Lesson summary “Class Mammals, or Animals General characteristics. External structure

Living environments Aquatic Terrestrial Soil Air

Study the external structure of mammals and fill in the missing words in the proposed text: The body of mammals is covered with _____________ and consists of the same departments as in other vertebrates: ___________, neck, ____________, ___________ and two pairs of _________________. On the head, ____________ and cranial regions are well distinguished. The mouth opening is surrounded by soft _________, and at the end of the muzzle there is _______. Closer to the lateral surfaces of the head are __________, protected by movable ____________, along the outer edges of which there are long ________________.

general characteristics mammals 4. The body is subdivided into the head, neck, trunk, paired fore and hind limbs, tail. The limbs are located under the body, due to which it is raised above the ground, which makes it possible for animals to move at high speed.

Underfur, or undercoat - soft, thick, short hair Long, large, sensitive hair, at the base of which there are nerve fibers that perceive contact with foreign objects. Long, strong, hard guard hairs Perform the function of the organs of touch. They retain heat well, as a lot of air is trapped between this type of hair Protects the skin from damage

Types of skin glands of mammals Sweat Odorous Milky Sebaceous 5. The skin is relatively thick, strong and elastic, covered with hair, well retains the heat produced by the body. The skin contains sebaceous, sweat, milk and odorous glands.

Mammals are the highest warm-blooded, woolly vertebrates. They give birth to live cubs, feed them with milk. They have a large brain with well-developed forebrain hemispheres, organs of smell, sight, and hearing. They are varied and complex behavior. These are the most highly organized vertebrates in evolutionary terms, demonstrating a huge variety of adaptations to conditions. environment. It is known that about 4 thousand modern species, distributed throughout the globe and mastered all habitats.
22 The spine is made up of five sections. There are always seven vertebrae in the cervical region. Musculature is represented by a complex system of differentiated muscles. There is a thoracoabdominal muscular septum diaphragm. Developed subcutaneous muscles provide a change in the position of the hairline, as well as various facial expressions. The types of movement are varied: walking, running, climbing, jumping, swimming, flying. Digestive system highly differentiated. Saliva contains digestive enzymes. In herbivorous animals, the caecum is significantly developed. Most have no cloaca. The heart is four-chambered. All organs and tissues of the body are supplied with pure arterial blood. The respiratory organs of the lungs have a large respiratory surface due to the alveolar structure. In respiratory movements, in addition to the intercostal muscles, the diaphragm also participates. Excretory organs pelvic kidneys. Urine is excreted through the urethra to the outside.

In the body of mammals, the same sections are distinguished as in other terrestrial vertebrates: head, neck, trunk, tail and two pairs of limbs. The limbs have departments typical of vertebrates: shoulder (thigh), forearm (shin) and hand (foot). The legs are not located on the sides, as in amphibians and reptiles, but under the body. Therefore, the body is raised above the ground. This expands the possibilities in the use of limbs. Among the animals known climbing trees, plantigrade and digitigrade animals, jumping and flying.

Rice. 190. Representatives of mammals: 1 - beaver; 2 - cheetah; 3 - dolphin; 4 - macaque; 5 - bat; 6 - antelope

The structural features of mammals allow them to perform a variety of movements, develop great speed when running, fly well, swim in water. This indicates a long evolution of animals and the ability to adapt to a variety of conditions.

In the structure of the head, the facial and cranial sections are clearly distinguishable (Fig. 191). In front is a mouth surrounded by soft lips. At the end of the muzzle there is a nose covered with bare skin with a pair of nasal openings. In front, on the sides of the head, there are eyes protected by movable eyelids, along the outer edges of which are long eyelashes. The lacrimal glands are well developed, the secret of which washes the eyes and has a bactericidal effect. Closer to the back of the head, above the eyes, on the sides of the head, large auricles protrude, which turn towards the source of the sound and allow you to directionally capture it.

Most mammals have a well-developed coat that protects them from sudden changes in temperature - from cooling and overheating.

Rice. 191. External structure mammal: 1 - facial section of the head; 2 - cranial department of the head; 3 - mouth; 4 - nose; 5 - ears; 6 - torso; 7 - front and 8 - hind limbs; 9 - claws

In wool, there are harder and longer guard hairs and short soft hairs that form the undercoat. Long stiff hairs located on the muzzle and performing a tactile function are called vibrissae. Animals periodically molt seasonally: the thickness and color of the coat changes. In winter, the coat is thicker, and in animals living on a snow cover it becomes white. In summer, the coat is sparse and colored in protective dark colors.

The lower end of each hair is immersed in the skin, there is a hair bag around it (Fig. 192), small muscles approach it, so the hair can rise like a frightened cat or a barking dog. At the base of the hair are sebaceous glands. Their secret lubricates the coat, giving it elasticity, reducing wettability and stickiness of the coat. The fur of mammals comes from the same epithelial rudiments as the scales of reptiles. Horny scales located on the tail of rats, mice, and beavers testify to their common origin. This is one of the signs confirming the relationship of mammals and reptiles. Depending on the living conditions, the coat is modified. So, in burrowing animals, there are no guard hairs in the wool, it is short and even, it can fit in any direction without preventing the animals from moving underground. In echidna, hedgehog and porcupine, the awns are modified into hard, sharp needles that serve for protection. The horny formations of the skin of mammals include claws, nails, horns and hooves.

Rice. 192. The structure of the skin of a mammal: 1 - sweat gland; 2 - sebaceous gland; 3 - hair; 4 - hair bag; 5 - body fat; 6 - muscles

There are many glands in the skin of mammals. In addition to the grape-shaped sebaceous glands, which have already been mentioned, there are tubular sweat glands (see Fig. 192). The sweat they produce evaporates, cooling the body of the animal. Many animals have developed scent glands. Their secretions serve to mark their territory, as a warning to enemies and competitors, and facilitate meetings of individuals of the same species.

The mammary glands are important. They are modifications of the sweat glands. Their tubular ducts merge together and open at the top of the nipples. The number of mammary glands usually corresponds to the number of babies. Milk is produced in the mammary glands - a high-calorie product with which mothers feed their young. On this basis, the name of the entire class came about - Mammals.

Mammals are a class of evolutionarily highly developed vertebrates with progressive features: they bear, give birth and feed their young with milk. These signs, combined with an intensive metabolism, constant high temperature body, good developed brain and complex behavior allowed mammals to master all habitats, spread widely across the Earth, achieve great diversity and high numbers.

Lesson learned exercises

1. name common features mammals using figures 190 and 191.
2. What is the structure of the skin of mammals?
3. What are the similarities and differences in the structure of the integuments of the body of mammals and reptiles?
4. What kind horn formations develop from the epidermis of the skin of mammals?
5. What glands are found in the skin of mammals?

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Topic: Habitat and external structure of mammals

The purpose of the lesson: to give a general description of the animals of the Mammals class, to reveal the features of their external structure in connection with the habitat. Show similarities and differences in the external structure of mammals, birds and reptiles.

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Which of these animals belong to the group of mammals and are called animals?

Platypus Horse Porcupine Dolphins Bat Armadillo

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Mammals also vary in size.

Most little animal baby shrew - has a body weighing 2 grams: The largest animal that has ever lived on Earth - the blue whale - has a body weighing 130 tons. The blue whale is 65 million times heavier than the shrew!

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Lifestyle and behavior of animals.

In a platypus, a baby hatches from eggs: \\ A baby kangaroo is born underdeveloped: Newborn foals can follow their mother: Newborn kittens are completely helpless:

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Lifestyle and behavior of animals:

Many animals stay awake all year: And some spend almost half a year in hibernation:

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Complete the task based on the existing knowledge:

1. Remember what life environments are on Earth. Write their names. 2. Sort the following animals by habitat: brown bear, saiga, mole, dolphin, elk, bat, whale, camel, hippopotamus.

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Mammals have now mastered different habitats:

Ground-air Air Soil Water Ground-water

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Ecological groups of mammals:

Aquatic and semi-aquatic mammals have a streamlined body shape or webbed feet:

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Ungulates living in open areas have high slender legs, dense torso, long movable neck:

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Thanks to the variety of adaptations and the wide use of food resources, mammals have gained a dominant position in the animal world.

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Task: Study the features of the external structure of mammals using the text of the textbook (§ 63, p. 2) and answer the questions:

What departments are distinguished in the body of mammals? What organs are located on the head and body of mammals? What are the features of the arrangement of limbs in mammals? What is the body of mammals covered with?

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The location of the limbs of reptiles and mammals: