The crown is the top portion of the

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple ani ...

behind the vertex. The

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

of the crown varies between different

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s. The human crown is made of three layers of the

scalp The scalp is the area of the head where head hair grows. It is made up of skin, layers of connective and fibrous tissues, and the membrane of the skull. Anatomically, the scalp is part of the epicranium, a collection of structures covering th ...

above the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. The crown also covers a range of bone sutures, and contains

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

s and branches of the

trigeminal nerve In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions ...

. The structure of the human crown provides a protective cavity for the brain and optimizes the crown's ability to ensure the

neocortex The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, ...

is safe. Different parts of the neocortex, such as the

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...

and the

parietal lobe The parietal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integra ...

, are protected by the

meninges In anatomy, the meninges (; meninx ; ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid spac ...

and bone structures. Other organisms, such as

whale Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea ...

s, have their blowholes on their crown, causing a flattened head shape. Some bird species have a crest located on their crown, used for

communication Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether Intention, unintentional or failed transmissions are included and whether communication not onl ...

and

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage or committed romantic, ''de facto'' relationship. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marri ...

Macroevolution Macroevolution comprises the evolutionary processes and patterns which occur at and above the species level. In contrast, microevolution is evolution occurring within the population(s) of a single species. In other words, microevolution is the ...

of the human crown has led to different structures between modern and archaic

human species Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are great apes characterized by their hairlessness, bipedalism, and high intelligenc ...

, such as significant changes to the

cranial vault The cranial vault is the space in the skull within the neurocranium, occupied by the brain. Development In humans, the cranial vault is imperfectly composed in newborns, to allow the large human head to pass through the birth canal. During bir ...

. The human crown is prone to different

injuries Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants. Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with b ...

and disorders with various causes,

medical sign Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

s and

symptom Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

s, methods of

diagnosis Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...

, and treatments. For example, illnesses such as

cerebrospinal fluid leak A cerebrospinal fluid leak (CSF leak or CSFL) is a medical condition where the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord leaks out of one or more holes or tears in the dura mater. A CSF leak is classed as either spontane ...

, which results in intense

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

s that are localised underneath the crown. Other diseases include

meningioma Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing ...

, a tumor surrounding essential blood vessels and nerves that may be near the crown, causing symptoms such as memory loss.

Structure

The crown is at the top of the

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

, and contains the different layers of the scalp. The scalp has three distinct layers including the cutaneous layer, a subcutaneous connective tissue layer, and a

muscular layer The muscular layer (muscular coat, muscular fibers, muscularis propria, muscularis externa) is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa. It is responsible for gut movement such as peristalsis. The Latin ...

. The crown covers bone layers of the skull. It is between thick, and varies between different people. It tends to increase in thickness with age. Sobo 1909 46

Below the crown, the

frontal bone In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...

and the

parietal bone The parietal bones ( ) are two bones in the skull which, when joined at a fibrous joint known as a cranial suture, form the sides and roof of the neurocranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four bord ...

s are separated by a range of

fibrous joint In anatomy, fibrous joints are joints connected by Fibrous connective tissue, fibrous tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull, the ...

s called sutures. The sutures are an essential part of growth and development, allowing the skull to expand as the brain increases in size. Different sutures between the frontal and parietal

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

s of the skull expand in specific directions, causing a symmetrically shaped human head. The frontal bone and the

s are joined at the

frontal suture The frontal suture is a fibrous joint that divides the two halves of the frontal bone of the skull in infants and children. Typically, it completely fuses between three and nine months of age, with the two halves of the frontal bone being fused t ...

. The frontal bone has a number of parts, including the squamous part, the orbital part, and the nasal parts. The frontal bone connects to the parietal bone at the

coronal suture The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull. Structure The coronal suture lies between the paired parietal bones and the frontal bone of the skull ...

to shape the crown and sides of the skull. The two separate parietal bones are joined at the

sagittal suture The sagittal suture, also known as the interparietal suture and the ''sutura interparietalis'', is a dense, fibrous connective tissue joint between the two parietal bones of the skull. The term is derived from the Latin word ''sagitta'', meaning ...

, ensuring the crown is stable. Other structures of the human crown include blood vessels and nerves, which are essential for the allocation of nutrients to the brain, and the transmission of information to the brain. The

superficial temporal artery In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic ar ...

branches from the common

external carotid artery The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland. Structure Origin T ...

and delivers oxygenated

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

to the crown. The crown also contains branches of the

Organisms such as whales and birds have different crown structures and species use them in different situations. Sperm whales have their blowholes situated asymmetrically on the crown of the head to breathe, causing a flattened head shape. In

bird anatomy Bird anatomy, or the physiological structure of birds' bodies, shows many unique adaptations, mostly aiding flight. Birds have a light skeletal system and light but powerful musculature which, along with circulatory and respiratory systems capa ...

, the crown is the top of the head, or more specifically the zone from the

frons Insect morphology is the study and description of the physical form of insects. The terminology used to describe insects is similar to that used for other arthropods due to their shared evolutionary history. Three physical features separate insec ...

, or forehead, extending posteriorly to the

occiput The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lobes of the ...

and laterally on both sides to the

temples A temple (from the Latin ) is a place of worship, a building used for spiritual rituals and activities such as prayer and sacrifice. By convention, the specially built places of worship of some religions are commonly called "temples" in Engli ...

. The upper part of the head, including frons, crown, and occiput, is called the pileum. A bird with a crest covering the pileum is described as "pileated" such as the pileated woodpecker. The range of

feather Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and an exa ...

s that make up the crest determines the bird's emotions and courtship behaviors. For instance, bird species such as the

northern cardinal The northern cardinal (''Cardinalis cardinalis''), also commonly known as the common cardinal, red cardinal, or simply cardinal, is a bird in the genus ''Cardinalis''. It can be found in southeastern Canada, through the eastern United States fro ...

move the crest intensely to signify dominance and communication.

Function

The main function of the crown is to protect the brain from specific physical injuries. The

neurocranium In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the cal ...

has the frontal and parietal bones that make up the crown and protect parts of the brain including the frontal lobe as well as the parietal lobe. The three

membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...

s of the meninges ensures stability and prevents injuries directed to these lobes. For instance, the meninges which include flexible sheets between the brain,

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

, and skull aim to protect the frontal lobe, located behind the

forehead In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the fo ...

. The cerebrospinal fluid within the ventricles of the skull reduces the extent of the injury by acting as a cushion. Protecting the frontal lobe allows humans to perform motor movements and to execute functions. The parietal lobe of the neocortex which contains a strip targeting the sense of touch and allows for the representation of space for action is protected due to the thick layers of the crown.

Injuries and diseases

The crown or human head is subjected to a range of injuries and diseases causing the brain to be vulnerable. The extent of the injuries and diseases directed to the human crown causes additional implications to the brain, impacting the individual's ability to function normally. The range of injuries and disorders have specific causes, medical signs and symptoms, diagnosis methods and treatments.

Cerebrospinal fluid leak

A common disease associated with the crown includes the cerebrospinal fluid leak, which involves the excess removal of fluid within the meninges. The cerebrospinal fluid leak is mainly caused by a head, brain, or spinal injury which tears the meninges membrane. The excessive leakage of the cerebrospinal fluid leads to symptoms that include intense headaches often localised to the crown. An extreme sign of this disorder includes the leakage of fluid from the patient's ears and nose. The

of the cerebrospinal fluid leak is determined from examinations including a computerised tomography scan which involves an

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

image of parts of the skull including the crown.

Health professional A health professional, healthcare professional (HCP), or healthcare worker (sometimes abbreviated as HCW) is a provider of health care treatment and advice based on formal training and experience. The field includes those who work as a Nursing, nur ...

s offer treatments to manage the symptoms associated with the disease. For example, consuming

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

s such as water aims to stop excess leakage and reduce headaches, and

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

s are also provided if signs of

infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

are clear such as

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

and

chills Chills is a feeling of coldness occurring during a high fever, but sometimes is also a common symptom which occurs alone in specific people. It occurs during fever due to the release of cytokines and prostaglandins as part of the inflammatory ...

Meningioma

Meningioma is a cranial disorder and is characterised by tumor growth on the meninges, surrounding the blood vessels and nerves near the crown. The causes of the disorder include a rapid division of

cells Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a d ...

around the area. The patients that have meningioma develop signs and symptoms including

amnesia Amnesia is a deficit in memory caused by brain damage or brain diseases,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be temporarily caused by t ...

and

epileptic seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

s. The direct impact to the frontal lobe of the brain causes symptoms such as weakness to the

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between ...

s and

legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...

. Diagnosis is made via imaging tests such as

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRI) which involves high-frequency

radio wave Radio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths g ...

s and a strong

magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

allowing for the measurement of

proton A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

s in the water. The treatments involve

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

to remove the tumor from the patient's meninges and the extent of the surgery depends on the size and aggression of the meningioma. Cleidocranial2

Fractures

Bone fracture A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a ''c ...

s to the crown of the head are linear or depressed and range in severity based on the impact to the skull. The linear fracture involves a break to the skull whereas the depressed fracture results in the scatter of skull fragments. The skull fractures are mainly caused by incidents involving a vehicle, assault, or a fall. In more severe cases, penetrating skull fractures are caused by an object such as a metal rod or bullet breaking through the skull completely. Based on the severity of the fracture, symptoms may include

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

, memory loss,

concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include headache, dizziness, difficulty with thinking and concentration, sleep disturbances, a brief ...

bruise A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur c ...

, and

lethargy Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overw ...

. Another symptom such as

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethr ...

results in the build-up of pressure in the skull since it is an enclosed cavity and thus pushes the brain to the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

opening leading to a

coma A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to Nociception, respond normally to Pain, painful stimuli, light, or sound, lacks a normal Circadian rhythm, sleep-wake cycle and does not initiate ...

. Diagnosis occurs due to a range of physical exams which identifies the extent of the injury and possible treatments. For example, the computerised tomography scan identifies the site of the fracture and any associated injuries to the brain, whereas magnetic resonance imaging highlights the damaged tissue. The treatments of severe skull fractures include surgery and

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

to avoid infection, however, for linear fractures treatment involves rest for approximately 5 to 10 days, so that the crown can heal.

Gorham's disease

Gorham's disease Gorham's disease (pronounced GOR-amz), also known as Gorham vanishing bone disease and phantom bone disease, is a very rare bone disease, skeletal condition of unknown etiology, cause. It is characterized by the uncontrolled proliferation of dis ...

is a condition that targets the

human musculoskeletal system The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provi ...

including the crown of the skull. The chronic disorder involves the progressive loss of bone, although, symptoms such as intense

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

are not evident during the initial stages. The cause of the Gorham disease has not been discovered, however, cells associated with the breakdown of fragile and old bones which include

osteoclast An osteoclast () is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and bone remodeling, remodeling of bones of the vertebrate, vertebral skeleton. The osteoclast disassembles and digests th ...

s are considered to be the main link towards identifying the cause. The symptoms of the disease are clear after a fracture to the crown of the skull causing patients to experience abnormal deformities as well as issues to the nervous system. Diagnosis occurs through physical exams such as X-rays and magnetic resonance imaging which find the decrease in bone mass ( osteolysis) and deformities. Treatment of the disease involves a range of techniques to prevent spread from the skull to the spine or chest of the patient.

Chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...

and surgery, as well as lifestyle changes such as consuming a

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

of high

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

, aim to minimise the severity of the disease.

Evolution

The macroevolution of the human species resulted in changes such as the increase in bone and muscle structures that support the crown of the head, compared to

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

s. Modern human species have a cranial base which is more angled and a cranial vault that is rounded, compared to

archaic human ''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...

species. Modern human species have their

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pr ...

s positioned under the cranial base signifying the increase in the size of the human brain and skull. The sagittal vault's

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

, which is the area that joins the two parietal bones together to make up the structure of the crown, has remained the same for archaic and modern human species. The

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

embedded within the skull plays a major role in the changes of the crown. The cartilage evident within the cranium were an essential part in defending the central nervous system, however, over time the cartilage began to shape the crown by a process known as

endochondral ossification Endochondral ossification is one of the two essential pathways by which bone tissue is produced during fetal development and bone healing, bone repair of the mammalian skeleton, skeletal system, the other pathway being intramembranous ossificatio ...

. This process involves the replacement of grown cartilage with bone to develop the bone structure of the skull.

References

External links

Visible Interactive human
(

Ohio University Ohio University (Ohio or OU) is a Public university, public research university with its main campus in Athens, Ohio, United States. The university was first conceived in the 1787 contract between the United States Department of the Treasury#Re ...

Heritage College of Osteopathic Medicine)
Head Injury
(

Columbia university Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

department of neurology) {{DEFAULTSORT:Crown (Anatomy) Bird anatomy Human head and neck