Tissues + Structures - Subcut Tissue, Raphes, Cartilages, Tendons, Ligaments. Flashcards
What is aerolar tissue?
Connective tissue which connects the skin to underlying structures.
What is the panniculus adiposus?
Blanket of fat beneath the skin.
What passes through the panniculus adiposus to get to the skin?
- Blood vessels.
- Nerves.
- Lymphatics.
What occurs in the panniculus adiposus?
Panniculus carnosus.
What is the panniculus carnosus?
Flat sheets of muscle.
What is the purpose of panniculus carnosus?
To allow for muscle fibre to be attached to skin and then also deep fascia or bone.
What areas is the panniculus carnosus well developed?
- Platysma muscle.
- Palmaris brevis (remnants).
- Corrugator cutis ani.
- Dartos sheet of scrotum.
- Subareolar muscle in nipple.
What makes up deep fascia?
Fibrous tissue.
What does deep fascia do?
Covers limbs and body wall.
Does the deep fascia vary in thickness?
Yes it does.
1. Fascia lata - very well developed.
2. Rectus sheath and external oblique aponeurosis - thin.
3. Face and ischioanal fossa - absent.
How does deep fascia connect to bone?
It never passes freely over bone but is always anchored firmly to the periosteum.
What is the purpose of the deep fascia?
Attachment of the skin by way of fibrous strands in the subcutaneous tissue.
Where does deep fascia get its nerve supply from?
Overlying skin. Nerves to the muscles do not supply the investing layer of deep fascia.
What is a ligament?
Dense connective tissue (white fibrous tissue - mainly collagen) band that connects bone to bone.
What is a ligaments physical property?
Non-elastic and unstretchable.
What happens if the ligaments stretch too much?
Then mobility which was not previously possible can occur e.g. contortionists.
Why are ligaments arranged they are?
So that they are never subjected to prolonged strain. Except sacroiliac ligaments and intervertebral discs.
What is the second type of ligament?
Ligament made of elastic tissue that can regain its former length after stretching.
What is the colour of this 2nd ligament?
Yellow.
Where can you find this 2nd type of ligament?
- Ligamenta flava - laminae of vertebrae.
- Ligaments of joints of the auditory ossicles.
What do tendons do?
Attach muscle to bone.
What shape can tendons have?
- Cylindrical.
- Flat.
Where do tendons get their blood supply from?
Vessels which descend from muscle belly and anastomose with vessels coming from the periosteum at the bony attachment.
What happens to blood supply in long tendons?
Intermediate vessels from a neighbouring artery will join the longitudinal anastomoses.
What is a synovial sheath?
Sheath that covers a tendon, especially when the tendon loops or is a pulley.
Where does the parietal layer of the sheath attach to?
Surrounding structures.
Where does the visceral layer of the sheath attach to?
Tendon.
What allows the two layers of the sheath to glide over each other?
Synovial fluid - secreted by lining cells of the sheath.
Do the layers of the synovial sheath fully close up?
No - there is a space that allows for blood vessels to enter into the tendon. (Like a sausage in a bun).
What is a raphe?
Interdigitation of the short tendinous ends of fibres of flat muscle sheets.
What can raphe do?
They can elongate passively by separation of its attached ends.
What is the purpose of a raphe?
To allow for stretch in places that need to be stretched e.g. mandible.
What are examples of raphe?
- Pterygomandibular raphe.
- Mylohyoid.
- Pharyngeal.
- Anococcygeal.
What is cartilage?
Dense connective tissue in which cells and fibres are embedded in a firm ground substance or matrix.
What are the types of cartilage?
- Hyaline.
- Fibrocartilage.
- Elastic.
What does hyaline cartilage do?
- Cover the articular surfaces of typical synovial joints.
- Forms epiphyseal growth plates of growing bones.
Describe the vascular nature of cartilage?
Cartialge is avascular for hyaline and elastic - capable of small amount of deformation. It has a certain resistance to fracture. Fibrocartilage has ordinary blood supply but is sparse due to metabolic rate being low.
What happens when cartilage is damaged?
It is repaired by formation of fibrous tissue, not new cartilage.
When can new cartilage be formed?
New cartialge can develop by the differentiation of osteochondrogenic cells.
What is fibrocartilage?
Cartilage that is similar to ligaments and tendons.
What does fibrocartilage contain?
Small islands of cartilage cells and ground substance between the collage bundles.
Where is cartilage found?
- Intervertebral discs.
- Labrum of shoulder and hip joints.
- Menisci of knee joint.
- Articular surfaces of clavicle and mandible.
- Attachment sites of tendons to bone epiphses - leave a smooth marking on bone.
What happens to hyaline cartilage and fibrous cartilage with age?
Calcify and ossify.
What is elastic cartilage?
Ground substance that contains large numbers of elastic fibres.
What is the purpose of elastic cartilage?
Cartilage that can be easily distorted and can easily spring back to original shape at reast.
Where can you find elastic cartilage?
- Epiglottis.
- Pinna.
- Auditory tube.
Can elastic cartilage ossify or calcify?
No.
