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.