"And Yaakov went out of Be'er Sheva and he went to Charan. And he prayed in the place ..."
This translation of vayifga as prayer follows the opinion of Rabbi Yosi Bar Chanina (Brachot 26b). He thus maintains that Yaakov was the founder of our daily evening prayer, arvit. Nonetheless, certain laws of the prayer were later instituted by the Anshei Knesset Hagdola [The Great Assembly] based upon the Temple service of burning the various parts of the karbanot during the night. Another opinion - Rabbi Yehoshua Ben Levi (ibid.) - denies any connection between Yaakov Avinu and arvit; it is rather, totally a product of Anshei Knesset Hagdola. [The actual text of our shmonah esrei was surely composed by the Great Assembly, even according to the first opinion. (See Gemara Megillah 17b) See also our article a few weeks ago, Parshat Vayeira.]
II
Our daily tefillat arvit is comprised of three basic parts: kriat shma, shmonah esrei, and birchot kriat shma (the blessings pre and post kriat shma).
It is interesting to note that the latest time for arvit shmonah esrei differs -at times- from the latest acceptable time for kriat shma. The halachic night ends at alot hashachar [listed on any comprehensive Jewish calendar] - which is well before sunrise. Accordingly, the nighttime prayer of arvit may not be said past alot hashachar. This applies to shmonah esrei of arvit. (Mishnah Brurah 235:34, based on Rambam. See Aruch Hashulchan.) However, kriat shma differs. Although, ideally, shma should be recited at once upon nightfall, or minimally by chatzot [check your calendar!], b'dieved (post facto) he may recite it until alot hashachar. However, in a case of o'ness, such as a sick person who could not do so before alot hashachar, kriat shma may be performed as a valid mitzvah even after alot hashachar, until sunrise. (Shulchan Aruch O.C. 235:4) The reasoning for this leniency regarding shma as opposed to shmonah esrei is that shma is not dependent upon the halachic night, per se. Rather, it is governed by the word "uv'shachb'cha", when people sleep. Since there are people who sleep past alot hashachar, the time slot between alot and sunrise satisfies the requirement of "uv'shachb'cha" for kriat shma. Shmonah esrei on the other hand, has nothing to do with "uv'shachb'cha", rather halachic night. It may not be recited, in any circumstance, after alot hashachar.
III
What about our sick man saying birchot kriat shma after alot? Are these blessings considered to be part of the unit of kriat shma as their name may imply, and thus, follow the guidelines of "uv'shachb'cha" too? Or, are they an independent unit of our davening, following the more standard rules of halachic night? [...and their name is merely a result of their location.]
Shulchan Aruch (O.C. 235) states that birchot kriat shma may be recited after alot, in a case of o'ness, just as kriat shma. [Only the last brachah, hashkiveinu, must be omitted since it is too late for people to first go to sleep (thus the prayer of hashkiveinu is no longer relevant).] Apparently, the birchot kriat shma are considered to be a part of the kriat shma unit.
IV
Not so simple! We are all familiar with the announcement made at the early-Friday-night minyan. "Remember to repeat shma after nightfall." We cannot fulfill the mitzva of kriat shma beforehand. Nonetheless, we do recite birchot kriat shma at that early hour!
Similarly, the late-Shabbat-morning minyan misses z'man kriat shma of shacharit. Hopefully, all recite shma before shul. Nonetheless, they do recite birchot kriat shma in shul, at a time totally unacceptable for shma itself!
It seems [Tshuvat haRashba, quoted by Bet Yosef O.C. 59, 235] that birchot kriat shma do have independent status and are not governed by the laws of kriat shma. This appears to contradict our conclusion in section 3.
V
Perhaps, both aspects apply to birchot kriat shma. They have independent status as a distinct section of our prayers, but also join as part of the unit of kriat shma. Accordingly, the kriat shma aspect of the birchot kriat shma allows them to be recited even after alot (section 3) whereas their independent status allows them to be said even at times illegal for shma.
[Our discussion leads to the accepted conclusion that it is preferable to daven on Shabbat morning in a minyan which says kriat shma in its proper time.]