Class Notes (808,549)
Canada (493,288)
BISC 101 (291)
Lecture 5

Week 5

31 Pages
Unlock Document

Simon Fraser University
Biological Sciences
BISC 101
Derek Bingham

BIOL1103–W eek5 Bone Cartilage Human Skeleton Ossification ComponentsandFunctionsoftheSkeleton Composed of two types of connective tissues: 1.Bone (cell – osteocyte) 2.Cartilage (cell – chondrocyte) Functions of Bones: 1.Supports and protects soft tissues 2.Attachment for muscles 3.Storage of minerals like calcium and phospha(mineral homeostasis) 4.Blood cell production in red bone marro(hemopoiesis) 5.Triglyceride storage in yellow bone marrow HistologyofBone • A connective tissue made of widely spaced cells separated by a matrix • The matrix is composed of • 15% water • 30% collagen fibers (organic matter) • 55% crystalized mineral salts • Four types of cells in bone • Osteogenic cells  osteoblasts  osteocytes • Osteoclasts OsteogenicCells • Undifferentiated cells • Can divide to replace themselves when they become osteoblasts • Found in the inner layer of periosteum and endosteum • Periosteum – tough outer membrane of bone • Endosteum – inner lining of marrow cavity 4 Osteoblasts • Forms matrix and collagen fibers by secreting mineral salts • Can’t divide any further • Responsible for forming bone tissue 5 Osteocytes • Mature osteoblasts • Can’t secrete matrix anymore • Responsible for maintaining bone tissue 6 Osteoclasts • Huge cells formed from fused monocytes (WBC’s) • Functions in bone resorption • Destroys older matrix to maintain proper bone girth 7 Compact(Dense)Bone • Solid layer of bone • Makes up the shaft of long bones and external layer of all bones • Resists stresses produced by weight and movement HistologyofCompactBone • Osteon – concentric rings (lamellae) of calcified matrix surrounding a vertical blood vessel • Each ring is a lamella • Osteocytes found in spaces called lacunae (cavities) • Osteocytes communicate through canaliculi (small channels) filled with extracellular fluid (like little strings) that connect one cell to the next cell 10 HyalineCartilage • Bluish-shiny white rubbery substance • Chondrocytes sit in spaces called lacunae • No blood vessels or nerves so repair is very slow • Reduces friction at joints (articular cartilage) Fibrocartilage • Many more collagen fibers causes rigidity & stiffness • Strongest type of cartilage (intervertebral discs) TypesofBones Skeletons • Axial Skeleton (blue) • 80 bones • Longitudinal axis • Skull, hyoid, vertebrae, ribs, sternum, ear ossicles • Appendicular Skeleton (brown) • 126 bones • Upper/lower limbs • Pelvic/pectoral girdles 14 TheSkull Thorax • Sternum (breastbone) • Ribs • 1-7 are true ribs (vertebrosternal) • 8-12 are false ribs (vertebrochondral) – not directly connected to the sternum • 11-12 are floating ribs – only connected to the vertebral column at the back) • Costal cartilage – hyaline cartilage that connects the sternum and the ends of the ribs V ertebralColumn • 26 vertebrae • Five vertebral regions • Cervical (neck)  7 • Thoracic (thorax)  12 • Lumbar (lower back)  5 • sacrum (upper tail bone)  5 fused • coccyx (tail bone)  4 fused • To remember C, T, L  “Eat breakfast at 7, lunch at 12, and dinner
More Less

Related notes for BISC 101

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.