Transcript connective tissue

Connective Tissues of
the Human Body
Types of connective tissues
• LIGAMENT: Connects muscle to bone to allow
movement across the joints.
• TENDON: Connects bone to bone, holds the bones in
place and provides stability to the joint.
• JOINT CAPSULE: Contains the fluid at the joint
surface which lubricates the joint while it is active.
Connective Tissue
• The knee is the largest joint in your body, forming a hinge
between your thigh bone (femur) above and the bones of your
lower leg — the tibia (shin bone) and fibula, below.
• Strong bands of fibrous tissue called ligaments help stabilise
the knee joint and align the bones that meet at the knee.
• There are 2 main sets of ligaments in the knee joint: the
collateral ligaments, which run along either side of your knee
joint, and the cruciate ligaments, which sit inside your knee
joint.
• Collateral ligaments
The lateral collateral ligament strengthens the knee joint on
the outer side of the knee. It runs between your thigh bone
(femur) and the top of your fibula — the long, thin bone on
the outside of your main shin bone.
• The medial collateral ligament strengthens the knee joint
on the inner side of the knee. It runs between your femur
and the upper inside edge of your shin bone (tibia).
• Together the collateral ligaments resist side-to-side
movement of the knee joint and help prevent rotation
between your thigh bone and your shin.
• The lateral collateral ligament can be torn when
your knee twists, is hit on the inner side, or is
forced outwards while your foot is pushed
inwards. A lateral collateral ligament tear rarely
occurs on its own, and usually accompanies a tear
to other knee ligaments.
• Tears to the medial collateral ligament are
relatively common and can arise from a direct hit
to your knee, twisting of your knee, or a force that
pushes your foot outwards and your knee inwards.
• Cruciate ligaments
The cruciate ligaments are short strong bands of fibrous tissue that
cross each other inside your knee joint and join your tibia to your
femur. They are named according to where they attach on the top of
the tibia.
• The anterior cruciate ligament (ACL) runs from the front of your tibia,
backwards and slightly outwards, to the base of your femur. This
ligament stops your shin bone from moving forwards in front of your
thigh bone.
• The posterior cruciate ligament (PCL) runs from the rear of your tibia,
forwards and slightly inwards, to the base of your femur. This ligament
stops your shin bone from moving backwards, relative to your thigh
bone. It is generally stronger than the ACL.
• Tearing of the anterior cruciate ligament is a very common sporting
injury. An ACL tear can happen when you change direction rapidly,
slow down when running, land after a jump, or receive a direct blow to
your knee.
• Injuries to the posterior cruciate ligament are less common. They can
result if your knee is over-straightened or over-flexed (bent too
strongly), or the shin is forced backwards.
• A tear of the anterior cruciate ligament tends to be a more serious
injury than an equivalent tear to any of the other knee ligaments, as
joint stability is more profoundly affected, and surgery is often
necessary.
• Partial or even complete tears of the posterior cruciate or the collateral
ligaments can often heal with a prescribed rehabilitation programme.
However, if more than one ligament is injured, surgery is often needed.
Muscular system
Functions
• The human body has over 600 muscles. These muscles function to allow a
range of physical movements that we either consciously or subconsciously
control.
• These movements range from fine motor skills such as blinking an eye or
writing, to gross body movements such as sprinting or throwing a ball (see
chapters 1 and 3 for more information on skilled movement).
• The body’s health relies on essential subconscious movements that need
muscle effort; for example, the diaphragm and intercostal muscles help
breathing, while muscular contractions around the intestines aids in the
movement of food throughout the digestive tract.
The digestive tract
Adequate posture
• Muscles are continually in a state of ‘tone’ that affects their ability to help
our body to maintain an upright posture when awake and to function safely
during sleep.
• People with poor muscle tone generally have poor posture and resultant
aches and pains because gravity is defeating the muscles’ resistance.
• Muscles of the upper back — such as the trapezius, rhomboids and the
latissimus dorsi — particularly influence posture maintenance.
• Regular exercise helps improve muscle tone, which allows resting muscles
to resist being stretched and keeps them in constant readiness.