A subcutaneous injection is delivered into which tissue?

A subcutaneous injection is delivered into which tissue?

• A. They are injected into a joint cavity
• B. They are injected into the spinal canal
• C. They are injected into muscle
• D. They are injected into the fatty tissue under the skin

Answer: (D)

Subcutaneous injections are delivered into the fatty tissue just beneath the skin, the subcutaneous layer. This tissue is primarily adipose and loose connective tissue with relatively few blood vessels compared with muscle, so absorption is slower and more prolonged. That slower uptake makes it ideal for medications that need steady, gradual absorption, like insulin or certain vaccines. Injections into a joint cavity target the synovial space, injections into the spinal canal access the epidural or intrathecal space, and injections into muscle deposit the drug into a highly vascular muscle tissue for faster absorption—all distinct from the fatty under-the-skin layer.

Subcutaneous injections are delivered into the fatty tissue just beneath the skin, the subcutaneous layer. This tissue is primarily adipose and loose connective tissue with relatively few blood vessels compared with muscle, so absorption is slower and more prolonged. That slower uptake makes it ideal for medications that need steady, gradual absorption, like insulin or certain vaccines. Injections into a joint cavity target the synovial space, injections into the spinal canal access the epidural or intrathecal space, and injections into muscle deposit the drug into a highly vascular muscle tissue for faster absorption—all distinct from the fatty under-the-skin layer.