1. CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 38 Nervous and Sensory Systems

2. © 2014 Pearson Education, Inc. Do Now: Integration of Synapses  Differentiate between inhibitory and excitatory postsynaptic potential  Differentiate between temporal summation and spatial summation  HW: watch the bozeman video on the nervous system (the brain) & make a concept map from all the terms listed in this PPT

3. © 2014 Pearson Education, Inc. Figure 38.2 (a) Hydra (cnidarian) Spinal cord (dorsal nerve cord) Brain (b) Planarian (flatworm) (c) Insect (arthropod) (d) Salamander (vertebrate) Sensory ganglia Brain Nerve cords Eyespot Transverse nerve Segmental ganglia Brain Nerve net Ventral nerve cord

4. © 2014 Pearson Education, Inc. Overview: Sense and Sensibility  Gathering, processing, and organizing information are essential functions of all nervous systems  nerve net, which controls contraction and expansion of the gastrovascular cavity  Nerves,the axons of multiple nerve cells are often bundled together  Cephalization, Animals with elongated, bilaterally symmetrical bodies have even more specialized systems  Ganglia: clusters of neurons

5. © 2014 Pearson Education, Inc.  In vertebrates there is a clear division of the nervous system:  The CNS (interneurons)  Brain  Spinal cord  The PNS is composed of nerves and ganglia  Afferent neurons (sensory)  Efferent neurons (motor)

6. © 2014 Pearson Education, Inc. Figure 38.4 Spinal cord Central nervous system (CNS) Peripheral nervous system (PNS) Cranial nerves Spinal nerves Ganglia outside CNS Brain

7. © 2014 Pearson Education, Inc. The Peripheral Nervous System  The PNS transmits information to and from the CNS and regulates movement and the internal environment  Afferent neurons—interneurons—efferent neurons  PNS  CNS  PNS

8. © 2014 Pearson Education, Inc. Figure 38.5 Afferent neurons Sensory receptors Internal and external stimuli Autonomic nervous system Motor system Control of skeletal muscle Sympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands Parasympathetic division Efferent neurons Peripheral Nervous System Central Nervous System (information processing)

9. © 2014 Pearson Education, Inc. Afferent Pathway:  Much brain activity begins with sensory input  A sensory receptor detects a stimulus, which alters the transmission of action potentials to the CNS  This is done through signal transduction: conversion of stimulus energy into a change in membrane potential  What is the RMP?  What happens when there is a change in membrane potential?

10. © 2014 Pearson Education, Inc. Figure 38.15 (a) Receptor is afferent neuron. Afferent neuron (b) Receptor regulates afferent neuron. Sensory receptor To CNS Stimulus Afferent neuron Receptor protein To CNS Sensory receptor cell Stimulus Neurotransmitter Stimulus leads to neuro- transmitter release.

11. © 2014 Pearson Education, Inc. Transmission  Sensory information is transmitted as nerve impulses or action potentials  Neurons that act directly as sensory receptors produce action potentials and have an axon that extends into the CNS  Non-neuronal sensory receptors form chemical synapses with sensory neurons  They typically respond to stimuli by increasing the rate at which the sensory neurons produce action potentials

12. © 2014 Pearson Education, Inc. Types of Sensory Receptors  Based on energy transduced, sensory receptors fall into five categories  Mechanoreceptors  Electromagnetic receptors  Thermoreceptors  Pain receptors  Chemoreceptors

13. © 2014 Pearson Education, Inc. Mechanoreceptors  Mechanoreceptors sense physical deformation caused by stimuli such as pressure, touch, stretch, motion, and sound  For example:  cats and many rodents have sensitive whiskers that provide detailed information about nearby objects  Human fingers contain the mechanoreceptor: pacinian corpuscle which when deformed, leads to an increase in the permeability to sodium.  What happens then????

14. © 2014 Pearson Education, Inc. Electromagnetic Receptors  Electromagnetic receptors detect electromagnetic energy such as light, electricity, and magnetism  Some snakes have very sensitive infrared receptors that detect body heat of prey against a colder background

15. © 2014 Pearson Education, Inc. Electromagnetic Receptor:Light-Detecting Organs  One of the simplest light-detecting organs is that of planarians

16. © 2014 Pearson Education, Inc.  Insects and crustaceans have compound eyes, which consist of up to several thousand light detectors called ommatidia  Compound eyes are very effective at detecting movement Compound Eyes

17. © 2014 Pearson Education, Inc.  Single-lens eyes are found in some jellies, polychaetes, spiders, and many molluscs  They work on a camera-like principle: the iris changes the diameter of the pupil to control how much light enters  The eyes of all vertebrates have a single lens Single-Lens Eyes

18. © 2014 Pearson Education, Inc.  Thermoreceptors detect heat and cold  In humans, thermoreceptors in the skin and anterior hypothalamus send information to the body’s thermostat in the hypothalamus  Are thermoreceptors more likely to be found in ectotherms or endoderms?  What kinds of thermoregulation does the body undertake? Thermoreceptors

19. © 2014 Pearson Education, Inc. Pain Receptors  In humans, pain receptors, or nociceptors, detect stimuli that reflect conditions that could damage animal tissues  Chemicals such as prostaglandins worsen pain by increasing receptor sensitivity to noxious stimuli;  How might we use this knowledge to block pain?  What is the advantage of having pain receptors?

20. © 2014 Pearson Education, Inc. Chemoreceptors  General chemoreceptors transmit information about the total solute concentration of a solution  Which body system is in charge of osmoregulation?  Specific chemoreceptors respond to individual kinds of molecules  Olfaction (smell)  gustation (taste)

21. © 2014 Pearson Education, Inc. Figure 38.5 Afferent neurons Sensory receptors Internal and external stimuli Autonomic nervous system Motor system Control of skeletal muscle Sympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands Parasympathetic division Efferent neurons Peripheral Nervous System Central Nervous System (information processing)

22. © 2014 Pearson Education, Inc. Figure 38.UN03 Cerebral cortex Forebrain Hindbrain Midbrain Thalamus Pituitary gland Hypothalamus Spinal cord Cerebellum Pons Cerebrum Medulla oblongata

23. © 2014 Pearson Education, Inc. Figure 38.6b Medulla oblongata Embryonic brain regions Brain structures in child and adult Forebrain Hindbrain Midbrain Telencephalon Myelencephalon Metencephalon Forebrain Hindbrain Midbrain Diencephalon Cerebrum (includes cerebral cortex, white matter, basal nuclei) Medulla oblongata (part of brainstem) Pons (part of brainstem), cerebellum Midbrain (part of brainstem) Diencephalon (thalamus, hypothalamus, epithalamus) Telencephalon Myelencephalon Metencephalon Diencephalon Mesencephalon Embryo at 1 month Embryo at 5 weeks Spinal cord Child Diencephalon Midbrain Cerebellum Spinal cord Pons Cerebrum

24. © 2014 Pearson Education, Inc. Imaging the brain: MRI

25. © 2014 Pearson Education, Inc. Cerebrum Most vertebrate brains have similar parts. However, humans have larger cerebrums Frontal lobe –Speech, decision making, motor cortex Parietal lobe –Senses, touch Temporal lobe –hearing Occipital lobe –Vision

26. © 2014 Pearson Education, Inc. Figure 38.11 Frontal lobe Temporal lobe Occipital lobe Parietal lobe Cerebellum Motor cortex (control of skeletal muscles) Somatosensory cortex (sense of touch) Wernicke’s area (comprehending language) Auditory cortex (hearing) Broca’s area (forming speech) Prefrontal cortex (decision making, planning) Sensory association cortex (integration of sensory information) Visual association cortex (combining images and object recognition) Visual cortex (processing visual stimuli and pattern recognition)

27. © 2014 Pearson Education, Inc. Figure 38.6c Basal nuclei Cerebellum Cerebrum Corpus callosum Cerebral cortex Left cerebral hemisphere Right cerebral hemisphere Adult brain viewed from the rear

28. © 2014 Pearson Education, Inc. Lateralization of Cortical Function The left side of the cerebrum is dominant regarding language, math, and logical operations The right hemisphere is dominant in recognition of faces and patterns, spatial relations, and nonverbal thinking The two hemispheres exchange information through the fibers of the corpus callosum

29. © 2014 Pearson Education, Inc. Thalamus Relay center Input center for sensory information Directs which part of cerebrum to go to

30. © 2014 Pearson Education, Inc. Hypothalamus Maintains homeostasis Controls actions of anterior and posterior pituitary glands –Anterior pituitary: LH, FSH, HGH, TSH, ACTH, Prolactin –Posterior pituitary: ADH, Oxytocin

31. © 2014 Pearson Education, Inc. Figure 38.6d Diencephalon Thalamus Pineal gland Hypothalamus Pituitary gland Spinal cord Brainstem Midbrain Medulla oblongata Pons

32. © 2014 Pearson Education, Inc. Midbrain  Upper portion of brainstem  Connection of spinal cord to cerebrum

33. © 2014 Pearson Education, Inc. Hindbrain  Brainstem- control of breathing, circulation, digestion  Pons  Medulla  Cerebellum  Coordination

34. © 2014 Pearson Education, Inc. Emotions  Generation and experience of emotions involve many brain structures including the amygdala, hippocampus, and parts of the thalamus  Also involves the cerebrum  These structures are grouped as the limbic system

35. © 2014 Pearson Education, Inc. Figure 38.8 Thalamus Hypothalamus Amygdala Olfactory bulb Hippocampus

36. © 2014 Pearson Education, Inc. Figure 38.5 Afferent neurons Sensory receptors Internal and external stimuli Autonomic nervous system Motor system Control of skeletal muscle Sympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands Parasympathetic division Efferent neurons Peripheral Nervous System Central Nervous System (information processing)

37. © 2014 Pearson Education, Inc.  The PNS has two efferent components:  motor system carries signals to skeletal muscles and can be voluntary or involuntary  CHAPTER 39! (movement of muscles)  autonomic nervous system regulates smooth and cardiac muscles and is generally involuntary  Sympathetic  Fight or flight  Parasympathetic  Rest and digest  Enteric  Digestive, pancreas, gall bladder