how nostrils regulate the temperature with the help of blood vessels
Answers
Explanation:
The nasal cavity refers to the interior of the nose, or the structure which opens exteriorly at the nostrils. It is the entry point for inspired air and the first of a series of structures which form the respiratory system. The cavity is entirely lined by the nasal mucosa, one of the anatomical structures (others include skin, body encasements like the skull and non-nasal mucosa such as those of the vagina and bowel) which form the physical barriers of the body’s immune system. These barriers provide mechanical protection from the invasion of infectious and allergenic pathogens.

Anatomy of the nasal cavity
The nasal cavity extends from the external opening, the nostrils, to the pharynx (the upper section of the throat), where it joins the remainder of the respiratory system. It is separated down the middle by the nasal septum, a piece of cartilage which shapes and separates the nostrils. Each nostril can be further divided into roof, floor, and walls. The nasal cavity can be divided into the vestibule, respiratory and olfactory sections.
Nasal vestibule
The nasal vestibule is the dilated area at the nostril opening.
Respiratory section
The respiratory section of the nasal cavity refers to the passages through which air travels into the respiratory system. The respiratory section of each nostril contains four conchae (protrusions or bumps) which are also referred to as turbinate bones or lobes and are covered by the nasal mucosa. Underlying these conchae are meatuses (passages to interior body structures). The meatuses of the nasal cavity connect to the paranasal sinuses.
Olfactory region
The olfactory receptors (receptors for smell sensations) are found in this section of the nasal cavity. Bowman’s glands are also found in this section of the nasal cavity.
Surrounding structures
Para-nasal sinuses
The nasal cavity is surrounded by a ring of paranasal sinuses and meatuses in the nasal cavity connect to these structures. The sinuses develop as outgrowths of, and drain into, the nasal cavity. The mucosa of the sinuses connects to the nasal mucosa.
Nasolacrimal ducts
Nasolacrimal ducts are the ducts which connect the lacrimal (tear) ducts in the eye to the nasal cavity.
Oral cavity
The nasal cavity is separated from the oral cavity (interior of the mouth) by the hard palate.

For more information about the other sections of the respiratory system and how they work, see Respiratory System.
Anatomy of the nasal mucosa
The nasal mucosa, also called respiratory mucosa, lines the entire nasal cavity, from the nostrils (the external openings of the respiratory system) to the pharynx (the uppermost section of the throat). The external skin of the nose connects to the nasal mucosa in the nasal vestibule. A dynamic layer of mucus overlies the nasal epithelium (the outermost layer of cells of the nasal mucosa).
The initial one-third of the nasal cavity is lined by stratified squamous epithelium (smooth epithelium consisting of flat surfaced cells), several cell layers thick. The outmost layer of squamous cells overlies a layer of proliferative cells (cell which divide and replicate to form new cells) which is attached to a basement membrane, a network of tough fibres which supports the epithelium.
The posterior two-thirds of the cavity is lined with pseudostratified columnar ciliated epithelium (a type of epithelium in which cells arrange themselves in columns and project tiny hairs called cilia) containing goblet cells (mucus producing cells), and which overlies a basement membrane.
The nasal sub-mucosa underlies the basement membrane. This layer is made up of glands which secrete watery substances and mucus, nerves, an extensive network of blood vessels and cellular elements like blood plasma. The entire mucosa is highly concentrated with blood vessels and contains large venous-like spaces; bodies which have a vein-like appearance and swell and congest in response to allergy or infection.
Mucosa of the olfactory system
Unlike other nasal mucosa, the epithelium of the olfactory system does not project cilia. This mucosa contains nerves which connect to the olfactory nerve.
Physiology of the nasal cavity
The nasal cavity functions to allow air to enter the respiratory system upon respiration. Structures within the cavity regulate the flow of air and particles it contains. The olfactory region of the nasal cavity regulates the sense of smell.
Conchae (turbinate bones)
The conchae (turbinate bones) of the nasal mucosa expand the total surface area of the mucosa and create turbulence in air entering the respiratory passage. This causes air to swirl as it moves through the nasal cavity and increases contact between infiltrating air and the nasal mucosa, allowing particles in the air to be trapped before entering other parts of the respiratory system (e.g. the lungs).
Olfactory system
The olfactory system functions to process sensory information related to smell.
Explanation:
there are tiny blood vessels in nose...they regulate the temperature if the nostrils as a part of homeostatic control of metabolism