EC

Anatomy and Physiology lab apr 23

Agrovitae and Brain Structure

  • Agrovitae: Composed of flaming fibers, previously mentioned in class.

  • Midbrain: Defined as the section between the brain and belly, akin to the neck of the brain stem.

  • Nerve Root: Introduction to the concept of a nerve root, crucial for brain-to-spinal cord connections.

  • Neuron to Nerve Fascicle:

    • The deeper structure from a neuron is called a nerve fascicle.

    • A nerve is further composed of layers: perimysium and epimysium (similar to muscle anatomy).

    • Axon: Surrounded by endoneurium, forming the basic building blocks of muscles and nerves.

Types of Nerves

  • Granular Nerves: Six important types discussed in class, focusing on their function and location.

  • Trigeminal Nerve: Important to know its location.

Nerve Plexuses

Cervical Plexus

  • Composed of nerve roots C1-C5, forms a plexus.

  • Phrenic Nerve: Vital for innervating the diaphragm. Critical in respiration.

Brachial Plexus

  • Contains significant nerves including

    • Ulnar, Medial, Radial, Musculoskeletal.

  • Responsible for innervation of upper extremity muscles (e.g., biceps, brachialis, deltoid).

Lumbar Plexus

  • Important nerve: Femoral Nerve - innervates the front thigh muscles.

  • Related roots: L4, L5, S1, S2.

Sacral Plexus

  • Discussed anatomical significance and relevance to functioning.

Clinical Correlates

  • Notable issues with nerves in the lumbar area may lead to incontinence, signaling severe complications. Immediate surgery advised in such cases.

  • Common symptoms include:

    • Low back pain

    • Urgency issues (different from incontinence)

Ear Anatomy

  • External Ear: Extends to the tympanic membrane.

  • Middle Ear: Contains three ossicles (malleus, incus, stapes), critical structures for hearing.

  • Eustachian Tube: Conditional importance for ear infections; positioned differently at various ages.

  • Inner Ear:

    • Contains Vestibule and Cochlea.

    • The Vestibulocochlear Nerve: Innervates both structures.

    • Vestibule is crucial for balance, while cochlea is essential for hearing.

Eye Anatomy

  • Cornea: First layer; prone to scratches.

  • Iris: Contains intrinsic muscles controlling the pupil size.

  • Sclera: Outer layer of the eye.

  • Optic Nerve: Cranial Nerve II; transmits signals from the eye to the brain.

  • Fovea Centralis: Critical for acute vision; darker appearance in diabetic patients due to vascular changes.

Summary of Key Structures

  • Always identify the specific roles of nerves and their associated muscle groups.

  • Understand the pathways and connections within nerves from plexuses to their target muscles.

  • Recognize clinical implications of nerve damage or dysfunction, especially related to the lumbar and sacral plexuses.