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It is a resilient and smooth elastic tissue, rubber-like padding that covers and protects the ends of long bones at the joints, and is the structure of the rib cage, the ear, the nose, etc.

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It is a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.

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Are the connection made between bones in the body which link the skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement.

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Bone marrow that is yellow with fat; found at the ends of long bones in adults.

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It contain the developmental stages of redblood cells, white blood cells, and megakaryocytes.

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The tissue that makes up the interior of bones.

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What Is Cancellous Bone?

Cancellous bone, also known as spongy or trabecular bone, is one of the two types of bone tissue found in the human body. Cancellous bone is found at the ends of long bones, as well as in the pelvic bones, ribs, skull, and the vertebrae in the spinal column. It is very porous and contains red bone marrow, where blood cells are made. It is weaker and easier to fracture than cortical bone, which makes up the shafts of long bones.

Types of Bone Tissue

The bones of the arms and legs in humans are the largest in the body and are known as long bones. Long bones are made up of two types of tissue. The central part of a long bone is composed of cortical bone. Cortical bone is very dense and strong and, therefore, difficult to fracture. Its primary purpose is providing structural support to the body and its organs and tissues. In the center of long bones is a central canal where blood vessels, nerves, and bone marrow are found. At the ends of the long bones, cortical bone gives way to cancellous bone. Cancellous bone is also found in the pelvic bones, and in the ribs and vertebrae.

In total, cancellous bone makes up about 20% of the typical adult human skeleton. Cancellous bone is much more porous and, therefore, weaker than cortical bone. Although it is still strong, it is more easily fractured than cortical bone. In addition to providing structural stability, cancellous bone contains most of the body's red bone marrow, which produces blood cells. The bone marrow found in cancellous bones also contains many stem cells that are used to repair damaged or broken bone.

Structure of Cancellous Bone

Cancellous bone is also known as spongy bone because it resembles a sponge or honeycomb, with many open spaces connected by flat planes of bone known as trabeculae. Inside the trabeculae are three types of bone cells: osteoblasts, osteocytes and osteoclasts. Osteoblasts are the cells that make new bone. They produce layers of hard tissue made primarily of calcium and phosphate until they are completely surrounded, at which point they become osteocytes. Finally, osteoclasts are larger cells that breakdown and destroy old or damaged bone so that it can be repaired and replaced by osteoblasts. This repair and rebuilding cycle is constantly ongoing to keep bones strong and healthy.

Cancellous Bone in Children

In babies, most of the skeleton is composed of cancellous bone, and all the bone marrow is red bone marrow. As children grow up, the bones get longer and cancellous bone is slowly converted into stronger cortical bone in the long bones. The red bone marrow is also slowly converted to yellow bone marrow, which is composed primarily of fat cells. During the teenage years, the growth plates close and cancellous bone is only left at the ends of the long bones. It remains into adulthood in the vertebrae, ribs, pelvis, and skull, and the bone marrow in these areas continues to produce blood cells. Yellow bone marrow in cortical bone can be converted back into red bone marrow even in adulthood following severe illness or blood loss.

Bone starts as cartilage in the fetus and as it develops during infancy and childhood the cartilage is converted first into cancellous (spongy) bone and then finally into cortical (compact) bone in the center of the long bones in the arms and legs. Children have a much higher percentage of cancellous bone in their skeleton than adults.

Cancellous Bone and Osteoporosis

Osteoporosis, 'osteo' (bone) and 'poros' (pore or passage), is a progressive degenerative bone disease characterized by a loss of bone density and strength and resulting in an increased risk of fracture. Osteoporosis is caused when excessive amounts of bone are removed by osteoclasts and the bone is not adequately replaced by osteoblasts. Because osteoclasts live on the surface of bone tissue and cancellous bone has a much larger surface area than cortical bone, it is the primary bone tissue affected by osteoporosis.

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structure & function - video & lesson transcript | study.com

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Cancellous Bone: Definition, Structure & Function - Video & Lesson Transcript | Study.com

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Cancellous bone, also known as spongy or trabecular bone, is one of the two types of bone tissue found in the human body. Cancellous bone is found at the ends of long bones, as well as in the pelvic bones, ribs, skull, and the vertebrae in the spinal column.

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Is a dense bone in which the bony matrix is solidly filled with organic ground substance and leaving only tiny spaces that contain the osteocytes.

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What is Compact Bone?

Bone is actually a type of connective tissue (a tissue type responsible for supporting, connecting, or separating tissues). It composes the structural support system of our bodies, which accounts for fourteen percent of your total body weight. Twenty percent of your skeleton is composed of a less rigid bone called trabecular ( spongy bone), while the other eighty percent is dense, strong cortical ( compact bone). Spongy bone gets its name because, you guessed it, it looks like a sponge and has many porous spaces, whereas compact bone is dense, appearing as if it were 'compacted' together.

Compact bone has a sturdy calcified matrix with very few spaces. This layer not only forms a protective shell around the spongy bone tissue, but it also gives our bones their rigidity, strength, and resistance. Can you imagine going to the gym or even trying to support your own body weight relying solely on porous spongy bone? I doubt we'd survive long enough to make it out of our house!

Structure and Function

Under magnification you can clearly see the system of concentric circles that forms compact bone. You can think of compact bone as being very similar to a bundle of cut trees or logs. Each 'log,' or long cylindrical unit, is called an osteon and, just like trees, osteons have rings of growth. Now, unlike trees, you can't figure out a person's age by counting their growth rings, called lamellae, but they do grow like the rings of a tree.

As bone grows, it creates new lamellae around older lamellae until different osteons meet and fuse together. These osteons, when fused, create a unit that becomes stronger than any one osteon could be on its own. Just like wires can be bundled to create those giant cords that support huge suspension bridges, osteons, when bundled, form amazingly strong pillars of support, structural strength, and rigidity.

Inside each osteon is a space called a central canal, which houses blood vessels and nerves within the bone. These vessels supply blood to the interior spongy bone as well as the living cells housed within the compact bone. That's right...bone is actually a living tissue!

Between the growth rings of lamellae are spaces, called lacunae, that contain osteocytes. Osteocytes are cells that deposit bone. Osteocytes are proactive cells, too; they respond to repeated stress on your bones (such as consistent exercise) and can actually make your bones stronger so that they can withstand the additional stress applied onto your bones by your muscles. Each lacunae is connected to the others through a fine network of canals, called canaliculi. The canaliculi supply nutrients to the osteocytes, remove cellular wastes, and enable communication between cells.

Finally, compact bone is covered by a double-layered membrane called a periosteum. The inner layer of the periosteum contains osteoblasts, which are cells that secrete collagen as well as mineral salts, which increase bone's resistance to breakage. You could think of osteoblasts as cells whose job it is to 'blast' bone with hardening and flexibility agents.

Lastly, the exterior layer of the periosteum contains the blood vessels and nerve fibers that pass into the bone and weave throughout the large central canals, into the little canaliculi, and to the osteocytes sitting within the lacunae of the bone tissue.

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structure & function - video & lesson transcript | study.com

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Compact Bone: Definition, Structure & Function - Video & Lesson Transcript | Study.com

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Bone is actually a type of connective tissue (a tissue type responsible for supporting, connecting, or separating tissues). It composes the structural support system of our bodies, which accounts for fourteen percent of your total body weight.

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Is a membrane that covers the outer surface of all bones, except at the joints of long bones.

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the carpal tunnel is a narrow passageway on the palm side of your wrist made up of bones and ligaments.

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It forms the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist which forms the connection to the forearm.

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the outer and thinner of the two bones of the human leg, extending from the knee to the ankle. It stabilizes and supports your ankle and lower leg muscle

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The clavicle/collarbone is a long bone that is between the shoulder blade and the sternum or breastbone.

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The patella/kneecap, is a thick, circular-triangular bone which contributes with the femur (thigh bone) and covers and protects the anterior surface of the knee joint.

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series of small bones forming the backbone, having several projections for articulation and muscle attachment and a hole through which the spinal cord passes through.

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It is the shoulder blade or wing bone and the bone connects the humerus (upper arm bone) with the clavicle (collar bone).

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Ribs are the long curved bones which form the rib cage. It surrounds the chest, enabling the lungs to expand. They serve to protect the lungs, heart, and other internal organs of the thorax.

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It is a long flat bone located in the center of the chest. It connects to the ribs via cartilage, forming the front of the rib cage, and helps protect the heart, lungs, and major blood vessels.

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It is the only bone located within the human thigh. It is both the longest and the strongest bone in the human body, extending from the hip to the knee.

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The humerus is the long bone in the upper arm. It is located between the elbow joint and the shoulder.

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The bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna.

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The thinner and longer of the two bones in the human forearm, on the side opposite to the thumb.

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The skull is a bony structure that forms the head in most vertebrates. It supports the structures of the face and provides a protective cavity for the brain.

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Cells responsible for forming bone. Osteoblast come together to form an osteoid matrix, which forms bone tissue when it is needed. It responds to physical activity and growth factors.

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Osteoclast is a large multinucleated cell responsible for the break down and absorption of bone.

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Calcium and how it relates to the Skeletal System

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Calcium and how it relates to the Skeletal System

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Calcium is a mineral that is necessary for life. alcium helps our blood clot, nerves send messages and muscles contract.

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Human Skeleton

Inside your body, there is a structure so perfectly designed and constructed that it puts modern skyscrapers to shame. I am talking about your skeleton, which is the internal framework of your body. This tower of bones is pieced together so perfectly that you can stand upright and walk on two legs. Without it, we would slither along on the ground like a worm.

When you were born, you had about 300 bones, but some of those bones fused together as you got older. By the time you are an adult, your skeleton will consist of 206 bones. Let's take a look at five things your bones do for you.

Support

The first function we'll talk about is the one that separates you from a worm; in other words, the bones of your skeleton provide support. The bones in your feet and legs are the foundation of your body and support the weight of your body when you're standing. The bones that make up your rib cage support your chest cavity and keep it open so your heart and lungs have room to work. All of the bones together support your muscles by giving them the framework to attach to, just like the framework of your house gives the walls something to hold them up.

Protection

Another function of your bones is that they provide protection. Your bones are very hard and strong, which makes them great protectors of the soft and delicate organs of your body, like your brain. Your skull has bones that are fused together so tightly it's almost like they are glued in place. This provides a solid fortress that shields your brain from injury.

The vertebrae are the bones that make up your spine or backbone. They are another example of how your bones protect important structures; in this case, your vertebrae protect your spinal cord. We already mentioned that the rib cage supports your chest cavity, and because of this, we see that it protects your heart and lungs from injury.

Movement

The third function of your bones deals with movement. Now, you probably know that it's your muscles that contract and relax to make you move, but you wouldn't go anywhere if your muscles weren't attached to and pulling your bones. Skeletal muscles attach to a bone at one end and then cross over a joint to attach to another bone. The first bone acts as an anchor and pulls the other bone toward it by contracting. This creates movement.

For example, when you kick a soccer ball, muscles in the front of your thigh pull the part of your leg below the knee joint forward in a kicking motion. Without your bones, muscles and joints working together, you would be completely stiff and have to waddle to get anywhere.

Storage

Now, this fourth function might surprise you if you think of bones as solid structures that never change. In reality, your bones act as storage sheds for things your body needs. The most notable substance that is stored in your bones is calcium. Calcium is a mineral important for strong bones.

Most of the calcium in your body is stored in your bones, but your body uses this mineral for a variety of things, such as sending messages through your nervous system and contracting your muscles. Your body can break down bones and pull calcium from them when it needs it for other tasks. Some of your bones even have a cavity in the middle that is used to store fat, but have no fear; this is a limited storage area, so you don't have to worry about your bones gaining too much weight.

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overview of the human skeleton & the functions of bones - video & lesson transcript | study.com

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Overview of the Human Skeleton & the Functions of Bones - Video & Lesson Transcript | Study.com

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Inside your body, there is a structure so perfectly designed and constructed that it puts modern skyscrapers to shame. I am talking about your skeleton, which is the internal framework of your body. This tower of bones is pieced together so perfectly that you can stand upright and walk on two legs.

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Any of the small bones of the fingers or toes in humans or the digits of many other vertebrates.

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The metatarsal bones are connected to the bones of the toe, or phalanges, at the knuckle of the toe. Metatarsals are convex in shape (arch upward), are long bones, and give the foot its arch.

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The proximal tarsals bones are the talus and the calcaneus. They form the bony framework around the proximal ankle and heel area.

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The pelvis is the lower end of the spine or the large bony structure near the base of the spine to which the hind limbs or legs are attached in humans.

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The mandible is the bone of the lower jaw. It forms the lower part of the skull. The lower jaw consisting of a single bone or of completely fused bones.