What does it mean that deep fascia invests in deeper structures...?"?

Question

I'm a medical student, and I'm studying from Moore and Agur's Essential Clinical Anatomy and I was somewhat confused about something. Since I haven't taken a human physiology class, I decided to read the intro chapter that most people skip, but I'm very lost on something:

It says that extensions of the deep fascia of the integumentary system "invest deeper structures, such as individual muscles and neurovascular bundles (investing fascia)"

I was hoping someone could explain this a little better and maybe give an example.

Thanks!

Answer 1

It wraps around and between them and forms a connection to the superficial fascia.

Answer 2

it means that deep fascia unlike superficial fascia cover muscles and sometimes the vessels. For instance in the dissection of the breast you'll notice the superficial fascia under the skin lies on top of the fat while the deep fascia is under the fat covering pectoralis major muscle.