Chapters 11-14

Describe the anatomy, histology, and physiology of the central and peripheral nervous systems and name the major divisions of the nervous system.

Identify the parts of a reflex arc.

Describe signal transmission across a myoneural junction.

Identify the major functions associated with the sympathetic and parasympathetic nervous systems.

Identify the major parts of a cross section through the spinal cord.

Identify the functions of the major parts of the brain, including the meninges, medulla, pons, midbrain, hypothalamus, thalamus, cerebellum and cerebrum.

Control and communication center of the body

Sensory input Integration Motor output

Central Nervous System (CNS) • Spinal cord and brain • Integration & command center

Peripheral Nervous System (PNS)

• Paired spinal and cranial nerves • Carries messages to and from the CNS

CNS

Red is CNS

Blue is PNS

Divided into 2 divisions:

Afferent division • Sensory • Receptors (eye/ear) send info to CNS

Efferent division

• Motor response • Effectors – something happens (movement)

Somatic nervous system (SNS) • Conscious control of skeletal muscles • Voluntary

Autonomic nervous system (ANS)

• Regulates smooth muscle, cardiac muscle, and glandular secretions

• Subconscious

2 divisions: Parasympathetic:

• Dominates during rest • Maintenance activities

Sympathetic

• Preparation of energetic/stressful activity • “fight or flight”

Basic functional unit of the nervous system

Composed of a cell body, axon, and dendrites

Structural • Mutlipolar • Bipolar • Unipolar

Functional

• Sensory (afferent) • Motor (efferent) • Interneurons (associated

neurons)

~45 cm long ~14mm wide 31 segments

Provide physical stability and shock absorption

3 layers: • Dura mater • Arachnoid mater • Pia mater

Outermost covering of the spinal cord

Middle layer

Between dura mater and arachnoid mater is the subarachnoid space • Where cerebrospinal fluid (CSF)

is Shock absorber Medium for dissolved gases,

nutrients, chemical messengers, and waste products Where spinal taps take place

Innermost layer

Made of elastic and collagen fibers

Bound to underlying neural tissue

31 pairs

Rapid, automatic responses to specific stimuli

5 steps in a reflex arc: 1. Arrival of stimulus and activation of

receptor 2. Activation of a sensory neuron 3. Information processing in CNS 4. Activation of a motor neuron 5. Response by effector

Postural reflex • Maintain a normal upright posture

Tendon reflex • Monitors tension, prevents breaking of

tendon Withdrawal reflex

• Moves parts away from a stimulus Plantar reflex

• Toes curling

Cerebrum Cerebellum Diencephalon Mesencephalon Pons Medulla oblongata

Where conscious thought and intelligent functions originate

Frontal lobe • Voluntary control of skeletal muscle

Parietal lobe • Conscious perception of touch, pressure,

pain, vibration, taste, and temperature Occipital lobe

• Conscious perception of visual stimuli Temporal lobe

• Conscious perception of auditory and olfactory stimuli

Adjusts the postural muscles of the body

Fine tune muscle control

Epithalamus • Contains pineal gland which

secretes melatonin Regulates day/night cycles

Hypothalamus • Controls

autonomic/subconscious functions

• Secretes hormones • Produces emotions

Thalamus

Relates visual/auditory information to produce reflexes

Helps control respiration

Links cerebellum with the brain stem, cerebrum, and spinal cord

Connects brain and spinal cord Center for the coordination of

autonomic functions Controls visceral functions