Week 2

Question 1

anatomical pathway for relaying sensory information from the body to the brain

Answer 1

-information from anterior/posterior rami, into spinal nerve, into the dorsal nerve root, dorsal root ganglia, dorsal root, dorsal rootlets, into dorsal horn of grey matter, up the spinal cord, to the brain

Question 2

anatomical pathway for relaying efferent motor output to the muscles of the body

Answer 2

brain sends signal down to specific cell body in ventral horn of grey matter, into ventral rootlets, into the ventral root, into the spinal nerve and then into the anterior/posterior rami depending on which part of the body it is traveling to

Question 3

31 spinal nerves

Answer 3

8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 4

Layers of Integumentary System

Answer 4

• Epidermis
• Dermis
• Sub cutaneous
• Skin ligaments

Question 5

Epidermis

Answer 5

• Keratinzed epithelium in superficial lauyer
• Protective outer surface with regenerative/pigmented inner surface (basal layer)
• Avascular and is nourished by the dermis
• Has afferent nerve endings

Question 6

Dermis

Answer 6

• collagen and elastic fibers
• Provides skin tone which accounts for strength and toughness of skin
• Fibers over the body run in all direction to provide toughness, but in localized areas they usually run same direction
• Fiber deteriorate with time and not replaced
• Has hair follicles with associated arrector muscles
• Vascular helps to nourish epidermis and also allow for thermal regulation

Question 7

sub cutaneous

Answer 7

• Loose connective tissue and stored fat
• Holds cutaneous nerves and superficial vessels allowing only their terminal ends to branch into the dermis
• Allows for storage of body fat

Question 8

skin ligaments

Answer 8

Pass through subcutaneous layer to dermis to anchor deep surface of dermis to underlying fascia

Question 9

superficial fascia

Answer 9

fascial sheet lying directly beneath the skin (eg, a subcutaneous fat layer)

Question 10

deep fascia

Answer 10

intricate series of connective sheets and bands that hold the muscles and other structures in place throughout the body, wrapping the muscles in gray feltlike membranes.

Question 11

two subdivisions of the skeleton

Answer 11

1. Axial: Head (skull), neck (hyoid bone and cervical vert), and trunk (ribs, sternum, vertebrae, and sacrum) 2. Appendicular: Bones of limbs (forming pectoral and pelvic girdles)

Question 12

bone types

Answer 12

• Long: tubular
• Short: cuboidal; only found in carpus and tarsus
• Flat: serve protection function
• Sesamoid: develop in tendons and found where tendons cross a long bone, protect tendons from excessive wear and change angle of tendons as they pass to attachments

Question 13

2 types of bone tissue

Answer 13

○ Compact-has more solid matter and less spacing

○ Spongy-less solid matter and more spacing

Question 14

Endochondral ossification

Answer 14

cartilage model of bones form during embryonic stage, mesenchyme differentiates into chondroblasts forming cartilage. The mid region of the bone calcifies and periosteal capillaries grow into the calcified cartilage to form a periosteal bud. The periosteal bud is the primary ossification center because the bone it grows replaces the cartilage in the mid region of the bone (diaphysis).

Question 15

Intramembranous ossification

Answer 15

mesenchymal model of bones form during embryonic period, direct ossification of mesenchyme

Question 16

Types of joints

Answer 16

• Synovial
• Fibrous
• Cartilaginous

Question 17

Cartilaginous joint

Answer 17

a. Bones untied by cartilage
b. Primary:
i. Uses hyaline cartilage; permits slight bending during early life, used for temporary union, particularly to permit bone to grow until it eventually is converted into bone
ii. Ex: shaft of bone in infant
c. Secondary:
i. Uses fibrocartilage to form strong, slightly flexible joints; can be seen in intervertebral discs which allow for disc to be strong yet absorb shock and be flexible to bending.

Question 18

Fibrous joint

Answer 18

a. Bones are united by fibrous tissue
b. Movement of joint depends on how long fibers of joint are
i. Syndesmosis: unites bones with sheet of fibrous tissues, no movement, bones in skull
ii. Dento-alveolar syndesmosis: unites bones that forms peg fitting into hole (tooth), allows for some movement, but too much movement is usually caused by pathological state
Ex: joints between flat bones in skull

Question 19

Synovial joint

Answer 19

a. Bones united by joint capsule which encloses the joint
b. Bones have cartilage on articulating ends allowing for smooth movement, rest of cavity is filled with synovial fluid and the internal aspects are covered with synovial membrane
c. Allow for lots of movement and are reinforced by separate ligaments or thickening of portion of joint capsule
Ex: knee joint

Question 20

achondroplasia

Answer 20

the chondrocytes in long bones are unable to calcify therefore decreasing the size of the bone

Question 21

Types of Synovial Joints

Answer 21

A: Pivot; rotation around central axis point
B: Ball and socket; Extension, Flexion, Abduction, Adduction, Rotation
C: Plane; guiding/sliding
D: Hinge joint; Flexion, Extension
E: Saddle; Abduction, adduction, flexion, extension, circumduction
F: Condyloid: Abduction, adduction, flexion, extension