The crown is the top portion of the head behind the

vertex Vertex, vertices or vertexes may refer to: Science and technology Mathematics and computer science *Vertex (geometry), a point where two or more curves, lines, or edges meet * Vertex (computer graphics), a data structure that describes the positio ...

. The

anatomy Anatomy () is the branch of biology concerned with the study of the 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 science, having it ...

of the crown varies between different

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

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

scalp The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back. Structure The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic: * S: The ski ...

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

blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away ...

s and branches of the

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

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

and the

parietal lobe The parietal lobe is one of the four 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 integrates sensory informa ...

, are protected by the meninges and bone structures. Other organisms, such as

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

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

crest Crest or CREST may refer to: Buildings *The Crest (Huntington, New York), a historic house in Suffolk County, New York *"The Crest", an alternate name for 63 Wall Street, in Manhattan, New York *Crest Castle (Château Du Crest), Jussy, Switzerla ...

located on their crown, used for

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inqui ...

and

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...

Macroevolution Macroevolution usually means the evolution of large-scale structures and traits that go significantly beyond the intraspecific variation found in microevolution (including speciation). In other words, macroevolution is the evolution of taxa abov ...

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

human species Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, an ...

, 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 bi ...

. The human crown is prone to different

injuries An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, or o ...

and disorders with various causes,

medical sign Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...

s and symptoms, methods of

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...

, 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) surrounding the brain or spinal cord leaks out of one or more holes or tears in the dura mater. A cerebrospinal fluid leak can be either cr ...

, which results in intense headaches that are localised underneath the crown. Other diseases include meningioma, 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'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

, 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 The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...

and the

parietal bone The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is nam ...

s are separated by a range of fibrous joints 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. It ...

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'', meanin ...

, 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 a ...

branches from the common external carotid artery 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 in the cir ...

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 cap ...

, 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 overlies the occipital lobes of the cereb ...

and laterally on both sides to the

temples A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...

. 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 feathers that make up the crest determines the bird's emotions and courtship behaviors. For instance, bird species such as the northern cardinal 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, or brain-pan 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 calvaria or skul ...

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. ...

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, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

, and skull aim to protect the frontal lobe, located behind the forehead. 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 (CSF 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, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

image of parts of the skull including the crown. Health professionals offer treatments to manage the symptoms associated with the disease. For example, consuming fluids such as water aims to stop excess leakage and reduce headaches, and antibiotics are also provided if signs of

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

are clear such as

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

and chills.

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

epileptic seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

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 th ...

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 ...

. Diagnosis is made via imaging tests such as magnetic resonance imaging (MRI) which involves high-frequency radio waves and a strong magnetic field allowing for the measurement of protons in the water. The treatments involve surgery to remove the tumor from the patient's meninges and the extent of the surgery depends on the

size Size in general is the magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to linear dimensions ( length, width, height, diameter, perimeter), area, or volume. Size can also be m ...

and aggression of the meningioma. Cleidocranial2

Fractures

Bone fractures 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. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

, memory loss, concussion,

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 close ...

, 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, overwo ...

. 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, urethra, vag ...

results in the build-up of pressure in the skull since it is an enclosed cavity and thus pushes the brain to the brainstem opening leading to a coma. 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 A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

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

Gorham Disease

Gorham disease 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 prov ...

including the crown of the skull. The chronic disorder involves the progressive loss of bone, although, symptoms such as intense pain 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 remodeling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated pro ...

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 A deformity, dysmorphism, or dysmorphic feature is a major abnormality of an organism that makes a part of the body appear or function differently than how it is supposed to. Causes Deformity can be caused by a variety of factors: *Arthritis an ...

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 to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...

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 residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

, 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 are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians ( monkeys and apes, the latter including ...

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

archaic human A number of varieties of '' Homo'' are grouped into the broad category of archaic humans in the period that precedes and is contemporary to the emergence of the earliest early modern humans (''Homo sapiens'') around 300 ka. Omo-Kibish I (Omo I) f ...

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 pro ...

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 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. 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 is a public research university in Athens, Ohio. The first university chartered by an Act of Congress and the first to be chartered in Ohio, the university was chartered in 1787 by the Congress of the Confederation and subseq ...

Heritage College of Osteopathic Medicine)
Head Injury
(

Columbia university Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

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