap is called the _________ \_\_\_\_\_\_. The _______ and the _______ make up the bony vertebral arch that surrounds the spinal cord. The ____ \_\_\_\_\_\_ and the _ \_\_\_\_\_ ________ all provide points of attachment for muscles. Each vertebra has _ \_\_\_\_\_\_\_ processes, _ \_\_\_\_\_\_\_ and _________ (only visible from an inferior aspect), that form joints with the neighbouring vertebrae. The 4 articulating surfaces are called \_\_\_\_\_\_.

Answer 43

The **body** of the vertebra is thick and disc shaped. The body is the **weight bearing** part of the vertebra and it contacts on either side with the **intervertebral discs**. The **spinal cord** runs through the gap in the center of the vertebra. This gap is called the **vertebral foramen**. The **laminae** and the **pedicles** make up the bony vertebral arch that surrounds the spinal cord. The **spinal process** and the **2 transverse processes** all provide points of attachment for muscles. Each vertebra has **4 articular** processes, **2 superior** and **2 inferior** (only visible from an inferior aspect), that form joints with the neighbouring vertebrae. The 4 articulating surfaces are called **facets**.

Question 44

Cervical Vertebrae 1. How many cervical vertebrae are in the neck? 2. The top cervical vertebra (C1) is called the ?, which permits what movement? 3. The second (C2) is called the ?. The joint between C1 & C2 is a what?, allowing the head to ? 4. The remaining 5 cervical vertebrae (C3 - C7) are typically structured as shown below. 5. Describe how Cervical vertebrae Differ from thoracic vertebrae:

Answer 44

1. The 7 cervical vertebrae are in the neck. 2. The top cervical vertebra (C1) is called the **atlas**, which permits the **nodding** movement. 3. The second (C2) is the **axis**. The joint between the atlas and the axis is a **pivot joint**, allowing the head to **rotate** from side to side. 4. The remaining 5 cervical vertebrae (C3 - C7) are typically structured as shown below. 5. Cervical vertebrae are * **smaller** than thoracic vertebrae but their **vertebral arches are larger**. * Each transverse process has a gap called a **transverse foramen** through which the vertebral artery, vein and nerve pass.

Question 45

Thoracic Vertebrae 1. How many thoracic vertebrae are there and which are are they located in? 2. How do they differ from the cervical vertebrae? 3. What do these pair with?

Answer 45

1. The **12** thoracic vertebrae (T1 - T12) are located in the **chest area**. 2. They are **larger** and **stronger** than the cervical vertebrae and their **spinal and transverse processes are longer**. 3. Each **thoracic vertebra articulates with a pair of ribs**.

Question 46

Lumbar Vertebrae 1. How many lumbar vertebrae are there? 2. Where are they located? 3. How do they differ from other vertebrae? * A) * B) * C)

Answer 46

1. There are 5 lumbar vertebrae (L1 - L5), 2. They are located in the lower back, 3. They differ by: * They are the largest and the strongest of the vertebrae * Their various projections are short and thick. * The spinal process is nearly straight.

Question 47

Sacrum 1. The sacrum is what? 2. It is formed by the fusion of how many vertebrae? And between what ages does this fusion occur? 3. The sacrum provides what?

Answer 47

1. The sacrum is a **triangular** bone. 2. It is formed by the fusion of **5 sacral vertebrae** (S1 - S5), which gradually occurs usually between the ages of **16 and 25**. 3. The sacrum **provides a strong base** for the vertebral column.

Question 48

Coccyx 1. The coccyx is a what? 2. Located where? 3. It is formed by the fusion of how many coccygeal vertebrae? 4. This fusion usually occurs when?

Answer 48

1. The coccyx is a triangular bone 2. at the very tail of the vertebral column. 3. It is formed by the fusion of the 4 coccygeal vertebrae (Co1 - Co4). 4. This fusion usually occurs between the ages of 20 and 30.

Question 49

The vertebrae, along with other structures such as \_\_\_\_\_\_\_\_, _____ and \_\_\_\_, protect the spinal cord. The spinal cord is a mass of nerve tissue from which __ \_\_\_\_\_\_ __ \_\_\_\_\_ ____ originate and then run to all parts of the body.

Answer 49

The vertebrae, along with other structures such as **ligaments**, **fat** and **fluid**, protect the spinal cord. The spinal cord is a mass of nerve tissue from which **31 pairs of spinal nerves** originate and then run to all parts of the body.

Question 50

Area Bones Skull and Face frontal, parietal, temporal, occipital, zygomatic, sphenoid, ethmoid, nasal, maxilla, mandible Shoulder Girdle clavicle, scapula Vertebral Column cervical, thoracic, lumbar, sacral and coccygeal vertebrae Thorax ribs, sternum Upper Limb humerus, ulna, radius, carpals, metacarpals, phalanges Lower Limb femur, tibia, fibula, patella, tarsals, metatarsals, phalanges 4 arches of the foot. Pelvic Girdle ilium, ischium, pubis

Answer 50

Area Bones Skull and Face frontal, parietal, temporal, occipital, zygomatic, sphenoid, ethmoid, nasal, maxilla, mandible Shoulder Girdle clavicle, scapula Vertebral Column cervical, thoracic, lumbar, sacral and coccygeal vertebrae Thorax ribs, sternum Upper Limb humerus, ulna, radius, carpals, metacarpals, phalanges Lower Limb femur, tibia, fibula, patella, tarsals, metatarsals, phalanges 4 arches of the foot. Pelvic Girdle ilium, ischium, pubis

Question 51

What are the bones in the Skull and Face?

Answer 51

**Frontal** -The one bone that forms the forehead and the upper part of the eye sockets. It contains the two frontal sinuses, one above each eye near the midline. **Parietal** - Two bones that form the upper sides and the posterior roof (crown) of the cranial cavity. **Temporal** - Two bones that form the inferior sides (temples) of the cranium and the cranial floor. **Occipital** - One bone that forms the posterior part and base of the cranium. **Zygomatic** - two bones that form the cheeks **Sphenoid** - One wedge shaped bone that lies in the middle part of the base of the skull. It is known as the "keystone" of the cranial floor because it articulates with the other cranial bones. **Ethmoid** - The one bone located in the anterior part of the cranial floor between the orbits. It is a major supporting bone in the nasal cavity. **Nasal Bone** - Two bones that make up part of the bridge of the nose **Maxilla -** Two fused bones that form the upper jaw and support the teeth. Each contains a maxillary sinus that empties into the nasal cavity. **Mandible** - The one bone of the lower jaw. It is the only moveable bone of the skull.

Question 52

What are the bones in the Shoulder Girdle?

Answer 52

**Clavicle** - Long bone, commonly called the collar bone. It articulates with the sternum and the scapula. **Humerus** - The long bone of the upper arm. It articulates with the scapula at the shoulder and the ulna and radius at the elbow. **Scapula** - Large, triangular flat bone, commonly called the shoulder blade. It articulates with the clavicle and the humerus.

Question 53

What are the bones in the Vertebral Column?

Answer 53

**Rib** - One of the 12 pairs of bones that make up the thoracic cavity. Each pair articulates posteriorly with the corresponding thoracicvertebra. Anteriorly, the top 7 pairs attach to the sternum and are referred to as 'true' ribs. The remaining 5 pairs are called 'false' ribs. The top 3 pairs of false ribs attach indirectly to the sternum via cartelidge and rib pair 7. The bottom 2 pairs do not attach to the sternum at all and are called 'floating' ribs. **Sternum** - Flat bone, commonly called the breast bone. The sternum articulates with the clavicles and the 7 pairs of 'true' ribs.

Question 54

What are the bones in the Pelvic Girdle?

Answer 54

**Femus** - The longest, heaviest and strongest bone in the body, commonly called the thigh bone. It articulates with the pelvis, tibia and patella. **Ilium** - The largest of the 3 main pelvic bones. The ilium, ischium and pubis fuse to form the innominate bone. The 2 innominate bones join anteriorly at the pubic symphysis and posteriorly at the sacrum to form the pelvic girdle. **Ischium** - Forms the posterior part of the pelvis. **Pubic symphysis** - The slightly moveable cartilaginous joint between the anterior surfaces of the innominate bones. **Pubis** - Forms the anterior part of the pelvis **Sacrum** - A triangular bone formed by the fusion of 5 sacral vertebrae (S1-S5).

Question 55

What are the bones in the Upper Limb - Elbow?

Answer 55

**Humerus** - The long bone of the upper arm. It articulates with the scapula at the shoulder and the ulna and radius at the elbow. **Radius** - Long bone of the forearm that articulates with the wrist on the thumb (lateral) side. It is shorter than the ulna and articulates with the humerus at the elbow. **Ulna** - Long bone of the forearm that articulates with the wrist on the little finger (medial) side. It is longer than the radius and articulates with the humerus at the elbow.

Question 56

What are the bones in the Upper Limb - Wrist & Hand?

Answer 56

**Carpal** - One of the 8 small bones (trapezoid, trapezium, capitate, scaphoid, lunate,triquetrum, pisiform and hamate) called the carpals that make up the wrist (carpus) **Metacarpal** - One of the 5 long bones that make up the hand. They articulate with the fingers and the wrist. **Phalanges** - The 14 bones that make up the fingers and thumb. There are 3 phalanges in each finger and 2 phalanges in the thumb. **Radius** - Long bone of the forearm that articulates with the wrist on the thumb (lateral) side. It is longer than the radius and articulates with the humerus at the elbow. **Ulna** - Long bone of the forearm that articulates with the wrist on the little finger (medial) side. It is longer than the radius and articulates with the humerus at the elbow.

Question 57

What are the bones in the Lower Limb - Knee?

Answer 57

**Femur** - The longest, heaviest and strongest bone in the body, commonly called the thigh bone. It articulates with the pelvis, tibia and patella. **Fibula** - The smaller of the two bones in the lower leg. It is situated on the lateral side of the tibia and articulates with the tibia and the lateral part of the ankle. **Patella** - A sesamoid bone, commonly called the knee cap. It stabilises and protects the knee joint. **Tibia** - The larger of the two bones in the lower leg, commonly called the shin. It is the medial bone and bears most of the weight. It articulates. With the femur, fibula and the tarsals (bones of the ankle).

Question 58

What are the bones in the Lower Limb - Ankle and Foot?

Answer 58

**Tibia** - The larger of the two bones in the lower leg, commonly called the shin. It is the medial bone and bears most of the weight. It articulates with the femus, fibula and the tarsals (bones of the ankle). **Fibula** - The smaller of the two bones in the lower leg. It is situated on the lateral side of the tibia and articulates with the tibia and the lateral part of the ankle. **Tarsal** - One of the 7 small bones (first cuneiform, second cuneiform, third cuneiform, navicular, talus, calcaneus and cuboid) called the tarsals that make up the ankle (tarsus). **Metatarsal** - One of the 5 long bones that make up the foot. They articulate with the toes and the ankle. **Phalanges** - The 14 bones that make up the toes. There are 3 phalanges in each toe except for the big toe which has only 2.

Question 59

Name the four main Arches of the Foot? The bones of the foot are arranged into **arches**. These arches enable the foot to be able to **support** the weight of the body, distribute the weight over the foot, and provide leverage while walking. The arches are maintained by **ligaments** and **muscles**.

Answer 59

**Anterior transverse arch** - Runs across the anterior end of the metatarsals. **Lateral Longitudinal arch** - On the little-love side of the foot. It runs from the calcaneus to the anterior end of the metatarsals. **Medial longitudinal arch** - The highest arch on the big-toe side of the foot. It runs from the calcaneus to the anterior end of the metatarsals. **Posterior transverse arch** - Runs across the posterior end of the metatarsals.

Question 60

The skeleton provides a strong structure to support the body, but it also facilitates \_\_\_\_\_\_\_\_\_. The skeleton provides the site of ___________ for muscles and tendons. The contraction of the muscles is therefore able to create skeletal movement. Movement occurs at the joints. The structure of the joint will determine the movement permitted. The main movements are: (6)

Answer 60

The skeleton provides a strong structure to support the body, but it also facilitates **movement**. The skeleton provides the site of **attachment** for muscles and tendons. The contraction of the muscles is therefore able to create skeletal movement. 1. **Gliding** – the simplest movement where the bones can only move side to side and back and forth (e.g. the movements that occur between the carpals and between the tarsals). 2. **Flexion** – when the angle between the articulating bones decreases (e.g. when the elbow is bent to pull the forearm towards the upper arm). 3. **Extension** – when the angle between the articulating bones increases (e.g. when a bent arm is straightened). 4. **Abduction** – when the bone is moved away from the midline (e.g. moving the leg out to the side). 5. **Adduction** – when the bone is moved towards the midline (e.g. moving a leg that is out to the side back to the normal position). 6. **Rotation** – when the bone moves in a single plane around its longitudinal axis (e.g. turning the head from side to side as if indicating “no”).

Question 61

A combination of these movements can create others. For example, a combination of flexion, extension, abduction and adduction can create a circular movement. This circular movement is called \_\_\_\_\_\_\_\_\_\_\_\_. Name these specific terms for movements that the elbow and ankle joints enable: 1. A rotational movement of the forearm in which the palm of the hand is moved to face the anterior (e.g. as in the anatomical position or as when waving) or upward. = ? 2. A rotational movement the forearm to turn the palm of the hand to face the posterior (e.g. a 180 degree anti-clockwise rotation of the right arm from the anatomical position or rotating the forearm in front of the face to look at the palm) or downward. = ? 3. The movement of the sole of the foot outward at the ankle joint. = ? 4. The movement of the sole of the foot inward at the ankle joint. = ? 5. The movement of the foot in the direction of the upper surface, i.e. pulling the foot up to lessen the angle between the top of the foot and the shin. = ? 6. The movement of the foot in the direction of the plantar surface (sole), i.e. stretching the foot out, increasing the angle between the top of the foot and the shin. = ?

Answer 61

A combination of these movements can create others. For example, a combination of flexion, extension, abduction and adduction can create a circular movement. This circular movement is called **circumduction** 1. **Supination** - a rotational movement of the forearm in which the palm of the hand is moved to face the anterior (e.g. as in the anatomical position or as when waving) or upward. 2. **Pronation** - a rotational movement the forearm to turn the palm of the hand to face the posterior (e.g. a 180 degree anti-clockwise rotation of the right arm from the anatomical position or rotating the forearm in front of the face to look at the palm) or downward. 3. **Eversion** - the movement of the sole of the foot outward at the ankle joint. 4. **Inversion** - the movement of the sole of the foot inward at the ankle joint. 5. **Dorsiflexion** - the movement of the foot in the direction of the upper surface, i.e. pulling the foot up to lessen the angle between the top of the foot and the shin. 6. **Plantar flexion** - the movement of the foot in the direction of the plantar surface (sole), i.e. stretching the foot out, increasing the angle between the top of the foot and the shin.

Question 62

There are many different types of joint in the body. Joints can be classified either by their structure or by the type of movement they allow. Structurally a joint can be classified as: (3)

Answer 62

1. **Fibrous -** when there is no cavity between the bones and the bones are held together by fibrous connective tissue. 2. **Cartilaginous** - when there is no cavity between the bones and the bones are held together by cartilage. 3. **Synovial** - when there is a joint cavity and the bones are surrounded by a fluid-filled capsule.

Question 63

Functionally, there are again 3 classifications of joint - name them?

Answer 63

1. **immovable**, 2. **slightly movable** and 3. **freely movable**.

Question 64

Immovable Joints: Describe and give example.

Answer 64

As the name suggests, there is no freedom of movement between bones at an immovable joint. Fibrous, immovable joints exist between the bones of the cranium. Here the irregular bones are held together by fibrous connective tissue. The interlocking of the bones strengthens the joints. These joints are also called **sutures**.

Question 65

Slightly Moveable Joints ## Footnote There are two types of slightly moveable joints; name and give an example:

Answer 65

1. Syndesmosis - is a fibrous joint that has more connective tissue than in an immovable joint to allow a little movement. An example of a syndesmosis is the distal joint between the tibia and fibula, the two long bones in the lower leg. 2. **Symphysis -** is a cartilaginous joint, for example the intervertebral joints (joints between the vertebrae). A symphysis also exists in the pelvis. The joint is called the _pubic symphysis_.

Question 66

This last functional classification of joints encompasses a variety of joints that give the skeleton considerable flexibility but they all have some similar features. Freely movable joints are characterized by having a _____ between the bones. The bone ends are protected by _______ (\_\_\_\_) _________ and the bone ends are _________ and held together by the ________ \_\_\_\_\_\_\_. The space within this capsule is called the ______ \_\_\_\_\_, Which is filled with a lubricating fluid called ______ \_\_\_\_\_\_. Structurally, therefore, all freely movable joints are _______ \_\_\_\_\_\_.

Answer 66

Freely movable joints are characterized by having a **space** between the bones. The bone ends are protected by **articular (hyaline) cartilage** and the bone ends are **surrounded** and held together by the **articular capsule**. The space within this capsule is called the **synovial cavity**, which is filled with a lubricating fluid called **synovial fluid**. Structurally, therefore, all freely movable joints are **synovial joints**.

Question 67

The articular capsule consists of 2 layers. The inner layer is called the _______ \_\_\_\_\_\_\_\_, which secretes the nourishing and lubricating _______ \_\_\_\_. The outer layer of the articular capsule is \_\_\_\_\_\_. This fibrous layer has to be flexible enough to allow the movement, but strong enough to resist dislocation. In some joints this layer consists of bundles of dense, parallel fibres called \_\_\_\_\_\_\_\_\_\_. These ________ add _______ to the joints.

Answer 67

The articular capsule consists of 2 layers. The inner layer is called the **synovial membrane**, which secretes the nourishing and lubricating **synovial fluid**. The outer layer of the articular capsule is **fibrous**. This fibrous layer has to be flexible enough to allow the movement, but strong enough to resist dislocation. In some joints this layer consists of bundles of dense, parallel fibres called **ligaments**. These Ligaments add **strength** to the joints.

Question 68

Although called freely movable joints there are _____ to the possible movement. The most obvious limitation is that other body parts can get in the way! For example you cannot over bend your elbow as your hand hits your shoulder. Structurally, the shapes of the articulating bones and how they fit together, the strength of the joint ligaments and the tension of the surrounding muscle are all limiting factors. ________ can also affect joint flexibility.

Answer 68

Although called freely movable joints there are **limits** to the possible movement. The most obvious limitation is that other body parts can get in the way! For example you cannot over bend your elbow as your hand hits your shoulder. Structurally, the shapes of the articulating bones and how they fit together, the strength of the joint ligaments and the tension of the surrounding muscle are all limiting factors. **Hormones** can also affect joint flexibility.

Question 69

There are 6 types of freely movable joint:

Answer 69

1. Gliding (or plane) joint 2. Hinge joint 3. Pivot joint 4. Ellipsoidal (or condyloid) joint 5. Saddle Joint 6. Ball & Socket Joint

Question 70

Describe the Gliding (Plane) Joint and give examples:

Answer 70

* This is the simplest of the freely movable joints. * The articulating surfaces of bones at a gliding joint are usually **flat**. * Only **side to side** and **back and forth** movements are permitted. An example of a gliding joint is the joint between the clavicle (collar bone) and the scapula (shoulder blade). Gliding joints also exist between the navicular and second and third cuneiforms of the tarsus (shown here) and in some intercarpal joints.

Question 71

Describe the Hinge Joint & give Examples of:

Answer 71

* In a hinge joint, the **convex** surface of one bone fits into the **concave** surface of another. * Hinge joints work like a hinge on a door in that the movement is restricted to a **single direction**. Examples of hinge joints include the **knee**, **elbow** and **ankle**. They allow **flexion** and **extension**.

Question 72

Describe a Pivot Joint and give examples:

Answer 72

* A pivot joint is like a **peg in a hole**. A rounded or pointed surface of one bone articulates with a ring formed by another bone and partly by a ligament. * The main movement allowed is **rotation**. A pivot joint exists at the proximal ends of the radius and the ulna. This joint allows the palms to be turned upward or downward. The joint between the atlas and the axis is also a pivot joint.

Question 73

Describe an Ellipsoidal (Condyloid) joint and give examples:

Answer 73

* In an ellipsoidal joint, also called a condyloid joint, the oval end of one bone fits into another. * It allows **flexion, extension, abduction, adduction** and **circumduction**. An ellipsoidal joint exists between the radius and the scaphoid and lunate bones of the carpus.

Question 74

Describe a Saddle Joint and give examples:

Answer 74

* In a saddle joint, one bone sits over another like a rider in a saddle. * Movement is **side to side** and **back and forth** but is freer than in the ellipsoidal joint. * **Flexion, extension, abduction, adduction** and **cicumduction** are allowed. An example is the joint between the trapezium and the metacarpal of the thumb.

Question 75

Describe the Ball & Socket Joint and give examples:

Answer 75

* They consist of the **ball-shaped end** of one bone fitting into a **cup-shaped** depression of another. * Ball and socket joints give **maximum** movement. They allow **flexion, extension, abduction, adduction and rotation.** The **hip** (shown here) and the **shoulder** are the only ball and socket joints in the body.