1. Prayer
Attendance
Homework

2. Musculoskeletal System

3. Skeletal System Function:
physical support of an organism (생물 Noun: 유기체 , 생물체 , 유기적 조직체 )
Protect organs
Stem cells in the bone marrow
arthropods (example: spider) have an exoskeleton.
Video: molting: Spider removing its exoskeleton
Vertebrates have an endoskeleton.

4. Mammalian Skeleton 2 parts: Axial Appendicular
Basic framework of the body: skull, vertebral column, and rib cage.
Appendicular
Limb bones, pelvic and pectoral girdles.

5. Cartilage Cartilage A connective tissue
Softer and more flexible (유연한) than bone.
Made of chondrin, which is firm (회사 Adjective: 굳은) but elastic (탄성).
Chondrocytes, specialized cells, secrete (분비 Verb: 비밀로 하다 , 분비하다) chondrin.
Primary component of embryonic skeletons in higher mammals.
As the child develops, most cartilage becomes hard and calcifies into bone.

6. Where is cartilage in adults?
The external ear,
The nose,
The walls of the larynx and trachea,
Skeletal joints.

7. Cartilage Avascular (i.e., contains no blood or lymph vessels)
has no nerves
Receives nourishment from capillaries located in nearby connective tissue and bone via diffusion through the surrounding fluid. (주변의 유체 를 통해 확산 을 통해 근처의 결합 조직 및 뼈 에있는 모세 혈관 에서 영양을 수신합니다.)

8. Bone: Macroscopic Structure
Two types of bone: compact bone and spongy bone.
Compact bone
Dense (밀도 Adjective: 밀집한 , 농밀한 , 머리가 나쁜 , 이해하기 힘든) bone
No cavities when see with the naked eye
Spongy bone (Cancellous bone)
Has interconnecting lattice of bony spicules (trabeculae)
Cavities in between spicules are filled with yellow and/or red bone marrow

9. Spongy Bone Spongy bone (Cancellous bone)
Has interconnecting lattice of bony spicules (trabeculae)
Cavities in between spicules are filled with yellow and/or red bone marrow
Yellow marrow is inactive and has adipose tissue.
Red marrow helps with blood cell formation.

10. Long Bones Long bones (Bones of the appendages)
Have a diaphysis and epiphyses (pl. for epiphysis)
Diaphysis
Compact bone surrounding a cavity containing bone marrow.
Epiphyses
Spongy bone surrounded by a thin layer of compact bone.
Epiphyseal line (epiphyseal plate)
A disc of cartilaginous cells
separates the diaphysis from the epiphysis.
area of longitudinal growth
Periosteum
Surrounds the long bone
Area of attachment to muscle tissue
Some periosteum cells differentiate into bone forming cells

11. Questions