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This allows the brain to grow and develop before the bones fuse together to make one piece. Consequently, the maximum surface tension that the arachnoid can develop in response to the internal pressure of the cranial subarachnoid system is less in the areas of maximum parietal and . 2. Thus, the zone of calcified matrix connects the epiphyseal plate to the diaphysis. O diaphysis. The periosteum then secretes compact bone superficial to the spongy bone. - A) From cartilage models - B) Within fibrous membranes - C) From a tendon - D) Within osseous membranes The main function of the cranium is to protect the brain, which includes the cerebellum, cerebrum, and brain stem. The process in which matrix is resorbed on one surface of a bone and deposited on another is known as bone modeling. Ribas GC. Cambridge, Cambridge University Press. The hollow space taken up by the brain is called the cranial cavity. Certain cranial tumors and conditions tend to show up in specific areas of the skull baseat the front (near the eye sockets), the middle, or the back. Bone is a replacement tissue; that is, it uses a model tissue on which to lay down its mineral matrix. Learn the major cranial bone names and anatomy of the skull using this mnemonic and labeled diagram. The cranial vault (which encloses the brain) bones are formed by intramembranous ossification. Bones at the base of the skull and long bones form via endochondral ossification. growth hormone The 22 skull bones make up part of the axial skeleton, and they can be divided into two main sections: the 8 cranial bones, and the 14 facial bones. For example, the hypoglossal nerve controls the movements of the tongue so that you can chew and speak. a. bones b. muscles c. bone and muscle d. cartilage and bone; 1. The picture also helps us to view the cranial vault in its natural position; the cranial floor is at a distinct angle, starting at the level of the frontal sinus and continuing at an angle to include the small pocket that contains the cerebellum. Research is currently being conducted on using bisphosphonates to treat OI. It articulates with the mandible by way of a synovial joint. Cranial bones develop ________. On the epiphyseal side of the epiphyseal plate, cartilage is formed. The trabecular bone crowds nearby blood vessels, which eventually condense into red marrow (Figure \(\PageIndex{1.d}\)). Skull & Bones, Ubisoft's pirate battler that's been in development limbo for years now, has been delayed yet again. Mayo Clinic Staff. The cranium houses and protects the brain. The epiphyseal plate is composed of four zones of cells and activity (Figure \(\PageIndex{3}\)). As osteoblasts transform into osteocytes, osteogenic cells in the surrounding connective tissue differentiate into new osteoblasts. Suture lines connect the bones, where they develop together. The last bones to ossify via intramembranous ossification are the flat bones of the face, which reach their adult size at the end of the adolescent growth spurt. Chondrocytes in the next layer, the zone of maturation and hypertrophy, are older and larger than those in the proliferative zone. As for hematomas caused by fractures, a severe hematoma may require prolonged observation in the hospital, while a mild one may require only rest and ice at home. Some additional cartilage will be replaced throughout childhood, and some cartilage remains in the adult skeleton. For more details, see our Privacy Policy. Subscribe to our newsletter The raised edge of this groove is just visible to the left of the above image. O fibrous membranes O sutures. Like fractures, hematomas can range from mild to severe. This can cause an abnormal, asymmetrical appearance of the skull or facial bones. A bone grows in length when osseous tissue is added to the diaphysis. In endochondral ossification, what happens to the chondrocytes? The total 8 cranial bones form the cranial cavity, which protects the brain, these are frontal bone, 2 parietal bones, 2 temporal bones, the occipital bone, the sphenoid bone, and the ethmoid bone. Considering how a long bone develops, what are the similarities and differences between a primary and a secondary ossification center? 1.2 Structural Organization of the Human Body, 2.1 Elements and Atoms: The Building Blocks of Matter, 2.4 Inorganic Compounds Essential to Human Functioning, 2.5 Organic Compounds Essential to Human Functioning, 3.2 The Cytoplasm and Cellular Organelles, 4.3 Connective Tissue Supports and Protects, 5.3 Functions of the Integumentary System, 5.4 Diseases, Disorders, and Injuries of the Integumentary System, 6.6 Exercise, Nutrition, Hormones, and Bone Tissue, 6.7 Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems, 7.6 Embryonic Development of the Axial Skeleton, 8.5 Development of the Appendicular Skeleton, 10.3 Muscle Fiber Excitation, Contraction, and Relaxation, 10.4 Nervous System Control of Muscle Tension, 10.8 Development and Regeneration of Muscle Tissue, 11.1 Describe the roles of agonists, antagonists and synergists, 11.2 Explain the organization of muscle fascicles and their role in generating force, 11.3 Explain the criteria used to name skeletal muscles, 11.4 Axial Muscles of the Head Neck and Back, 11.5 Axial muscles of the abdominal wall and thorax, 11.6 Muscles of the Pectoral Girdle and Upper Limbs, 11.7 Appendicular Muscles of the Pelvic Girdle and Lower Limbs, 12.1 Structure and Function of the Nervous System, 13.4 Relationship of the PNS to the Spinal Cord of the CNS, 13.6 Testing the Spinal Nerves (Sensory and Motor Exams), 14.2 Blood Flow the meninges and Cerebrospinal Fluid Production and Circulation, 16.1 Divisions of the Autonomic Nervous System, 16.4 Drugs that Affect the Autonomic System, 17.3 The Pituitary Gland and Hypothalamus, 17.10 Organs with Secondary Endocrine Functions, 17.11 Development and Aging of the Endocrine System, 19.2 Cardiac Muscle and Electrical Activity, 20.1 Structure and Function of Blood Vessels, 20.2 Blood Flow, Blood Pressure, and Resistance, 20.4 Homeostatic Regulation of the Vascular System, 20.6 Development of Blood Vessels and Fetal Circulation, 21.1 Anatomy of the Lymphatic and Immune Systems, 21.2 Barrier Defenses and the Innate Immune Response, 21.3 The Adaptive Immune Response: T lymphocytes and Their Functional Types, 21.4 The Adaptive Immune Response: B-lymphocytes and Antibodies, 21.5 The Immune Response against Pathogens, 21.6 Diseases Associated with Depressed or Overactive Immune Responses, 21.7 Transplantation and Cancer Immunology, 22.1 Organs and Structures of the Respiratory System, 22.6 Modifications in Respiratory Functions, 22.7 Embryonic Development of the Respiratory System, 23.2 Digestive System Processes and Regulation, 23.5 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder, 23.7 Chemical Digestion and Absorption: A Closer Look, 25.1 Internal and External Anatomy of the Kidney, 25.2 Microscopic Anatomy of the Kidney: Anatomy of the Nephron, 25.3 Physiology of Urine Formation: Overview, 25.4 Physiology of Urine Formation: Glomerular Filtration, 25.5 Physiology of Urine Formation: Tubular Reabsorption and Secretion, 25.6 Physiology of Urine Formation: Medullary Concentration Gradient, 25.7 Physiology of Urine Formation: Regulation of Fluid Volume and Composition, 27.3 Physiology of the Female Sexual System, 27.4 Physiology of the Male Sexual System, 28.4 Maternal Changes During Pregnancy, Labor, and Birth, 28.5 Adjustments of the Infant at Birth and Postnatal Stages. The two parietal bones continue the shape of the cranial vault; these are quadrilateral, smooth, and curved bony plates. Intramembranous ossification begins in utero during fetal development and continues on into adolescence. It is, therefore, perfectly acceptable to list them in both groups. The cranial bones develop by way of intramembranous ossification and endochondral ossification. These nerves are essential to everyday functioning, including smelling, seeing, and chewing. ", Biologydictionary.net Editors. In the embryo, the vault bones develop through ossification of the ectomeninx - the outer membranous layer surrounding the brain; while the cranial base develops through an additional cartilaginous stage, 2, 16 the significance of which will be discussed later (Individual bones spanning both regions fuse at a later stage). The Peripheral Nervous System, Chapter 18. In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue, but in endochondral ossification, bone develops by replacing hyaline cartilage. When the chondrocytes in the epiphyseal plate cease their proliferation and bone replaces all the cartilage, longitudinal growth stops. On the epiphyseal side of the epiphyseal plate, hyaline cartilage cells are active and are dividing and producing hyaline cartilage matrix. The adult human skeleton has about 206 different bones, each develop with their own specific bone timeline. Those with the most severe forms of the disease sustain many more fractures than those with a mild form. A vertical groove passes through the middle of the cranial vault the sagittal groove or sulcus that provides space for the superior sagittal sinus (part of the drainage mechanism for cerebrospinal fluid and blood). For instance, skull base meningiomas, which grow on the base of the skull, are more difficult to remove than convexity meningiomas, which grow on top of the brain. Bowing of the long bones and curvature of the spine are also common in people afflicted with OI. Embryos develop a cartilaginous skeleton and various membranes. But if you have other symptoms, you may have an underlying condition. Several injuries and health conditions can impact your cranial bones, including fractures and congenital conditions. Find information on why a bone scan is done and what to expect during. Considering how a long bone develops, what are the similarities and differences between a primary and a secondary ossification center? The Anatomy of the Central Nervous System, Cerobrospinal Fluid (CSF) Rhinorrhea Symptoms and Treatment, An Overview of a Newborns Skull: Parietal Bones and Sutures, The Anatomy of the Middle Meningeal Artery, Halo Vest vs. Spinal Fusion: Uses, Benefits, Side Effects, and More. There are some abnormalities to craniofacial anatomy that are seen in infancy as the babys head grows and develops. There are several types of skull fracture that can affect cranial bones, such as: In many cases, skull fractures arent as painful as they sound, and they often heal on their own without surgery. The process begins when mesenchymal cells in the embryonic skeleton gather together and begin to differentiate into specialized cells (Figure 6.4.1a). The more mature cells are situated closer to the diaphyseal end of the plate. Bones grow in diameter due to bone formation ________. Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. A cranial CT scan of the head is a diagnostic tool used to create detailed pictures of the skull, brain, paranasal sinuses, and eye sockets. (2017). Their number and location vary. What do ligaments hold together in a joint? The cranial bones are the strongest and hardest of these layers of protection. More descriptive terms include skull base and cranial floor. Usually, during infancy the sutures . The cranial bones remain separate for about 12 to 18 months. A. This process is called modeling. This is why damaged cartilage does not repair itself as readily as most tissues do. Once entrapped, the osteoblasts become osteocytes (Figure 6.4.1b). Babys head shape: Whats normal? Osteogenesis imperfecta (OI) is a genetic disease in which bones do not form properly and therefore are fragile and break easily. Because collagen is such an important structural protein in many parts of the body, people with OI may also experience fragile skin, weak muscles, loose joints, easy bruising, frequent nosebleeds, brittle teeth, blue sclera, and hearing loss. Other conditions of the cranium include tumors and fractures. A single primary ossification center is present, during endochondral ossification, deep in the periosteal collar. (2018). Function Because collagen is such an important structural protein in many parts of the body, people with OI may also experience fragile skin, weak muscles, loose joints, easy bruising, frequent nosebleeds, brittle teeth, blue sclera, and hearing loss. Evolutionary,it is the expansion of the neurocranium that has facilitated the expansion of the brain and its associated developments. The Cellular Level of Organization, Chapter 4. During intramembranous ossification, compact and spongy bone develops directly from sheets of mesenchymal (undifferentiated) connective tissue. Prenatal growth of cranial base: The bones of the skull are developed in the mesenchyme which is derived from mesoderm. The two main parts of the cranium are the cranial roof and the cranial base. The epiphyseal plate is the area of elongation in a long bone. The cranium is the sum of the cranial and facial bones, as well as the bony part of the larynx. In endochondral ossification, bone develops by replacing hyaline cartilage. Anatomic and Pathologic Considerations. Chondrocytes in the next layer, the zone of maturation and hypertrophy, are older and larger than those in the proliferative zone. (2018). In some cases, metal rods may be surgically implanted into the long bones of the arms and legs. This growth within a tissue is calledinterstitial growth. It makes new chondrocytes (via mitosis) to replace those that die at the diaphyseal end of the plate. cranial bones: [plural noun] those bones of the skull that enclose the brain compare cranial segment. The answer is A) mark as brainliest. The reserve zone is the region closest to the epiphyseal end of the plate and contains small chondrocytes within the matrix. Cranial bones develop from: tendons O cartilage. Without cartilage inhibiting blood vessel invasion, blood vessels penetrate the resulting spaces, not only enlarging the cavities but also carrying osteogenic cells with them, many of which will become osteoblasts. Mayo Clinic Staff. Under normal conditions, the region expected to have the lowest pco2 is the ___________________. The cranial bones are fused together to keep your brain safe and sound. As distinct from facial bones, it is formed through endochondral ossification. They are not visible in the above image. All that remains of the epiphyseal plate is the epiphyseal line (Figure \(\PageIndex{4}\)). On the diaphyseal side of the growth plate, cartilage calcifies and dies, then is replaced by bone (figure 6.43, zones of hypertrophy and maturation, calcification and ossification). The cranial floor is much more complex than the vault. It also allows passage of the cranial nerves that are essential to everyday functioning. Which bone sits in the center of the skull between the eye sockets and helps form parts of the nasal and orbital cavities? In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue, but in endochondral ossification, bone develops by replacing hyaline cartilage. Neuroanatomy, Middle Meningeal Arteries. Chapter 1. This developmental process consists of a condensation and thickening of the mesenchyme into masses which are the first distinguishable cranial elements. Compare and contrast interstitial and appositional growth. How does the cranium provide protection to the human brain? Treatment for Pagets disease depends on the type. A) from a tendon B) from cartilage models C) within osseous membranesD) within fibrous membranes D ) within fibrous membranes 129. The cranium houses and protects the brain. Appositional growth allows bones to grow in diameter. . At the side of the head, it articulates with the parietal bones, the sphenoid bone, and the ethmoid bone. Once entrapped, the osteoblasts become osteocytes (Figure \(\PageIndex{1.b}\)). The two main forms of ossification occur in different bones, intramembranous (eg skull) and endochondral (eg vertebra) ossification. Development of the Skull. The two parietal (pah-ri '-e-tal) bones form the sides and roof of the cranium. Intramembranous ossification is complete by the end of the adolescent growth spurt, while endochondral ossification lasts into young adulthood. Which of the following nerves does not arise from the brachial plexus? The cranium has bones that protect the face and brain. The proliferative zone is the next layer toward the diaphysis and contains stacks of slightly larger chondrocytes. Development of cranial bones The cranium is formed of bones of two different types of developmental originthe cartilaginous, or substitution, bones, which replace cartilages preformed in the general shape of the bone; and membrane bones, which are laid down within layers of connective tissue. Cranial nerves send electrical signals between your brain, face, neck and torso. Cranial bones develop ________. Sutural (Wormian) bones are very small bones that develop within sutures. https://quizack.com/biology/anatomy-and-physiology/mcq/cranial-bones-develop, Note: This Question is unanswered, help us to find answer for this one. Frontoethmoidal suture: very short suture between the orbital projections of the frontal and ethmoid bones, Petrosquamous suture: refers to the join between the petrous and squamous parts of the temporal bone, close to the middle ear and at the skull base, Sphenoethmoidal suture: between the sphenoid and ethmoid bones, Sphenopetrosal suture: joins the greater wing of the sphenoid bone with the petrous part of the temporal bone, Sphenoid bone (1 depending on the source), Ethmoid bone (1 depending on the source), Maxillae (2 sometimes considered to be 1 fused bone), Mandible (1 sometimes considered to be 2 fused bones). One type of meningioma is sphenoid wing meningioma, where the tumor forms on the base of the skull behind the eyes; it accounts for approximately 20% of all meningiomas. (n.d.). In what ways do intramembranous and endochondral ossification differ? Craniosynostosis is a birth defect in which the bones in a baby's skull join together too early. D) distal epiphysis. There are 22 bones in the skull. Fibrous dysplasia. Pagets disease of bone. Frequent and multiple fractures typically lead to bone deformities and short stature. Emily is a health communication consultant, writer, and editor at EVR Creative, specializing in public health research and health promotion. Together, the cranial floor and cranial vault form the neurocranium, Anterior cranial fossa: houses the frontal lobe, olfactory bulb, olfactory tract, and orbital gyri (, Middle cranial fossa: a butterfly-shaped indentation that houses the temporal lobes, features channels for ophthalmic structures, and separates the pituitary gland from the nasal cavity, Posterior cranial fossa: contains the cerebellum, pons, and medulla oblongata; the point of access between the brain and spinal canal, Coronal suture: between the two parietal bones and the frontal bone, Sagittal suture: between the left and right parietal bones, Lambdoidal suture: between the top of the occipital bone and the back of the parietal bones, Metopic suture: only found in newborns between the two halves of the frontal bone that, once fused (very early in life), become a single bone, Squamous suture: between the temporal and parietal bones. A. proliferation, reserved, maturation, calcification, B. maturation, proliferation, reserved, calcification, C. calcification, maturation, proliferation, reserved, D. calcification, reserved, proliferation, maturation. Mayo Clinic Staff. 1. . The Viscerocranium is further divided into: How does skull bone develop? There are a few categories of conditions associated with the cranium: craniofacial abnormalities, cranial tumors, and cranial fractures. Just above the occipital bone and close to the midline of the skull cap are the parietal foramina. A separate Biology Dictionary article discusses the numerous cranial foramina. The osteoblasts secrete osteoid, uncalcified matrix, which calcifies (hardens) within a few days as mineral salts are deposited on it, thereby entrapping the osteoblasts within. The sphenoid is occasionally listed as a bone of the viscerocranium. During the maturation of the skull, it is categorically divided into two main parts: the viscerocranium and the neurocranium. In a press release today, Ubisoft has given a new . D cells release ________, which inhibits the release of gastrin. The Nervous System and Nervous Tissue, Chapter 13. A single primary ossification center is present, during endochondral ossification, deep in diaphysis. In endochondral ossification, bone develops by replacing hyaline cartilage. The genetic mutation that causes OI affects the bodys production of collagen, one of the critical components of bone matrix. In the cranial vault, there are three: The inner surface of the skull base also features various foramina. In the early stages of embryonic development, the embryos skeleton consists of fibrous membranes and hyaline cartilage. The cranial base is composed of the frontal, sphenoid, ethmoid, occipital, parietal, and temporal bones. Primary lateral sclerosis is a rare neurological disorder. Once fused, they help keep the brain out of harm's way. In a long bone, for example, at about 6 to 8 weeks after conception, some of the mesenchymal cells differentiate into chondrocytes (cartilage cells) that form the cartilaginous skeletal precursor of the bones (Figure \(\PageIndex{2.a}\)). Cranial fossae are three depressions in the floor of the cranium. Interstitial growth only occurs as long as hyaline is present, cannot occur after epiphyseal plate closes. The cranium is part of the skull anatomy. Smoking and being overweight are especially risky in people with OI, since smoking is known to weaken bones, and extra body weight puts additional stress on the bones. More Biology MCQ Questions Cross bridge detachment is caused by ________ binding to the myosin head. Learn about its causes and home exercises that can help. It does feature a few bumps and grooves. The inner surface of the vault is very smooth in comparison with the floor. O Diaphysis The rate of growth is controlled by hormones, which will be discussed later. While these deep changes are occurring, chondrocytes and cartilage continue to grow at the ends of the bone (the future epiphyses), which increases the bones length at the same time bone is replacing cartilage in the diaphyses. They stay connected throughout adulthood. Somites form the remainder of the axial skeleton. Applied Cranial-Cerebral Anatomy: Brain Architecture and Anatomically Oriented Microneurosurgery. Common symptoms include a sloped forehead, extra bone. The frontal crest is an attachment point for a fold in the membranes covering the brain (falx cerebri). "Cranial Bones." During intramembranous ossification, compact and spongy bone develops directly from sheets of mesenchymal (undifferentiated) connective tissue. While bones are increasing in length, they are also increasing in diameter; growth in diameter can continue even after longitudinal growth ceases. Q. Connected to the cranial bones are facial bones that give structure to the face and a place for the facial muscles to attach. The flat bones of the face, most of the cranial bones, and the clavicles (collarbones) are formed via intramembranous ossification. Blood vessels in the perichondrium bring osteoblasts to the edges of the structure and these arriving osteoblasts deposit bone in a ring around the diaphysis this is called a bone collar (Figure 6.4.2b). Fourteen are facial bones and eight are cranial bones. Canes, walkers, or wheelchairs can also help compensate for weaknesses. Johns Hopkins Medicine. As the matrix calcifies, nutrients can no longer reach the chondrocytes. See Answer Question: Cranial bones develop ________. The flat bones of the face, most of the cranial bones, and the clavicles (collarbones) are formed via intramembranous ossification. Radiation therapy and surgery are the most common initial treatments, while sometimes the best thing is close observation; chemotherapy is rarely used. The cranial bones of the skull join together over time. The world of Skull and Bones is a treasure trove to explore as you sail to the furthest reaches of the Indian Ocean. Skull development can be divided into neurocranium and viscerocranium formation, a process starting between 23 and 26 days of gestation. The ethmoid bone, also sometimes attributed to the viscerocranium, separates the nasal cavity from the brain. However, more severe fractures may require surgery. Appointments & Locations. The cranial floor (base) denotes the bottom of the cranium. The following words are often used incorrectly; this list gives their true meaning: The front of the cranial vault is composed of the frontal bone. The midsagittal section below shows the difference between the relatively smooth upper surface and the bumpy, grooved lower surface. The spongy bone crowds nearby blood vessels, which eventually condense into red bone marrow (Figure 6.4.1d). The cranial bones, scapula (shoulder blade), sternum (breast bone), ribs, and iliac bone (hip) are all flat bones. Normally, the human skull has twenty-two bones - fourteen facial skeleton bones and eight cranial bones. Together, the cranial and facial bones make up the complete skull. The neurocranium consists of the occipital bone, two temporal bones, two parietal bones, the sphenoid, ethmoid, and frontal bonesall are joined together with sutures. All rights reserved. Brain size influences the timing of. For skeletal development, the most common template is cartilage. Biologydictionary.net Editors. The cranial vault develops in a coordinated manner resulting in a structure that protects the brain. Curvature of the spine makes breathing difficult because the lungs are compressed. This can occur in up to 85% of pterion fracture cases. The facial bones are the complete opposite: you have two . Bones continue to grow in length until early adulthood. Looking down onto the inner surface of the skull base, the first thing you notice is a series of divisions. Some of these cells will differentiate into capillaries, while others will become osteogenic cells and then osteoblasts. With a scientific background and a passion for creative writing, her work illustrates the value of evidence-based information and creativity in advancing public health. Craniofacial Development and Growth. There are several types of craniosynostosis, depending on the sutures they affect: Craniosynostosis requires surgical treatment to avoid later complications. It is subdivided into the facial bones and the cranium, or cranial vault (Figure 7.3.1).The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws. Your cranial nerves help you taste, smell, hear and feel sensations. This allows babies to pass through the narrow birth. There is no known cure for OI. The Cardiovascular System: The Heart, Chapter 20. Craniometaphyseal dysplasia, autosomal dominant. The development of the skeleton can be traced back to three derivatives[1]: cranial neural crest cells, somites, and the lateral plate mesoderm. The neurocranium is a group of eight bones that form a cover for the brain and brainstem. At birth, the skull and clavicles are not fully ossified nor are the sutures of the skull closed. The last bones to ossify via intramembranous ossification are the flat bones of the face, which reach their adult size at the end of the adolescent growth spurt. Many prenatal bones fuse postnatal developing neonate and child (about 275). C) metaphysis. However, it also provides important structures at the side and base of the neurocranium. The cranial bones are fused together to keep your brain safe and sound. It is dividing into two parts: the Neurocranium, which forms a protective case around the brain, and the Viscerocranium, which surrounds the oral cavity, pharynx, and upper respiratory passages. Introduction. Here's a cool thing to remember about the skull bones: in the cranium, two bones come in pairs, but all the others are single bones. 2021 All rights reserved, Internal layer of spongy bone in flat bones. Smoking and being overweight are especially risky in people with OI, since smoking is known to weaken bones, and extra body weight puts additional stress on the bones. These chondrocytes do not participate in bone growth but secure the epiphyseal plate to the osseous tissue of the epiphysis. Cranial bone anatomy can be confusing when we consider the various terms used to describe different areas. Cranial bones develop ________ Elevated levels of sex hormones Due to pus-forming bacteria Within fibrous membranes Internal layer of spongy bone in flat bones Previous Next Is This Question Helpful? The foundation of the skull is the lower part of the cranium . Most of the chondrocytes in the zone of calcified matrix, the zone closest to the diaphysis, are dead because the matrix around them has calcified, restricting nutrient diffusion. Cranial Bones. Cranial bones develop A) within fibrous membranes B) within osseous membranes C) from cartilage models Development of the Skull. The sutures are flexible, the bones can overlap during birthing, preventing the baby's head from pressing against the baby's brain and causing damage.What are t rachellelunaa rachellelunaa 04/09/2021 Although they will ultimately be spread out by the formation of bone tissue, early osteoblasts appear in a cluster called an ossification center. A. Injury, exercise, and other activities lead to remodeling. However, in infancy, the cranial bones have gaps between them and are connected by connective tissue. Differentiate between the facial bones and the cranial bones.