Anatomy and Physiology

🧠 The foramen ovale is an important skull base opening.

The mnemonic OVALE helps recall its contents:
• Otic ganglion
• V3 (mandibular division of the trigeminal nerve)
• Accessory meningeal artery
• Lesser petrosal nerve
• Emissary veins

There is, of late, talk of 'turbo-cancers'.
No one has asked the question of their relation to having the Covid-19 jab.
I truly believe that there is a fundamental fear to ask this question in scientific circles, such that they won't even look that way, let alone think it, leading to a 'meta-study'

Elbow Joint Anatomy: The Foundation of Stability and Movement

The elbow is a complex synovial hinge joint that allows precise flexion, extension, pronation, and supination of the forearm. Its stability depends on the coordinated interaction of bony articulations, collateral ligaments, and musculotendinous attachments.

In this illustration, the lateral epicondyle serves as the common origin of the forearm extensor muscles, while the medial epicondyle gives rise to the common flexor tendon.

The radial collateral ligament, ulnar collateral ligament (UCL), and annular ligament play crucial roles in maintaining joint stability during movement and load-bearing activities. Understanding these anatomical relationships is essential for diagnosing conditions such as lateral epicondylitis (tennis elbow), medial epicondylitis (golfer's elbow), ligament injuries, and elbow instability.

A strong anatomical foundation leads to better clinical understanding, accurate diagnosis, and effective rehabilitation strategies.

[Elbow anatomy, elbow joint, lateral epicondyle, medial epicondyle, radial collateral ligament, ulnar collateral ligament, annular ligament, common flexor origin, common extensor origin, biceps tendon, radius, ulna, orthopedic anatomy, sports injuries, clinical anatomy, musculoskeletal education, upper extremity anatomy, medical illustration, anatomy teaching, rehabilitation medicine]

The most curious thing about the spinal accessory (CNXI) is the the roots emerge from the cervical region of the spinal cord, not with the motor roots, as one might think, but in-between the motor and sensory roots, before ascending up through the foramen magnum, then re-emerging via the Jugular Foramen

🟣 Spinal Nerve Roots — Understanding Sensory & Motor Levels

This image illustrates the relationship between the spinal cord, spinal nerve roots, and the body regions they control. Each spinal nerve contributes to specific sensory functions (feeling) and motor functions (movement), helping clinicians identify neurological injuries or nerve compression patterns.

━━━━━━━━━━━━━━━

🟣 What Are Spinal Nerves?

🔹 Spinal nerves emerge from the spinal cord at different levels.
➟ They carry signals between the brain and the body.

🔹 These nerves control:
➟ Sensation
➟ Muscle movement
➟ Reflexes
➟ Organ function

━━━━━━━━━━━━━━━

🟣 Sensory Levels (Dermatomes)

🔹 Sensory nerves supply specific skin regions called dermatomes.
➟ Changes in sensation may help identify which nerve root is affected.

🔹 Examples:
➟ C5 → Shoulder region
➟ T10 → Umbilicus (belly button)
➟ L1–L3 → Femoral region
➟ S1–S2 → Perineal and posterior leg regions

━━━━━━━━━━━━━━━

🟣 Motor Levels (Myotomes)

🔹 Motor nerve roots control specific muscle groups.
➟ Weakness in certain muscles may indicate spinal nerve dysfunction.

🔹 Examples:
➟ C5–C6 → Biceps and shoulder muscles
➟ C7 → Triceps
➟ L2–L4 → Quadriceps
➟ L5 → Foot dorsiflexion
➟ S1 → Calf muscles and plantar flexion

━━━━━━━━━━━━━━━

🟣 Major Nerve Plexuses

🔹 Cervical Plexus
➟ Supplies parts of the neck and diaphragm.

🔹 Brachial Plexus
➟ Controls the shoulder, arm, and hand.

🔹 Lumbar Plexus
➟ Supplies the anterior thigh and hip region.

🔹 Sacral Plexus
➟ Controls the posterior leg, foot, bladder, and pelvic floor.

━━━━━━━━━━━━━━━

🟣 Why This Is Clinically Important

🔹 Neurological examination often uses dermatome and myotome testing.
➟ Helps identify the level of spinal cord or nerve root injury.

🔹 Common conditions affecting spinal nerves:
➟ Disc herniation
➟ Sciatica
➟ Spinal stenosis
➟ Peripheral neuropathy
➟ Spinal cord injury
➟ Cauda equina syndrome

━━━━━━━━━━━━━━━

🟣 Common Signs & Symptoms of Nerve Root Compression

🔹 Numbness or tingling
🔹 Muscle weakness
🔹 Radiating pain
🔹 Reduced reflexes
🔹 Balance or coordination difficulties
🔹 Loss of bladder or bowel control in severe cases

━━━━━━━━━━━━━━━

🟣 Red Flag Symptoms

🚨 Progressive weakness
🚨 Saddle numbness
🚨 Sudden bladder or bowel dysfunction
🚨 Severe bilateral leg symptoms

➟ These may indicate serious spinal cord or nerve compression requiring urgent medical evaluation.

━━━━━━━━━━━━━━━

🟣 Management Depends on the Cause

🔹 Physiotherapy
🔹 Postural rehabilitation
🔹 Anti-inflammatory treatment
🔹 Nerve decompression therapy
🔹 Exercise rehabilitation
🔹 Surgery in severe neurological compression

━━━━━━━━━━━━━━━

⭐ Medical Disclaimer

This educational content is intended for informational and educational purposes only and should not replace professional medical evaluation, diagnosis, or treatment.

This image illustrates common lower limb nerve pathologies arising from the lumbar and sacral spinal nerve roots L2 to S3.

It shows the major peripheral nerves, including the obturator, femoral, common peroneal, tibial, superior gluteal, and inferior gluteal nerves, alongside their root origins and associated injuries.

Each nerve injury is linked to specific clinical causes and movement deficits. For example, femoral nerve injury affects thigh flexion and leg extension, while common peroneal nerve damage causes foot drop with loss of dorsiflexion.

Superior gluteal nerve injury leads to Trendelenburg gait. The diagram helps students understand nerve anatomy, muscle actions, and clinical correlations effectively.

Anybody heard of the iliocapsularis muscle?
It's a new one on me as well!

I love the world of anatomy.
Unfortunately, all the books on anatomy are written by the man with the knife (and could draw - as with Andreus Versalius, or now with a decent camera or AI).
Anatomists would cut tissues off, cite their origin and insertion and, through that, define its function.
What they fail to teach is how things are attached together and, through that, their relationships.
I have always said that you cannot have a neck without a shoulder, or a low back without a hip ( 'hip' is to be used synonymously with 'pelvis' here).
Here, psoas can give a person symptoms in the low back (as that's where it comes from), low chest (as that's where it comes from) ,and groin (as that's where it first to).
In addition to this, some nerve roots pass through the belly of psoas (though there can be anatomical differences - so not all people), causing symptoms along the femoral and obturator nerves causing pain in the anterior and medial thigh, respectively.
Iliacus can also manifest as pain in the gluteal fossa (posterior pelvis). Mind you, if both posterior back muscles (errector spinae, lower collective fibres of multifidus - quite a meaty muscle, here) and the anterior muscles (iliopsoas) are tight together, they just creates pain and reduced mobility in the low back (and pelvis).
Then, of course, there is the Sacroiliac joint. This is a diarthroidial joint, the synovial part of which has a very small range of movement. Hence, there are no muscles, per se, to move that joint. However there are muscles associated with it: iliopsoas and piriformis. Now, the jury will be forever out which causes which. Just know they are associated.

✅ Iliopsoas & Quadratus Lumborum Region — Core Muscles Linking the Spine, Pelvis & Hip

▪️The iliopsoas and quadratus lumborum (QL) muscles are deep stabilizing muscles of the lower back and pelvis. They play a major role in posture, walking, hip movement, spinal stability, and pelvic balance.

▪️This anatomical region is closely related to important nerves, blood vessels, abdominal organs, and the lumbar plexus.

━━━━━━━━━━━━━━━

🟣 Main Structures Shown in This Diagram

🔹 Psoas Major Muscle
➟ A deep hip flexor connecting the lumbar spine to the femur.
➟ Essential for walking, running, and lifting the leg.

🔹 Iliacus Muscle
➟ Works together with the psoas major as the iliopsoas muscle group.

🔹 Quadratus Lumborum (QL)
➟ Stabilizes the lumbar spine and pelvis during standing and walking.

🔹 Lumbar Plexus
➟ A network of nerves supplying the lower abdomen, pelvis, and legs.

🔹 Iliac Blood Vessels
➟ Major arteries and veins supplying the pelvis and lower limbs.

━━━━━━━━━━━━━━━

🟣 Important Functions of the Iliopsoas Muscle

🔹 Hip flexion
➟ Helps raise the thigh during walking or climbing stairs.

🔹 Postural stability
➟ Maintains upright posture and spinal alignment.

🔹 Lumbar spine support
➟ Assists in stabilizing the lower back during movement.

🔹 Pelvic balance
➟ Works with abdominal and gluteal muscles to maintain pelvic mechanics.

━━━━━━━━━━━━━━━

🟣 Common Problems Related to These Muscles

🔹 Tight iliopsoas muscle
➟ Often associated with prolonged sitting and anterior pelvic tilt.

🔹 Psoas syndrome
➟ Can cause deep lower back, groin, or hip pain.

🔹 Quadratus lumborum trigger points
➟ May produce lower back pain and pelvic asymmetry.

🔹 Lumbar nerve irritation
➟ Nearby nerves can become compressed or irritated.

🔹 Hip flexor strain
➟ Common in athletes, runners, and people performing repetitive hip movements.

━━━━━━━━━━━━━━━

🟣 Common Signs & Symptoms

🔹 Lower back pain
🔹 Groin or hip pain
🔹 Difficulty standing upright
🔹 Pain during walking or climbing stairs
🔹 Tight hip flexors
🔹 Pelvic imbalance
🔹 Reduced spinal mobility
🔹 Pain radiating into the thigh

━━━━━━━━━━━━━━━

🟣 Clinical Importance

🔹 Psoas sign in appendicitis
➟ Pain during hip extension may suggest irritation near the inflamed appendix.

🔹 Important surgical landmark
➟ Surgeons use these anatomical relationships during abdominal and pelvic procedures.

🔹 Key muscle in biomechanics
➟ The iliopsoas strongly influences posture, gait, and spinal loading.

🔹 Important in rehabilitation
➟ Physical therapists often assess iliopsoas and QL function in chronic back pain.

━━━━━━━━━━━━━━━

🟣 Management & Treatment

🔹 Stretching exercises
➟ Improve flexibility of the hip flexors and lower back.

🔹 Strengthening core and gluteal muscles
➟ Helps restore pelvic stability.

🔹 Posture correction
➟ Reduces excessive lumbar stress from prolonged sitting.

🔹 Manual therapy and physiotherapy
➟ May help release muscle tightness and improve mobility.

🔹 Activity modification
➟ Avoid repetitive strain and prolonged sitting when symptoms flare.

━━━━━━━━━━━━━━━

⭐ Medical Disclaimer
This post is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. Seek professional evaluation for persistent back, groin, or hip pain.

This diagram shows the vestibulocochlear apparatus inside the petrous region of the temporal bone (the temporal bone has two bony regions: the squamous [scale-like], and petrous [hard]).
It also shows, though not quite so distinctly, the three regions here.
The party on the outside, everything outside the tympanic membrane (ear drug) is the outer ear: the pinna and the external auditory canal. This is an air-filled cavity
Inside the tympanic membrane is the middle ear. This is also an air-filled cavity, and is connected to the outside via the eustachian tube, connecting it to the pharynx/palate. It also has the auditory ossicles. The malleus, incus and stapes (hammer, anvil and stirrup), which collectively transfer movement of the tympanic membrane (i.e. from sound), to the inner ear.
What is not clear here is the 'dividing line' between the middle and inner ear.
If you can see the ossicles, there, see the one that looks like a stirrup. It connects directly with a membrane enclosing the inner ear which, unlike the external and midfle ear,is a fluid-filled cavity.
Here, the semicircular canals are concerned with balance, whereas the cochlear (the structure looking like a snail's shell, is concerned with perception of sound.
The whole structure (barring the skin and middle ear supplied by C2) is supplied by CNVIII, the vestulibulocochlear nerve

The brachial plexus originates as nerve roots C5 - T1.
These roots come together and then separate. Then, once again, come together and separate.
All the nerves supplying muscles around the shoulder aside, it becomes 4 nerves that enter the arm, three of which reach the hand

This diagram highlights the brachial plexus, a complex network of nerves originating from spinal roots C5 to T1 that supplies the upper limb.

Key Anatomical Features
Structure: It maps the progression from roots to trunks (upper, middle, lower) beneath the clavicle, dividing into cords (lateral, posterior, medial) wrapped around the axillary artery.

Terminal Branches: It traces major peripheral nerves, including the musculocutaneous, median, ulnar, radial, and axillary nerves, demonstrating their specific muscular destinations in the arm and hand.

Muscular Innervation: Insets show the posterior axilla (rotator cuff innervation) and the anterior axilla (pectoral and serratus anterior innervation).