sfh v: neuron dan sistem saraf; mekanisme gerak

SFH V:

Neuron dan Sistem Saraf;

Mekanisme GerakMekanisme Gerak

May 27/28, 2013

Neurons use two types of signals to

communicate: electrical signals (long-

distance) and chemical signals (short-

distance)

Neurons and Nervous System

Conus geographus

Killer snail

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

K78: Mahasiswa mampu menerangkan organisasi neuron

Sensor Integration

Effector

Motor output

Peripheral nervous

system (PNS)

Central nervous

system (CNS)

• 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

Effector

Motor output

Peripheral nervous

system (PNS)

Central nervous

system (CNS)

Dendrites

Stimulus

Nucleus

Cellbody

Axonhillock

Presynapticcell

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

Neuron Structure and Function

Axon

Synaptic terminals

Synapse

Postsynaptic cell

Neurotransmitter

•An axon joins the cell body at

the axon hillock


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

K79: Mahasiswa mampu mendeskripsikan komunikasi neuron

Postsynapticneuron

Synapticterminalsof pre-synapticneurons

5 µ

m

Voltage-gatedCa2+ channel Postsynaptic

membrane

Presynapticmembrane

Synaptic vesiclescontainingneurotransmitter

5K+

Na+

A chemical synapse

Ca2+12

3

4

Synapticcleft

Ligand-gatedion channels

Postsynapticmembrane

6

K79: Mahasiswa mampu mendeskripsikan komunikasi neuron

Concept 3: Nervous systems consist of circuits of neurons

and supporting cells

Organization of the

Peripheral nervoussystem (PNS)

Cranialnerves

Brain

Central nervoussystem (CNS)

GangliaoutsideCNS

Spinalnerves

Spinal cord

Organization of the

Vertebrate Nervous

System

nerves

K80: Mahasiswa mampu menerangkan sistem saraf vertebrata

Gray matter

•The central canal of the spinal cord and the

ventricles of the brain are hollow and filled with

cerebrospinal fluid

Whitematter

Ventricles

Gray matter

K80

Gray matter

•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

Whitematter

Ventricles

Gray matter

K80

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 bodyupper 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

Efferentneurons

Motorsystem

Autonomicnervous system

Afferent(sensory) neurons

PNS

Hearing

efferent neurons transmit information away from the CNS

afferent neurons transmit information

to the CNS

K80

Locomotion

CirculationGas exchange DigestionHormone

action

Entericdivision

Sympatheticdivision

Parasympatheticdivision

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

Pons (part of brainstem), cerebellum

Forebrain

Midbrain

Hindbrain

Telencephalon

Diencephalon

Mesencephalon

Mesencephalon

Metencephalon

Metencephalon

Myelencephalon

Cerebrum (includes cerebral cortex, white matter,basal nuclei)

Diencephalon (thalamus, hypothalamus, epithalamus)

Midbrain (part of brainstem)

Medulla oblongata (part of brainstem)

Cerebrum Diencephalon:

Hypothalamus

ThalamusMidbrain

Forebrain

Hindbrain

Telencephalon

DiencephalonMyelencephalon

Spinal cord

Spinal cord

Pituitary

gland

Cerebellum

Central canal

Thalamus

Pineal gland

(part of epithalamus)

Brainstem:

Midbrain

Pons

Medullaoblongata

(c) Adult(b) Embryo at 5 weeks(a) Embryo at 1 month

K80; K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon,

brainstem

The Brainstem

• The brainstem

coordinates and

conducts information

between brain centers

• The brainstem has • The brainstem has

three parts: the

midbrain, the pons,

and the medulla

oblongata

K81: Mahasiswa mampu mendeskripsikan struktur dan fungsi cerebrum, cerrebelum, dienchepalon, brainstem

The Cerebellum

• The cerebellum is

important for

coordination and error

checking during

motor, perceptual,

and cognitive and cognitive

functions

• It is also involved in

learning and

remembering motor

skills


The Cerebrum

• The cerebrum has right and left cerebral hemispheres

• Each cerebral hemisphere consists of a cerebral cortex of a cerebral cortex (gray matter) overlying white matter and basal nuclei


Left cerebralhemisphere

Right cerebralhemisphere

• 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

Corpuscallosum

Thalamushemisphere hemisphere

Cerebralcortex

Basalnuclei


Left cerebralhemisphere

Right cerebralhemisphere

• 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

Corpuscallosum

Thalamushemisphere hemisphere

Cerebralcortex

Basalnuclei


Diencephalon

• The diencephalon develops into three regions:

– Epithalamus– Epithalamus

– Thalamus

– Hypothalamus


Concept 3: The cerebral cortex controls voluntary

movement and cognitive functions

• Each side of the cerebral cortex has four lobes:

frontal, temporal, occipital, and parietal

• Each lobe contains primary sensory areas and

association areas where information is integrated

Speech

Frontal lobeParietal lobe

Somatosensoryassociationarea

Frontalassociationarea

Reading

Taste

Hearing

Speech

K82: Mahasiswa mampu menyebutkan empat lobus cerebral cortex

Occipital lobe

Vision

Temporal lobe

Visualassociationarea

Hearing

Auditoryassociationarea

Smell

Emotions

• Emotions are generated and experienced by the

limbic system and other parts of the brain including

the sensory areas

Thalamus

Hypothalamus

Prefrontalcortex

Olfactorybulb

Amygdala Hippocampus

Emotions

Thalamus

Hypothalamus

• The limbic system is a ring of structures around the

brainstem that includes the amygdala,

hippocampus, and parts of the thalamus

Prefrontalcortex

Olfactorybulb


Emotions

Thalamus

Hypothalamus

• The amygdala is located in the temporal lobe and

helps store an emotional experience as an

emotional memory

Prefrontalcortex

Olfactorybulb


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

Bundle ofmuscle fibers

Muscle

Single muscle fiber(cell)

Nuclei

Z lines

Plasma membrane

Myofibril

Concept 5: The

physical interaction of

protein filaments is

required for muscle

function

K92: Mahasiswa mampu mendeskripsikan

struktur otot rangka

TEM

Thickfilaments(myosin)

M line

Sarcomere

Z line Z line

Thinfilaments(actin)

Sarcomere

0.5 µm

Vertebrate Skeletal

Muscle

Bioflix

• 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

Thickfilaments(myosin)

M line

Z line Z line

Thinfilaments(actin)

Sarcomere

0.5 µm

K92: Mahasiswa mampu mendeskripsikan

struktur otot rangka

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 attachmuscles attach

• Skeletons function in support, protection, and

movement

K93: Mahasiswa mampu menerangkan fungsi kerangka

GrasshopperHuman

Bicepscontracts

Tricepsrelaxes

Forearmflexes

Tibiaflexes

Flexormusclecontracts

Extensormusclerelaxes

Tricepscontracts

Forearmextends

Bicepsrelaxes

Tibiaextends

Flexormusclerelaxes

Extensormusclecontracts

K93

Types of Skeletal

Systems

1. hydrostatic

skeleton

• consists of fluid

held under

pressure in a

closed body

Circularmusclecontracted

Circularmusclerelaxed

Longitudinalmuscle relaxed(extended)

Longitudinalmusclecontracted

Bristles

Head end

K94: Mahasiswa mampu membedakan tiga tipe membedakan tiga system rangka

closed body

compartment

• cnidarians,

flatworms,

nematodes, and

annelids

Head end

Head end

2. exoskeleton

– hard encasement deposited on the surface of

an animal

–molluscs and arthropods


3. endoskeleton

– hard supporting

elements, such as

bones, buried in

soft tissue

–mammalian

Examplesof jointsSkull

Shouldergirdle

RibSternum

Clavicle

Scapula

Vertebra

Humerus

Radius

Pelvic girdle

Ulna

Carpals

1

2

3

–mammalian

skeleton has more

than 200 bones

K94: Mahasiswa mampu membedakan tiga tipe

membedakan tiga system rangka

Phalanges

Metacarpals

Femur

Patella

Tibia

Fibula

Tarsals

Metatarsals

Phalanges

Humerus

Ball-and-socket joint

Scapula

Head ofhumerus

1

Radius

Ulna

Hinge joint

Ulna

Pivot joint3

2

K95: Mahasiswa mampu mendeskripsikan tiga tipe sendi dan

memberikan contohnya

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– Paddling with their legs as oars

– Jet propulsion

– Undulating their body and tail from side to side, or up

and down


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

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


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 3: Nervous systems consist of circuits of neurons

and supporting cells

4: The vertebrate brain is regionally specialized

Summary

5: The physical interaction of protein filaments is

required for muscle function

6: Skeletal systems transform muscle contraction

into locomotion

Others

• Next Lecture

– Ecology and AnimalBehaviour I

• Population Ecology

• Community Ecology• Community Ecology

• Tugas Terstruktur

• Tutorial

sfh v: neuron dan sistem saraf; mekanisme gerak

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