1 / 22

THE BIOLOGICAL BASIS OF BEHAVIOUR

Chapter 3. THE BIOLOGICAL BASIS OF BEHAVIOUR. What is the biological basis of behaviour and why is it important? Describe the role of genetics in human behaviour Discuss the significance of the nervous system in human behaviour

shalin
Download Presentation

THE BIOLOGICAL BASIS OF BEHAVIOUR

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3 THE BIOLOGICAL BASIS OF BEHAVIOUR

  2. What is the biological basis of behaviour and why is it important? • Describe the role of genetics in human behaviour • Discuss the significance of the nervous system in human behaviour • Discuss the endocrine system and its contributions to the promotions of effective human behaviour • Explain the importance of muscle system in the executions of human behaviour.

  3. Genetics Cells • Basic functional units comprised in all living organism • DNA molecules (genes) control heredity from one generation to generation Mitosis • 23 Chromosomes constant • New cells 23 pairs of chromosomes • Continuous split and reproduction of new cells throughout the entire body to sustain life DNA • Deoxyribo-nucleic acid – contains genetic origins • Thousands of DNA molecules combine to form a chromosome.

  4. Meiosis ... simplified

  5. Genes Twins • Identical genes (monozygotic) • Non-identical genes (dizygotic) Sex determination • Certain attributes only carried by X-chromosomes – e.g. gender and certain illnesses Genotype • All genes Phenotype • Some genes, observable features, environment influence Multiple determination (polygenic heredity) • Combined influence of various genes, most human characteristics • Examples – Intelligence, temperament, personality, etc.

  6. The structure of the neuron Cell membrane • Surrounds the entire neuron and it is semi permeable Dendrites • Bushy, branch-like extensions of a neuron • Receive and conduct information toward the cell body Axon • Terminal branches form junctions with other cells Myelin sheath • Fatty tissue increasing speed of transmission Nodes of ranvier • Gaps on the axon which the myelin does not enclose A synaptic cleft • Space between the axon of one neuron and the dendrite of another (spatial or temporal summation).

  7. The structure of a neuron

  8. A synapse • The nerve synapse transfers nerve impulse information from a pre-synaptic membrane to a postsynaptic membrane neurotransmitters • The synapse operates as an on/off switch and as a filter for information flow.

  9. How the neuron functions Arousal threshold • The minimum intensity which a stimulus must have in order to trigger a nervous impulse Neurotransmitters • A chemical that accumulates in the synapse from presynaptic neurons and stimulates the postsynaptic neuron to produce nerve impulses Action potential • Electrochemical potential of the neuron resulting in a selective influx of positively charged ions Spatial summation • Impulses from a number of neurons combine to provide a stimulus strong enough to exceed the threshold of the post synaptic neuron Temporal summation • Successive impulses from one axon collectively activate the post synaptic neuron.

  10. Classifying neurons Receptor neurons • Vision, sound, smell, taste, cold, heat, pressure, touch Sensory neurons • Conduct information from the receptors to the Central Nervous System Motor neurons • Conduct information from the Central Nervous System to the effectors (muscles and glands) Association neurons • Connect sensory and motor neurons.

  11. “ Hi Mate. Hang in there! It will all become easier with more revision …

  12. The central nervous system The spinal cord • Situated in the spinal column and enclosed by 31 vertebrae • Connecting structure enables • sensory impulses from the body to reach the brain • motor impulses from the brain to descend to control motor activities of the body The brain • Enables humans to think, plan and process all sensory information gained from the environment • Composed of some 10 billion nerve cells • Cerebral activity is sustained by oxygen and nutrients • Electrical activity of the brain is measured by an electroencephalograph (ECG).

  13. The cerebral cortex and cerebrum Cerebral cortex (grey matter) • The outer layer of the brain • Comprises 80% of the brain capacity • Processes complex mental processes • Surrounds the Cerebrum – constituting its outer part Cerebrum • Two cerebral hemispheres • Left • Logical, serial, order, maths, language • Right • Spatial, imagination, intuition, emotions.

  14. The four lobes of the cortex • Frontal cortex – control of information processing by sending information to other parts of the body • Parietal cortex – receipt of sensory input from various parts of the body • Occipital cortex – controls visual perception • Temporal cortex – controls hearing and visual perception.

  15. Subcortical areas The thalamus • Processes all sensory impulses, except sense of smell The hypothalamus • Unconscious activities of various organs • Body temperature, appetite and feeding behaviour The limbic system • Electric stimulation evokes emotional responses Reticular activation system (RAS) • Coordinating centre with diffused cells, inhibitory/facilitating functions that include activation, sleep and wakefulness Medulla oblongata • Respiration and blood pressure Cerebellum • Coordination of muscle activity, muscle tone and balance.

  16. Peripheral nervous system The autonomic nervous system • Responsible for regulation of visceral organ activities • Sympathetic Nervous System ─ Activation functions • Parasympathetic Nervous System ─ Inhibitory functions • The two sub-systems work together to maintain the homeostasis of the autonomic nervous system Somatic nervous system • Connected to receptors in skin, inner tissue, joints and skeletal muscles (voluntary muscles) • Somatic reflexes generally do not involve the autonomic nervous system.

  17. Endocrine system • Consists of glands • Ovaries, testes, adrenals, pancreas, pineal gland, parathyroid and pituitary • Secrete hormones which are transmitted via the bloodstream to brain and other parts of the Central Nervous System • Pituitary gland (master gland) determines numerous behavioural aspects through direct release of its own hormones as well as its effects on other glands • Neuroendocrine functions also affect and are affected by the immune system • Stress.

  18. The muscle system Structure and functioning of muscles • Connected to both motor and sensor nerves Dynamic and static muscle activity • Dynamic (rhythmic activity) • Static (fixed position) Repetitive strain • Repetitive use of certain body elements • Carpal Tunnel Syndrome (CTS) – over-use Working body posture • Body size, standing, sitting and lying down.

  19. The muscle system (continued) Loss of muscle power • Measured on a scale of zero to five • Complete loss of muscle power – plegia (paralysis) • muscle weakness affecting movement in limbs – paresis Work station design • Ergonomics recommendation for work station design.

  20. Well done! You have completed chapter 3. Remember to complete the assessment activities.

  21. Thank you.

More Related