Lecture 1: Introduction Flashcards
The body is constantly reacting and adjusting to changes in the internal and external environment in order to maintain
homeostasis
Two main control systems of the body
endocrine and nervous systems
The nervous system uses ____ _____ to coordinate rapid activities of the body such as muscle movements
electrical impulses
The nervous system also releases ______ that travel across the synaptic cleft to induce effects
neurotransmitters
Is the nervous system fast or slow
Very fast (milliseconds)
The endocrine system
secretes hormones into the blood for delivery to distant sites of action
The endocrine system primarily controls
metabolic and other activities that require duration (ex. maintenance of glucose levels)
Endocrine system duration of action
Long (minutes to days)
Two parts of the nervous system
Central nervous system
Peripheral nervous system
CNS is composed of
the brain and the spine
CNS is responsible for
Integrating, processing, and coordinating sensory data and motor commands
Sensory data (input) conveys
information about external and internal conditions
Motor commands control or adjust
the activities of peripheral organs
The PNS includes
all neuronal tissue outside of the CNS
PNS is responsible for
- Delivery of sensory info to the CNS
- Carrying motor commands to peripheral tissue and system
What carries info and commands in the PNS?
Bundles of nerve fibers called axons
Cranial nerves
Nerves connected to the brain
Spinal nerves
Nerves connected to the spine
Three components of the nervous system pathway
- Sensory afferent fibers (detects)
- Integrative component (processes and stores data)
- Motor efferent fibers (generates movements and glandular secretions)
Afferent neurons (sensory)
Has sensory neuron at its peripheral end which generates action potentials in response to a certain stimulus (ex stretch)
Cell bodies of afferent neurons are devoid of
Dendrites
Efferent neurons generally lie in the ____ but cell bodies originate and receive inputs in the _____.
PNS
CNS
Efferent neuron axons extend from ____ to ___ ____.
CNS
effector organ
An autonomic nerve pathway consists of
A two-neuron chain between the CNS and effector organ
Interneurons lie entirely in the
CNS
About ___% of neurons are interneurons
99
Interneurons are between
efferent and afferent neurons
Interneurons integrate
Peripheral responses to peripheral information
Interneurons are responsible for
distribution of sensory information and the coordination of motor activity organs
The sensory systems receive information from the environment via
specialized receptors in the periphery and transmit this information to the CNS (sensory receptors)
3 types of sensory receptors
- Exteroceptors
- Propioceptors
- Interoceptors
Exteroceptors
Provides info about the external environment in the form of touch, temp, and the five senses
Propioceptors
Monitors the position and movement of skeletal muscles and joints
Interoceptors
Monitors the digestive, respiratory, cardiovascular, urinary, and reproductive systems
