Skeletal System: Bones and Joints

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of osteoblasts in the skeletal system?

Producing collagen and proteoglycans (correct)

Maintaining bone matrix

Breaking down bone tissue

Storing minerals

Which component of the extracellular matrix is primarily responsible for providing flexibility to bone?

Collagen (correct)

Water

Minerals

Ground substance

What is the role of osteocytes within the bone?

To destroy old bone

To produce new bone matrix

To transport calcium in the blood

To maintain the bone matrix (correct)

Which of the following is NOT a function of the skeletal system?

Hormone production Signup and view all the answers

What constitutes the inorganic material in bone matrix?

Hydroxyapatite Signup and view all the answers

How are osteoclasts significant in bone remodeling?

They remove existing bone Signup and view all the answers

What are the structural layers of mature bone referred to as?

Lamellae Signup and view all the answers

Which component is most abundant in the extracellular matrix of tendons and ligaments?

Collagen fibers Signup and view all the answers

What is the main function of parathyroid hormone (PTH)?

Increasing osteoclast activity Signup and view all the answers

Which part of the skeleton consists of the bones of the upper and lower limbs?

Appendicular skeleton Signup and view all the answers

How many bones are present in the average adult human skeleton?

206 Signup and view all the answers

What is the classification of a bone that is longer than it is wide?

Long bone Signup and view all the answers

Which bone shape is specifically noted for having a relatively thin and flattened shape?

Flat bone Signup and view all the answers

Which terminology refers to a hole in a bone?

Foramen Signup and view all the answers

Which classification includes bones such as the vertebrae and facial bones that do not fit into other bone shape categories?

Irregular bones Signup and view all the answers

What is the function of calcitonin in the body?

Lowers blood calcium levels Signup and view all the answers

What is the primary function of the auditory ossicles?

To transmit sound vibrations to the inner ear Signup and view all the answers

Which bone is located in the midline of the nasal cavity and forms part of the nasal septum?

Vomer Signup and view all the answers

Which of the following bones is not part of the skull?

Hyoid Signup and view all the answers

How many principal sutures connect the cranial bones?

Four Signup and view all the answers

Which bone forms the lateral walls of the nasal cavity and is also part of the hard palate?

Palatine Signup and view all the answers

What is the unique characteristic of the hyoid bone compared to other bones in the body?

It has no direct bony attachment to other bones Signup and view all the answers

Which of the following bones forms the floor of the cranium?

Sphenoid Signup and view all the answers

What does the cervical region of the vertebral column do?

Curves anteriorly Signup and view all the answers

What is the initial process that takes place during the formation of the primary ossification center?

Osteoblasts invade calcified cartilage. Signup and view all the answers

How does bone increase in width?

By appositional growth via osteoblast activity. Signup and view all the answers

What primarily drives the growth in length of a bone?

Endochondral ossification at the epiphyseal plate. Signup and view all the answers

What sequence occurs during bone repair after a fracture?

Hematoma, callus, spongy bone, compact bone. Signup and view all the answers

Which of the following is a role of osteoclasts during bone remodeling?

Removing existing bone. Signup and view all the answers

Which hormones are primarily involved in maintaining calcium homeostasis in the body?

Parathyroid hormone and calcitonin. Signup and view all the answers

What is a significant consequence of successful bone remodeling?

Changes in bone shape and structure. Signup and view all the answers

What primarily occurs to the cartilage matrix during lengthening of bones?

It gets calcified as chondrocytes die. Signup and view all the answers

Which vertebrae support the head and allow for its rotation?

Cervical: Atlas and Axis Signup and view all the answers

What is the primary function of the vertebral column?

Supports body weight Signup and view all the answers

How are the true ribs classified in relation to the sternum?

They attach directly to the sternum by cartilage. Signup and view all the answers

Which joint classification is characterized by being non-movable?

Synarthrosis Signup and view all the answers

Which component is part of the pectoral girdle?

Clavicle Signup and view all the answers

What type of joint is characterized by a fluid-filled cavity?

Synovial joint Signup and view all the answers

Which of the following bones is part of the lower limb?

Femur Signup and view all the answers

Which type of joint classification allows for slight movement?

Amphiarthrosis Signup and view all the answers

Study Notes

Components of Skeletal System

Composed of bones, cartilages, tendons, and ligaments.

Functions of the Skeletal System

Provides body support and structure.
Protects vital organs.
Facilitates body movement.
Acts as a reservoir for mineral storage.
Responsible for blood cell production.

Bone Histology

Bone and cartilage are connective tissues characterized by their extracellular matrix.
Contains collagen, ground substance, and water with minerals.
Collagen offers flexibility and withstands tension/compression.
Cartilage ground substance includes proteoglycans for resilience and smoothness.
Tendons and ligaments have abundant collagen fibers for added strength.

Bone Matrix

Bone matrix consists of approximately 35% organic material (mainly collagen) and 65% inorganic material (primarily hydroxyapatite).
Collagen provides flexible strength; minerals contribute to weight-bearing capacity.

Bone Cells

Osteoblasts: Cells that form new bone and repair existing bone; responsible for ossification.
Osteocytes: Mature bone cells that maintain matrix; account for 90-95% of bone cells; reside in lacunae and communicate via canaliculi.
Osteoclasts: Cells that break down bone (bone reabsorption); essential for releasing calcium into the bloodstream.

Bone Growth

Width: Occurs through appositional growth, adding new lamellae to existing bone.
Length: Achieved at the epiphyseal plate through endochondral ossification, with chondrocytes proliferating and then replaced by osteoblasts.

Bone Remodeling

Involves osteoclast-mediated removal and osteoblast-mediated deposition of bone; crucial for adapting to stress and regulating calcium ion levels.

Bone Repair Process

Begins with hematoma formation from broken bone.
A callus forms connecting bone fragments, followed by woven spongy bone replacement.
Compact bone later replaces spongy bone.

Calcium Homeostasis

Calcium plays a vital role in muscle contraction and neural signaling.
Bone serves as the primary calcium reservoir; its mobilization is regulated by osteoblasts and osteoclasts.
Parathyroid hormone (PTH) increases osteoclast activity and enhances intestinal calcium absorption.
Calcitonin lowers elevated blood calcium levels by inhibiting osteoclast activity.

Skeletal Anatomy Overview

Average adult skeleton contains 206 bones, categorized into axial and appendicular skeletons.
Axial Skeleton: Comprises skull, vertebral column, and thoracic cage.
Appendicular Skeleton: Consists of upper/lower limb bones and girdles.

Bone Shapes

Classified into long, short, flat, and irregular shapes; each has unique examples specific to their classification.

Axial Skeleton

Composed of 22 skull bones (8 cranial and 14 facial).
Cranial bones protect the brain and are fused by immovable joints (sutures): coronal, sagittal, lambdoid, squamous.

Major Cranial Bones

Frontal Bone: Forehead region.
Parietal Bones: Sides and roof of the cranium.
Occipital Bone: Back of the skull.
Temporal Bones: Located below parietal bones; house the temporomandibular joint.
Sphenoid Bone: Forms part of the cranium's floor and eye orbits.
Ethmoid Bone: Contributes to the nasal cavity and eye orbits.

Facial Bones

Maxillae: Upper jaw and hard palate.
Palatine Bones: Posterior hard palate.
Zygomatic Bones: Cheekbones.
Mandible: Only movable skull bone.

Paranasal Sinuses

Include frontal, ethmoid, sphenoid, and maxillary sinuses; reduce skull weight and enhance resonance.

Vertebral Column

Central skeletal axis with 26 bones segmented into cervical, thoracic, lumbar, sacral, and coccygeal regions.
Major functions: support body weight, protect spinal cord, site for muscle attachment.

Thoracic Cage

Composed of 12 pairs of ribs and sternum, protects vital organs.
Rib Types: True ribs (direct attachment), false ribs (indirect), and floating ribs (no attachment).

Pectoral Girdle

Contains scapula (shoulder blade) and clavicle (collar bone); connects upper limbs to the body.

Lower Limb Bones

Include femur (thigh), tibia (larger leg bone), fibula (smaller leg bone), along with foot's tarsals, metatarsals, and phalanges.

Articulations (Joints)

Classified structurally (fibrous, cartilaginous, synovial) and functionally (synarthroses, amphiarthroses, diarthroses).
Synovial Joints: Surrounded by fluid-filled cavities, allowing for greater mobility.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the essential components and functions of the skeletal system in this Chapter 6 quiz. Test your knowledge on bones, cartilages, tendons, ligaments, and their roles in body support and movement. Delve into aspects like mineral storage and blood cell production.

Skeletal System: Bones and Joints - Chapter 6

Choose a study mode