Human Anatomy: Guide to Bones, Muscles, Organs, Systems, Functions & Diagram

📅 Published on July 1, 2026 | 🕒 Last Reviewed & Updated on August 8, 2026

Overview of Human Anatomy and Physiology

The human body has 206 bones,[1] more than 600 muscles,[2] and a wide network of organs and blood vessels. All of these parts work together, with each cell playing its own role to keep us alive. Two main fields help us understand how our bodies function: physiology, which looks at how the body works inside, and anatomy, which studies its structure. Anatomy examines everything from the smallest cells to tissues, organs, and entire systems. By learning about human anatomy, we better understand how our bodies are built and how all the parts work together to keep us alive.

On organ counts. Popular articles often claim the body has “78 organs.” No U.S. federal health agency publishes an official organ count, because the total depends on how an organ is defined and whether paired structures, glands, and accessory organs are counted separately. Authoritative anatomical resources describe the body by organ system rather than by organ tally, and this article follows that convention.

Human Anatomy Diagram

Detailed Human Anatomy

Human Bone Anatomy

In human anatomy, the skeleton is the internal framework of the body. It is responsible for both structure and function. At birth, it is composed of approximately 270 bones. However, by adulthood, this number reduces to roughly 206 due to bone fusions.[1] Bone is living tissue that is constantly renewed: older bone is broken down and new bone formed in its place, a process called remodelling, and almost all bone in adults is replaced about every 10 years.[3] Bone mass is gained during growth and typically peaks during a person’s twenties.[3]

Skull

The skull is a bony structure that covers and protects the brain. It comprises three main types of bones: cranial bones, facial bones, and ear ossicles.[4]

In humans, the skull is divided into the neurocranium (the braincase) and the viscerocranium (the facial skeleton), which includes the mandible.[4] This structure is an example of cephalization, where the brain and sensory organs are concentrated at the head.

The skull is located at the uppermost part of the skeleton, a result of cephalization.[4] It houses the brain along with key sensory organs such as the eyes, ears, nose, and mouth.

The human skull is made up of 22 bones,[4] or 29 if you include the six middle ear ossicles and the hyoid bone. These bones are mainly connected by ossified joints known as sutures.[4]

The skull has several crucial functions: it protects the brain, provides attachment for muscles, and allows blood vessels and nerves to pass between the inside and outside of the cranium.[4] Its structure also maintains the proper distance between the eyes for stereoscopic vision and positions the ears to help with sound localization.

Read More – Skull Anatomy: Parts of the Skull, Structure, Cranial, Facial Bones & Functions

Vertebral Column or Spine

The vertebral column, or the spine, is an essential human body part of the axial skeleton. It safeguards the spinal cord and nerves while maintaining an upright posture.[5]

This complex skeletal framework bears most of the body’s weight to maintain a vertical pose.[5] Its distinctive feature is the transformation of the flexible rod found in all chordates into a segmented array of bones referred to as vertebrae. In humans there are 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal.[5]

These vertebrae are interposed with intervertebral discs, which enhance the spine’s durability and flexibility.[5] Each vertebra is named according to its position within the spinal column.[5]

The spinal canal is enclosed within the vertebral column, a protective cavity that envelops and shields the spinal cord.[5]

Read More – Spine Anatomy: Parts of the Spine, Vertebrae, Curves, Spinal Cord & Diagram

Hip Bone

The hip is also known as the coxa in medical terms. It is a key area in vertebrate anatomy found on the outer side of the pelvis. It is located to the side and front of the buttocks, below the bony ridge of the iliac crest, and beside the obturator foramen.[6]

This area includes muscles, tendons, and soft tissues that cover the prominent greater trochanter of the femur.[7]

In adults, the hip bones forms from the fusion of three pelvic bones (the ilium, ischium, and pubis).[6] It creates the sturdy inner and upper walls of the hip region.

Read More – Hip Bone Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Femur

The femur, commonly called the thigh bone, is essential within the human skeletal system. It is the bone in the lower limb between the hip joint and knee joints, and it is the longest, heaviest, and strongest bone in the body.[7] This bone shapes the hip joint at its proximal end and forms an articulation point with the pelvic socket.[7]

Moreover, the femur’s distal end engages with the tibia and patella to form a knee joint structure.[7] Beyond this, the femur bears the human body’s weight during stationary and dynamic activities.[7]

Additionally, the femur is an essential anchor point for muscles, tendons, and ligaments that help move the hip joint and knee joints.[7]

Read More – Femur Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Rib Cage

The rib cage, or thoracic cage, forms a vital part of the vertebrate skeleton. It consists of the ribs, sternum, and thoracic vertebrae.[8] This structure protects the heart, lungs, and major blood vessels while supporting the shoulder girdle and axial skeleton.

In humans, the thoracic cage has 12 pairs of ribs, but they do not all connect to the sternum in the same way. Ribs 1–7 (the true ribs) connect directly to the sternum through their own costal cartilage; ribs 8–10 (the false ribs) attach indirectly, their costal cartilages joining the seventh costal cartilage; and ribs 11–12 (the floating ribs) do not attach to the sternum at all.[8] The sternum includes three parts: the manubrium, body, and xiphoid process.[8]

Together with the 12 thoracic vertebrae, the rib cage provides muscle attachment sites for the neck, upper limbs, abdomen, and back.[8] It also forms the chest wall with the skin and surrounding tissues.

Sternum

The sternum, or breastbone, is a flat, vertical bone situated in the center of your chest. It forms the front of the rib cage and has three parts:

• Manubrium: The upper section with the suprasternal notch and clavicular notches that form the sternoclavicular joints.
• Body (Gladiolus): The longest section, where the costal cartilages of ribs 2–7 attach. It joins the manubrium at the sternal angle (Angle of Louis).[8]
• Xiphoid Process: The small, triangular lower section that varies in shape and size.[8]

The sternum protects vital organs, including the heart and lungs.[8]

Human Muscle Anatomy

In human anatomy, muscle tissues are made up of specialized cells that can contract and allow movement.[2] This movement includes not just the motion of body parts and limbs but also the flow of blood, food, and other substances within the body.

Muscles are essential for moving the skeleton and making the heart beat. They are found in the walls of organs like the intestines, uterus, and stomach.[2]

Biceps

The biceps brachii is a large muscle in the anterior upper arm that extends from the shoulder to the elbow. It has two unique heads, the long and short heads, which emerge from the scapula.[9] These heads join together to produce a muscular system that joins to the upper section of the forearm.[9]

Function—The biceps brachii is a strong supinator of the forearm and also flexes the elbow, although the brachialis is the primary elbow flexor.[10] It helps with various activities and daily tasks. Curling the forearm at the elbow joint is referred to as forearm flexion.

Read More – Ultimate Guide to Bicep Anatomy: Parts, Names, Functions & Diagram

Triceps

The triceps brachii is an extensor muscle in various vertebrates at the back of the upper limb. These muscles originate from the humerus and scapula, and comprise three distinct parts: the medial, lateral, and long heads.[9]

Function—The triceps brachii muscle extends the forearm at the elbow joint [9]. Its long head helps extend and adduct the arm at the shoulder joint.[9]

Forearm

The forearm is the part of your arm between the elbow and wrist. It is made up of two bones: the outer radius and the inner ulna.[11]

It has 20 muscles grouped into front (flexor) and back (extensor) compartments, which control elbow, wrist, and hand movements.[11]

There are two types of muscles: front flexors and back extensors.[11] Fascia organizes and supports these muscles around the ulna and radius.

Two structures, the intermuscular septum and interosseous membrane, create compartments and offer extra support.[12]

Read More – Complete Guide to Forearm Anatomy: Parts, Names, Functions & Diagram

Hip Muscles

The muscles around the hip joint are essential for movement. Anatomists group them into four categories based on their location: the gluteal, lateral rotator, adductor, and iliopsoas groups.[13] The exact number counted as a “hip muscle” varies between classification schemes.

Hip movements result from the coordinated action of multiple muscles, and most muscles assist in more than one movement.[13]

• Flexion — chiefly iliopsoas, assisted by rectus femoris and sartorius.
• Lateral rotation — obturators, quadratus femoris, gemelli; assisted by gluteus maximus, sartorius, piriformis.
• Medial rotation — tensor fasciae latae, fibres of gluteus medius and minimus.
• Abduction — gluteus medius and minimus.
• Adduction — adductor longus, brevis, magnus; assisted by gracilis and pectineus.

Read More – Hip Muscle Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Thigh

The thigh is a significant part of human anatomy in the lower limb. It lies between the hip joint and the knee joint. The femur is the prominent bone within the thigh and has exceptional strength, density, and robustness.[7]

Functionally, the femur forms a ball and socket joint at the hip[13] and a modified hinge joint at the knee[16]. Remarkably, the thigh region houses various main muscles in the human body, divided into anterior, medial, and posterior compartments.[14]

These muscles enable various body movements, including flexion, extension, adduction, and rotation.[14]

Additionally, they bear most of the body’s total weight. Furthermore, these muscles help maintain the structural integrity of the hips and legs.[14]

Read More – Complete Guide to Thigh Muscle Anatomy: Learn Parts, Names & Diagram

Human Body Parts – Joints

Wrist Joint

In human anatomy, the wrist is scientifically termed the carpus or carpal bones. It is a crucial part of the hand’s structure, consisting of eight distinct bones that create the foundational framework for the upper part of the hand.[15]

The wrist joint is scientifically known as the radiocarpal joint. It acts as the vital connection between the radius and the carpal bones.[15] It includes both the carpus and the lower portions of the forearm bones.

The metacarpus is formed by the five metacarpal bones. A network of interconnected joints exists among these anatomical components, making hand movement possible.[15]

Read More – Wrist Anatomy: Ultimate Guide to Parts, Names, Functions & Diagram

Hip Joint

The hip joint connects your thigh bone (femur) to your hip bone (pelvis). It is a crucial body part, second in size only to your knee joint.[13][16]

This ball-and-socket joint consists of the rounded head of the femur fitting snugly into a cup-like cavity in the pelvis, known as the acetabulum.[13] This structure allows for extensive movement and helps your legs support your body weight.

This universal joint is essential for everyday activities, enabling a wide range of motions and providing stability and support.[13]

Read More – Hip Bone Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Knee Joint

The knee joint, or a synovial joint, is an essential link between the femur, tibia, and patella bones. It is the body’s largest joint, mainly allowing leg bending and straightening.[16] It contains two primary components: the tibiofemoral and patellofemoral articulations.[16]

The tibiofemoral joint forms a connection between the tibia and the femur, while the patellofemoral joint forms between the patella and the femur.[16]

Your knees are vital in supporting your body weight and allowing leg movement. This joint helps in activities like walking, running, and jumping.[16]

Read More – Knee Anatomy: Complete Guide to Parts, Names, Functions & Diagram

Ankle Joint

Your ankle is a hinge joint connecting your lower leg and foot. It is a hinge-like joint formed by the talus, tibia, and fibula bones.[17]

The bony bump on the lower fibula (lateral malleolus) forms the outer boundary on one side, and the bony bump on the lower tibia (medial malleolus) creates the inner boundary. Together, they make up the ankle mortise.[17]

The talus bone acts like a connector, linking with the calcaneus below and the navicular in front.[17] The top part of the talus has a smooth surface, allowing comfortable up-and-down movement of your foot.

It snugly fits between the bony bumps, making the ankle most stable when you lift your toes towards your shin (dorsiflexion).[17]

Shoulder Joint

The human shoulder anatomy has three bones: the collarbone, shoulder blade, and upper arm bone. These bones are connected by joints, with the main one being the shoulder joint or glenohumeral joint.[18]

Other joints, like the acromioclavicular joint, are also part of the shoulder.[18] The shoulder joint allows circular rotation and lifting of the arm away from the body.

It is like a ball in a socket formed by the shoulder blade. A soft tissue envelope called the joint capsule surrounds the shoulder joint, lined with a smooth synovial membrane.[18]

A group of four muscles maintains the shoulder’s stability, called the rotator cuff. These muscles attach to the shoulder blade and the upper arm bone. They are the supraspinatus, subscapularis, infraspinatus, and teres minor.[19]

Human Anatomy – Alimentary System

Mouth

The mouth is necessary for digestion.[20] It is a complex structure with different parts that work together to make the digestion system more efficient.

The lips create two regions: the vestibule and the oral cavity. The tongue occupies the central cavity and is surrounded by teeth, cheeks, and the isthmus of the fauces at the back.

The hard palate forms the front roof, and the soft palate makes up the rear, with the uvula hanging down. The inner lining is called the oral mucosa. It is made of stratified squamous epithelium.

Salivary glands provide fluid to keep the mouth moist and begin the chemical breakdown of food.[20] Nerves and blood vessels form a network essential for the mouth’s diverse functions in human life.

Read More – Mouth Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Teeth

Teeth are essential for chewing food and helping with digestion. Although they may look like bones, they develop from ectoderm and ectomesenchyme, with the enamel arising specifically from the ectoderm.[21]

In adults, the 32 permanent teeth work together to cut, tear, mix, and grind food into smaller pieces.[21] The tongue and oropharynx shape the food into a ball for easy swallowing.

Teeth have four main layers. The outer layer, called enamel, is the hardest and most highly mineralized tissue in the body and protects against cavity-causing bacteria.[22]

Below the enamel is dentin, which is softer than enamel but harder than bone.[22] If enamel wears away, it exposes dentin, increasing the risk of cavities.

The tooth root is covered by cementum, which, along with periodontal tissues, anchors the tooth in the jaw.[21] The innermost layer, tooth pulp, houses nerves, blood vessels, and connective tissues, contributing to overall tooth health.[21]

Read More – Complete Guide to Tooth Anatomy: Learn Parts, Names & Diagram

Lips

The lips are an essential part of the human face, pivotal in expressing emotions, talking, feeling, chewing, and romantic moments. Soft structures connected to the jaws are visible in many animals, including humans.

The upper and lower lips are scientifically called labium superius oris and labium inferius oris. Both lips have inner mucosal membranes, a colored vermilion layer, and outer skin.

In animals, including humans, lips are soft and flexible, helping with tasks like eating (such as sucking and swallowing) and forming sounds for speech.[20]

Stomach

The stomach is a J-shaped crucial component of the digestive system, made up of four regions: the cardia, fundus, body, and pylorus.[23] It makes enzymes and acids that chemically decompose food.[23]

This process helps digestion before the food passes into the small intestine via the gastrointestinal (GI) tract.[20] This tube extends from the mouth to the anus, through which food travels and waste exits.

The primary function of the stomach is to temporarily store food, mixing and breaking it down through muscular contractions and producing specialized cells and enzymes necessary for digestion.[23]

Read More – Stomach Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Intestine

The intestine, or bowel, is a long muscular tube that runs from the stomach to the anus. It digests food, produces hormones, and supports the immune system.[20]

The small intestine connects to the stomach and measures about 10–16 feet (3 to 5 metres) long. It has three parts: the duodenum, jejunum, and ileum.[24] Its folded lining increases the surface area for nutrient absorption.

The small intestine uses enzymes to break food into sugars, amino acids, and fatty acids. It then absorbs these nutrients into the bloodstream for distribution throughout the body.[20]

The large intestine is shorter than the small intestine but has a much larger lumen. It includes the cecum, appendix, entire colon, rectum, and anal canal.[25]

The large intestine absorbs water and salts from digested food to form stool.[25] Muscular contractions move the stool to the anus for elimination.[20]

Liver

The liver is a critical organ found only in vertebrate animals that helps maintain the body healthy. It performs multiple critical functions, like removing toxins from the blood and producing proteins and other compounds required for digestion and development.[26]

In humans, the liver is positioned in the upper right abdomen, just below the diaphragm, and protected by the lower ribs.[26]

One of the liver’s primary functions is to assist in controlling the body’s carbohydrate utilization, which includes storing glycogen and releasing glucose.[27] It also promotes the breakdown of old red blood cells and the production of proteins such as albumin and clotting factors.[27]

Read More – Liver Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Pancreas

The pancreas is a big gland found deep within the belly. It works in both your digestive and endocrine systems.[20] This dual-role organ functions as a factory with two independent manufacturing lines:

• Enzymes for Digestion: It creates enzymes that help break down the food you ingest.[20]
• Hormones for Blood Sugar Regulation: It secretes hormones that control blood sugar levels in your body.[20]

Each day, it secretes about 1 to 2 liters of enzyme-rich juice[28][29], with the exact amount depending on your food intake — flow rises from roughly 0.2 to 0.3 mL per minute at rest to about 4.0 mL per minute during a meal.[28]

Human Anatomy – Respiratory System

Nose

The nose is an essential facial organ that allows air to enter the body. It filters, warms, and humidifies the air before it reaches the lungs.[30] Bones and cartilage give the nose its unique shape.[30]

Inside the nose, shell-like nasal conchae help condition the air [30], while tiny nasal hairs trap dust and other large particles.[30] When irritants such as dust or allergens enter the nose, the body triggers a sneeze to remove them.

The nose also enables the sense of smell[31] and plays a key role in facial appearance. Common conditions, such as nasal congestion and nosebleeds, can affect breathing, smell, and overall comfort.

Read More –Nose Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Human Anatomy – Sense Organs

Eye

Our eyes are incredible organs that respond to light and allow us to see and understand the world around us. The human brain cannot sense the environment directly.

Our eyes collect crucial information about what’s happening and help us to see things and keep our body balanced.

For each eye, the normal field of vision extends about 60 degrees upward, 70 to 75 degrees downward, 60 degrees toward the nose, and 100 to 110 degrees outward.[32] Because the outward field of each eye reaches well past the midline, the two fields overlap in the centre — and it is that overlap which lets us perceive depth and see in 3D. Each eye also has a small physiological blind spot, corresponding to the optic disc, about 15 degrees to the outer side of the point of focus.[32]

Read More – Ultimate Guide to Eye Anatomy: Parts, Structure, Functions & Diagram

Ear

Your ears help us hear and stay balanced. When sound enters your ear, it makes your eardrum vibrate. This vibration passes through tiny bones in your middle ear, making the sound louder.[33] Then, in your inner ear, small hair cells turn the vibrations into electrical signals and send them to your brain.[33]

Your inner ear also has fluid-filled canals that help you stay balanced. These canals have hair-like sensors. When you move, the fluid shifts and sends signals to your brain.

Your brain uses these signals to help your muscles keep you steady. So, your ears do much more than hear—they help you stay on your feet!

Read More – Ultimate Guide to Ear Anatomy: Parts, Structure, Functions & Diagram

Tongue

The tongue is a muscular organ that helps you eat, speak, and taste food. Tiny bumps on its surface contain taste buds, which detect sweet, sour, salty, bitter, and umami (savoury) tastes.[34] At birth there are about 10,000 taste buds, and after age 50 they may begin to be lost.[34] Saliva keeps the tongue moist and helps you taste and chew food.[20]

The tongue moves food around your mouth for chewing and pushes it into your throat for swallowing.[20]

In humans, the tongue forms words and speech sounds. In other animals, it helps produce different vocalizations.

The tongue has two main parts: the front part inside the mouth and the back part near the throat. A groove down the middle divides it into left and right halves.

Read More – Tongue Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Human Body Parts – Integument

Nails

Nails, found on our fingers and toes, are rigid plates made of keratin.[35] This protein is also in other animals’ claws, hooves, and horns.

Nails are attached to the nail bed and can be used for scratching. The visible part is the “nail plate,” made of compact, hardened cells called onychocytes.[35]

They have lateral folds on each side and a proximal nail fold at the base.[35] The cuticle, a thin layer of skin, protects and enhances sensory experiences.[35]

Read More – Complete Guide to Nail Anatomy with all Parts, Names & Diagrams

Hair

Hair is a protein-based filament that emerges from follicles embedded in the dermis layer of the skin.[36] It is a distinctive feature of mammals.

Except for areas of smooth, hairless skin — the palms, soles, lips, and parts of the external genitalia — the human body is largely covered with follicles that produce two types of hair: thick terminal hair and fine vellus hair.[36][37]

While much attention is given to hair growth, types, and care, hair also serves a protective role, enhancing sensation and helping regulate temperature.[37]

Skin

Skin is the soft outer layer that covers and protects the bodies of humans and many animals, and it is the largest organ of the body.[38] It has three main jobs: protecting, controlling, and sensing[39]

First, the skin acts as a shield, keeping out harmful things like germs and preventing the body from losing too much water.[39] It also helps keep us warm or cool by controlling our body temperature.[38]

Additionally, the skin lets us feel sensations like touch.[39] When exposed to sunlight, skin helps make vitamin D, which is important for our health.[39]

The thickness of the skin changes depending on where it is on the body.[38] For example, the skin of the eyelids has no underlying fat layer and is the thinnest skin on the body, making it more prone to wrinkles.[40]

Human Anatomy – Nervous System

Brain

The brain is the body’s control center and a vital part of the nervous system. It lies inside the skull, where cerebrospinal fluid cushions and protects it.[41]

The brain and spinal cord together form the central nervous system, which processes sensory information and controls almost every body function.[41]

An adult brain weighs roughly 1.4 to 1.5 kg and contains an estimated 86 billion nerve cells, along with a similar number of non-neuronal cells.[42] At birth, the brain is only about one-quarter to one-third of its adult volume.[43]

The brain grows rapidly during the first years of life, reaching about 80% of adult volume by age three[43] and approximately 95% by age six[44] Growth after that involves refinement rather than bulk — unused connections are pruned away and nerve fibres become progressively insulated.[44]

Read More – Parts of the Brain Anatomy: Complete Guide with Names, Functions & Diagram

Lobes of the Brain

The cerebrum is the brain’s largest part and sits at the top of the skull. Its folded surface, made of sulci (grooves) and gyri (ridges), increases surface area without enlarging the skull.

A thin layer of gray matter processes information, while the white matter beneath carries signals throughout the brain.

The cerebrum has two hemispheres connected by the corpus callosum, which allows communication between them. Each hemisphere controls the opposite side of the body.[41]

Each hemisphere contains four lobes: the frontal lobe controls movement, planning, and problem-solving; the parietal lobe processes touch, temperature, and taste; the temporal lobe handles hearing, language, and memory; and the occipital lobe processes vision.[41]

Read More – Lobes of the Brain: Complete Guide with Names, Functions & Diagram

Human Anatomy – Cardiovascular System

Heart

The heart is a vital organ of muscles that pumps blood throughout the body and delivers oxygen and nutrients to every human body part.[46] While doing this, it removes waste like carbon dioxide from the body.

In humans, the heart is a muscular organ situated in the center of the chest behind the sternum, between the lungs and leaning to the left.[45] It is roughly the size of a closed fist, though its size varies with body size, age, and sex.

Humans, birds, and mammals have four heart chambers: the two upper chambers are the right and left atria, and the two lower chambers are the right and left ventricles.[45] The right atrium and right ventricle together are often called the right heart, and the left atrium and left ventricle form the left heart.[45]

The heart is separated by the muscular wall called the septum.[46] Blood is pumped from the right side of the heart through the pulmonary artery for oxygen, and this blood goes to the lungs.[47]

Four valves — the tricuspid, pulmonary, mitral, and aortic — open and close in time with the pumping chambers, preventing blood from flowing backward as it moves through the heart.[47] After the lungs add oxygen, the left side receives the blood through the pulmonary veins.[47]

Read More – Heart Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Arteries

In the human body, arteries carry blood away from the heart to all our organs, while veins carry blood back toward the heart.[47] They work closely with the heart, like tubes that transport blood from the heart to all parts of the body.

This blood, with oxygen and nutrients, is essential for the proper functioning of the different organs. Arteries can change based on signals from the nervous system and outside factors like pressure and temperature.

Nerves in the arteries help them respond to these signals. Hormones like catecholamines can narrow or widen arteries, influencing blood pressure and flow. So, arteries are dynamic vessels that ensure our body gets the oxygen and nutrients it needs.

Human Anatomy – Urinary System

Ureter

The ureters are two muscular tubes that carry urine from the kidneys to the bladder.[48] The kidneys filter blood to produce urine, which flows through the collecting ducts, calyces, and renal pelvis before entering the ureters.[48]

Blood reaches the ureters from several vessels, including the renal arteries, the abdominal aorta, and the common iliac and gonadal arteries.[48] Sympathetic fibres from T10 to L2 and parasympathetic fibres from S2 to S4 supply them, although the peristaltic wave itself is generated by pacemaker cells in the minor calyces rather than by these nerves.[48]

In adults, the ureters average about 26 cm long, with a range of 22 to 30 cm, and are 3 to 4 mm wide.[48] Their urothelial lining and smooth muscle walls use peristaltic contractions to move urine to the bladder.[48]

Kidney

The kidneys are two bean-shaped organs in your urinary system that filter your blood, each about the size of a fist.[50] Each day, they filter about 120 to 150 quarts of blood.[50]

They remove waste by producing about 1 to 2 quarts of urine, while your body reabsorbs and reuses the rest.[49][50]

The kidneys also maintain fluid balance, regulate electrolytes such as sodium, calcium, phosphorus, and potassium, and remove acid and waste products.[49] Together, they filter about half a cup of blood every minute.[49]

Read More – Kidney Anatomy: Complete Guide with Parts, Names, Functions & Diagram

Human Body Parts

Leg

The leg is part of your body between your knee and foot. It is made up of two bones: the tibia and the fibula.[51] These bones give support and balance to your body, and they work with muscles to help you move around.[51]

The tibia connects with the femur at your knee, and at the bottom, it joins with the fibula to form the ankle joint with the talus bone.[52] The tibia is the weight-bearing bone of the leg and the second largest bone in the body.[52]

When your ankle joint works properly, it lets your foot move smoothly while staying stable, which makes walking and moving around comfortable.[17]

Read More – Complete Guide on Leg Anatomy with Parts, Functions & Diagram

Arm

The upper extremity, or arm, is a crucial part of the human anatomy. It has three main sections: the upper arm, forearm, and hand. It starts from the shoulder and reaches to the fingers, and its skeleton is made up of the humerus, the radius and ulna,[12] and the 27 bones of the hand[15] — 30 bones in all, together with nerves, blood vessels, and muscles.

Starting at the shoulder joint, a ball-and-socket joint.[18] It allows for a wide range of movement, though it is less stable than the hip joint because the socket is shallow and holds less than a third of the head of the upper arm bone.[18]

Next is the elbow joint, a hinge joint that facilitates arm bending and straightening. Because the radius can pivot around the ulna, the forearm also has the abilities of pronation and supination.[12]

Read More – Comprehensive Guide to Arm Anatomy: Parts, Names & Diagram

Hand

A hand is a helpful part at the end of our arm. Humans and some animals like monkeys and koalas have hands. Even raccoons are said to have hands but don’t have thumbs like we do.

A human hand usually has five parts called fingers. We count the thumb as one of them. There are 27 bones in a hand, not depending on a particular bone. There are 14 finger bones connecting to the wrist bones.[15]

Each hand has five long metacarpal bones and eight small carpal bones.[15] Thus, a hand comprises fingers, thumbs, and bones that help it move and work.

Read More – Comprehensive Guide to Hand Anatomy: Parts, Functions & Diagram

Finger

Fingers are essential parts of our hands and similar limbs in many animals. Most animals with limbs, like humans and primates, have five fingers, while shorter ones are called toes.

Fingers are flexible and opposable in humans. They help us feel things and make precise movements, and they are vital for skills like grabbing and moving objects.

The thumb is the first digit, followed by the index finger, the middle finger, the ring finger, and the little finger, also known as the pinkie.

Read More – Complete Guide to Finger Anatomy with Parts, Names, Functions & Diagram

FAQ’s

References-

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Read More-

Human Body-

• Human Skeleton Anatomy: All 206 Bones Explained with Functions & Diagrams
• Human Muscle Anatomy: Validated Guide to Every Major Muscles & Functions

Head, Face & Senses-

• Nose Anatomy: Parts of the Nose, Structure, Nasal Cavity & Sinuses Explained
• Skull Anatomy: Parts of the Skull, Structure, Cranial, Facial Bones & Functions
• Mouth Anatomy: Guide on Parts of Mouth, Lips, Palate, Gums & Oral Cavity
• Eye Anatomy: Parts of the Eye, Cornea, Lens, Retina, Optic Nerve & Diagram
• Ear Anatomy: Parts of the Ear, Outer, Middle & Inner Ear & Structures

Brain & Nervous System-

• Brain Anatomy: Parts of the Brain, Structure, Functions & Regions Explained
• The 4 Lobes of the Brain: Complete Guide with Locations & Functions

Spine & Back-

• Cervical Spine Anatomy: C1–C7 Vertebrae, Muscles & Nerves Explained
• Spine Anatomy: Parts of the Spine, Vertebrae, Curves, Spinal Cord & Diagram
• Neck Muscle Anatomy: Guide with Key Muscles, Groups, Functions & Diagrams
• Rib Cage Anatomy: Ribs, Sternum, Thoracic, Vertebrae & Functions Explained

Organs-

• Pancreas Anatomy: Parts of Pancreas, Structure, Location, Functions & Role
• Thyroid Anatomy: Guide on Key Parts, Location, Structure & Functions
• Stomach Anatomy: Parts of Stomach, Regions, Layers & Digestive Function
• Heart Anatomy: Guide on Parts of Heart, Chambers, Valves & Blood Flow
• Liver Anatomy: Key Parts of Liver, Functions, Lobes, Segments & Diagram
• Kidney Anatomy: Guide on Parts of Kidney, Structure, Functions & Diagram

Upper Limb-

• Shoulder Anatomy: Parts of the Shoulder, Bones, Joint Structure & Diagram
• Hand Anatomy: Parts of the Hand, Bones, Muscles with Functions & Diagram
• Arm Anatomy: Parts of Arm, Bones, Muscles & Joints with Functions & Diagram

Lower Limb-

• Hip Muscle Anatomy: Guide on Key Muscle Groups, Names, Functions & Diagram
• Hip Bone Anatomy: Parts of Hip Bone, Ilium, Pubis, Functions & Diagram
• Leg Anatomy: Parts of the Leg, Bones, Muscles & Lower Leg with Functions
• Knee Anatomy: Parts of Knee, Bones, Ligaments, Cartilage & Joint Structure
• Thigh Muscle Anatomy: Key Muscle Groups, Names, Functions & Diagram

Authors

Author: Ian W,

Ian Whitmore MD, MB, BS, LRCP, MRCS – Human Anatomy

Reviewer: Wojciech Pawlina,

Wojciech Pawlina MD – Human Anatomy Education

Editor: Joy S. Reidenberg

Joy S. Reidenberg PhD – Mammalian Anatomy and Adaptations