Nervous System

Question 1

Label Brain structure diagram

Answer 1

Question 2

State functions of the Cerebellum

Question 3

Name 3 parts of brain stem and their function

Answer 3

1) Midbrain

• Pain suppression
• Creates a link between Limbic System and Sympathetic NS pathways
• Major role in control of Skeletal muscle moveemnt

2) Pons

• Communication pathway between Motor Cortex and Cerebellum
• regulate breathing rhythm

3) Medulla Oblongata

• Descending tracts for motor output going to muscles
• Cardiovascular centre (force /rate of contractions/ vasomotor control
• Respiratory centre -rhythm / rate / depth of respiration
• Regulation of other centres (Vomiting, coughing, sneezing)
• Reticular formation - overall arousal / stimulation of brain

Question 4

Thalamus

Answer 4

Relay + ‘Sorting’ centre

receives sensory input, Sorts/ relays this to cerebral Cortex

Responsibilities include mediating sensations, motor activity, learning and memory

Question 5

What is function of Hypothalamus (exam)

Answer 5

1) Both NS and ES organ
2) Autonomic Control centre

• Processes sensory Info from Visceral sensory neurons
• Controls motor output to smooth + cardiac muscles; and glands

3) Regulates many survival mechanisms
* - regulation of food intake / water intake/ sleep + wake cycles, body temperature, endocrine system functioning

Question 6

State function of Pituitary Gland

Answer 6

Production + Releaase of Hormones

Store and release hormones produced by Hypothalamus

Question 7

state a function of the meninges

Answer 7

protection

Connective Tissue membrane that covers and protect the CNS (Contains CSF)

Question 8

state a function of the Limbic System

Answer 8

Control and regulation of emotions

Question 9

Summarise key functions of Frontal lobe (motor, sensory, association areas)

Answer 9

1. Motor function

• Receives input from other motor areas
• Plan motor movements
• Sends impulses to skeletal muscles

Association function

• Higher order functioning (logic, reasoning, planning, personality)
• decide motor actions + relay to motor cortex

Question 10

Summarise key functions of occipital lobe

Answer 10

• Sensory function
  
  • contains visual cortex which detects and interprets sensory input from eyes
• Association area
  
  • ​involved in Posterior association area- recogition / integration of inputs / understanding

Question 11

Summarise key functions of temporal lobe

Answer 11

•Sensory function

• Receive + interpret visceral sensations (visceral sensory cotex), taste buds (gustatory cortex), nose (olfactory cortex), ears (Auditory cortex) sensory organs

•Association function

• Part of Posterior association area
• Wernickes area (language dev)

Question 12

Summarise key functions of Parietal lobe

Answer 12

• Sensory Function
  
  • ​receives somatosensory input from afferent neurons
  • determines location of sensation using spatial discrimination
• Associative Function
  
  • ​integrates somatosensory input to generate understanding of sensation
  • uses memory
  • part of posterior association area

Question 13

Describe Flow of CSF

Answer 13

Lateral ventricles

–> 3rd ventricle (in centre of diencephalon)

—> 4th ventricle (btwn brainstem and cerebellum)

–> Subarachnoid space and around brain + Spinal Cord

—> Central canal of Spinal Cord

Question 14

Describe Process that occurs at Synapse

Answer 14

Neurotransmitters packed in vesicles at Axon Terminal

Action Potential causes depolarisation of Axon Terminal Membrane, opening Ca channels that allow Ca ions to flow into AT membrane

Ca ions stimulate vesicles to move to Presynaptic Membrane, and release Neurotransmitters into Synaptic Cleft by exocytosis

Neurotransmitters diffuse across synaptic cleft, and attach to receptors on post synaptic membrane

this triggers local graded potentials across the membrane

Question 15

Draw / label a neuron

Question 16

Describe process for Action Potentials

Answer 16

• ‘Resting’ Membrane Potential of a cell is normally ~70mV
• stimuli from neurons cause cell to DEPOLARISE towards threshold potential
• if threshold potential is reached, Na+ channels open and membrane depolarises
• At peak action potential, K+ channels open, and K+ exits cell, whilst Na+ channels close
• Membrane becomes hyperpolarised as K+ leaves.
• hyperpolarised Membrane is in refractory period and cannot fire.
• K+ channels close, and Sodium/Potassium pump restores Resting Potential

Question 17

Define Resting Membrane potential

Answer 17

this is the voltage charge of the cell membrane, when it is not receiving / sending impulses

whilst there is a charge (~70mV), there is no change in voltage

RMP is negative, due to more Na+ outside cell than K+ inside cell.

Question 19

List divisions of NS

Answer 19

• CNS (Brain + Spinal Cord)
• PNS
  
  • Sensory NS
    
    • Afferent Route
  • Motor NS
    
    • Somatic Motor NS (Voluntary)
      
      • Effectors are Skeletal Muscle
    • Autonomic NS
      
      • Effectors are Cardiac and Smooth Muscle + Endocrine Glands