Nervous System Flashcards
CNS is compromised of:
Brain and spinal cord
PNS is compromised of:
All other neurons/nerves in the body
Sensory (afferent) neurons:
Transmit nerve impulses toward the CNS
Motor (efferent) neurons:
Transmit nerve impulses away from the CNS toward the effector organs (muscles, glands, digestive organs)
Major parts of the brain:
Cerebrum
Cerebellum
Medulla oblongata
Cerebrum:
Associated with movement and sensory input
-Voluntary activities
Cerebellum:
Responsible for muscular coordination and balance
-Motor skills
Medulla oblongata:
Controls respiration, heart rate, swallowing
Simple spinal reflexes:
Nerve impulses travel through the spinal cord only and do not reach the brain
How many nerves exit the spinal cord?
31
Spinal cord extends from:
Base of the skull (foramen magnum) to the first or second lumbar vertebra
Sensory impulse reflex pathway:
Enter the dorsal horns of the spinal cord
Motor impulse reflex pathway:
Leave through the ventral horns of the spinal cord
Main parts of a neuron:
Cell body, axon, dendrites
Dendrites:
Transmit impulses toward the cell body through synapses
Axon:
Transmits impulses away from the cell body to other neurons
Neurons:
Transmit action potentials
Neuroglia:
Connective tissue cells that connect and supports neurons
Hypothalamus:
Controls hormones, memory, emotions
2 divisions of the PNS:
Autonomic and somatic nervous system
Autonomic nervous system:
Nerves?
Governs involuntary and reflexive body functions (CNS to cardiac muscles, smooth muscles, glands)
- Sympathetic nerves: fight or flight
- Parasympathetic nerves: rest and digest
Somatic nervous system:
Neurons?
Governs conscious or voluntary control of skeletal muscles
- Sensory (afferent)
- Motor (efferent)
Shwann cells:
Produce myelin sheaths
Myelin sheaths:
A layer of fatty tissue that encases the neuron fibers, which allows for greater transmission speed of neural impulses
