diff --git a/sentry_sdk/api.py b/sentry_sdk/api.py
index 44472f2720..51a584bf26 100644
--- a/sentry_sdk/api.py
+++ b/sentry_sdk/api.py
@@ -1,6 +1,6 @@
 import inspect
 
-from sentry_sdk import tracing, tracing_utils, Client
+from sentry_sdk import tracing_utils, Client
 from sentry_sdk._init_implementation import init
 from sentry_sdk.tracing import POTelSpan, Transaction, trace
 from sentry_sdk.crons import monitor
@@ -233,14 +233,17 @@ def flush(
 
 
 def start_span(
+    *,
+    root_span=None,
+    custom_sampling_context=None,
     **kwargs,  # type: Any
 ):
     # type: (...) -> POTelSpan
     """
-    Alias for tracing.POTelSpan constructor. The method signature is the same.
+    Start and return a span.
     """
     # TODO: Consider adding type hints to the method signature.
-    return tracing.POTelSpan(**kwargs)
+    return get_current_scope().start_span(root_span, custom_sampling_context, **kwargs)
 
 
 def start_transaction(
@@ -282,7 +285,11 @@ def start_transaction(
         constructor. See :py:class:`sentry_sdk.tracing.Transaction` for
         available arguments.
     """
-    return start_span(**kwargs)
+    return get_current_scope().start_span(
+        root_span=transaction,
+        custom_sampling_context=custom_sampling_context,
+        **kwargs,
+    )
 
 
 def set_measurement(name, value, unit=""):
diff --git a/sentry_sdk/scope.py b/sentry_sdk/scope.py
index 2d7af53ea4..45d82cc4ee 100644
--- a/sentry_sdk/scope.py
+++ b/sentry_sdk/scope.py
@@ -25,6 +25,7 @@
     NoOpSpan,
     Span,
     Transaction,
+    POTelSpan,
 )
 from sentry_sdk._types import TYPE_CHECKING
 from sentry_sdk.utils import (
@@ -963,6 +964,10 @@ def start_transaction(
     ):
         # type: (Optional[Transaction], Optional[SamplingContext], Unpack[TransactionKwargs]) -> Union[Transaction, NoOpSpan]
         """
+        .. deprecated:: 3.0.0
+            This function is deprecated and will be removed in a future release.
+            Use :py:meth:`sentry_sdk.start_span` instead.
+
         Start and return a transaction.
 
         Start an existing transaction if given, otherwise create and start a new
@@ -999,13 +1004,9 @@ def start_transaction(
 
         custom_sampling_context = custom_sampling_context or {}
 
-        # kwargs at this point has type TransactionKwargs, since we have removed
-        # the client and custom_sampling_context from it.
-        transaction_kwargs = kwargs  # type: TransactionKwargs
-
         # if we haven't been given a transaction, make one
         if transaction is None:
-            transaction = Transaction(**transaction_kwargs)
+            transaction = POTelSpan(**kwargs)
 
         # use traces_sample_rate, traces_sampler, and/or inheritance to make a
         # sampling decision
@@ -1031,26 +1032,16 @@ def start_transaction(
 
         return transaction
 
-    def start_span(self, **kwargs):
-        # type: (Any) -> Span
+    def start_span(self, root_span=None, custom_sampling_context=None, **kwargs):
+        # type: (Optional[Span], Optional[SamplingContext], Any) -> Span
         """
-        Start a span whose parent is the currently active span or transaction, if any.
+        Start a span whose parent is the currently active span, if any.
 
         The return value is a :py:class:`sentry_sdk.tracing.Span` instance,
         typically used as a context manager to start and stop timing in a `with`
         block.
 
-        Only spans contained in a transaction are sent to Sentry. Most
-        integrations start a transaction at the appropriate time, for example
-        for every incoming HTTP request. Use
-        :py:meth:`sentry_sdk.start_transaction` to start a new transaction when
-        one is not already in progress.
-
         For supported `**kwargs` see :py:class:`sentry_sdk.tracing.Span`.
-
-        The instrumenter parameter is deprecated for user code, and it will
-        be removed in the next major version. Going forward, it should only
-        be used by the SDK itself.
         """
         with new_scope():
             kwargs.setdefault("scope", self)
@@ -1065,7 +1056,7 @@ def start_span(self, **kwargs):
                     if propagation_context is not None:
                         kwargs["trace_id"] = propagation_context.trace_id
 
-                span = Span(**kwargs)
+                span = POTelSpan(**kwargs)
             else:
                 # Children take `trace_id`` from the parent span.
                 span = span.start_child(**kwargs)