Lecture #17 - Human movement and sensation (full)

Question 1

Central Nervous system has what two parts?

What two parts in Peripheral Nervous System?

Answer 1

CNS = brain and spinal cord

PNS = spinal nerves and cranial nerves

Spinal = Nerves that originate from from the spinal cord and don’t exit the skull

Cranial = Nerves that originate from the brain or exit through the skull

Question 2

Types of information transmitted in and out of nervous system:

1. Somatic (soma = body) =
   - SOMATIC EFFERENT (or somatic motor):
   - SOMATIC AFFERENT (somatic sensory):
2. Autonomic =
   - AUTONOMIC EFFERENT (autonomic motor):
   - AUTONOMIC AFFERENT (autnomic sensory):

Answer 2

Types of information transmitted in and out of nervous system:

1. Somatic (soma = body) = the stuff we are aware of that happens in our body, have control over/conscious awareness of
   - SOMATIC EFFERENT (or somatic motor): information flowing out of CNS eg voluntary muscle control (we can choose to flex a muscle)
   - SOMATIC AFFERENT (somatic sensory): stuff coming into the CNS sensory information we are aware of telling us about what’s going on in our world (sensory information we are aware of) eg vision
2. Autonomic = the stuff we are not aware of, have no voluntary control over
   - AUTONOMIC EFFERENT (autonomic motor): information flowing out of our CNS that happens without our conscious control over it. Involuntary muscle control eg our heart - we don’t control it’s contractions
   - AUTONOMIC AFFERENT (autnomic sensory): information flowing into our CNS that we don’t have voluntary control of. Sensory information that we don’t know about eg our blood pressure - we don’t consciously know our blood pressure but our brain does

Question 3

What is Visceral Sensory sometimes called?

What’s an example of Somatic Efferent?

Answer 3

Visceral Sensory = Autonomic Afferernt

Skeletal muscle is an example

Question 4

Somatic Motor (Efferent) division:

1. Voluntary or involuntary?
2. How many neurons between CNS and effector (eg muscle)?
3. Cell body in what?
4. Axon in what?
5. Effectors = ?

Answer 4

1. Voluntary control
2. One neuron between CNS and effector (e.g. muscle)
3. Cell body in spinal cord (CNS)
4. Axon in spinal nerves (PNS)

This is that one cell that goes from CNS to PNS so neurons are different to normal cells

5. Effectors (= things the nerves go to and control) skeletal muscle fibres

Question 5

Anatomical organisation of Somatic motor (efferent)

• ____ motor neuron between the CNS and the effector
• ____ motor neuron has its cell body in the spinal cord (CNS) and its axon in a spinal nerve (PNS)

1. What’s the pre-synaptic cell?
2. What’s the post-synaptic cell?
3. What kind of junction is in the middle then?
4. What does the electrical signal release?
5. What is the neurotransmitter?

Answer 5

• One motor neuron between the CNS and the effector
• Single motor neuron has its cell body in the spinal cord (CNS) and its axon in a spinal nerve (PNS)

1. What’s the pre-synaptic cell? Neuron
2. What’s the post-synaptic cell? Muscle cell
3. What kind of junction is in the middle then? Neuro muscular junction (NMJ)
4. What does the electrical signal release? The electrical signal will release neurotransmitters which will make the muscle contract
5. ACh - Acetylcholine released by somatic motor neuron

Question 6

Motor units:

1. A single neuron makes contact with?
2. A single muscle fibre is NEVER?

Answer 6

1. A single neuron makes contact with one or several muscle fibres
2. A single muscle fibre is NEVER innervated by more than one neuron

Question 7

Summary of the Somatic Motor division:

1. Voluntary or involuntary?
2. Efferent or afferent?
3. ___ neuron transmits the info to ___ motor unit (=___ or more muscle fibres)
4. Cell body is in ____
5. Axon is myelinated or nah?
6. Neutrotransmitter = ?

Answer 7

Summary of Somatic Motor divison:

1. Voluntary
2. Efferent - info flows away from CNS
3. One neuron transmits the info to one motor unit (= one or more muscle fibres)
4. Cell body is in CNS (spinal cord)
5. Axon is myelinated
6. Neutrotransmitter = ACh

Question 8

Autonomic Motor (Efferent):

1. Voluntary or nah?
2. ___ neurons between CNS and effector?
3. Neuron #1 has cell body in ____ and axon in ____
4. Neuron #2 has cell body and axon in ____
5. Effectors (= things that nerves go to and control) - four of them, name em

Answer 8

Autonomic Motor (Efferent):

1. Voluntary
2. Two neurons between CNS and effector?
3. Neuron #1 has cell body in CNS and axon in PNS
4. Neuron #2 has cell body and axon in PNS (makes contact with the effector)
5. Effectors (= things that nerves go to and control)
   i) smooth muscle
   ii) cardiac muscle
   iii) glands
   iv) adipose (fat) tissue

Question 9

Basic anatomical features of autonomic motor devision:

Neuron #1:

1. Cell body in ___
2. Axon extends outside ___
3. Synapse in ____
4. Neurotransmitter = ?
5. Myelinated or nah?

Neuron #2:

1. Cell body in ___, autonomic ganglion
2. Axon extends to ____
3. Synapse on ____
4. Post-ganglion neuron
5. Neurotransmitter = ?
6. Myelinated or nah?

General:

1. What’s ganglion?
2. Why is neuron #2 not myelinated?
3. Another name for noradrenalin?

Answer 9

Basic anatomical features of autonomic motor devision:

Neuron #1:

1. Cell body in CNS
2. Axon extends outside CNS
3. Synapse in Autonomic Ganglion
4. Neurotransmitter = ACh
5. Myelinated

Neuron #2:

1. Cell body in PNS, autonomic ganglion
2. Axon extends to effector organ
3. Synapse on effector organ
4. Post-ganglion neuron
5. Neurotransmitter = ACh (acetylcholine) or NE (noradrenaline)
6. Unmyelinated

General:

1. What’s ganglion? a collection of cell bodies so autonomic ganglion has bodies of #2 neurons
2. Why is neuron #2 not myelinated? Since effectors small and precise, need lots of axons so need em to be small in diameter - for small diameter axons, myelin doesn’t affect them. Myelin only effective on big and medium diamters
3. Another name for noradrenalin?

Question 10

Here

Answer 10

Yeah

Question 11

What’re the two divisions of the autonomic efferent?

Division #1:

1. Prepares the body for?
2. Nickname for it?
3. Effects include (6)

Division #2:

1. Prepares the body for?
2. Nickcame for it?
3. Four effects

Answer 11

SYMPATHETIC:

1. Prepares the body for acute/stress responses
2. ”FightorFlight”system.
3. Effects include:
   (i) increased (↑) heartrate
   (ii) constrictingbloodvessels to skin and viscera (↑ blood flow to muscles)
   (iii) ↓ gastric motility
   (iv) ↓ salivation
   (v)  ↑ pupil size
   (vi) ↑ sweating

• Same thing happens to us when we watch horrror - we get the thrill.
• We don’t need to rest and digest when we have a lion running after us.
• It’s like cat’s eyes - they increase pupil when you wave something at their face

PARASYMPATHETIC:

1. Prepares the body for restful situations:
2. “RESTANDDIGEST” system.
3. Effectsinclude:
   (i)  decreased(↓)heartrate

(ii)  ↑ gastric motility
(iii)  ↓ pupil size
(iv)  ↑ salivation.

• It’s more chilled
• We don’t need to send out heaps of oxygen etc so heart rate down

We have a balance of both systems but one predominates depending on the situation

Question 12

Structural and neurotransmitter differences in SN and PNS:

1. The first neuron in SN - short or long?
2. The ganglion is ___ ___ CNS
3. What neurotransmitter in SN?
4. The first neuron in PNS - long or short?
5. The ganglion is ____ ___ CNS
6. Which one of the second neruon’s axon is shorter?
7. Neurotransmitter for PNS?

Answer 12

1. The first neuron is short in SN
2. Ganglion for SN is close to CNS so has a long axon for neuron #2
3. Only NE in SN
4. The first neuron in PNS is long
5. The parasympathetic ganglion in PNS is far from CNS
6. The second axon is PNS is therefore shorter
7. PNS has ACh

Question 13

Sympathetic nervous system: Exit from CNS and position of ganglia

(1) Axon of preganglionic neurons leaves CNS at _____ levels (spinal cord)
(2) Axon extends a _____ distance
(3) Synapse and cell body of post- ganglionic neuron are in _____

Answer 13

(1) Axon of preganglionic neurons leaves CNS at thoracolumbar levels (spinal cord)
(2) Axon extends a short distance
(3) Synapse and cell body of post- ganglionic neuron are in sympathetic ganglion (all lined up like a chain)

Question 14

Sympathetic chain ganglia

1. ___ pairs
2. Alongside ____
3. Place where preganglionic (neuron #1) axons ____ - onto postganglionic (neuron #2) ___ zone

Answer 14

Sympathetic chain ganglia

1. 21-23 pairs
2. Alongside vertebral column
3. Place where preganglionic (neuron #1) axons synapse - onto postganglionic (neuron #2) input zone

Question 15

The red

Answer 15

Yeah

Question 16

Parasympathetic nervous system: Exit from CNS and position of ganglia

(1) Axon of preganglionic neuron leaves CNS at ____ (brainstem) and ____ (spinal cord) levels
* Sometimes called “____” nerves or nervous system
(2) Axon of preganglionic neurons is _____
(3) Synapse and post-ganglionic neuron cell body in ganglion in or near the ___ ____

Answer 16

Parasympathetic nervous system: Exit from CNS and position of ganglia

(1) Axon of preganglionic neuron leaves CNS at cranial (brainstem) and sacral (spinal cord) levels
* Sometimes called “craniosacral” nerves or nervous system
(2) Axon of preganglionic neurons is long
(3) Synapse and post-ganglionic neuron cell body in ganglion in or near the effector organs

Question 17

Appreciate this table

Answer 17

So the only time you use NE is in SN in autonomic efferent