Week 3

Question 1

What are the two mains parts of the integumentary system?

Answer 1

1. The cutaneous membrane made up of the epidermis (upper layer) and the dermis (lower layer).
2. The accessory structures, which include hair, hair follicles, exocrine glands and nails, all of which are imbedded in the dermis.

Question 2

What are the nine functions of the integumentary system?

Answer 2

1. Protection (separates internal environment from external environment).
2. Excretion (salt, water, organic waste).
3. Maintenance of body temperature (insulation and evaporative cooling).
4. Production of melanin (protects tissue from UV).
5. Production of keratin (a protein that makes hair, nails and surface layer skin).
6. Synthesis of vitamin D3 (a steroid that is converted into calcitriol, a hormone important for normal calcium ion metabolism).
7. Storage of lipids (in adipocytes in the dermis and adipose tissue in the subcutaneous layer).
8. Detection and relay of touch, pressure, pain, heat, vibration to the nervous system.
9. Coordination of immune response to pathogens and cancers of the skin.

Question 3

What is the difference between thin skin and thick skin?

Answer 3

Thin skin has 4 layers of keratinocytes, thick skin has 5 layers of keratinocytes.

Question 4

What are the five layers of the epidermis?

Answer 4

From deepest to surface:

1. Stratum basale, attached to basement membrane, contains basal cells (stem cells), melanocytes, and tactile cells (Merkel cells).
2. Stratum spinosum, keratinocytes are bound together by desmosomes.
3. Stratum granulosum, keratinocytes produce keratin and cells start to disintegrate.
4. Stratum lucidum, only in thick skin, glassy layer.
5. Stratum corneum, layers of flat, dead, interlocking keratinocytes (water resistant).

Question 5

What are the two layers of the dermis?

Answer 5

1. Superficial papillary layer, contains capillaries, lymphatic vessels and nerve fibres.
2. Reticular layer (deeper), made up of connective tissue which gives the skin strength and flexibility, it also connects to the subcutaneous layer via collagen fibres.

Question 6

What is the role of the subcutaneous tissue?

Answer 6

Made up of adipose tissue (fat), it connects the dermis to the underlying tissues.

Question 7

What determines skin colour?

Answer 7

Melatonin, carotene and the extent of blood flow.

Question 8

What are cleavage lines/tension lines?

Answer 8

Lines in the skin dictated by the strength and alignment of fibres, a parallel cut remains shut and heals well, a cross cut will pull open and scar.

Question 9

What are the accessory structures in the integumentary system?

Answer 9

Hair, hair follicles, sebaceous glands, sweat glands and nails.

Question 10

What is the basic structure of a hair follicle?

Answer 10

Hair follicles reside in the dermis layer of the skin, they are attached to surrounding tissue by a connective tissue sheath, the glassy membrane (a clear layer surrounded by the connective sheath), the external root sheath which extends from the hair matrix to the skin surface and the internal root sheath which is based nearer the root of the hair.

Question 11

Describe a typical strand of hair.

Answer 11

The innermost layer is the medulla (core), which contains soft, flexible keratin.
The cortex, which surrounds the medulla, made of thick layers of keratin (gives stiffness) .
The cuticle, a very tough thin outer layer containing keratin.

Question 12

What are sebaceous glands?

Answer 12

Secretory glands that produce lipid based liquids called sebum, which lubricates and protects the epidermis, they are normally associated with hair follicles although not always the case.

Question 13

What are sweat glands?

Answer 13

Two main types are:

1. Eccrine/merocrine glands - Responsible for sensible perspiration, mainly water and salts, responsible for evaporative cooling, excreting water and electrolytes, diluting/flushing of harmful chemicals on the skin.
2. Apocrine glands - Sticky, potentially odorous secretion. Modified apocrine glands include, mammary glands and ceruminous glands (produce earwax).

Question 14

What are nails?

Answer 14

Keratinised epidermal cells that protect the tips of fingers and toes.

Question 15

How does the integumentary system heal after injury?

Answer 15

1. Inflammation phase - bleeding causes inflammatory response.
2. Migration - Clotting occurs, immune and repair cells migrate with increased blood flow.
3. Proliferation - Epidermal cells proliferate under the clotting (scab).
4. Scarring - After serval weeks of proliferation, the scab sheds off and the epidermis is healed. Fibroblasts in the dermis continue to create scar tissue.

Question 16

What is Jaundice?

Answer 16

Yellow skin caused by the build-up of bilirubin in the blood due to irregular function of the liver, gallbladder or pancreas. Bilirubin is a yellowish pigment that is made during the normal breakdown of red blood cells.

Question 17

What is Vitiligo?

Answer 17

Vitiligo is a disease that causes loss of skin colour in patches. Occurs when melanin producing cells die or stop functioning.

Question 18

What are sutural bones?

Answer 18

Small, flat, oddly shaped bones found between the flat bones of the skull.

Question 19

Explain the structure of long bones.

Answer 19

Long bones consist of a shaft (diaphysis), which is made up of compact bone
Two ends (upper and lower epiphysis), which is made up of spongey bone.
The diaphysis and epiphysis are connected via the metaphysis section.

Question 20

What are the major functions of the axial skeleton?

Answer 20

Provides protection for the brain, spinal cord and ventral organs.
Provides attachment points for movement.
Preforms respiratory movement.
Helps stabilise the appendicular skeleton.

Question 21

What are the major functions of the appendicular skeleton?

Answer 21

The attachment and movement of the limbs.

Question 22

What is compact bone?

Answer 22

Strong, rigid bone composed of osteon which are osteocytes arranged in concentric layers around blood vessels, these layers form the concentric lamellae.

Question 23

What is spongey bone?

Answer 23

Bone with no present osteon, matrix forms a web of supporting fibres called trabeculae.
Red bone marrow, found in the epiphysis of long bones, creates blood cells.
Yellow bone marrow, found in the diaphysis of long bones, contains adipose tissue for energy reserve.

Question 24

Identify the four cell types in bone and list their major functions.

Answer 24

1. Osteogenic cells - stem cells that divide into osteoblasts.
2. Osteoblasts - Immature bone cells that secrete organic components of the matrix (protein fibres for example). Found on surface.
3. Osteocyte - Mature bone cells that maintain bone matrix. Found under surface.
4. Osteoclast - Multinucleated cells that secrete acids and enzymes to dissolve bone matrix.

Question 25

What are the six categories of the axial skeleton?

Answer 25

1. Neurocranial bones
2. Auditory ossicles (malleus, incus and stapes)
3. Hyoid (Bone that holds up the tongue and larynx/voice box)
4. Thoracic cage (ribcage)
5. Vertebral column (spine)
6. Facial bones

Question 26

What are the four categories of the appendicular skeleton?

Answer 26

1. Pectoral girdle (shoulders).
2. Upper limbs.
3. Pelvic girdle (hip bones).
4. Lower limbs.

Question 27

What are the five regions of the vertebral column?

Answer 27

1. Cervical - 7 vertebrae.
2. Thoracic - 12 vertebrae.
3. Lumbar - 5 vertebrae.
4. Sacrum - 5 (fused) vertebrae.
5. Coccyx - 3-5 (fused) vertebrae.

Question 28

What is the basic anatomy of all vertebral bones?

Answer 28

1. Vertebral body - Drum shaped, bares weight and compressions with the aid of the intervertebral discs.
2. The Vertebral foramen - Arch shaped cavity that protects the spinal cord.
3. Processes for muscle attachment - Irregular shaped protrusions.

Question 29

What is the basic anatomy of the intervertebral discs?

Answer 29

1. Annulus - fibrocartilage outer layer, connects vertebrae.
2. Nucleus - inner layer, consists of a gel-like substance, provides shock absorption.

Question 30

Explain differences in vertebrae between, cervical, thoracic and lumber.

Answer 30

Cervical - Small oval vertebral body, large vertebral foramen, long processes with spilt tips, allows for controlled head movement.
Thoracic - Medium heart shaped vertebral body, medium vertebral foramen, facets for rib articulation, long processes.
Lumbar - Large oval vertebral body, small vertebral foramen, short processes, supports most of upper body weight.

Question 31

What is the difference between C1 and C2?

Answer 31

C1 (Atlas) - Connects the skull and the vertebral column, very large vertebral foramen, has no spinous process.
C2 (Axis) - Has a upwards facing process that forms a pivot joint with C1 allowing for movement of the head.

Question 32

Name and label the neurocranial bones.

Answer 32

1. Frontal bone (bone over frontal lobe)
2. Parietal bone (bone over parietal lobe)
3. Temporal bone (bone over temporal lobe)
4. Occipital bone (bone over occipital lobe)
5. Sphenoid (middle of skull, towards front, articulates with many cranial bones which provides rigidity)
6. Ethmoid (spongey bone located in the roof of the nose, separates nostril cavity from the brain)

Question 33

Name and locate the facial bones.

Answer 33

1. Nasal bones (medial of zygomatic bones).
2. Lacrimal bone (medial to eyes, inner eye socket).
3. Vomer (runs along sagittal plane, posterior to nasal bones).
4. Zygomatic bone (the cheek bones, lateral to nose).
5. Maxilla (inferior to eyes).
6. Mandible (inferior to maxilla).
7. Palatine bone (small bone, located superior to tonsils).
8. Inferior nasal conchae (a small pair of bones lateral to the vomer).

Question 34

What are the major sutures of the skull?

Answer 34

1. Lambdoid suture - connects the parietal bones to the occipital bone.
2. Sagittal suture - connects the left and right parietal bones.
3. Coronal suture - connects the frontal and parietal bones.

Question 35

What bones articulate to create the orbital cavity?

Answer 35

1. Frontal bone
2. Sphenoid bone
3. Lacrimal bones
4. Ethmoid bones
5. Maxilla bones
6. Zygomatic bones

Question 36

What is the clinical presentation of an orbital blowout fracture?

Answer 36

1. Orbital pain.
2. Eyes displaced posteriorly into sockets.
3. Limitation of eye movement.
4. Seeing-double when looking up or down.
5. Loss of sensation.

Question 37

Describe the general structure of the thorax.

Answer 37

Made up of T1-T12 vertebrae, ribs, sternum and costal cartilage.

Question 38

Describe the pelvic girdle variances in between males and females.

Answer 38

Male hips: Narrower, smaller pubic arch (angle of opening), less smooth, heavier, more prominent muscle/ligament attachments.
Female hips: Wider, wide pubic arch (angle of opening), smoother, lighter, less prominent muscle/ligament attachments.

Question 39

Explain the anatomy of the sternum.

Answer 39

Sternum is made up of the manubrium, the body and the xiphoid process which are connected to the ribs via costal cartilage.

Question 40

How many ribs do humans have?

Answer 40

24 ribs (12 each side).

Question 41

How do ribs attach to vertebrae?

Answer 41

Via two joints (one on the head of the rib and one on the neck of the rib).

Question 42

What kind of ribs are attached to T1 to T7?

Answer 42

True ribs (connected directly to sternum via costal cartilages).

Question 43

What kind of ribs are attached to T8-T10?

Answer 43

False ribs (indirectly connected to sternum via costal cartilages).

Question 44

What kind of ribs are attached to T11-T12 and are not attached to the sternum?

Answer 44

Floating ribs.

Question 45

Describe the general anatomy of the pelvic girdle.

Answer 45

Made of two hip bones, the illium is the large flat surface of the hip bone, the inferior anterior section of bone is called the pubis and the inferior posterior section of bone is called the ischium.