Nervous System: Reflexes & Brain Lobes

(1) Reflex Arc• Reflex = Involuntary Movements to Stimuli

– Always happens same way– Always triggered same way– “Arc” = Predictable path message is sent

• Types of Reflexes:– Autonomic– Somatic

(2) Reflex Arc Pathway

1. Receptor notices stimulus

2. Organ is stimulated

3. Sensory Neuron

4. Motor Neuron

5. Reflex

(3) Autonomic Reflexes• Involuntary Movement of:

– Smooth Muscle (digestive)– Cardiac Muscle– Glands

• Examples:– Spit– Sweat– Increased Blood Pressure

(4) Somatic Reflexes• Involuntary Movement of Skeletal Muscle

• Examples:– Touching a Hot Stove– Knee-Jerk Reflex– Touching a Sharp Object

(5) Brain Hemispheres• Hemispheres = Different Sides of the Brain

– YOUR Right = Right Hemisphere • Controls Left side of body

– YOUR Left = Left Hemisphere• Controls Right side of body

(6) Brain Lobes• Lobes = Different Regions of Brain

• Each Region has a unique set of functions

• Functions based on which neurons are connected where

• Perpendicular to hemisphere line = Sensory & Motor Division

(7) Frontal Lobe• Speech Production (Broca’s Area)

• Concentration

• Problem Solving

• Planning

• Voluntary Muscle Control

(8) Parietal Lobe• Interpretation of speech, sounds,

surroundings

• Helps formulate words

• Skin sensations

(9) Temporal Lobe• Interpret sensations

• Visual & Auditory Memory• Hearing function• Ability to learn + connect concepts

• Includes:– Thalamus– Hypothalamus– Pituitary Gland– Limbic System

(10) Stuff In Your Temporal

(Thalamus, Hypothalamus, Pituitary, Limbic)

• Control Body Temperature

• Maintain fluid + ion levels

• Induce sleep

• Regulate hormone secretion

• Limbic = emotions

(11) Occipital Lobe• Vision

• Combines images to make complete picture

(12) Cerebellum• Coordinates muscle movement

• Maintains normal muscle tone

• DOES NOT MAKE MUSCLES MOVE!– Makes them move smoothly!

(13) Brain Stem• Passes info between spinal cord + brain

• Includes:– Midbrain– Pons– Medulla Oblongata

(14) Stuff in Brain Stem• Fight or Flight responses (based on past)

• Helps with vision + auditory senses

• Maintains Homeostasis:– Heartbeat– Breathing rate– Blood pressure– Respiratory + Digestive reflexes