Features of the dental system of mammals practical work. §52. The internal structure of mammals. III. Watching the arrival of birds in spring

Task 1. Perform laboratory work.

Topic: "The structure of the skeleton of mammals."

Objective: study the structural features of a mammal.
3. Color the bones of the mammalian skeleton (purple for the skull bones, green for the spine, blue for the forelimbs, brown for the forelimbs, red for the hind limbs, yellow for the hind limbs) and label them.

4. Write down the conclusion about the structural features of the skeleton of mammals.

Task 2. Fill in the table.

Task 3. Color the systems of the internal organs of a mammal (red - circulatory organs, green - digestive system, blue - respiration, brown - excretion, black - reproduction) and label them.

Task 4. The amount of food eaten during the day by a small mammal - a shrew, exceeds its body weight by 2-4 times. A tiger, weighing 250-300 kg, is content with 10-12 kg of meat per day. Why is there such a discrepancy in the amount of food eaten by different animals?

Task 1. Perform laboratory work.

Subject: "The structure of the skeleton of mammals".

Objective: study the structural features of the skeleton of mammals.

1. Make sure that the workplace has everything you need to complete the lab.

2. Using the instructions given in paragraph 52 of the textbook, complete the laboratory work.

3. Color the bones of the mammalian skeleton (purple for the skull bones, green for the spine, blue for the forelimbs, brown for the forelimbs, red for the hind limbs, yellow for the hind limbs) and label them.

4. Write down the conclusion about the structural features of the skeleton of mammals.

The structure and activity of the systems of internal organs of mammals testifies to their more perfect progressive development: intensive metabolism, constant high body temperature. Comparison with birds shows their independent and parallel historical development.

Task 2. Fill in the table.

The structure and functions of the skeleton of mammals (rabbit)
Department of the skeleton	Structural features	Functions
Scull	large, smaller bones than reptiles	protection of the internal organs of the head
Spine: cervical region chest, ribs, sternum lumbar sacral tail section	seven vertebrae twelve vertebrae six, seven vertebrae four fused vertebrae different number of vertebral bones	protection and support
Forelimb belt Forelimbs Rear limb belt Hind limbs	paired shoulder blades, paired clavicles 2 large pelvic bones	movement, support

Task 3. Color the systems of internal organs of a mammal (red - blood organs, green - digestive system, blue - respiration, brown - excretion, black - reproduction) and label them.

Task 4. The amount of food eaten during the day by a small mammal - a shrew, exceeds its body weight a 2-4 times. A tiger, weighing 250-300 kg, is content with 10-12 kg of meat per day. Why is there such a discrepancy in the amount of food eaten by different animals?

Because the shrew has a very fast metabolism, the heart beats faster than the heart of a tiger. Therefore, the shrew needs to constantly eat.

Task 5. Fill in the table.

The structure and functions of the systems of internal organs of a mammal
Organ system	Structural features	Functions
digestive	mouth, pharynx, teeth, esophagus, stomach, intestines, large intestine	digestion
Respiratory	pathways, lungs, trachea, larynx	supply of oxygen to the body and excretion carbon dioxide
circulatory	four-chambered heart: 2 ventricles and 2 atria	transport of nutrients throughout the body
nervous	forebrain, spinal cord	responsible for the senses, touch, smell
excretory	kidneys, ureters, bladder	excretion of metabolic products

Subject: Biology class: 7 Lesson number: 57 date:

Subject: general characteristics class. Mammal habitats. Features of the external and internal structure. Complication of the structure of the integument, digestive, respiratory, circulatory, excretory, nervous systems, sense organs, behavior in comparison with reptiles.

laboratoryand Iworksa No. 11.

observation of live animals. External building. The study of the structure of the skeleton of a mammal. The study of the internal structure of the finished wet preparations.

Target: Create conditions for the qualitative assimilation of material about mammals; to expand students' understanding of the diversity of the animal world; to acquaint with the general characteristics and distinctive features of animals of the class mammals; instill interest in the subject, cultivate diligence and accuracy when performing tasks in a notebook; develop independent skills academic work; continue the formation of the ability to work with a textbook and notebook, find the necessary information in the text to answer questions, compare, draw up tables and diagrams, draw conclusions; develop students' communication skills through dialogue.

Lesson type: combined

Pedagogical technologies: development critical thinking, problem-developing training

Equipment: presentation, interactive whiteboard, projector

Expected Result: students are able to characterize the Mammals class; know distinctive features class; are able to compare new class animals with previously studied; are able to describe the external and internal structure; actively participate in the dialogue, compare, generalize, draw conclusions; carefully, independently perform the tasks proposed by the teacher.

DURING THE CLASSES

Lesson stages	Teacher activity	Student activities	Notes
I. Organizing time	1. Organization of students' activities and a positive emotional mood for further creative work in class. 2. Voicing the lesson plan.	1. Full readiness of the class for work.
II. Updating knowledge, checking the assimilation of the studied material about birds	1. Compose 3 questions on the studied material "Class of a bird" 2. Competition of connoisseurs of birds. 3 people each go to the blackboard, answer the questions of the class. 3. Summing up the results of the stage.	1. Work on drafting questions 2. Competition for best question 3. Formulate conclusions.
III. Learning new material.	1. Motivational stage. Ensuring the motivation of students. 2. Sounding the topic of the lesson, organization to determine the goals of the activity in the lesson. Exercise: Consider photographs of animals, determine which class they belong to? Justify your answer. Creating a problem situation: why are mammals at the highest stage of development compared to other chordates? 1. General characteristics of the class Mammals: Mammology, teriology About 4 thousand species. Warm-blooded animals, coat. Live birth. Feeding babies with milk. Large brain (front hemispheres are well developed). Diverse and complex behaviour. They have different adaptations to their habitats. Tooth differentiation. The presence of an external ear. The presence of various glands. 2. Work with the textbook, p. 224. Living environments mammals: air, water, land-air, soil. 3. Learning new material using existing knowledge, working with a textbook Laboratory work №11 The study of the external and internal structure of mammals. GOAL: WORKING PROCESS: 6. Draw a conclusion.	2. Write down the topic of the lesson in notebooks. 3. Joint definition of lesson objectives 1. Work with the text of the textbook p. 224 choose characteristics mammals. Write down the definitions of the mammalian sciences. 2. Determine the features of the adaptability of animals to the environment. 3. Self-study new material, perform laboratory work.
IVSummarizing. Primary fastening	1. Summing up the results of laboratory work. 2. Comparison of birds and mammals, identification of distinctive features and signs of complication.	1. Participate in a conversation, formulate conclusions. 2. Reveal the distinctive features of mammals, signs of complication.
VSumming up the lesson. Reflection	The method of unfinished sentences: 1. At the lesson I worked _______ 2. With my work in the lesson, I ___________ 3. The lesson seemed to me _________ 4. For the lesson I _______ 5. The material of the lesson was _______ My mood:	Express their opinion about the lesson and their role in the lesson.
VIHomework	$61, abstracts, posts about birds, mammals	write down homework, grading

Lab #11

TOPIC: Observations of live animals. External building. The study of the structure of the skeleton of a mammal. The study of the internal structure of the finished wet preparations.

PURPOSE: to study the structural features of mammals and their skeleton

EQUIPMENT: illustrations of various representatives of the class Mammals, drawings of the textbook

WORKING PROCESS:

List the main characteristics of mammals. Determine their habitat. What science studies the Mammals class?

Study the external structure of mammals. Describe the shape of the body and indicate what departments it consists of.

What is the structure of the skin of mammals? What is the importance of the coat in the life of an animal?

Examine the head of a mammal. Determine which organs are located on it. Name the organs by which the animal navigates the environment.

Study the structural features of the skeleton of mammals. Make a drawing of the dog's skeleton, label the main parts of the skeleton.

Make a conclusion.

The structure of the skeleton of a dog

Musculoskeletal system. The skeleton of mammals consists of the same sections as those of other terrestrial vertebrates: the skull, spine, trunk skeletons, belts and free limbs (Fig. 193).

Rice. 193. Skeleton of a mammal: 1 - upper jaw; 2 - lower jaw; 3 - skull; 4 - teeth; 5 - cervical vertebrae; 6 - thoracic vertebrae; 7 - lumbar vertebrae; 8 - tail vertebrae; 9 - ribs; 10 - scapula; 11 - shoulder; 12 - forearm; 13 - brush; 14 - pelvic bone; 15 - thigh; 16 - lower leg; 17 - foot

The bones of mammals are strong, many grow together. The skull is large, consists of a smaller number of bones than in reptiles, since many fuse even in the embryonic period. The jaws are strong, armed with teeth, which are located in the recesses - the alveoli.

The spine consists of the following five sections: cervical (seven vertebrae), thoracic (twelve vertebrae), lumbar (six to seven vertebrae), sacral (four merged vertebrae) and tail section from a different number of vertebrae in different mammals. The vertebrae are massive, with flattened surfaces of the bodies. The ribs are attached to the vertebrae of the thoracic region, some of them are connected to the sternum, forming the chest. The girdle of the forelimbs consists of paired clavicles and paired shoulder blades. The bark-coids (crow bones) are reduced in most animals. In horses and dogs, in which the legs move only along the longitudinal axis of the body, the clavicles are also reduced. The girdle of the hind limbs (pelvic girdle) consists of two large pelvic bones. Each of them arose from the fusion of the pubic, ischial and ilium bones. The pelvic bones fuse with the sacrum.

Mammals have a complex system of muscles. The muscles that move the limbs are the most developed. They begin on the bones of the belts and are attached to the bones of the free limb. Long tendons fit the bones of the foot and hand, which ensures good mobility of the limbs, expanding their adaptive (adaptive) capabilities.

The intercostal respiratory muscles are well developed, the contraction of which raises and lowers the chest. There are muscles that connect to the skin: for example, facial muscles, the contraction of which causes twitching of the skin, movement of the coat, vibrissae.

In all mammals, the chest cavity is separated from the abdominal cavity by a muscular septum - the diaphragm. It enters the chest cavity with a wide dome and is adjacent to the lungs.

Lab #10

Subject. The structure of the skeleton of mammals.

Target. To study the structural features of the skeleton of mammals.

Equipment: tweezers, magnifier, skeleton (and parts thereof) of a rabbit (cat, rat).

Working process

1. Consider general structure skeleton. Find its parts: skeletons of the head, torso, limbs. Pay attention to the connection of the bones with each other.
2. Examine the skeleton of the skull. Pay attention to the size of the braincase, bone connections, differentiated alveolar teeth.
3. Determine the parts of the spine and their structural features.
4. Consider the structure chest, remember its meaning for the animal.
5. Consider the structure of the skeletons of the belts and free limbs - front and rear. Find and name their main parts. Consider muscle attachment points.
6. Find similarities and differences in the structure of the skeletons of mammals and reptiles.
7. Write down your conclusions in a notebook, make the necessary drawings.

Nervous system. The central nervous system of mammals consists of the same departments as in other vertebrates (Fig. 194). The most developed forebrain, which has large hemispheres. The surface of the hemispheres is formed by several layers of nerve cells - the so-called cortex.

Rice. 194. The nervous system of a mammal: A - overall plan structures: 1 - brain; 2 - spinal cord; 3 - peripheral nerves; B - rabbit brain: 1 - olfactory lobes of the forebrain; 2 - hemispheres of the forebrain; 3 - convolutions of the cortex; 4 - diencephalon; 5 - midbrain; 6 - cerebellum; 7 - medulla oblongata

In mammals with relatively simple behavior (rabbits, mice), the hemispheres are smooth, while in predatory mammals and primates with complex behavior, the cerebral cortex has numerous convolutions (folds) and grooves that increase their surface. The large hemispheres of the forebrain cover the diencephalon and midbrain from above. The cerebellum is well developed, where the centers of coordination of movements are located.

The peripheral nervous system, like in other vertebrates, is represented by twelve pairs of cranial nerves (departing from the brain) and numerous nerves extending from spinal cord. Powerful nerve trunks are sent from the spinal cord to the fore and hind limbs.

Of the sense organs in animals, the most developed sense of smell, hearing, vision. The parts of the brain associated with the olfactory, auditory and visual analyzers are well developed.

The more complex structure of the musculoskeletal and nervous systems of mammals, in comparison with reptiles, indicates their progressive development, further differentiation in the vertebrate series, and enormous adaptive capabilities.

Digestive system in mammals it is more complex than in reptiles (Fig. 195). The mouth is surrounded by fleshy lips that make it easier to grab and hold food. The teeth are differentiated (subdivided into groups) into incisors, canines, premolars and molars. Representatives different families they are developed differently depending on the mode of feeding and the nature of the food. So, rodents and hares have well-defined incisors, predators have fangs, etc.

Rice. 195. Internal structure rabbit (female): 1 - trachea; 2 - esophagus; 3 - heart; 4 - lungs; 5-stomach; 6 - caecum; 7 - liver; 8 - spleen; 9 - small intestine; 10 - pancreas; 11 - kidney; 12 - large intestine; 13 - ovary; 14 - uterus; 15 - oviduct; 16 - bladder

Between the teeth and lips is the vestibule of the mouth. Rodents and monkeys have cheek pouches in which they carry food. Animals tear off food and chew with their teeth, abundantly wetting with saliva. Saliva enzymes act on complex sugars (starch, fiber), breaking them down to simpler compounds. The food bolus passes into the pharynx, esophagus and enters the stomach (Fig. 196, A). Most mammals have a simple stomach: it consists of one chamber. In its walls are glands that secrete digestive substances and acid that digest proteins.

Rice. 196. Schemes of the structure of the digestive systems of mammals: A - general plan of the structure (rabbit): 1 - mouth; 2- oral cavity; 3 - pharynx; 4 - esophagus; 5 - stomach; 6 - liver; 7 - pancreas; 8 - small intestine; 9 - large intestine; 10 - caecum: 11 - rectum; 12 - anus; B - the structure of the stomach of a ruminant artiodactyl: 1 - a scar; 2 - grid; 3 - book; 4 - rennet

In ruminant artiodactyls, the stomach is complex, consisting of four sections - a scar, a mesh, a book and an abomasum (Fig. 196, B). Only the last of these is actually the stomach. The previous sections are extensions of the esophagus and serve to ferment food. Here, under the influence of protozoa, bacteria and yeast, indigestible fiber is processed. A cow secretes up to 50 liters of saliva per day, and food from the stomach is periodically burped and chewed with teeth (hence the name "ruminant"). In the intestine, food is exposed to enzymes secreted by the digestive glands located in the intestinal wall and supplied from the liver and pancreas. They affect all food groups: proteins, fats and sugars. Digested food is absorbed in the small intestine, and undigested residues enter the large intestine, where feces are formed and removed to the outside.

Respiratory system consists of the same departments as in reptiles: pathways and lungs (see Fig. 195). The lungs of animals are more complex than those of reptiles, they have a large surface that provides perfect gas exchange.

The trachea divides into two bronchi, which enter the lungs and branch many times here. The thinnest branches are the bronchioles. They end in pulmonary vesicles, or alveoli, whose respiratory surface is 50-100 times larger than the body surface. The alveoli are richly entwined with blood capillaries. This is where gas exchange takes place. Carbon dioxide from the blood is released into the alveoli due to the pressure difference, and oxygen enters the capillaries from the alveoli, combines with the hemoglobin of erythrocytes and is carried by the blood throughout the body. Ventilation of the lungs occurs through inhalation and exhalation. Inhalation occurs due to the contraction of the intercostal muscles and the diaphragm, thereby increasing the volume of the chest cavity. With relaxation of the intercostal muscles and the diaphragm, the volume of the chest cavity and the volume of the lungs decrease - exhalation occurs.

Circulatory system mammals is similar to the circulatory system of birds. The heart is four-chambered: two atria and two ventricles. In the left half of the heart is arterial blood, in the right - venous (Fig. 197).

Rice. 197. Scheme of the structure of the circulatory system of a mammal: 1 - heart; 2 - left aortic arch; 3 - carotid artery; 4 - dorsal aorta; 5 - jugular vein; 6 - pulmonary artery; 7 - pulmonary vein; 8 - posterior vena cava; 9 - capillary network of internal organs

Purely arterial blood from the left ventricle moves through the systemic circulation to all organs and tissues of the body. True, unlike birds, mammals retained not the right, but the left aortic arch. Venous blood from the right ventricle through the vessels of the pulmonary circulation is sent to the lungs, where it is enriched with oxygen. The rapid movement of purely arterial and purely venous blood (especially to the head through the carotid arteries and from the brain through the jugular veins) provides the body with oxygen and quickly removes harmful waste products. This provides a fast metabolism, high and constant body temperature of mammals.

excretory system presented by the kidneys. They are located in the pelvic region and are compact bodies. In the kidneys, the products of protein metabolism are filtered out of the blood: urea and some salts along with water. Through the ureters, urine flows into the bladder and through the urethra is removed to the outside (Fig. 198).

Rice. 198. The structure of the excretory and reproductive systems of mammals - male (A) and female (B): 1 - kidneys; 2 - ureters; 3 - bladder; 4 - testes; 5 - ovary; b - seed ducts; 7 - oviducts; 8 - uterus; 9 - urethra

The structure and activity of the systems of internal organs of mammals testifies to their more perfect, progressive development: intensive metabolism, constant and high temperature body. The comparison of mammals with birds shows their independent and parallel historical development.

Lesson learned exercises

1. What are the similarities and differences in the structure of the integument of the body of mammals and reptiles?
2. List the main features of the structure of the skeleton of the head, torso, limbs associated with the terrestrial lifestyle, with the type of nutrition.
3. Explain how the structure of the cortex differs hemispheres predators and primates from the bark of rodents.
4. Using the example of rodents and ruminants, explain characteristics structures of the digestive system.
5. What complications have occurred in the structure and activity of the systems of internal organs of mammals in comparison with reptiles?

Laboratory workshop on the topic "Mammals"

We have analyzed the biology programs of different authors: N.I. Sonina, I.N. Ponomareva, V.V. Pasechnik.

According to the program edited by N.I. Sonin in the section "Mammals, or animals" provides two laboratory work: "Determining the belonging of mammals to orders", "Identification of adaptations in mammals to the environment." They are held within the same lesson.

According to the program edited by I.N. Ponomareva provides for four laboratory works: “Studying external structure mammal”, “Study of the internal structure of a mammal”, “Identification of adaptations of mammals to the environment”, “Recognition of domestic animals”.

According to the program edited by V.V. Pasechnik, two laboratory works are provided: “The study of the external structure of mammals”, “Identification of structural features of mammals in connection with the lifestyle”. They are held within the same lesson.

Under the laboratory classes mean any kind of independent activity of students. The most clear and reasoned position on this issue is taken by V.F. Shalaev, V.A. Tetyurev, B.V. Vsesvyatsky and V.N. Fedorov. Recognizing laboratory classes as an independent organizational form educational process, they indicate the following characteristic features:

1. Classes are held in classroom or laboratory conditions

2. Students work independently using observational and experimental methods

3. The teacher directs and controls the work of students.

The listed features do not reveal the differences between laboratory classes and other forms. pedagogical process, because they do not reveal the specifics of the observations carried out in these classes. Firstly, observations are carried out both on excursions and in the process of demonstrating the studied animals (in illustrations, dummies, stuffed animals); secondly, not all students' independent observation of the object under study is typical for laboratory classes.

Pedagogical experience shows that when teaching biology, it is advisable to distinguish two types of observations:

1. Contemplative observation, i.e. without affecting the object under study,

2. Effective observation, i.e. accompanied by an impact on the object of study.

For example, contemplative observation in the process of studying mammals is carried out when considering appearance animals, in the process of phenological observations of animal life.

Effective observation in the study of mammals is carried out when examining the internal structure and skeleton, hairline when students perform actions with dummies, they can disassemble them, consider individual parts. The structure of the hairline can be seen under a microscope. Undoubtedly, contemplative observation as a method of independent work is important in teaching biology, students directly, purposefully perceive the distinctive features of the studied natural subject, although they do not influence it. As a result of such observations, students have perceptions, ideas and concepts are formed about the observed phenomena and objects of nature, for example, on excursions into nature, in class lessons when working with natural handouts, as well as when the teacher demonstrates experiments and studied objects.

Next, we will consider the main methods, techniques for conducting laboratory work. Basic methods of conducting independent work- observation, experiments on animals and practical work. We are talking about laboratory, not about independent work.

Conducting independent observations ensures the activity of students and additional interest in studying the subject of biology.

Observational knowledge is usually distinguished by clarity and solidity. In the process of own observations in the performance of laboratory work, interest in the study of animals develops, initiative, accuracy, and responsibility for the work performed are brought up.

Students, through laboratory work, master the skills and scientific methods study of the animal world. Therefore, independent observation of students during laboratory work in biology must be given Special attention.

Experiments with animals

By applying experience as a method of learning, students practice this essential method. scientific research and gradually master it. All this poses a task for the teacher of zoology - to use, as far as possible, independent experimental work of students, including observations and experiments on animals.

Practical work of students

The combination of physical labor with the study of animals is most characteristic of this method. The practical work of students with animals to a certain extent can be considered educational and cognitive work. Therefore, in addition to material value, it also has a great educational value, it teaches children to work, instills in them a love for physical labor, and prepares them for practical activities after graduation.

To organize the activities of students in the performance of laboratory work, it is advisable to divide them into groups (small groups consist of 3-5 people). Each group of students is given a worksheet with an illustration of the studied type of adaptation of organisms and a presentation of problematic information, a training text, with a task and an algorithm for performing the practical part. The content of the proposed worksheets allows not only to create a problem situation, but also to organize the activities of students in understanding the research problem, searching educational information and testing the hypothesis, to obtain, discuss and generalize the results obtained, to stimulate the reflective activity of students.

In the process of studying mammals, the following teaching aids can be used:

· Tables “Type Chordata. Class Mammals.

· Model "Structures of the skull", "Structures of the skeleton".

· Electronic media: illustrated textbook, interactive models - the movement of reptiles.

· Photographs of mammals.

· Drawings and schemes.

Questions and tasks of varying complexity on the topic of the lesson.

When carrying out laboratory work, general-purpose devices are used: a computer measuring unit, a pulse, respiration, temperature sensor; preparations (test tubes): toothless, the internal structure of a rat, pockmark, frog, trion, grass snake, viper, crucian carp, etc. Skeleton models, dummies, laboratory devices: training microscopes, a set for microscopy, a device for comparing carbon dioxide in inhaled and exhaled air, etc.

As an example of a laboratory work that has a research problematic character, we will cite the work in the "Mammals" section on the topic "Identification of the adaptability of organisms to the environment."

The objectives of this laboratory work are as follows:

Creation of conditions for students to understand the concepts of "fitness", "expediency", "adaptation", "relativity of fitness";

Developing interest in learning and scientific information concerning the problem of the diversity of adaptive features in mammals;

· Formation of students' skills to apply knowledge about the evolutionary patterns of the occurrence of adaptation to explain the mechanism of the emergence of a particular fitness, to predict the consequences and formulate conclusions.

The problematic approach to the study of educational content creates conditions for students to put forward hypotheses, versions, arguments, to generalize individual facts in the context of the overall picture of events or processes; to prove their validity or reject them. In the course of searching for information on the problems under study, students are led to independent conclusions and generalizations.

The presentation of the problem situation ends with the following questions and tasks: What do you think is the problem here and how would you formulate the problem question? Formulate a hypothesis explaining this contradiction. How would you test the truth of your own judgment?

Suggested: Carefully consider the objects of study (natural and / or illustrative material). Determine the conditions of habitats that cause the appearance of specific adaptations in objects. describe character traits objects under study, contributing to their adaptation to environmental conditions. Using knowledge about the driving forces of evolution and about the main genetic patterns, the analyzed information, as well as your own observations, describe possible path emergence of specific traits of adaptation.

Assess the feasibility of adapting the objects of study to environmental conditions and justify your opinion.

Of particular importance at the end of the laboratory work are the discussions by all students of the class of the problem task for each group, the solutions of which can also be students from other groups.

Laboratory work on the topic: "The skeleton of a mammal."

Purpose: to study the structural features of the skeleton of mammals.

Equipment and materials:

1. Skeleton of a rabbit, cat or rat (one for two students).

2. Vertebrae from different parts of the body (one for two students).

3. Fore and hind limbs with belts (one for two students).

4. Skulls of insectivores, rodents, carnivores, ungulates (one for two students).

5. Tables: 1. skeleton of a mammal; 2. the structure of the vertebrae from different parts of the body; 3. skull (side and bottom view); 3. The skeleton of the limbs and their belts.

brain skull

Occipital region: occipital bone; occipital foramen; occipital condyles.

Skull sides: squamosal bones with zygomatic processes; zygomatic; maxillary; intermaxillary (anterior); lacrimal; oculocuneate; pterygoid bones.

Skull roof: parietal; interparietal; frontal; nasal bones.

Skull floor: main wedge-shaped; anterior wedge-shaped; rocky; pterygoid; palatines; palatine processes of the maxillary bones; lattice labyrinths; coulter; drum bone; choanae; exit openings for nerves, blood vessels, and the Eustachian tube.

Visceral skull

Lower jaw: dentaries with coronal, articular and angular processes.

Spine

Spine: cervical, thoracic, lumbar, sacral caudal.

The structure of the trunk platycoelous vertebra, atlas and epistrophy.

Thorax: true and false ribs; sternum (handle and xiphoid process).

Limb belts

Forelimb: shoulder; forearm (radius and ulna); brush (wrist, metacarpus, phalanges of fingers).

Hind limb: thigh; lower leg (large and small tibia); foot (tarsus, metatarsus, phalanges).

Sketch:

Skull (side and bottom view)

Laboratory work