THE HUMAN NERVOUS SYSTEM AND THE BRAIN

Question 1

DEFINITION: The human nervous system

Answer 1

• It is a complex structure
• Composed of billions of interlinked neurons
• The human nervous system is categorized into the Central Nervous System and the Peripheral Nervous system.
• Each division work in an integrated way to enable us to produce a variety of mental processes and behaviours

Question 2

DEFINITION: Central Nervous System

Answer 2

• It is composed of the brain and the spinal cord

- The messages are further processed in the brain

Question 3

DEFINITION: Peripheral Nervous system

Answer 3

• Nerves that are outside the Central Nervous System

- It is divided into the Autonomic and the Somatic Nervous system

Question 4

DEFINITION: SOMATIC NS

Answer 4

• Controls voluntary muscles
• Transmits information to the CNS
  Communicate from senses to the CNS
• These are known as conscious responses

Question 5

DEFINITION: AUTONOMIC NS

Answer 5

• Controls involuntary muscles and body functions
• It is connected to the Central nervous system
• CNS to involuntary muscles, organs, or glands

Question 6

DEFINITION: BRAIN

Answer 6

• A complex organ
• Receives, Processes, and Integrates information around the body
• Three main regions: Hindbrain, Midbrain, and Forebrain.

Question 7

DEFINITION: HINDBRAIN (5 x Controls)

Answer 7

• Known as the brain stem
• Controls heart rate
• Controls breathing
• Controls sleep and arousal
• Controls reflexive actions
• Controls voluntary muscle movement
• Cerebellum: coordination and balance, as well as voluntary movement.
• Medulla: regulates organs that are vital for life (Breathing).

Question 8

DEFINITION: MIDRAIN (MAIN STRUCTURE)

Answer 8

• Contains structures that help keep us AWAKE, ALERT, VIGILANT
• Reticular formation: A network of neurons that helps focus our attention and alertness as well as controlling physiological arousal.

Question 9

DEFINITION: FOREBRAIN (3 x structures)

Answer 9

• Highly developed part of the brain
• Controls higher cognitive functions (Emotions, motivations, memory)
• Cerebrum: Top of the forebrain. It is the outer layer also known as the cortex
• Thalamus: Two small structures that are sued as a relay system for sensory messages on their way to the cerebral cortex.
• Hypothalamus: Tiny structure that controls sleep-wake cycle, hunger, thirst, sex drive, body temperature. The nerves are connected to the endocrine system.

Question 10

DEFINITION: SPINAL CORD/TRACTS

Answer 10

Spinal cord
- It is a DELICATE cable of nerve fibers. It connected the Brian to the rest of the body via its connection with the PNS
Tracts
- Axon columns (Simulatory nerve pathways)
within the white matter of the spinal cord
- Transmit information via action potentials
- Two types of tracts (ascending (stimulus - CNS) and descending (CNS - Body)

Question 11

AUTONOMIC DIVISIONS

Answer 11

• Sympathetic: Controls arousal. It arouses the body to expend energy. STRESS HORMONES are released. (Sweat increases, Heart rate increases, pupils are dilated…)
• Parasympathetic: Calms the body back down. It returns the body to homeostasis ( a stable level). It CONSERVES energy whilst reverses the effects of the Sympathetic NS

Question 12

THE NERVOUS SYSTEM CONSCIOUS RESPONSE

Answer 12

• The majority of our movements are voluntary
  Occur: communication between the brain and the SOMATIC Nervous System.
  SAME: SA (Sensory, Afferent)
• Somatic NS: Aware of stimuli and therefore, will make a conscious decision about what our response will be.

Question 13

THE NERVOUS SYSTEM UNCONSCIOUS RESPONSE

Answer 13

• This involves spinal reflexes
• Operate independently from the brain.
• ALSO: Autonomic NS