The middle temporal artery is a small branch of the superficial temporal artery, which itself arises from the external carotid artery. It supplies blood to the temporalis muscle and parts of the scalp.
Location
The middle temporal artery originates from the superficial temporal artery just above the zygomatic arch, near the anterior part of the external ear. From its origin, the artery courses superiorly and posteriorly, passing beneath the temporalis muscle, which it supplies. It travels between the skin and the temporalis muscle in the temporal region of the head. Along its path, the middle temporal artery gives off branches that contribute to the vascular supply of the scalp and sometimes anastomoses with branches of the deep temporal arteries from the maxillary artery.
Structure and Anatomy
Origin
The middle temporal artery arises from the superficial temporal artery, a terminal branch of the external carotid artery. It typically originates just above the zygomatic arch, close to the anterior portion of the external ear. This location places the artery in the temporal region, where it contributes to the blood supply of the scalp and the temporalis muscle.
Course
After its origin, the middle temporal artery ascends obliquely, running toward the temporalis muscle, a fan-shaped muscle on the side of the head that is involved in mastication (chewing). The artery passes superiorly and posteriorly, traveling deep to the fascia of the temporalis muscle. As it progresses, the middle temporal artery runs between the skin and the superficial layers of the temporalis muscle. In its course, it remains relatively superficial but is protected by the temporalis fascia and muscle layers.
Branches
The middle temporal artery gives off small branches that supply blood to surrounding tissues. Some of the key branches include:
- Muscular Branches: These branches supply the temporalis muscle, ensuring that the muscle fibers receive adequate oxygen and nutrients for their function in jaw movement and mastication.
- Scalp Branches: As it courses through the temporal region, the middle temporal artery sends small branches to supply the scalp. These branches provide oxygenated blood to the skin and subcutaneous tissues of the scalp, contributing to the overall vascularization of the scalp, particularly in the region over the temporalis muscle.
Anastomoses
The middle temporal artery forms important anastomoses (connections) with other arteries in the region, ensuring collateral circulation. Key anastomoses include:
- Deep Temporal Arteries: The middle temporal artery frequently anastomoses with the deep temporal arteries, which arise from the maxillary artery (another branch of the external carotid artery). The deep temporal arteries also supply the temporalis muscle and nearby structures. This connection provides a robust vascular network to the muscle, ensuring it remains well-nourished even if blood flow from one source is reduced.
- Other Scalp Arteries: The middle temporal artery also forms anastomoses with smaller branches of other scalp arteries, including those arising from the occipital artery and posterior auricular artery. These connections help create a dense blood supply to the scalp, particularly in the temporal region.
Termination
The middle temporal artery terminates in the temporalis muscle and scalp, where its branches supply the muscle fibers and overlying skin. Its course provides extensive blood flow to the temporalis muscle and contributes to the overall vascular supply of the lateral scalp.
Surrounding Structures
As it travels through the temporal region, the middle temporal artery is closely related to several important anatomical structures:
- Zygomatic Arch: The artery originates just superior to the zygomatic arch, a bony structure that forms part of the cheekbone. The proximity to the zygomatic arch makes the artery accessible during certain surgical procedures involving the temporal region.
- Temporalis Muscle: The artery runs deep to the temporalis fascia and supplies the temporalis muscle, a key muscle involved in the elevation and retraction of the mandible (jaw). The artery’s relationship to the temporalis muscle is crucial for providing the necessary blood supply to support the muscle’s function.
- Superficial Temporal Artery: The middle temporal artery is a branch of the superficial temporal artery, which continues its course upward to supply the scalp and forehead. The middle temporal artery remains relatively close to its parent vessel during its course.
- Deep Temporal Arteries: These arteries, arising from the maxillary artery, run in close proximity to the middle temporal artery as they also supply the temporalis muscle.
Fascia and Muscle Layers
The middle temporal artery travels deep to the temporalis fascia, which provides a protective covering over the temporalis muscle. The artery’s course places it between the muscle layers and the overlying skin, allowing it to supply both the muscle and the superficial tissues of the scalp.
Relationship with Nearby Nerves
The middle temporal artery is located near several important nerves in the temporal region, particularly:
- Auriculotemporal Nerve: This nerve, a branch of the mandibular nerve (a division of the trigeminal nerve), runs in proximity to the middle temporal artery as it courses through the temporal region. The nerve provides sensory innervation to the scalp in the area around the ear and temple, and its close relationship to the artery is important in surgical considerations.
- Facial Nerve (Temporal Branches): The temporal branches of the facial nerve, which innervate the muscles of facial expression, run near the middle temporal artery. These branches are important in facial movement and may be at risk of damage during surgical procedures involving the temporal region or the middle temporal artery.
Blood Supply to the Temporalis Muscle
The middle temporal artery is a key supplier of blood to the temporalis muscle. The muscle, which spans the temporal fossa and attaches to the coronoid process of the mandible, is one of the major muscles involved in chewing and jaw movement. The blood supplied by the middle temporal artery ensures that the muscle can function efficiently during mastication and other jaw movements. This blood supply is further supported by the anastomoses with the deep temporal arteries, forming a robust vascular network that supports the high metabolic demands of the temporalis muscle.
Blood Supply to the Scalp
In addition to its role in supplying the temporalis muscle, the middle temporal artery contributes to the blood supply of the scalp, particularly the lateral aspect of the scalp overlying the temporalis muscle. By forming anastomoses with nearby arteries, the middle temporal artery helps maintain the health and integrity of the scalp tissues, supporting hair follicles, skin, and subcutaneous structures in the region.
Variations
The anatomy of the middle temporal artery can show variations in terms of its origin and course. In some individuals, the artery may arise from a different location on the superficial temporal artery or may have variations in the size of its branches. These anatomical variations are important considerations during surgical procedures in the temporal region, such as temporal muscle biopsies or reconstructive surgeries.
Surrounding Vascular Structures
The middle temporal artery is situated near other important vascular structures, including:
- Superficial Temporal Artery: The parent vessel of the middle temporal artery, the superficial temporal artery continues its upward course to supply the scalp and forehead.
- Maxillary Artery: The deep temporal arteries, which arise from the maxillary artery, form anastomoses with the middle temporal artery, ensuring a strong blood supply to the temporalis muscle.
Function
Blood Supply to the Temporalis Muscle
The primary function of the middle temporal artery is to provide oxygenated blood to the temporalis muscle, one of the main muscles involved in mastication (chewing). The temporalis muscle plays a crucial role in elevating and retracting the mandible (lower jaw), enabling efficient chewing and biting. By supplying the muscle with blood, the middle temporal artery ensures that the muscle receives the oxygen and nutrients required for its function. The artery’s role in nourishing the muscle supports the high metabolic demands of this active muscle, especially during vigorous jaw movements.
The muscular branches of the middle temporal artery distribute blood to different areas of the temporalis muscle, ensuring that the entire muscle mass is well-supplied. This is particularly important during periods of muscle contraction, where oxygen consumption increases, and a steady blood supply is essential for maintaining muscle performance and endurance.
Collateral Blood Supply to the Temporalis Muscle
The middle temporal artery forms an important part of the collateral blood supply to the temporalis muscle through its anastomoses with the deep temporal arteries, which arise from the maxillary artery. This collateral network provides a secondary route for blood flow in case one of the arteries becomes blocked or compromised. This redundancy ensures that the temporalis muscle continues to receive adequate blood supply, even if there is a disruption in the blood flow from one of its primary sources.
By maintaining this collateral circulation, the middle temporal artery helps protect the temporalis muscle from ischemic injury or reduced function in cases of trauma or vascular compromise. This is particularly relevant during surgical procedures in the temporal region, where damage to the deep temporal arteries might occur.
Blood Supply to the Scalp
In addition to supplying the temporalis muscle, the middle temporal artery contributes to the blood supply of the scalp in the temporal region. It provides small branches that nourish the skin, hair follicles, and subcutaneous tissues of the scalp. This blood supply is essential for maintaining the health of the scalp, ensuring that the skin remains nourished and that hair growth is supported.
The artery also helps supply the connective tissues and fascia in the temporal region, which support the scalp and provide structural integrity to the area. By forming anastomoses with other scalp arteries, such as the superficial temporal, posterior auricular, and occipital arteries, the middle temporal artery plays a role in creating a rich vascular network that sustains the scalp’s health and functions.
Contribution to Thermoregulation
The middle temporal artery also plays a role in thermoregulation of the scalp by adjusting blood flow in response to changes in temperature. During periods of physical activity or exposure to high temperatures, increased blood flow through the middle temporal artery helps dissipate heat from the scalp and head. Conversely, in colder environments, blood flow may be reduced to conserve body heat. This regulation is important for maintaining a stable internal temperature, particularly in the head, where temperature changes can affect cognitive and sensory functions.
Nutrient Delivery and Waste Removal
Like all arteries, the middle temporal artery plays an essential role in the delivery of nutrients and removal of waste products in the tissues it supplies. The artery provides oxygen, glucose, and other essential nutrients to the temporalis muscle and scalp tissues, ensuring that these areas can function efficiently. In turn, the artery helps remove carbon dioxide, lactic acid, and other metabolic byproducts generated during muscle activity.
This constant exchange of nutrients and waste products supports the metabolic health of the temporalis muscle, allowing it to function during periods of sustained activity, such as chewing or clenching the jaw. The removal of waste products is also crucial in preventing muscle fatigue and cramping.
Contribution to Jaw Movement and Mastication
Through its role in supplying the temporalis muscle, the middle temporal artery indirectly supports jaw movement and mastication. The temporalis muscle is one of the key muscles involved in the elevation and retraction of the mandible, movements necessary for effective chewing, biting, and grinding of food. By ensuring that the muscle receives an adequate blood supply, the middle temporal artery allows the muscle to perform these functions efficiently.
The blood supply from the middle temporal artery helps the muscle maintain endurance during prolonged chewing or when forceful jaw movements are required, such as during the consumption of tough or fibrous foods. Without this blood supply, the temporalis muscle would be unable to sustain these movements over time, leading to muscle fatigue or weakness.
Facilitation of Tissue Repair and Healing
The middle temporal artery plays a role in tissue repair and healing by delivering essential blood flow to the temporalis muscle and scalp. In the event of injury, trauma, or surgery in the temporal region, the artery provides the necessary nutrients and oxygen to support the repair of damaged tissues. Adequate blood supply is critical for tissue regeneration, wound healing, and preventing complications such as infection or scarring.
In cases where the temporalis muscle is injured or strained, the artery’s blood supply helps facilitate muscle recovery and healing by delivering growth factors and immune cells to the injured area. This process ensures that the muscle can heal and regain its normal function over time.
Support for Hair Growth and Scalp Health
By supplying the scalp in the temporal region, the middle temporal artery plays a role in supporting hair growth and maintaining scalp health. Hair follicles rely on a steady blood supply to receive the nutrients and oxygen required for the production of new hair. The artery’s role in delivering these nutrients ensures that hair growth is sustained and that the scalp remains healthy.
The small branches of the middle temporal artery that supply the scalp help nourish the skin and subcutaneous tissues, ensuring that the scalp remains hydrated and well-maintained. Adequate blood flow to the scalp also supports the skin’s natural regenerative processes, allowing it to heal from minor injuries and remain elastic and resilient.
Clinical Significance
The middle temporal artery is clinically significant due to its role in supplying blood to the temporalis muscle and the scalp. Its superficial location near the zygomatic arch makes it relevant in various surgical and diagnostic settings.
Surgical Considerations
During temporal region surgeries or procedures involving the temporalis muscle, such as temporal muscle biopsies or craniofacial reconstructions, the middle temporal artery must be carefully managed to avoid excessive bleeding. Damage to the artery could disrupt the blood supply to the muscle and scalp, leading to complications in healing.
Scalp Lacerations and Trauma
In cases of scalp trauma, especially in the temporal region, the middle temporal artery may be damaged, resulting in significant bleeding. Prompt control of the bleeding is important due to the rich vascularization of the scalp.
Vascular Complications
Rarely, the middle temporal artery can be involved in vascular conditions, such as arteriovenous malformations (AVMs) or aneurysms in the temporal region. In such cases, careful diagnostic imaging and possible embolization or surgical intervention may be required to manage the condition.
Temporal Headaches
The artery’s location and course can make it a site of irritation or pressure in certain types of temporal headaches or migraine conditions, where blood vessel dilation plays a role in the headache’s pathophysiology.
