Major muscle groups. The human muscular system. The main muscle groups of the human body. Objective: to become familiar with the main muscle groups and their functions. Back muscles anatomy presentation

Krasnoturinsk branch

GBPOU "SOMK"

Muscles of the trunk 2016 Nov.

Anatomy and Physiology Teacher

Anfilofieva Yulia Alexandrovna


Plan:

1. Classification of the muscles of the trunk. Back muscles. Fascia of the back.

2. Muscles of the chest. Fascia of the chest. Chest lines.

3. Aperture.

4. Abdominal muscles.

5. Fascia and topographic formations of the abdomen.


1. Muscles of the trunk

M. back M. chest M. abdomen


Back muscles

SURFACE

DEEP

1. Muscles attached to the bones of the upper limb:

1. Long muscles:

  • Trapezoidal m.
  • The widest m.
  • M. scapula lifting
  • Large and small diamond-shaped
  • Belt m. ​​Head and neck
  • M. straightening the spine
  • Transverse spinous m.

2. Muscles attached to the ribs:

2. Short muscles:

  • Rear upper toothed m.
  • Rear lower toothed m.
  • Interspinous m.
  • Transverse m.
  • Suboccipital m.

Trapezius muscle

Start: from the external occipital protuberance, spinous processes of the VII cervical and all thoracic vertebrae

Attachment: acromial end of the clavicle, acromion and spine of the scapula

Function: bringing the scapula closer to the spine, lowering and raising the scapula, tilting the head back


Latissimus dorsi

Start: from the spinous processes of the six lower thoracic and all lumbar vertebrae, from the posterior third of the iliac crest, as well as from the four lower ribs

Attachment: crest of the lesser tubercle of the humerus

Function: lowers and raises the arm, rotates the shoulder inward, with the upper limbs fixed, brings the body closer to them


Large and small rhomboid muscles

Start: small - from the spinous processes of the VII cervical and I thoracic vertebrae, large - from the spinous processes of the II - IV thoracic vertebrae

Attachment: small - the medial edge of the scapula, above the spine, large - the medial edge, below the spine

Function: when both muscles contract, the shoulder blades approach the spine


Back fascia

1. Superficial fascia of the back, located behind the subcutaneous fatty tissue.

2. Own fascia of the back, called the thoracolumbar fascia, it covers the muscles of the back.


2. Muscles of the chest

Own chest muscles

  • External and internal intercostal m.
  • Podcostal m.
  • Transverse chest m.
  • M. lifting ribs

Muscles attaching to bones

  • Large and small chest m.
  • Subclavian m.
  • Front toothed m.

Pectoralis major muscle

Start: the medial half of the clavicle, sternum and cartilage of the five upper ribs, from the anterior wall of the vagina, straight m. abdomen

Attachment: crest of the greater tubercle of the humerus

Function: brings and rotates the shoulder inward, lowers the raised hand, lowers - pulls forward and medially, if the hand is fixed - raises the ribs


Pectoralis minor

Start: outer surface of III - V ribs near their junction with cartilage

Attachment: coracoid process of the scapula

Function: lowers the shoulder girdle and shifts it forward, with a fixed shoulder blade - raising the ribs


External intercostal muscles

Start:

Attachment:

Function: raise the ribs, together with the diaphragm, providing inhalation


Internal intercostal muscles

Start: upper edge of underlying rib

Attachment: lower edge of the overlying rib

Function: lower the ribs, together with the diaphragm, providing exhalation


Breast fascia

1. Superficial fascia, located behind the subcutaneous fatty tissue. In women, it covers the mammary gland, gives out into the depths of her partitions, dividing the gland into lobes.

2. Own fascia of the breast

3. Intrathoracic fascia, covers the inner surface of the walls of the chest cavity.


Chest lines

To determine the boundaries of the internal organs, the following vertical lines are drawn:

1 - anterior midline 1 - anterior axillary 1 - vertebral line

2 - sternum line 2 - paravertebral

3 - parasternal line 2 - mid axillary line

4 - midclavicular line line 3 - scapular line

3 - posterior axillary

line


3. The diaphragm is an unpaired thin muscle that separates the chest and abdominal cavities

Function: the diaphragm is a respiratory muscle. When contracted, it flattens, increases volume chest(the act of inhalation), and when relaxing, it reduces the volume of the chest (the act of exhalation). Contracting simultaneously with the abdominal muscles increases intra-abdominal pressure and constitutes the abdominal press.



Diaphragm

Tendon center

Muscular part

  • Cardiac depression
  • Opening of the inferior vena cava

1. Rib part

2. Lumbar

  • Aortic opening
  • Esophageal opening

3. Sternum


4. Abdominal muscles

Anterolateral group

Back group

1. Long:

  • Square m. Loin
  • Straight m. Abdomen
  • Pyramidalnaya m.

2. Wide:

  • Outer and inner oblique m.
  • Cross m.

Rectus abdominis muscle

Start: xiphoid process of the sternum, cartilage of the V - VII ribs

Attachment: pubic bone

Function: tilts the body forward. It is part of the abdominal muscles and provides intra-abdominal pressure, takes part in the acts of urination, defecation and childbirth


External oblique muscle of the abdomen

Start: outer surface of the eight lower ribs

Attachment: the lower bundles attach to the iliac crest, and the middle bundles form the inguinal ligament

Function: flexion of the spine (with bilateral contraction), rotation of the body in the opposite direction (with unilateral contraction), lowering of the ribs. It is part of the abdominal muscles.


Internal oblique muscle of the abdomen

Start: lumbo-thoracic fascia, iliac crest and inguinal ligament

Attachment: the upper bundles - the cartilage of the three lower ribs, the anterior bundles pass into the aponeurosis, which forms the vagina of the straight m. of the abdomen, the lower bundles - descend along the spermatic cord and are part of the m. lifting the testicle

Function: with a one-sided contraction, it turns the body in its direction. It is part of the abdominal muscles.


Fascia of the abdomen

1. Superficial fascia located behind the subcutaneous fatty tissue.

2. Own fascia, consists of three plates that cover the external and internal oblique muscles, the transverse muscle.

3. Intra-abdominal fascia, lining the inside of the abdominal wall, growing together with the parietal peritoneum.


Topography of the abdomen

  • a - epigastrium
  • b - womb
  • c - hypogastrium
  • 1, 3 - right and left hypochondrium
  • 2 - epigastric region
  • 4 - base area
  • 5, 7 - right and left side area
  • 6 - umbilical region
  • 8, 10 - right and left groin area
  • 9 - pubic region

Anatomical formations of the abdomen

1. The vagina of the rectus abdominis muscle

2. White line of the abdomen (umbilical ring)

3. Inguinal canal

These are "weak points" in which hernias are formed - saccular protrusions of the wall, which may contain internal organs


Check yourself!

1. From the list of muscle names, select the back muscles:

1.pyramidal m.

2.large chest m.

3.belt m. ​​Neck

4.transverse m.

5.m. Lifting scapula

6. subclavian m.

7.the front toothed m.

8. broadest m.

9. subcostal m.

10.Rhomboid m.

11.Outer oblique m.

12.back lower toothed m.

13.trapezoidal m.

14.Intercostal m.

Answer: 3,5,8,10,12,13


2. Find a match between the name of the muscle and its function:

A - brings the shoulder blades closer to the spine

B - lowers and raises the shoulder blades, throws his head back;

B - lowers and raises his hand, rotates the shoulder;

G - lowers the shoulder girdle and shifts it down;

D - turns the body in its direction;

E - tilts the body forward;

F - lowers the raised hand, lowered - pulls forward and medially;

Z - turn of the body in the opposite direction.

1. Large chest m.

2. Small chest m.

3. The widest m.

4. Trapezoidal m.

5. Large and small

diamond-shaped m.

7. Outer oblique m.

8. Internal oblique m.

Answer: 1-f, 2-c, 3-d, 4-a, 5-b, 6-th, 7-z, 8-d


"Human axial skeleton" - Frontal bone. Conclusions from the comparison of human and mammalian skeletons. Examination homework... The number of bones in the human body. Lower limb. Conditions for active familiarization and consolidation by students of the structure of the skeletal departments. Torso skeleton. Spine. Skeleton. Independent work skills. Axial skeleton and skeleton of the limbs.

"Skeleton" - Frame, shape. Earthworm. Hydro skeleton. Frog. What types of skeleton do you know? Turtle. Sea bass. Damage protection. Snail. Bony plates covering the respiratory organs of fish. Cat. Digestive system. Cancer. Sea urchin. Human. Skeleton functions. Skeleton. The likeness of a cylinder. Stem.

"Disorders of the musculoskeletal system" - the state of the musculoskeletal system. The structure of the spine. The degree of preparedness. Cervical scoliosis. The reasons for the increase in the incidence of scoliosis. The importance of the musculoskeletal system. Lumbar sciatica. Flat feet. Lumbar scoliosis. Thoracic scoliosis. Medical examination results. Assessment of the state of ODA of students.

"Physical activity" - Punishing a child by deprivation of a walk is unacceptable! Motor mode. Exercise. Correct physical activity of a person. The motor regime of the child. The change in the magnitude of motor activity in different training quarters was noted. Team games are well disciplined: volleyball, basketball, football.

"The structure of the human skeleton" - Bones differ from each other in shape and structure. 1. Support. Giants and dwarfs. The shape of the bones. The joint is usually reinforced with ligaments. The formation and destruction of bone matter occurs throughout life. The bones are tubular, flat, mixed and airy. Axial skeleton. The endoskeleton (internal skeleton) of a person protects the internal organs.

"Musculoskeletal system" - Activity "Support and movement". Completed by the teacher of biology of the gymnasium 22 Ketukh Aida Genrikhovna. Lesson 1. Musculoskeletal system: composition and functions. ". Types of bones. Written planning and slides are provided for each lesson and activity. Performance. Muscle work. Axial skeleton and skeleton of the limbs.

Slide 1

MUSCLES of our body

Slide 2

2
Our muscles have amazing abilities
In the right situation, we can quickly pick up speed, survive a fall from a great height, lift incredibly heavy objects.

Slide 3

3
It is the muscles that allow the full variety of movements.
A person walks, smiles, talks, eats, jumps, takes different body positions just because he has muscles.

Slide 4

4
Each muscle has its own name. Front view:
1 - the frontal abdomen of the occipital-frontal muscle; 2 - circular muscle of the mouth; 3 - chin; 4 - sternohyoid; 5 - trapezoidal; 6 - three-headed shoulder; 7 - straight abdomen; 8 - external oblique abdomen; 9 - radial flexor of the hand; 10 - stretching the wide fascia of the thigh; 11 - iliopsoas; 12 - scallop, 13 - long leading; 14 - tailor; 15 - straight thighs; 16 - tender; 17 - wide inner; 18 - abductor thumb; 19 - tendons of the long muscle, extending the fingers; 20 - long muscle, extensor fingers; 21 - soleus; 22 - anterior tibial; 23 - gastrocnemius; 24 - wide outer; 25 - short muscle, extensor thumb; 26 - long muscle, abductor thumb; 27 - elbow extensor of the hand; 28 - short radial extensor of the hand; 29 - finger extensor; 30 - long radial extensor of the hand; 31 - brachioradial; 32 - three-headed shoulder; 33 - front toothed; 34 - two-headed shoulder; 35 - large chest; 36 - deltoid; 37 - front staircase; 38 - middle staircase; 39 - sternocleidomastoid; 40 - lowering the angle of the mouth; 41 - chewing; 42 - large zygomatic; 43 - temporal.

Slide 5

5
Back view:
1 - the occipital abdomen of the occipital-frontal muscle; 2- trapezoidal; 3 - deltoid; 4 - three-headed shoulder; 5 - double-headed shoulder: 6 - round pronator; 7 and 23 - brachioradial; 8 - radial flexor of the hand; 9 - long palmar; 10 - elbow flexor of the hand; 11 - superficial flexor of the fingers; 12 and 13 - semi-membranous; 13 - semitendinosus; 14 - tender; 15 - biceps femur; 17 - gastrocnemius; 18 - soleus; 19 - gluteus maximus; 20 - short muscle abducting the thumb; 21 - middle gluteal; 22 - external oblique abdomen; 24-widest back; 25 - front toothed; 26 - large round; 27 - small round; 28 - cavity; 29 - sternocleidomastoid; 30 - belt head; 31 - chewing; 32 - semi-awned head; 33 - temporal.

Slide 6

6
When you move, the muscles in your body stretch and relax. Try to run in place and feel how your muscles are working.

Slide 7

7
To bring a cup to your mouth, you need to strain 70 muscles. When driving a car - 100 muscles. A simple walk uses 200 muscles.

Slide 8

8
A person can store energy that is stored in the muscles. Muscles are like a battery that stores a charge.

Slide 9

9
Muscles are thousands of fibers, millions of threads that are our micromotors.
A person has more than 600 muscles. But each muscle taken separately is useless; several muscles must be contracted.

Slide 10

10
The arm is made up of 27 bones, 30 muscles, and over 30 km of nerve fibers and blood vessels. The well-coordinated work of bones and muscles requires complex brain activity. Arm muscles, for example, are controlled by 4,000 nerves!

Slide 11

11
Even simple hand control is almost half the brain load. This creates many connections between brain cells. However, these connections are absent at birth. This is why a newly born child cannot hold a spoon or walk. He needs to develop the necessary connections in the brain.

Slide 12

12
How is the skill developed?
Every time a football player hits the ball, his brain remembers the time of the hit and the force applied in the muscles. Thanks to this, each next blow is easier. And soon signals from the brain arrive without delay at a speed of 10 thousand cm per second. Thus, automatism is developed.

Slide 13

13
The connection between the muscles and the brain that developed during exercise is strengthened during sleep. Sleep can be as effective as your daytime workout. On average, we spend 6 years of our life sleeping.

Slide 14

14
During exercise, the energy in the muscles is depleted. And then the body switches to another store of energy - fat.
In order to burn fat, the body needs extra air. Under heavy loads, a person begins to breathe heavily. The muscles in the bronchi begin to work hard, then stretching, then contracting.

Slide 15

15
The heart is also a muscle.
Typically, the heart pumps 5-6 liters of blood in 1 minute. The heart of a trained person pumps up to 30 liters per minute! So the organs are better supplied with oxygen and less tired.
It decreases throughout a person's life. The heart provides the movement of blood through the vessels, and the blood delivers all the nutrients to any cell. Contractions of the heart muscle are spontaneous, although they are also regulated nervous system.

Slide 16

16
What happens inside the muscle? How does it work?
You will probably be surprised when you find out that the work of muscle filaments is similar to ... the movement of the caterpillar's legs along a leaf.

Slide 17

17
Look, the red legs seem to be walking along the leaf.
The caterpillar with legs is called the filament myosin, and the leaf on which it crawls is called the filament actin. The paws pull the leaf towards them, and the muscle contracts. One foot is very weak, but the strength of millions of feet can work wonders.

Slide 18

18
There are many of the same threads around them. And these threads are very tightly "packed" in a tube called a sarcomere. Many of these sarcomeres are connected in a muscle fiber, which is covered with a sheath. If we collect several of these fibers, we get skeletal muscle. Why skeletal, you ask? The answer is simple. Because this muscle attaches to the bones of the skeleton and makes them move.
Find the myosin filament and actin filament in the picture.

Slide 19

19
How do muscles attach to bones?
All muscles end in a tendon. A tendon is a dense, fibrous connective tissue. It can resemble a ribbon or lace in shape. The tendon attaches to the bone, firmly fused with the periosteum.

Slide 20

20
Look at the periosteum. This is the "diaper" in which the bone is wrapped. It is to her that the tendon is attached.

Slide 21

21
Different muscles have tendons of different lengths, widths, and shapes. Some muscles have a tendon in the middle of their fiber. Others resemble a feather. By the look of the muscles, people came up with names for them: fusiform, two-headed, two-abdominal, ribbon-shaped, two-finned, single-finned.

Slide 22

22
What needs to be done to make a person grow muscles?
Have you guessed? The body needs to have the necessary elements from which muscles will be built.

Slide 23

23
See how many times a week you need to eat sweets. And how many times meat, vegetables, fruits, bread, cereals, beans. And, of course, you need exercise!

Slide 24

24
Follow these simple rules and your body will be healthy and beautiful.

Slide 25

25
But it also happens. When people do not know the measure either in food or in physical exercise... And then their muscles grow, but not for beauty and health, but to scare and surprise everyone.
The largest biceps measured in one American was 73 cm in circumference. How many hours of your life do you need to spend in the gym to build such muscles?

Slide 26

26
How would you feel next to such a person? And what would you like to talk to him about?

Slide 27

27
What kind of male figure would you like to have?

Slide 28

28
Which of these women is more feminine?

Slide 29

29
In order to be strong and courageous, it is not at all necessary to have such a mountain of muscles. On earth, a huge number of people have simply developed muscles and from this they become attractive. And they have time to work on their inner world, to develop the strength of the spirit.
Both the spirit and the body must develop harmoniously.

Slide 30

30
These people lead healthy image life. See how beautiful their bodies are.

Slide 31

31
Even the most muscular people on our planet are inferior in strength to an ant. If we had the same strength, we could easily lift the car at arm's length!

MUSCLE SYSTEM, a collection of muscles and muscle bundles, usually united by connective tissue. Absent in unicellular organisms and sponges, well developed in vertebrates. The human muscular system includes about 400 skeletal muscles; in an adult, they make up 40% of the body weight. The muscular system is characterized by the following functions: motor, protective, form-building, energy.


Muscle is an organ of the body, consisting of muscle tissue that can contract under the influence of nerve impulses. Muscle is an organ of the body, consisting of muscle tissue that can contract under the influence of nerve impulses. The muscle has a complex structure. It is formed by bundles of muscle fibers, which in turn consist of the muscle fiber nucleus, contractile filaments, integumentary membrane and blood vessels. Outside, the muscle is covered with a connective tissue membrane - fascia. The muscle has a complex structure. It is formed by bundles of muscle fibers, which in turn consist of the muscle fiber nucleus, contractile filaments, integumentary membrane and blood vessels. Outside, the muscle is covered with a connective tissue sheath - fascia. Muscles are attached to bones using tendons. Tendons are composed of dense, fibrous connective tissue and are highly durable. Muscles are attached to bones using tendons. Tendons are composed of dense fibrous connective tissue and are highly durable.


Muscle work Muscles by contracting. Or straining to produce work. Distinguish between dynamic and static work. Joint movement is provided by at least two muscles acting opposite to each other. The nervous system controls the muscles. This work is of a reflex nature.


Characteristics of the main groups of skeletal muscles group Main muscles of function Head muscles: 1. Chewing 2. Mimic Chewing, temporal, external, internal, pterygoid Circular muscles of the mouth and eyes, buccal supracranial Move the lower jaw Open and close the mouth, eyes, change facial expression , verbal articulation Neck muscles (superficial and deep) Subcutaneous dorsal-clavicular, scalene Support and set in motion the head, neck, lower the lower jaw, raise the first and second ribs Back muscles Trapezius, broadest, rhomboid, etc. They set in motion the shoulder blades, head, neck, arms, ribs during breathing, maintain the vertical position of the body. Muscles of the chest Large and small pectorals, anterior dentate, external and internal intercostal They set in motion the shoulder girdle, ribs during breathing Abdominal muscles Oblique, transverse and straight (abdominal), diaphragm Set in motion the torso (inclined forward and to the sides); respiratory movements Muscles of the extremities a) upper; b) lower; Biceps, triceps, deltoid, subscapularis, forearm and hand muscles Sciatica, biceps femoris, gastrocnemius, triceps calf muscles, foot muscles Drive arms Drive legs


Static muscle work is the active fixation of organs relative to each other and giving a certain position to the body, while the muscle develops tension without changing the length. Static muscle work is the active fixation of organs relative to each other and giving a certain position to the body, while the muscle develops tension without changing the length. The dynamic work of muscles is the displacement of some organs relative to others and the movement of the body in space, while the muscle changes its length and thickness. The dynamic work of muscles is the displacement of some organs relative to others and the movement of the body in space, while the muscle changes its length and thickness. Muscle work is associated with energy expenditure. The energy for muscle contractions is provided by the ATP molecule (Muscle work is associated with the expenditure of energy. The energy for muscle contractions is provided by the ATP molecule (




Prolonged muscle tension leads to the development of fatigue. Fatigue is understood as a temporary decrease in muscle performance that occurs as they work. Prolonged muscle tension leads to the development of fatigue. Fatigue is understood as a temporary decrease in muscle performance that occurs as they work. The causes of fatigue are associated with the accumulation of decay products of organic substances at the points of contact: neuron-neuron, neuron-muscle. The causes of fatigue are associated with the accumulation of decay products of organic substances at the points of contact: neuron-neuron, neuron-muscle.


Them. Sechenov found that with rhythmic work, fatigue occurs later, since in the intervals between contractions the muscle rests, intensive muscle work with a heavy load leads to rapid fatigability, average loads and rhythm are most optimal for muscles, and The best way restore muscle performance - active rest (with active activity of other muscles) Sechenov found that with rhythmic work, fatigue occurs later, since in the intervals between contractions the muscle rests, intensive muscle work with a heavy load leads to rapid fatigue, the most optimal for muscles are medium loads and rhythm, and the best way to restore muscle performance is active rest (with vigorous activity of other muscles)














Among the muscles of the head, chewing muscles and facial muscles are distinguished. The chewing muscles include the temporal, chewing, and pterygoid muscles. Contractions of these muscles cause complex chewing movements of the lower jaw. The circular muscles of the eye of the mouth are also among the facial muscles. The mimic muscles are attached to the skin of the face with one and sometimes two of their ends. When they contract, they displace the skin, causing the corresponding facial expressions, that is, one or another facial expression.








The muscles of the trunk include the trapezius, pectoralis minor, rhomboid, serratus anterior and levator scapula, chest, abdomen and back muscles.The muscles located between the ribs, as well as other muscles of the chest, are involved in the function of breathing and are called respiratory. Among them is the diaphragm. Powerfully developed muscles of the chest set in motion and strengthen the upper limbs on the body (large and small pectorals, anterior dentate muscles).




On the back are numerous muscles along the spinal column. These are the deep muscles of the back. They are attached mainly to the processes of the vertebrae. These muscles are involved in the back and side movements of the spinal column. The superficial muscles of the back include the trapezius muscle and the latissimus dorsi muscle. They are involved in the movement of the upper limbs and chest.




The abdominal muscles are involved in bending the spinal column forward The abdominal muscles form the wall abdominal cavity and due to their tone, they keep the internal organs from displacement, lowering, loss. By contracting, the abdominal muscles act on the internal organs as an abdominal press, which promotes the excretion of urine, feces, as well as labor. Contraction of the abdominal muscles promotes the movement of blood in the venous system, the implementation of respiratory movements.


The muscles of the abdominal wall include the rectus abdominis muscle, the pyramidal muscle, the quadratus lumbar muscle and the large abdominal muscles, external and internal oblique and transverse. A dense tendon cord stretches along the midline of the abdomen. This is a white line. On the sides of the white line is the rectus abdominis muscle with the longitudinal direction of the fibers.


The muscles of the girdle of the upper limbs move the upper limb in the shoulder joint. Among them, the most important deltoid muscle. When contracted, this muscle flexes the arm at the shoulder joint and draws the arm to a horizontal position. In the area of ​​the shoulder, there is a group of flexor muscles in front, and in the back of the extensors. Among the muscles of the anterior group are the pseudorhaceus muscle, the posterior triceps muscle of the shoulder. The muscles of the forearm on the front surface are represented by the flexors, on the back by the extensors. Among the muscles are the palmar muscle, the flexors of the fingers.


The muscles located in the girdle of the lower extremities move the leg in the hip joint, as well as the spinal column. The anterior muscle group includes one large muscle, the iliopsoas. Among the posterior-external muscle groups of the pelvic girdle, the gluteus maximus, middle and small muscles. The legs have a more massive skeleton than the arms; their musculature has great strength, but at the same time less variety and limited range of motion.


The longest sartorius muscle in the human body (up to 50 cm) is located on the front of the thigh. She flexes her leg at the hip and knee joints. The quadriceps muscle of the thigh lies deeper than the sartorius muscle, hugging the femur from almost all sides. The main function of this muscle is to extend the knee joint. When standing, the quadriceps muscle prevents the knee joint from bending. Answers: 1. The temporalis muscle. 2. The sternocleidomastoid muscle. 3. Biceps brachii (biceps). 4. Triceps muscle of the shoulder (triceps). 5. Muscles of the extensors of the wrist and fingers. 6. Flexor muscles of the wrist and fingers. 7. Deltoid muscle. 8. Trapezius muscle. 9. Latissimus dorsi muscle. 10. Pectoralis major muscle Rectus abdominis muscle. 12. Oblique abdominal muscle. 13. The gluteus muscle 14. The sartorius muscle 15. The quadriceps muscle of the thigh. 16. Biceps femoris 17. Calf muscle. 18. Achilles tendon

Similar publications