Presentation on theme: "NOTES: CH 49 - NERVOUS SYSTEM ORGANIZATION; THE HUMAN BRAIN"— Presentation transcript:
1 NOTES: CH 49 - NERVOUS SYSTEM ORGANIZATION; THE HUMAN BRAIN
2 Recall…the nervous system is divided into 2 divisions: ● CENTRAL NERVOUS SYSTEM (CNS): information processing; integration ● PERIPHERAL NERVOUS SYSTEM (PNS): transmits info. to/from the CNS; plays a large role in regulating an animal’s movement & internal environment
4 Organization of the CENTRAL NERVOUS SYSTEM: ● consists of the BRAIN & SPINAL CORD● BRAIN: integration; complex behavior● SPINAL CORD: conveys info. to / from the brain; generates basic patterns of locomotion
5 SPINAL CORD:● can also act independently of the brain as part of simple nerve circuits: REFLEXES! ● a reflex protects the body by triggering a rapid, involuntary response to a particular stimulus ● EXAMPLE: knee-jerk reflex
7 Organization of the CENTRAL NERVOUS SYSTEM: ● CEREBROSPINAL FLUID:-formed in the brain by filtration of blood-circulates through brain, providing nutrients & hormones; carries away wastes-cushions the brain & spinal cord
8 GRAY & WHITE MATTER:● GRAY MATTER: -consists mainly of neuron cell bodies, dendrites, unmyelinated axons, & glia (support cells) ● WHITE MATTER: -consists of bundled axons w/myelin sheaths (gives the white appearance)
9 Organization of the PERIPHERAL NERVOUS SYSTEM: ● consists of NERVES that branch out from the CNS and connect it to other parts of the body.● includes:SPINAL NERVES and CRANIAL NERVES
10 CRANIAL NERVES ● mammals have 12 pairs of cranial nerves ● originate from the cerebrum & brain stem● innervate parts of the head, neck and trunk
19 ● Sympathetic and parasympathetic divisions may act antagonistically (in opposition), alternately activating or inhibiting the actions of some organs, glands, etc.
20 SYMPATHETIC DIVISION: ● prepares the body for energy-expending, stressful, or emergency situationsEXAMPLE: during an emergency, the sympathetic division will increase the heart rate and breathing rate, etc.
22 PARASYMPATHETIC DIVISION: ● is most active under ordinary, restful conditions;● counterbalances the effects of the sympathetic divisionEXAMPLE: after an emergency, the parasympathetic division decreases the heart rate, breathing rate, etc.
31 Brain Regions: ● Forebrain includes: cerebrum, thalamus, hypothalamus ● Midbrain● Hindbrain includes: pons, medulla oblongata, cerebellum**the midbrain, along with the pons and medulla oblongata form the BRAINSTEM
40 3) Midbrain:● receives and sends sensory information;● coordinates visual reflexes (eye movements with other movements)● coordinates auditory reflexes (move the head to hear a sound more distinctly)
41 CEREBELLUM:● coordination of movement;● balance;● hand-eye coordination
43 THALAMUS:● relay center that sorts out & transmits sensory information to and from cerebrum;● incoming information from all the senses is sorted here and sent on to the appropriate higher brain center;● involved in regulating emotion& arousal (wakefulness)
52 CEREBRUM: divided into hemispheres (R and L) each hemisphere divided into lobes (frontal, parietal, temporal, occipital) each hemisphere has an outer covering of gray matter = CEREBRAL CORTEX hemispheres are connected by white matter called CORPUS CALLOSUM
55 CEREBRUM – functions! where memories are stored interprets sensory impulses arrivingfrom sense organs centers for motor coordination; send motor impulses to muscles where conscious decisions are madeintelligence and personality stem from cerebral activitylanguage, cognition / thought / problem solving
63 2) Primary Somatosensory Cortex: receives and integrates signals from touch, pain, pressure, and temperature receptors; divided into specific areas so that we can associate specific stimuli with specific parts of the body.