SFH V: Neuron dan Sistem Saraf; May 27/28, 2013

Transcription

1 SFH V: Neuron dan Sistem Saraf; Mekanisme Gerak May 27/28, 2013

2 Neurons and Nervous System Neurons use two types of signals to communicate: electrical signals (longdistance) and chemical signals (shortdistance) Killer snail Conus geographus

3 Neurons and Nervous System Neurons use two types of signals to communicate: electrical signals (longdistance) and chemical signals (shortdistance) Killer snail Conus geographus

4 Concept 1: Neuron organization and structure reflect function in information transfer Nervous systems process information in three stages: sensory input, integration, and motor output Sensory input Sensor Integration Motor output Effector K78: Mahasiswa mampu menerangkan organisasi neuron Peripheral nervous system (PNS) Central nervous system (CNS)

5 Many animals have a complex nervous system A central nervous system (CNS) where integration takes place; this includes the brain and a nerve cord A peripheral nervous system (PNS), which brings information into and out of the CNS Sensory input Sensor Integration Motor output Effector K78: Mahasiswa mampu menerangkan organisasi neuron Peripheral nervous system (PNS) Central nervous system (CNS)

6 Neuron Structure and Function Nucleus Cell body Synapse Dendrites Axon hillock Stimulus Presynaptic cell Axon Most neurons have dendrites, highly branched extensions that receive signals from other neurons The axon is typically a much longer extension that transmits signals to other cells at synapses An axon joins the cell body at the axon hillock Synaptic terminals Neurotransmitter Postsynaptic cell K78: Mahasiswa mampu menerangkan organisasi neuron

7 Concept 2: Neurons communicate with other cells at synapses At electrical synapses, the electrical current flows from one neuron to another At chemical synapses, a chemical neurotransmitter carries information across the gap junction Most synapses are chemical synapses Postsynaptic neuron Synaptic terminals of presynaptic neurons 5 µm K79: Mahasiswa mampu mendeskripsikan komunikasi neuron

8 A chemical synapse 5 K + Na+ Synaptic vesicles containing neurotransmitter Presynaptic membrane Voltage-gated Ca 2+ channel 1 Ca Postsynaptic membrane 6 Synaptic cleft 3 Ligand-gated ion channels K79: Mahasiswa mampu mendeskripsikan komunikasi neuron

9 Concept 3: Nervous systems consist of circuits of neurons and supporting cells Central nervous system (CNS) Peripheral nervous system (PNS) Brain Spinal cord Cranial nerves Ganglia outside CNS Organization of the Vertebrate Nervous System Spinal nerves K80: Mahasiswa mampu menerangkan sistem saraf vertebrata

10 The central canal of the spinal cord and the ventricles of the brain are hollow and filled with cerebrospinal fluid Gray matter White matter Ventricles K80

11 The brain and spinal cord contain Gray matter, which consists of neuron cell bodies, dendrites, and unmyelinated axons White matter, which consists of bundles of myelinated axons Gray matter White matter Ventricles K80

12 The PNS The PNS transmits information to and from the CNS and regulates movement and the internal environment Cranial nerves originate in the brain and mostly terminate in organs of the head and upper body Spinal nerves originate in the spinal cord and extend to parts of the body below the head K80: Mahasiswa mampu menerangkan sistem saraf vertebrata

13 efferent neurons transmit information away from the CNS Efferent neurons PNS afferent neurons transmit information to the CNS Afferent (sensory) neurons Motor system Autonomic nervous system Hearing Locomotion Sympathetic division Parasympathetic division Enteric division Gas exchange Circulation Hormone action Digestion K80

14 Concept 4: The vertebrate brain is regionally specialized All vertebrate brains develop from three embryonic regions: forebrain, midbrain, and hindbrain K80; K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

15 Forebrain Telencephalon Diencephalon Cerebrum (includes cerebral cortex, white matter, basal nuclei) Diencephalon (thalamus, hypothalamus, epithalamus) Midbrain Mesencephalon Midbrain (part of brainstem) Hindbrain Metencephalon Myelencephalon Pons (part of brainstem), cerebellum Medulla oblongata (part of brainstem) Midbrain Hindbrain Mesencephalon Diencephalon Metencephalon Myelencephalon Cerebrum Diencephalon: Hypothalamus Thalamus Pineal gland (part of epithalamus) Brainstem: Midbrain Forebrain Telencephalon Spinal cord Pituitary gland Pons Medulla oblongata Spinal cord Cerebellum (a) Embryo at 1 month (b) Embryo at 5 weeks (c) Adult Central canal K80; K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

16 The Brainstem The brainstem coordinates and conducts information between brain centers The brainstem has three parts: the midbrain, the pons, and the medulla oblongata K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

17 The cerebellum is important for coordination and error checking during motor, perceptual, and cognitive functions It is also involved in learning and remembering motor skills The Cerebellum K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

18 The Cerebrum The cerebrum has right and left cerebral hemispheres Each cerebral hemisphere consists of a cerebral cortex (gray matter) overlying white matter and basal nuclei K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

19 A thick band of axons called the corpus callosum provides communication between the right and left cerebral cortices The basal nuclei are important centers for planning and learning movement sequences Left cerebral hemisphere Corpus callosum Cerebral cortex Right cerebral hemisphere Thalamus Basal nuclei K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

20 The left hemisphere is more adept at language, math, logic, and processing of serial sequences The right hemisphere is stronger at pattern recognition, nonverbal thinking, and emotional processing Left cerebral hemisphere Corpus callosum Cerebral cortex Right cerebral hemisphere Thalamus Basal nuclei K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

21 Diencephalon The diencephalon develops into three regions: Epithalamus Thalamus Hypothalamus K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

22 Concept Frontal lobe3: The cerebral cortex controls voluntary Parietal lobe movement and cognitive functions Each side of the cerebral cortex has four lobes: frontal, temporal, occipital, Speech and parietal Frontal Somatosensory association area Each association lobe contains primary sensory areas and area Taste association areas where information is Reading integrated Speech Smell Hearing Auditory association area Visual association area Vision Temporal lobe Occipital lobe K82: Mahasiswa mampu menyebutkan empat lobus cerebral cortex

23 Emotions Emotions are generated and experienced by the limbic system and other parts of the brain including the sensory areas Hypothalamus Thalamus Prefrontal cortex Olfactory bulb Amygdala Hippocampus

24 Emotions The limbic system is a ring of structures around the brainstem that includes the amygdala, hippocampus, and parts of the thalamus Hypothalamus Thalamus Prefrontal cortex Olfactory bulb Amygdala Hippocampus

25 Emotions The amygdala is located in the temporal lobe and helps store an emotional experience as an emotional memory Hypothalamus Thalamus Prefrontal cortex Olfactory bulb Amygdala Hippocampus

26 Sistem Pergerakan, Penunjang, dan Pelindung Muscle activity is a response to input from the nervous system The action of a muscle is always to contract

27 Muscle Concept 5: The physical interaction of protein filaments is required for muscle function Bundle of muscle fibers Single muscle fiber (cell) Plasma membrane Myofibril Z lines Nuclei Vertebrate Skeletal Muscle Sarcomere Bioflix TEM M line 0.5 µm Thick filaments (myosin) K92: Mahasiswa mampu mendeskripsikan struktur otot rangka Thin filaments (actin) Z line Sarcomere Z line

28 The myofibrils are composed to two kinds of myofilaments: Thin filaments consist of two strands of actin and one strand of regulatory protein Thick filaments are staggered arrays of myosin molecules TEM M line 0.5 µm Thick filaments (myosin) Thin filaments (actin) K92: Mahasiswa mampu mendeskripsikan struktur otot rangka Z line Sarcomere Z line

29 Concept 6: Skeletal systems transform muscle contraction into locomotion Skeletal muscles are attached in antagonistic pairs, with each member of the pair working against the other The skeleton provides a rigid structure to which muscles attach Skeletons function in support, protection, and movement K93: Mahasiswa mampu menerangkan fungsi kerangka

30 Human Grasshopper Biceps contracts Extensor muscle relaxes Tibia flexes Triceps relaxes Forearm flexes Flexor muscle contracts Biceps relaxes Extensor muscle contracts Tibia extends Triceps contracts Forearm extends Flexor muscle relaxes K93

31 Types of Skeletal Systems Longitudinal muscle relaxed (extended) Circular muscle contracted Circular muscle relaxed Longitudinal muscle contracted 1. hydrostatic skeleton consists of fluid held under pressure in a closed body compartment cnidarians, flatworms, nematodes, and annelids Bristles Head end Head end Head end K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka

32 2. exoskeleton hard encasement deposited on the surface of an animal molluscs and arthropods K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka

33 3. endoskeleton hard supporting elements, such as bones, buried in soft tissue mammalian skeleton has more than 200 bones Shoulder girdle Sternum Rib Humerus Vertebra Radius Ulna Pelvic girdle Carpals Phalanges Metacarpals Femur Patella Clavicle Scapula Skull Examples of joints Tibia Fibula Tarsals Metatarsals K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka Phalanges

34 Head of humerus Scapula 1 Ball-and-socket joint Humerus Ulna 2 Hinge joint Ulna Radius K95: Mahasiswa mampu mendeskripsikan tiga tipe sendi dan memberikan contohnya 3 Pivot joint

35 Types of Locomotion Swimming In water, friction is a bigger problem than gravity Fast swimmers usually have a streamlined shape to minimize friction Animals swim in diverse ways Paddling with their legs as oars Jet propulsion Undulating their body and tail from side to side, or up and down K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka

36 Locomotion on Land Walking, running, hopping, or crawling on land requires an animal to support itself and move against gravity Diverse adaptations for locomotion on land have evolved in vertebrates

37 Flying Flight requires that wings develop enough lift to overcome the downward force of gravity Many flying animals have adaptations that reduce body mass For example, birds lack teeth and a urinary bladder K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka

38 Summary 1: Neuron organization and structure reflect function in information transfer 2: Neurons communicate with other cells at synapses 3: Nervous systems consist of circuits of neurons and supporting cells 4: The vertebrate brain is regionally specialized

39 Summary 5: The physical interaction of protein filaments is required for muscle function 6: Skeletal systems transform muscle contraction into locomotion

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