Name: abdominal wall muscles and support
Uploaded: 2025-05-22T09:06:11.000Z
Duration: 1 min 21 s
Channel: JoVE

K12 Standards

Florida Department of Education

High School

Life Science

SC.912.L.14

SC.912.L.14.20

Muscles of the Abdomen

The wall around the abdominal cavity can be divided into anterolateral and posterior regions.
The walls of the anterolateral region comprise five paired muscles. They are classified into the lateral and anterior groups.
Starting from the surface and going inwards, the lateral group has three flat muscles: the external oblique, the internal oblique, and the transversus abdominis.
The internal oblique muscles run perpendicular beneath the superficial external oblique muscles, while the transversus abdominis muscle mainly runs transversely around the abdominal wall.
The aponeuroses of these muscles interlace, forming the linea alba, a vertical band of fibrous connective tissue running from the sternum to the pubic symphysis.
The anterior muscles &#8212; the rectus abdominis and the pyramidalis &#8212; are positioned bilaterally to the linea alba.
The posterior abdominal wall lies between the last thoracic and lumbar vertebrae. Its paired muscles include the quadratus lumborum, psoas major, and iliacus.
While the psoas major and iliacus muscles extend until the lower limbs, the quadratus lumborum muscle spans from the iliac crest to the last rib.

muscles of the abdomen

The abdominal wall encircles the abdominal cavity, providing flexible protection and shielding the internal organs from harm. It is bordered at the top by the xiphoid process and costal margins, at the back by the vertebral column, and at the bottom by the pelvic bones and inguinal ligament. The abdominal wall is divided into two regions &#8212; the anterolateral and posterior regions.
Anterolateral Region
The anterolateral region comprises five paired muscles classified into the lateral and anterior groups. The lateral group consists of three flat muscles &#8212; the external oblique, the internal oblique, and the transversus abdominis. The internal oblique muscles run perpendicular to the superficial external oblique muscles, while the transversus abdominis muscle mainly runs transversely around the abdominal wall. The aponeuroses of these muscles interlace and form the linea alba, a fibrous band of connective tissue running vertically from the xiphoid process of the sternum to the pubic symphysis.
The anterior muscles, specifically the rectus abdominis, and pyramidalis, are positioned bilaterally to the linea alba. The long, flat rectus abdominis muscle extends from the sternum and ribs to the pubic bone. Just beneath the lower portion of the rectus abdominis lies the pyramidalis, a small and often variable muscle that not everyone has. When present, it&#39;s located in front of the rectus abdominis and attaches to the pubic bone and linea alba.
Posterior Region
The posterior abdominal wall is located between the last thoracic and lumbar vertebrae and is made up of paired muscles, including the quadratus lumborum, psoas major, psoas minor, and iliacus. The quadratus lumborum is located deep in the lower back on either side of the lumbar spine. It is a key stabilizer muscle that extends from the iliac crest to the lower ribs and lumbar vertebrae, aiding in maintaining upright posture. The psoas major is a fusiform muscle that runs from the sides of the lumbar vertebrae to the lesser trochanter process of the femur. It works closely with the iliacus, a fan-shaped muscle that merges with the psoas major to form the iliopsoas muscle. Finally, the psoas minor, present in only about half of the population, runs parallel to the psoas major but is a much smaller and thinner muscle. When present, it assists in flexing the pelvis and spine.

The abdominal wall encircles the abdominal cavity, providing flexible protection and shielding the internal organs from harm. It is bordered at the top by ...

Education

JoVE Core

Anatomy and Physiology

Unit 1

The Muscular System

KEY TERMS AND CONCEPTS

abdominal wall muscles and support

The abdominal wall muscles support the abdominal cavity and help protect the internal organs. This flexible wall is bordered by the xiphoid process and costal margins at the top, the vertebral column at the back, and the pelvic bones and inguinal ligament at the bottom. It is divided into the anterolateral region and the posterior region.

The anterolateral region includes five paired muscles in two groups. The lateral group contains the external oblique, internal oblique, and transversus abdominis muscles. The internal oblique runs perpendicular to the more superficial external oblique, and the transversus abdominis wraps mainly across the abdominal wall.

The aponeuroses, or flat tendon-like sheets, of these muscles join together to form the linea alba. This is a vertical band of connective tissue that extends from the xiphoid process of the sternum to the pubic symphysis. The anterior muscles are the rectus abdominis and the pyramidalis. They lie on either side of the linea alba.

The rectus abdominis is a long, flat muscle that extends from the sternum and ribs to the pubic bone. Beneath its lower part lies the pyramidalis. This small muscle is variable, so it is not present in everyone. When it is present, it sits in front of the rectus abdominis and attaches to the pubic bone and linea alba.

The posterior abdominal wall lies between the last thoracic and lumbar vertebrae. It includes the quadratus lumborum, psoas major, psoas minor, and iliacus muscles. The quadratus lumborum is deep in the lower back on both sides of the lumbar spine and helps stabilize posture. It extends from the iliac crest to the lower ribs and lumbar vertebrae.

The psoas major is a fusiform, or spindle-shaped, muscle that runs from the sides of the lumbar vertebrae to the lesser trochanter of the femur. It works with the iliacus, a fan-shaped muscle, and together they form the iliopsoas muscle. The psoas minor runs parallel to the psoas major, but it is smaller and thinner. It is present in only about half of the population and, when present, helps flex the pelvis and spine.

Abdominal Wall Muscles and Support

the muscular system

Muscles, Bones, and Body Movement

The muscular system helps the body move, stay stable, and carry out internal work. It includes three kinds of muscle tissue: skeletal, smooth, and cardiac muscle. Each type has a different role in the body. Skeletal muscles are under conscious control, so people can move them on purpose. They attach to bones by tendons, and their contraction and relaxation make actions like walking and lifting possible. These muscles also produce heat during physical activity, which helps maintain body...

fascicle arrangement in skeletal muscles

How Muscle Fiber Layout Shapes Movement

Skeletal muscle fascicles are bundles of muscle fibers, and their layout helps determine how a muscle moves. The way these fascicles are arranged affects both power and range of motion. Different arrangements give muscles different mechanical strengths. Parallel muscles have fascicles that run parallel to the long axis of the muscle. Common examples are the biceps brachii and the rectus abdominis. When these muscles contract, they shorten and become wider. They can shorten by about 30% of...

muscle coordination and action

Muscles That Work Together in Movement

Muscles work together to create smooth, purposeful movement. Actions such as flexion, extension, adduction, abduction, and rotation depend on this coordination. The body uses several muscles in a controlled way so joints and bones move as needed. Four functional roles help describe how muscles act during movement: agonist, antagonist, synergist, and fixator. An agonist, also called the prime mover, is the main muscle that produces a specific motion. During a bicep curl, the biceps brachii is...

naming skeletal muscles

How Muscles Get Their Names

Skeletal muscle names are built from features that help identify each muscle. The names of the roughly 700 muscles in the human body can point to where a muscle is found, what it looks like, or how it works. That makes the names easier to learn and remember. Many muscle names describe the region of the body. The temporalis muscle is in the head region, while the brachialis is in the arm. Other names describe position and depth. Muscles near the surface may be called externus or superficialis,...

axial and appendicular muscles

Muscles for Movement and Body Support

Skeletal muscles support movement and body structure. They are grouped into axial muscles and appendicular muscles based on where they are found and what they do. Axial muscles lie along the body’s midline. They connect with the axial skeleton, which includes the skull, spine, ribs, and sternum. These muscles help with facial expressions, head and neck movement, speaking, and eating. They also help control movement of the vertebral column with the back muscles. The trunk also contains...

muscles for facial expressions

How Facial Muscles Shape Expression

Facial muscles shape human expression by moving the skin of the face and scalp. These craniofacial muscles are thin skeletal muscles that lie just beneath the skin. They help create the nonverbal signals people use to show emotion and intention. There are about 20 of these muscles. Most begin on bones or fibrous parts of the skull and then extend outward to attach to the skin. They are called muscles of facial expression, or mimetic muscles, because they reflect feelings through movement. <br...

muscles of the eye

Eye Muscles and How They Focus

The eye muscles control movement, focus, and eyelid opening. The human eye uses ten muscles: six extraocular muscles, three intraocular muscles, and one main eyelid retractor muscle. The six extraocular muscles sit around the eyeball and move it in different directions. The lateral rectus pulls the eye outward, and the medial rectus turns it inward toward the nose. The superior rectus and inferior rectus move the eye up and down, while the superior oblique and inferior oblique rotate the eye.

muscles of the anterior neck

Anterior Neck Muscles by Region

The anterior neck muscles are grouped by where they sit in the front of the neck. They include superficial muscles, suprahyoid muscles, and infrahyoid muscles. This layout helps show how the neck muscles are organized around the hyoid bone. The superficial muscles are the most visible muscles in the front of the neck. They include the platysma and sternocleidomastoid, often called the SCM. The platysma is a broad, thin muscle that stretches from the chest and shoulders to the lower jaw and...

muscles that move the head

How Neck Muscles Guide Head Motion

Neck muscles guide head motion by working together to bend, turn, and lift the head. They help with rotation, flexion, extension, and lateral bending. The sternocleidomastoid, or SCM, plus the suprahyoid and infrahyoid muscles are major head flexors. The SCM runs from the sternum and clavicle to the mastoid process of the temporal bone. When both SCM muscles contract, they bend the head forward. When only one side contracts, it bends the head toward that side or turns the head to the opposite...

muscles of the vertebral column

How Back Muscles Support Spine Movement

Back muscles that lie deep to the thoracolumbar fascia are called intrinsic, or true, back muscles. They are grouped into four layers. These layers are the superficial, intermediate, deep, and deepest layers. The superficial layer mainly includes the splenius muscles. These are the splenius capitis and splenius cervicis. They help move the head and cervical spine by supporting extension, rotation, and lateral bending. The splenius capitis runs from the upper thoracic and lower cervical...

muscles of the thorax

How Thorax Muscles Drive Breathing

Thorax muscles help breathing and support movement in the upper body. They also help keep the chest stable. Together, these muscles make the rib cage move while the lungs fill and empty. The diaphragm is the main breathing muscle in the thorax. It is a wide, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. It starts below the rib cage and lumbar vertebrae and attaches to the central tendon. When it contracts, it flattens and moves downward. This increases the...

The abdominal wall muscles support the abdominal cavity and help protect the internal organs. This flexible wall is bordered by the xiphoid process and costal margins at the top, the vertebral column at the back, and the pelvic bones and inguinal ligament at the bottom. It is divided into the anterolateral region and the posterior region. The anterolateral region includes five paired muscles in two groups. The lateral group contains the external oblique, internal oblique, and transversus...

muscles of the pelvic floor and perineum

Pelvic Floor Muscles and Continence

The pelvic floor and perineal muscles support the pelvic organs and help control continence. They also play roles in sexual function, childbirth, and core stability. These muscles are usually divided into a superficial perineal layer and a deeper pelvic floor layer. The perineum is a diamond-shaped area below the pelvic diaphragm. It is split into an anterior urogenital triangle and a posterior anal triangle. The urogenital triangle contains the external genitals and includes the superficial...

muscles of the shoulder

Shoulder Girdle Muscles and Scapula Motion

Shoulder girdle muscles stabilize the clavicle and scapula, and that support helps the humerus move efficiently. Scapular movement also works with humerus movement and extends the arm’s range of motion. Raising the arm overhead depends on upward rotation of the scapula. The anterior thoracic muscles include the serratus anterior, subclavius, and pectoralis minor. The serratus anterior, often called the boxer’s muscle, starts on the first to eighth or ninth ribs and inserts along the superior...

muscles that move the arm

Arm Muscles and Their Movements

Arm muscles move the humerus through flexion, extension, abduction, adduction, and rotation. Nine muscles help produce these arm movements. Two of them, the pectoralis major and latissimus dorsi, come from the axial skeleton. The other seven begin on the scapula and are called scapular muscles. The pectoralis major has two origins, or heads. Its clavicular head starts on the medial half of the clavicle. Its sternocostal head starts on the costal cartilages of ribs 1 through 6, the sternum, and...

muscles that move the forearm

Forearm Muscles for Elbow and Rotation

Forearm muscles help the arm bend, straighten, and rotate at the elbow and radioulnar joints. They are grouped as forearm flexors, forearm extensors, forearm pronators, and forearm supinators. The flexors and extensors act on the elbow joint. The pronators and supinators act on the radioulnar joints. The forearm flexors are the biceps brachii, brachialis, and brachioradialis. The biceps brachii has two heads. Its long head begins at the supraglenoid tubercle of the scapula, and its short head...

muscles of the forearm that move the hand and fingers

muscles-of-the-forearm-that-move-the-hand-and-fingers

Forearm Flexors, Extensors, and Wrist Support

The forearm muscles that move the wrist, hand, and fingers are grouped into anterior and posterior compartments. These muscles work together to bend, straighten, and stabilize the hand and digits. They also connect to the bones of the wrist and hand in organized layers. The anterior compartment contains the flexor muscles. These muscles usually start at the humerus and attach to the carpals, metacarpals, and phalanges. The superficial layer includes the flexor carpi radialis, palmaris longus,...

muscles that move the thigh

Hip Muscles That Move the Thigh

Hip muscles control thigh movement by connecting the pelvic girdle to the femur. The iliopsoas is one key muscle group. It is made of the psoas major and iliacus muscles. Both share a common insertion on the lesser trochanter of the femur. The gluteal muscles also play major roles. The gluteus maximus starts on the posterior ilium, sacrum, coccyx, and thoracolumbar fascia. It inserts on the iliotibial tract and the gluteal tuberosity of the femur. This muscle is the chief extensor of the femur.

muscles that move the leg

Thigh Muscles Behind Leg Motion

Thigh muscles help move the leg through flexion, extension, adduction, and rotation. They are grouped into the anterior, medial, and posterior compartments of the thigh. Each group supports a different part of leg motion at the hip and knee. The anterior compartment includes the quadriceps femoris, the most visible thigh muscle group. It helps extend the leg and flex the thigh. The quadriceps is made of four muscles: vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris.

muscles of the leg that move the foot and toes

muscles-of-the-leg-that-move-the-foot-and-toes

Leg Muscle Groups for Foot Motion

The leg muscles that move the foot and toes are organized into the anterior, lateral, and posterior compartments. Each compartment has a distinct set of muscles with its own actions. Together, they control dorsiflexion, plantar flexion, inversion, eversion, and toe movement. The anterior compartment includes the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and fibularis tertius. The tibialis anterior runs along the lateral surface of the tibia, is easy to feel, and...

key terms and concepts

Learn how the abdominal wall protects organs and how the external oblique, rectus abdominis, quadratus lumborum, and psoas muscles support movement and posture.

Abdominal Wall Muscles and Support | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Animal and Plant Cell Structure

Animal and plant cells not only differ in their structure, function, and mode of nutrition but also in how they reproduce, specialize, and organize into ...

Eukaryotic Evolution

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the ...

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

Chemistry of the Cell

The cell is chemically composed of water, organic molecules and inorganic ions.
Water
The polarity of the water molecule and its resulting hydrogen ...

Describe the scientific theory of cells (cell theory) and relate the history of its discovery to the process of science.

SC.912.L.14.1

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Microtubules

There are three types of cytoskeletal structures in eukaryotic cells&#x2014;microfilaments, intermediate filaments, and microtubules. With a diameter of ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Gap Junctions

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores between ...

The Extracellular Matrix

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, ...

Tissues

Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four main ...

Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For ...

Plasmodesmata

The organs in a multicellular organism&#x2019;s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way ...

What are Membranes?

A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable ...

Membrane Fluidity

Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are ...

Fluid Mosaic Model

The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of ...

What is an Electrochemical Gradient?

Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ...

Diffusion

Diffusion is the passive movement of substances down their concentration gradients&#x2014;requiring no expenditure of cellular energy. Substances, such as ...

Osmosis

Approximately 60% to 95% of the weight of living organisms is attributed to water. Therefore, maintaining appropriate water balance within cells is of ...

Tonicity in Animals

The tonicity of a solution determines if a cell gains or loses water in that solution. The tonicity depends on the permeability of the cell membrane for ...

Tonicity in Plants

Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity ...

Introduction to Membrane Proteins

The cell membrane, or plasma membrane, is an ever-changing landscape. It is described as a fluid mosaic where various macromolecules are embedded in the ...

Facilitated Transport

The chemical and physical properties of plasma membranes cause them to be selectively permeable. Since plasma membranes have both hydrophobic and ...

Primary Active Transport

In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or ...

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this ...

Receptor-mediated Endocytosis

Overview

Receptor-mediated endocytosis is a process through which bulk amounts of specific molecules can be imported into a cell after binding to cell ...

Pinocytosis

Cells use energy-requiring bulk transport mechanisms to transfer large particles, or large amounts of small particles, into or out of the cell. The cells ...

Phagocytosis

Cells pull particles inward and engulf them in spherical vesicles in an energy-requiring process called endocytosis. Phagocytosis (&#x201C;cellular ...

Exocytosis

Exocytosis is used to release material from cells. Like other bulk transport mechanisms, exocytosis requires energy.

While endocytosis takes particles ...

Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective barrier (passive and active transport).

SC.912.L.14.2

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

Compare and contrast the general structures of plant and animal cells. Compare and contrast the general structures of prokaryotic and eukaryotic cells.

SC.912.L.14.3

Overview of Microscopy Techniques

The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern ...

Introduction to Light Microscopy

The light microscope is an instrument used by researchers in many different fields to magnify specimens to as much as a thousand times their original ...

Overview of Electron Microscopy

The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can ...

phase-contrast-and-differential-interference-contrast-microscopy

Phase Contrast and Differential Interference Contrast Microscopy

Phase-Contrast Microscopes
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular ...

Confocal Fluorescence Microscopy

Confocal microscopy is an advanced microscopic technique. The prime advantage of the confocal microscope over other microscopy techniques is its ability ...

Introduction to Fluorescence Microscopy

Fluorescence microscopy is a very powerful analytical tool that combines the magnifying properties of light microscopy with visualization of fluorescence. ...

Super-resolution Fluorescence Microscopy

Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread ...

Compare and contrast structure and function of various types of microscopes.

SC.912.L.14.4

comparing-mitochondrial-chloroplast-and-prokaryotic-genomes

Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes

The present-day mitochondrial and chloroplast genomes have retained some of the characteristics of their ancestral prokaryotes and also have acquired new ...

the-tree-of-life-bacteria-archaea-eukaryotes

The Tree of Life - Bacteria, Archaea, Eukaryotes

The &#8220;tree of life&#8221; describes the evolution of life and the evolutionary relationships between organisms. The root of the tree is the common ...

The Anatomy of Chloroplasts

Green algae and plants, including green stems and unripe fruit, harbor specialized organelles called chloroplasts to carry out photosynthesis. They ...

Explain the evidence supporting the scientific theory of the origin of eukaryotic cells (endosymbiosis).

SC.912.L.14.5

An Overview of Genetics and Disease

Many human diseases are associated with mutations or variations in genetic sequences. Some of these genetic variants are heritable, passed down from ...

Factors Affecting Illness

When a person&#39;s physical, emotional, intellectual, social development or spiritual functioning is compromised, this deviation from a healthy normal ...

Gene-Environment Interactions

Gene expression is influenced by environmental factors such as radiation, temperature, behavior, nutrition, and stress.
The range of reaction suggests ...

Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both individual and public health.

SC.912.L.14.6

A. Cells have characteristic structures and functions that make them distinctive.

B. Processes in a cell can be classified broadly as growth, maintenance, reproduction, and homeostasis.

C. Life can be organized in a functional and structural hierarchy ranging from cells to the biosphere.

D. Most multicellular organisms are composed of organ systems whose structures reflect their particular function.

Abdominal Wall Muscles and Support

Description

Transcript

Tags

More videos by Standards