1. Higher Human Biology Neurobiology and Communication (0.5 Unit)
Divisions of the nervous system and parts of the brain
Perception and memory
The cells of the nervous system and neurotransmitters at synapses
Communication and social behaviour

2. What do you already know?
From your N5 course or from other areas of study or from LIFE what do you know about neurobiology and communication?
Take some time to brainstorm with a partner onto your paper.

3. What will you learn in this section
Divisions of the nervous system and parts of the brain
A general look at how the system works and its parts but more detail than N5
A more detailed looked at areas of the brain and their functions

4. General structure of the system
Central nervous system (CNS) includes the brain and spinal cord
Peripheral nervous system (PNS) all the other nerves in the body other than CNS
Flow of information through the nervous system
Stimuli receptors CNS effectors responses
sensory nerves motor nerves

6. Sensory system
External sensory system includes skin, eye retina, ear cochlea, nose chemoreceptors etc..
Internal sensory system includes CO2 receptors in the carotid arteries, thermoreceptors in the cerebellum etc..
The ability to sense changes in the internal and external environment is essential for survival.

7. General structure of the nervous system
The brain receives information from sensory pathways.
Information is analysed, interpreted, processed, stored constantly
The brain sends out impulses along motor pathways to effectors (e.g. muscles/glands)
This brings about a response or change in the body
such as contraction or secretion

9. Peripheral nervous system
Can be divided into 2 parts
Somatic nervous system SNS (mostly voluntary functions)
Autonomic nervous system ANS (involuntary functions)

10. Somatic nervous system
Includes spinal nerves and controls skeletal muscle
This is mostly voluntary movement of skeleton
Also involved with reflex actions which are involuntary
It involves sensory and motor pathways

11. Autonomic nervous system (ANS)
Regulates the internal environment
It controls the heart, blood vessels, bronchioles and the alimentary canal
The nerves for this come from the brain and come out of the spinal cord to control cardiac muscle, smooth muscle and glands
These are done on an involuntary basis working automatically without conscious thought being involved

12. Autonomic nervous system
This is split into 2 parts
Sympathetic system (prepares the body for action)
Parasympathetic system (calms body down returning to normal state)
These are antagonistic in their function.
They affect the same structures often but in opposite ways

14. Examples of antagonistic function
HEART
sympathetic parasympathetic
Increases rate and decreases rate and force
force of cardiac muscle of cardiac muscle
increasing output decreasing output

15. Examples of antagonistic function
BRONCHIOLES
sympathetic parasympathetic
smooth muscle relaxes smooth muscle contracts
tubes dilate so greater tubes constrict so lower
flow of air to lungs flow of air to lungs

16. Examples of antagonistic function
ALIMENTARY SYSTEM
sympathetic parasympathetic
smooth muscle contractions smooth muscle contractions
decreases, reducing peristalsis increases, increasing peristalsis
secretory glands inhibited so secretory glands stimulated so
fewer secretions produced more secretions produced

17. Examples of antagonistic function
ADRENAL GLAND
sympathetic parasympathetic
stimulates the gland no nerve to this
more adrenaline (epinephrine) so no affect
produced

18. System balance
The internal environment must be kept at a stable level so it can function well
This is called homeostasis
Organs will swing between extremes of function at times to cope with different circumstances

19. An exception in balance
An exception to the balance between sympathetic and parasympathetic systems is the control of the adrenal gland
Adrenaline is involved in the fight or flight response
Adrenalin stimulates the body for activity
It increases heart rate, blood pressure, blood flow to skeletal muscle, less blood flow to intestines, increases sweating

20. Adrenalin
The body is in an aroused state to cope with an emergency by either moving away (flight) or by staying and dealing with it (fight)
After the moment has passed the adrenal gland receives less impulses from Sympathetic nerves. Epinephrine levels fall
Heart rate and blood pressure return to normal.
Peristalsis increases and absorption resumes

21. To do Read Homeostasis example on exercise pages 209 to 212
Answer questions on page 212

22. What do you know? What is the CNS? What is the PNS?
What is the SNS? Explain what it does?
What is the ANS? Explain what the 2 parts do?
What is the flight or fight system and how does it work?
What are the 2 types of neuron mentioned and what do they do?

23. The Brain The Brain is composed of 3 layers The central core
The limbic system
The cerebral cortex
(cerebrum outer layer)

24. Central Core (including the medulla and cerebellum)
controls many essential processes e.g. breathing, heart rate, sleep and arousal (awake and aware)
Cerebellum
controls balance and muscular coordination (for movement and posture)

25. Limbic system Processes information for long term memory
Regulates emotional states (fear, anxiety, aggression)
Influences biological motivation (hunger, thirst, sex drive)
It is a composite region of the brain, projecting into the cerebral cortex

26. Limbic system includes the hypothalamus
Hypothalamus is connected to the pituitary gland
( a direct link between the nervous system and hormonal system)

27. Hypothalamus Has multiple receptors involved in homeostasis
Produces releaser hormones which directly affect the anterior pituitary gland. These stimulate the pituitary gland to produce:
Growth hormone (normal growth of body and long bone development)
Thyroid stimulating hormone (stimulates the thyroid gland to produce thyroxin controlling metabolism)
Gonadotrophic hormone (stimulates production and release of gametes)

28. Hypothalamus and smooth muscle contraction
Neurons from hypothalamus extend into sympathetic and parasympathetic centre in central core
This enables it to regulate contraction/relaxation of smooth muscle in homeostasis including blood vessel constriction and dilation for temperature regulation

29. Hypothalamus and body temperature
Hypothalamus has thermoreceptors.
It detects temperature of blood.
It sends messages to sweat glands, blood vessels as part of temperature regulation.

30. Hypothalamus and water balance
Hypothalamus has osmoreceptors.
These detect changes in water concentration of the blood caused by sweating, drinking, eating salty food etc..
This triggers changes in production of ADH
ADH increases permeability of tubules and collecting ducts in the nephrons (kidney). More water is reabsorbed into blood with increased ADH.

31. Cerebral cortex Outer layer of cerebrum (very complex).
Split into 2 halves called cerebral hemispheres.
Left hemisphere controls right side of body and processes right visual field information. (Right hemisphere vice versa).
They are connected by the corpus callosum nerve fibres.
This allows transfer of information, allowing coordination as both sides communicate with each other.

33. Areas of the cerebral cortex
It contains three types of functional area:
Sensory – these receive information from body’s receptors (external/internal).
Association – these analyse and interpret impulses from receptors (making sense and deciding on action).
Motor – receive information from association areas and send impulses to effectors.

34. Localised areas for functions
Cerebral hemisphere has distinct regions.
Both sides have similar areas except for speech.
Speech only occurs on one side of cerebrum (90% on left side).
Areas include somatosensory, visual and auditory.
They receive separate sets of sensory impulses and process them in their associated areas.

36. Brain connectivity and process
Areas of the brain on each side of the cerebral cortex communicate via the corpus callosum.
This allows complex and integrated processing and decision.
Areas of cerebral cortex also include higher mental processing areas such intelligence, personality, creativity, imagination, conscience and language.

37. Brain function analysis
Brain injuries and related function.
Electroencephalograms (EEG) measuring electrical activity.
Positron-emission tomography (PET) brain scan measuring metabolic activity in the brain
Functional magnetic resonance imaging (fMRI) analysis of brain activity using radio waves and magnetic fields and blood flow patterns

38. What you should know What is the role of the medulla?
What is the role of the cerebellum?
These 2 together make up the ……………of the brain?
What are the general functions of the limbic system?
What are the functions of the cerebral cortex?
What are the 3 localised areas of the brain?
What is the corpus callosum?
Which part of the brain controls the left side of the body?
Where is the left visual field information dealt with?