The Skin: Structure

1
The Skin Structure.

• a. Epidermis made of
• epithelial cells
• b. Dermis with
• sweat glands
• hair follicles
• oil glands
• capillaries
• nerve cells

2
The Skin....
the largest organ in the body

• Function
• protection
• temperature control
• sensory
• integrity of the body
• secretions from glands
• produces Vitamin D

3
Support Systems may be

• Exoskeleton

• Endoskeleton

Internal set of bones
Hard outer covering
4
Human Endoskeleton made of

1. Axial skull, backbone, ribs, sternum
2. Appendicular arms, legs, shoulders, hips,wrists,
   ankles

5
Endoskeletons also have.

• Ligaments that hold bone to bone
• Tendons that hold muscle to bone, muscle
  tenders
• Joints where 2 bones come together

6

• Cartilage is replaced by bone during the process
  of bone formation called ossification.
• Bone tissue forms as osteoblasts secrete mineral
  deposits.
• When the osteoblasts become surrounded by bone
  tissue, they mature into osteocytes.

7
Bone Structure
8
The Muscular System
9
SKELETAL
CARDIAC
SMOOTH
10
How Do Muscles Contract?
Muscle bundles work in opposite
pairs Contracting Relaxing (biceps triceps
in the arms)
11
Sliding Filament Theory of Muscle Contraction

• Lets Watch
• 3d view