Nervous System

Question 1

FUNCTIONS OF NERVOUS SYSTEM

Answer 1

Controls actions of all bodily systems 3 functions = SIM

1. Sensory- gather info from peripheral nervous system sensory areas of brain SENSORY/AFFERENT nerves carry incoming messages from peripheral NS to central NS (they are Affected by the external environment)
2. Integrative- Central Nervous system analyses info (association areas of brain)
3. Motor- respond (motor areas of brain) sends messages via peripheral nervous system to prompt action
   MOTOR/EFFERENT nerves carry outgoing messages to muscles/glands (they effect an action)

Question 2

STRUCTURE OF NERVOUS SYSTEM

Answer 2

Central nervous system = Brain and spinal column>
>
Peripheral nervous system (31 pairs of nerves)
I
1. Autonomic nervous system
internal environment
involuntary
I I
Sympathetic Parasympathetic
accelerator decelerator
(fight/flight)

2. somatic- conscious control of muscles (soma=body)

Question 3

SYMPATHETIC & PARASYMPATHETIC

Answer 3

Sympathetic nerves release adrenaline (epinephrine) and noradrenaline (norepinephrine)
increases heart rate
increases breathing rate
vasoconstriction of arteries (inc blood pressure)
Mobilises energy stores

Parasympathetic nerves release acetylcholine has opposite effect

work together to maintain HOMEOSTASIS

Question 4

DESCRIBE THE TRANSMISSION OF NERVE IMPULSES

Answer 4

Neurons/nerve cells transmit chemical messengers (neurotransmitters) around the body
A nerve impulse begins when a neuron receives a chemical stimulus.
* The nerve impulse travels down the axon membrane as an electrical action potential to the axon terminal.
* The axon terminal releases neurotransmitters that carry the nerve impulse to the next cell.

SYNAPSE = gap between neutrons where nerve impulse is transmitted from one to the other

Question 5

ACTION POTENTIAL

Answer 5

Action Potential = outside of neutron membrane positively charged compared to inside
Nerve impulse causes membrane to become permeable
>sodium ions flood in and depolarise cell
>membrane is more positively charged on inside
>impulse allowed to travel along neutron
> LOOK AT THIS AGAIN

Question 6

NERVE STRUCTURE

Answer 6

Nerve cells (neurons) Cell body contains nucleus (contains DNA and regulates activity)
Many dendrites (receives impulses) could be small but also up to 1m in length (lumbar spine to great toe)
And a single AXON sends impulses AWAY (covered with fatty myelin sheath (facilitates transmission of messages))
Axon/synaptic terminals contain sacs of chemical neurotransmitters

Question 7

what is the role of Muscle Spindles

Answer 7

They detect lengthening (spindles are spun out looong)
muscle lengthening too fast/too much
STRETCH REFLEX message is sent to muscles to contract

Question 8

What is the role of golgi tendon organs (GTO)

Answer 8

they detect excessive contraction or tension in muscles and inhibit motor signals to stop contraction INVERSE STRETCH REFLEX
REMEMBER
GolgIs don’t like getting too tIght (Inverse stretch reflex)
Spindles don’t like getting too Stretched (stretch reflex)

Question 9

What is reciprocal inhibition

Answer 9

working in pairs like muscles- 1 contracts while the other relaxes and vice versa
In very intense exercise, the signals can get mixed up leading to injury

Question 10

What is epinephrine?

Answer 10

adrenaline
a neurotransmitter released by the sympathetic nervous system
induces fight or flight response
ie heart rate and breathing rate rise, blood directed to muscles (vasodilation/vasoconstriction) energy stores mobilised

Question 11

What is acetylcholine

Answer 11

neurotransmitter released by parasympathetic system
decelerates system
ie lowers heart rate and breathing rate, blood directed away from muscles, blood pressure goes back to normal
“Ah see till co lean”

Question 12

the force of a muscular contraction is dependent on what?

Answer 12

frequency of signal

number of motor units recruited

Question 13

nervous system adaptations to exercise

Answer 13

connections stregthened and increased,
improves balance, coordination, speed, agility, reaction time, spatial awareness, reaction time, muscular coordination
increase speed and frequency of nerve impulses
improved synchronisation of motor recruitment

Question 14

WHATS THE DIFFERENCE BETWEEN SENSORY NEURONS AND MOTOR NEURONS

Answer 14

Sensory neurons transmit into from sensory organs to central nervous system (what’s happening in the environment)
Motor neurons transmit info from brain to muscles and glands (ie what action to take)

Question 15

WHAT IS A RECIPROCAL INHIBITION STRETCH

Answer 15

Recipriocal inhibition stretches both the agonist and antagonist
more effective and safer stretch

Question 16

what are the terms for incoming/outgoing messages?

Answer 16

Afferent messages come in to the
CNS which sends 
EFFERENT messages to the motor neurons
A
C
E

Question 17

How do merge impulsss cross synapse?

Answer 17

The electrical impulse is converted into chemical form. Like getting in a bost