8. Structure of the nervous sytem

Question 1

What are the 4 types of nervous and where do they carry info to?

Answer 1

1. Cranial nerves - 12x pairs from brain to muscles in head/neck
2. Spinal nerves - 31x pairs
3. Sensory nerves - info from skin, tendons, myofascia and joints
4. Motor nerves - info to skeletal, smooth, cardiac muscles and secretory glands

Question 2

What does the CNS consist of and what are all nerves outside of this called?

Answer 2

CNS: Brain, spinal cord and nerves

Outside: Peripheral nervous system (PNS)

Question 3

What type of nerves are

1. Sensory nerves
2. Motor nerves

and where do they pass information to?

Answer 3

1. Sensory are afferent nerves, passing info to CNS from distal organs, glands and tissues
2. Motor nerves are efferent nerves, passing info out to the distal organs, glands and tissues.

Question 4

How are the PNS and CNS connected and how are they divided up?

Answer 4

PNS and CNS connect via 31 pairs of spinal nerves.

Divided into somatic branch or autonomic branch.

Question 5

What is the difference between somatic and autonomic branch and how do the control their respective parts.

Answer 5

Somatic - carry signals that allow CNS to consciously monitor external environment and control body movements (via skeletal muscle)

Autonomic - carry signals that allow CNS to subconsciously monitor the internal rn ornament and control activity of glass and organs (via smooth and cardiac muscle)

Question 6

Which branch is responsible for key reactions and metabolic states, such as the parasympathetic branch and sympathetic branch?

Answer 6

Autonomic branch

Question 7

When a somatic sensory neurone sends info back to the CNS, what happens?

Answer 7

Interneurones will image and interpret information (it’s cold) to respond via the somatic motor efferent neurones which will require skeletal muscles to responds. (put jumper on)

Question 8

Name a somatic and autonomic reflex

Answer 8

Autonomic - shivering in response to body temp

Somatic - withdrawing foot after stepping on a nail

Question 9

Most ___ neurones don’t pass directly to the brain but connect in ______

Answer 9

Most sensory neurones connect in the spinal chord

Question 10

How are skeletal, smooth and cardiac muscles structured and why?

Answer 10

Skeletal - striated to allow movement via deliberate force generations

Smooth - peristalsis (spindle) to alternate between contraction and relaxation to move substances

Cardiac - striated with intercalated discs to transmit electrical impulses so heart can beat steadily

Question 11

Which of skeletal, smooth and cardiac are voluntary/involuntary and name an example

Answer 11

Skeletal - voluntary - biceps

Smooth - involuntarily - gut, blood vessels

Cardiac - involuntary - heart only

Question 12

There are 650 muscles, what are the 4 characteristics?

Answer 12

1. Excitability - recieve and respond to external stimulus
2. Contractibility - ability to shorten
3. Extensibility - ability to stretch/lengthen beyond normal range
4. Elasticity - ability of muscle to return to its original shape

Question 13

What are the muscles roles? 4)

Answer 13

Produce movement
Stabilise body
Store substances
Generate heat

Question 14

What is a tendon?

Answer 14

Cord-like fibrous connective tissue that connects muscle to bone and is capable of withstanding tension

Question 15

What do tendons consist of and why?

Answer 15

Closely packed collagen fibres running parallel to force generated by muscle - intertwined with elastin molecules (for elasticity)

Question 16

What is the origin/insertion?

Answer 16

Origin: stationary point at which muscle attatches to the body

Insertion: Attachment to the moving bone (normally distal go origin)