Thigh Anatomy and Leg Structure Quiz

Thigh Anatomy

• The femur is the only thigh bone, known for being the longest and strongest bone in the human body.
• Anterior thigh muscles are primarily responsible for thigh extension, including:
  • Quadriceps femoris composed of four muscles:
    • Vastus lateralis
    • Vastus medialis
    • Vastus intermedialis
    • Rectus femoris
  • Sartorius muscle
• The femoral region contains essential internal components, such as:
  • Muscles, blood vessels, lymph nodes, and lymphatic vessels.
• Key blood vessels include:
  • Femoral artery
  • Femoral vein
  • Femoral nerves
  • Inguinal lymph nodes

Posterior Compartment

• Known as the "bare string muscles," these muscles mainly flex the thigh, including:
  • Biceps femoris
  • Semitendinosus
  • Semimembranosus
• Medial thigh muscles are involved in thigh adduction, including:
  • Adductor magnus
  • Adductor brevis
  • Adductor longus
  • Gracilis
  • Pectineus

Leg Structure

• The leg is located between the knee and the foot, consisting of two bones:
  • Tibia (medially positioned, also known as the shin bone)
  • Fibula (laterally positioned)
• Muscle groups in the leg are categorized into three compartments:
  • Anterior compartment (includes:
    • Tibialis anterior
    • Extensors
    • Hallucis longus
    • Extensor digitorum longus
    • Fibularis muscles)
  • Lateral compartment (includes:
    • Fibularis longus
    • Fibularis brevis)
  • Posterior compartment (includes:
    • Gastrocnemius
    • Soleus
    • Deep muscles like tibialis posterior, popliteus, flexor hallucis longus, flexor digitorum longus)

Foot Anatomy

• The foot consists of 22 bones:
  • 7 tarsals
  • 5 metatarsals
  • 10 phalanges

Muscle Proteins

• Three classes of muscle proteins include:
  • Contractile proteins: Responsible for contraction and relaxation.
    • Myosin: Thick filament with one tail and two heads.
    • Actin: Thin filament with binding sights for myosin.
  • Regulatory proteins: Regulate contraction actions, including:
    • Troponin
    • Tropomyosin: Covers binding sights on actin when muscles are relaxed.
  • Structural proteins: Maintain filament alignment, including:
    • Titin
    • Nebulin
    • Myomesin
    • Alpha-actinin
    • Dystrophin

Mechanism of Muscle Contraction

• Contraction occurs when actin and myosin bind and slide over each other.
• Troponin and tropomyosin play crucial regulatory roles, enabling contraction.

Muscular System Functions

• Produces movement throughout the body.

Renal System: Glomerulus

• A capillary bed in the Bowman’s capsule plays a vital role in filtration.
• Comprised of afferent and efferent arterioles; the renal artery supplies 20% of cardiac output to the kidneys.
• Blood exits the kidney via the renal vein, with nerve supply from the renal plexus.

Renal Tubule Structure

• Contains:
  • Proximal convoluted tubule
  • Loop of Henle (thick and thin segments)
  • Distal convoluted tubule
  • Collecting duct

Physiological Functions of the Kidney

• Hormonal factors can lead to vasoconstriction, affecting glomerular fluid dynamics:
  • Angiotensin
  • Noradrenaline
  • Platelet activating factor
  • Endothelin

Urine Characteristics

• Volume: Typically 1-2 liters/24 hours.
• Color: Amber or straw-colored but may vary with diet/drugs.
• Odor: Aromatic when fresh, becomes ammonia-like with time.
• Specific gravity: Ranges from 1.001 to 1.035.
• pH: Ranges from 4.6 to 8.0.
• Turbidity: Freshly voided urine is transparent but can become turbid.

Ureter Anatomy

• A fibromuscular tube about 25 cm long, transporting urine from kidney to urinary bladder.
• Three tissue layers:
  • Mucosa (cuboidal epithelium)
  • Muscularis (smooth muscle in inner circular and outer longitudinal layers)
  • Adventitia (connective tissue)
• Peristaltic contractions move urine involuntarily.
• Blood supply comes from renal, rectal, and vesical arteries, with dual nerve innervation.

Urethra Characteristics

• Male urethra functions in urination and as a passage for semen; the female urethra is strictly urinary.
• The female urethra is positioned between the clitoris and vaginal orifice.

Body Regions

• The human body is divided into:
  • Axial Region (head, neck, torso)
  • Appendicular Region (upper and lower limbs)

Head Region

• The most superior body part, comprised of the cranium and the face.

Skin Structure

• The scalp skin is hairy, containing sebaceous glands.
• Consists of four layers:
  • Stratum Corneum
  • Stratum Spinosum
  • Stratum Basale
  • Stratum Granulosum
• The aponeurosis lies beneath, connecting skin to deeper layers.

Test your knowledge on the anatomy of the thigh and leg structure in this detailed quiz. Explore key features such as thigh muscles, blood vessels, and compartments. Enhance your understanding of human anatomy through targeted questions.