Random things I need to know

Question 1

What is epihelial tissue?

Answer 1

Covers exposed surface and lines internal pathways and chambers. Forms secretory glands. Provides physical protection, controls permeability, provides sensation, produces specialised secretions

Question 2

What is connective tissue?

Answer 2

Fills internal spaces, provides structural support, store energy, establish a structural framework for the body, transports fluids and dissolved materials, protects delicate organs.
e.g. cartilage, bone, blood, connective tissue

Question 3

Muscle tissue?

Answer 3

Contracts to produce movements. Includes skeletal, cardiac and smooth muscle.

Question 4

Nervous tissue?

Answer 4

Conducts electrical impulses, carries information, maintains physical structure of nervous tissue, repair after injury, provides nutrients and neurons.

Question 5

Vertebral column numbers?

Answer 5

Cervical - 7
Thoracic - 12
Lumbar - 5
Sacrum and coccxyx

Question 6

Number of bones in hand?

Answer 6

Carpals - 8
Metacarpals - 5
Phalanges - 14 in a hand

Question 7

What is an osteon? What is its function?

Answer 7

longitudinal (lengthwise) circular unit within compact bone (function= maintaining the osteocytes by providing nutrients - brought in by blood).

Question 8

Lamelle

Answer 8

tubes of ECM with collagen fibres aligned to resist forces. Wherever forces are coming from, the bone can resist them. Lamellae form a series of cylinders down the shaft - forming the osteon.

Question 9

Canaliculi

Answer 9

channels for osteocytes through the ECM

Question 10

What is remodeling?

Answer 10

Bone turn over. Maintains normal mature compact bone. Blood vessels bringing in osteoblasts after the osteoclasts have destroyed the ECM and they produce ECM and the osteocytes are trapped in this ECM and then they communicate by way of the lacunae/ canaliculi. This is a ongoing process. Turns into the osteon network.

Question 11

Trabeculae

Answer 11

(struts of lamella bone) each of the components of the cancellous bone is called a trabeculae made of lamella. Organisation of these trabecule isn’t random - organised inside the bones depending on the force (arranged in such a way to diffuse the forces going on in that area). Zone of weakness (less trabeculae)

Question 12

What is DFCT made up of?

Answer 12

Type of connective tissue that is made up of a large number of densely packed collagen fibres arranged in a parallel formation

Question 13

What is abduction and adduction at the ankle restricted by?

Answer 13

Restricted by the lateral and medial malleolus of the tibia, but also by collateral ligaments.

Question 14

What is the synovial membrane made up of?

Answer 14

Epithelial cells which secrete the synovial fluid.

Question 15

What are tendons and ligaments made up of?

Answer 15

DFCT = dense fiberous connective tissue

Question 16

How is fibrocartilage formed?

Answer 16

By chondrocytes surrounded by the ground substance of proteoglycans, with high amounts of collagen fibres embedded in the ground substance. They vary in directions of alignment, but are always aligned with the stress.

Question 17

How is DFCT formed?

Answer 17

Formed by fibroblasts with tightly packed collagen fibres surrounding them. These are aligned parallel.

Question 18

What is the postassium concentration of the outside vs inside of the cell

Answer 18

K is at a high concentration on the inside of cells and a low conc on the outside.

Question 19

How does high K inside the CHEMICAL cell affect movement?

Answer 19

There is a chemical gradient that favours K movement through the channels from the inside to the outside of the cell.

Question 20

The resting membrane potential is?

Answer 20

Negative. -70mV.

Question 21

What is the ELECTRICAL gradient for K ions?

Answer 21

Because the resting membrane potential is negative, the electrical gradients for K (because they are positively charged and will favour going to the negative side of the cell) is from the outside to the inside.

Question 22

What is the OVERALL concentration gradient for K ions?

Answer 22

Overall the large potassium chemical gradient is offset (at the resting membrane potential) but still from the inside to the outside - so K+ prefers to move out of the cell. (same way as chemical gradient)

Question 23

What are the roles of tropomyosin and troponin, with reference to regulating the interactions between actin and myosin?

Answer 23

Calcium ions from the sarcoplasmic reticulum bind to troponin which causes a structural change in tropomyosin, exposing the active binding site on actin for the myosin head to bind to.

Question 24

What does the myelinated motor axon do?

Answer 24

Forms a special synapse with each individual muscle fibre called the Neuromuscular junction (NMJ) at one single location on each muscle fibre membrane (sarcolemma).

Question 25

What does the presence of the NMJ allow for?

Answer 25

Allows for the excitation to spread along the sarcolemma in all directions, because it to is excitable tissue (just like a neuron).

Question 26

What are T-tubules function?

Answer 26

The sarcolemma has holes called T-tubules that allow for the electrical signal to spread all the way deep down inside the muscle cell to the location of the sarcoplasmic recticulum (SR).

Question 27

What is the sarcoplasmic retuculms primary role?

Answer 27

Its primary role is to store calcium, ready to be released, when the excitation comes along the ttubes and reaches the ‘triad’

Question 28

What is the triad?

Answer 28

The conncection point between the ttube and the terminal cisternae of the SR.

Question 29

What is the definition of a sarcomere?

Answer 29

The portion of a myofibril from one Z-line to the next, constituting to one contractile unit.

Question 30

What is the power stroke caused by?

Answer 30

ADP + Pi being released (cause the conformational change)

Question 31

What is the post-synaptic cell?

Answer 31

The cell that the neuron connects with and releases neurotransmitter on to (after the synapse)

Question 32

What does reversal of the membrane potential mean? / depolarisation

Answer 32

The membrane potential become positive (due to all of the positively charged ions that rush into the cell during an action potential). Cell membrane potential become less negative and therefore less polarised.

Question 33

Where does inversion and eversion occur?

Answer 33

At the foot joint, NOT the ankle joint

Question 34

What is the role of calcium in a axon terminal?

Answer 34

Calcium entering the axon terminal from the ECF that allows the neurotransmitter to be released.

Question 35

What do synovial joints consist of?

Answer 35

Bone tissue (bone ends), DFCT (dense fiberous connective tissue), hyaline cartilage and connective tissue (synovial membrane which is made of epipheleal cells which secrete synovial fluid)

Question 36

What is the neurotransmitter released with skeletal muscle called?

Answer 36

Acetyl chlorine (Ach) is the neurotransmitter released in all neuromuscular junctions with skeletal muscle.

Question 37

What happens in a synaptic transmission?

Answer 37

Ach is released via exocytosis by synaptic vesicles triggered by the CA ions entering through channels. Ach will bind to a stimulus-gated sodium channel. Opening of the stimulus gated sodium channel causes a depolarisation in the sarcolemma. This depolarisation is what causes the voltage-gated sodium channel to open up, initiating the spread of the action potential along the sarcolemma in all directions.

Question 38

What is depolarisation?

Answer 38

When the cell undergoes a shift in electric charge distribution, resulting in a less negative charge inside the cell.

Question 39

What is the structure of a fiberous joint?

Answer 39

Fiberous joints are ligamentous. Fibres are made of the same tissue but slightly different arrangements of ligaments.