The musculoskeletal system

Question 1

What are tendons vs ligaments?

Answer 1

Associated connective tissue (tendons) attach muscle to bone or muscle to muscle
Associated connective tissue (ligaments) attach bone to bone. They give stability to joints, holding them in place which prevents dislocation.

Question 2

What is the function of the skeletal system?

Answer 2

Protects and supports vital organs and body posture
Enables locomotion
Stores calcium and participate in Ca homeostasis
Site of haematopiosis which develops RBCs.

Question 3

Identify the main differences between cartilage and bone in terms of structure, function and location

Answer 3

Bones are tough, inflexible. Protect organs and support the body.
Cartilage= flexible and elastic. They cushion bones against impact which keeps joints in motion

Bones form the appendicular and axial skeleton, but cartilage is found at joints, growth plates and other sites.

Question 4

Identify the main differences between cartilage and bone in terms of blood supply, calcium salt levels, growth direction

Answer 4

Bones have a rich blood supply. Cartilage has no blood vessels, nutrients are obtained via diffusion.
Bones have rich Ca salt deposits. Cartilages may or may not have Ca deposits.
Bone growth is bi-directional, cartilage is unidirectional.
Bone Marrow is present in bones, absent in cartilages

Question 5

Describe and label the bones of the skull

Answer 5

The superior part of the ethmoid bone makes up the nasal cavity. The ethmoid and vomer form the bony bit of our nasal septum

Question 6

Describe the viscerocranium. Identify the highlighted images

Answer 6

The viscerocranium includes the facial skeleton and the mandible (or jaw)

Question 7

Draw and describe joints

Answer 7

Cartilage and sinovial fluid cushions the joints and prevents bones rubbing to allow easy, comfortable movements.

Question 8

Describe and label the bones of the upper arm

Answer 8

This is part of the axial skeleton

Question 9

Describe and label the bones of the lower limb

Answer 9

This is the appendicular skeleton

Question 10

Label the bones of the skull

Answer 10

.

Question 11

How can the cranium be divided?

Answer 11

The skull/cranium can be divided into neurocranium and viscerocranium.
The neurocranium consists of: cranial roof (calvarium/skull cap/cranial vault) and a Cranial base

Question 12

Describe and label the bones of the axial skeleton.

Answer 12

.

Question 13

Describe and label the bones of the appendicular skeleton

Answer 13

.

Question 14

State the function of muscles

Answer 14

Used for:
Joint stability
Blood circulation
Respiration
Digestion
Temperature regulation
Vision
Organ protection

James Buckley really doesn’t try voice projection
(how I remember this)

Question 15

What are the ways to classify and describe muscles?

Answer 15

Shape, number of heads (proximal attachments), orientation of fibres, their microstructure, their action, their position in the body

Question 16

Describe the structure of skeletal muscle

Answer 16

The widest diameter of the contracting muscle is the belly. It’s wrapped in a layer of epimysium.
In the cross-section of the muscle belly, thin layers of perimysium separate the muscle into fascicles.
Each fascicle consists of a bundle of muscle fibers.

Question 17

Describe the structure of a skeletal myocyte- incl the sarcolemma and sarcoplasm

Answer 17

Myocytes are long, multi nucleated. The plasma membrane of a myocyte is the sarcolemma.

The sarcolemma makes T tubules. The sarcoplasm has SR (stores Ca)

The sarcoplasm has myofibrils. Each myofibril=sarcomeres from actin and myosin.

Question 18

What are the types of pennate muscles?

Answer 18

Unipennate runs along the tendon. Parallel muscles DONT run along the tendon, they have tendons on either ends

Question 19

Describe and explain parallel, convergent, circular fusiform and non fusiform muscles.

Answer 19

Parallel muscles: fascicles are arranged along the longitudinal axis
Convergent muscle fibres arise from multiple points and converge at a single point.
Circular/sphincteral surround a body opening, and constricts it during contraction.
Fusiform muscles have a thick belly that’s tapered at both ends. eg the biceps brachii.
Non fusiform don’t get tapered at both ends

Question 20

Can we name muscles according to their actions?

Answer 20

The principal contracting muscle involved in an action is the agonist.
To lift a cup, the biceps brachii is the prime mover/agonist. It can be assisted by the brachialis, the asynergist in this action.
The antagonist is the triceps brachii, at the back of the arm because it relaxes/lengthens.

Question 21

Explain the terms origin and insertion.

Answer 21

Origin= The skeletal muscle is attached to a bone that remains immobile during an action (usually closer to the midline of our body).
Insertion= The skeletal muscle is attached to a bone that moves during the action.

Question 22

State the function of tendons and aponeurosis

Answer 22

Tendons anchor muscles to bone. They withstand compression, reserve energy /resist heat

Aponeurosis also attach muscles to bones but they are more delicate and thinner than tendons.

Question 23

What is a muscle compartment?

Answer 23

Muscles can be divided into muscle compartments, aka areas of muscles that are enclosed by a series of diff connective elastic tissues called fascia.
Function: keep muscles in place and reduce friction.

Question 24

Give an example of muscle compartments

Answer 24

The thigh has 3 muscle compartments: anterior, medial and posterior. Each compartment has its own arteries, innervation and is responsible for certain movements