physiology, digestion and life on earth

Question 1

what structure are cardiac and skeletal muscles?

Answer 1

striated

Question 2

where are smooth muscles located?

Answer 2

gut, blood, vessels

Question 3

what are fibres made up of?

Answer 3

myofibrils

Question 4

what are myofibrils made up of?

Answer 4

repeated sarcomere units

Question 5

what are sarcomeres made up of?

Answer 5

protein filaments- actin (thin) and myosin (thick)

Question 6

name the 4 categories of tissues

Answer 6

epithelium, connective, muscle and nerve

Question 7

name the 3 types of muscle tissue

Answer 7

skeletal, smooth and cardiac

Question 8

where are skeletal muscles located?

Answer 8

limbs

Question 9

what is the structure of smooth muscle?

Answer 9

non- striates

Question 10

describe the control of cardiac, skeletal and smooth muscle fibres

Answer 10

cardiac and smooth= involuntary
skeletal= voluntary

Question 11

describe the power of cardiac, skeletal and smooth muscle fibres

Answer 11

cardiac = high
skeletal = high (when moving limbs)
smooth = low

Question 12

describe the sliding filament model

Answer 12

a muscle fiber contracts when myosin filaments pull actin filaments closer together and thus shorten sarcomeres within a fiber. (thin filaments slide over thick filaments without changing length)

Question 13

what is the CNS made up of?

Answer 13

brain and spinal chord

Question 14

what is the PNS made up of?

Answer 14

sensory and motor nerves

Question 15

what do sensory nerves do?

Answer 15

they respond to stimuli

Question 16

what do motor nerves do?

Answer 16

they activate contraction

Question 17

describe the parts of the neuron

Answer 17

cell body, nucleus, axon (outgoing signals) and dendrites (incoming signals)

Question 18

describe myelin

Answer 18

extra membrane wrapped around axon as insulation

Question 19

how is myelin produced?

Answer 19

produced by accessory cells/ Schwann cells

Question 20

how does myelin speed transmission?

Answer 20

by saltatory conduction at nodes of ranvier (gaps in the myelin sheath)

Question 21

what what are the nodes of ranvier?

Answer 21

It is a depolarised region surrounded by Na+ channels

Question 22

what is saltatory conductance?

Answer 22

is the process of the potential changes at the nodes of ranvier, which happens in a leap frog fashion. These impulses are conducted by the myelin sheath

Question 23

describe the Na+ channels in non- myelinated nerve cells

Answer 23

their action is slower and more chaotic

Question 24

what does destroyed or damaged myelin result in?

Answer 24

scarring called sclerosis

Question 25

what is multiple sclerosis?

Answer 25

a degenerative disease that attacks the CNS as white blood cells attacks neuron's. This affects myelin around nerve fibres in brain and spinal cord.

Question 26

how are MS symptoms caused?

Answer 26

Nerve signals slowed or blocked, causing the symptoms

Question 27

uses of synapse

Answer 27

for the integration of information/ response