Chapter 9 Flashcards
Autonomic nervous system
In charge of our viscera (controls circulation, respiration, digestion, metabolism, secretions, body temp, and reproduction).
Efferent is a 4 neuron chain of command.
Sympathetic system
Fight or flight (mobilizes energy to either fight or flee) makes decision.
Thoracolumbar outflow- peripheral autonomic neurons of sympathetic poke our from T1 and L2 (uses energy)
Thoracolumbar outflow
Peripheral autonomic neurons of sympathetic poke out from T1 to L2
Parasympathetic system
Rest and digest system (feed and breed system).
Craniosacral outflow- peripheral parasympathetic neurons poke out of brainstem and poke out of S2, S3, and S4.
Stores energy (while resting it is packing glycogen for storage that can be used when needed).
Mechanoreceptors
- Pressure and Stretch
- Sinus at carotid artery, when it gets stretched it sends more blood vessels into the brain to restore homeostasis
Chemoreceptors
- Chemical environment
- Sample blood and composition of blood to ensure homeostasis is being maintained.
Nociceptors
- Stretch, Ischemia, Chemicals
- Nerve endings that respond to extreme inputs (pain) will signal too much stretch, ischemia, chemicals
Thermoreceptors
- Hypothalamic and Cutaneous
- Can adjust blood vessels and sweat glands to restore thermal homeostasis
Afferent Pathways
Afferent messages travel , through cranial nerves 7, 9, and 10 (cranial nerves provide input)
-for the rest of the body, the signals get in through the peripheral nerves and spinal cord.
Central Regulation
- 4 neuron control pathway Modulatory (central) Modulatory (central) Control (central) Pre-ganglionic (peripheral)
Modulatory (central)
Neurons are part of our efferent system, cell bodies up in the limbic lobe (emotion system) or in the hypothalamus- influence the activity of the autonomic system broadly. Set a general direction and relay information to reticular formation (control)
in the head
Control (central)
Neurons with cell bodies in the reticular formation (core of pons and medulla is a long cluster of cells, they send autonomic control signals down to the spinal cord).
In brainstem
I control the tv remote, I send signals on TV remote, Wife modulates the channel by telling me what channel to turn to
Pre-ganglionic (peripheral)
Starts in the spinal cord and goes out into the periphery. Before the synapse, starts in the spinal cord and it ends at the synapse (ganglion)
-has cell bodies in spinal cord (cell bodies in lateral horn) leaves from ventral root and heads to peripheral synapse
Thoracolumbar, sacral
Anterior Insula, Amygdala, Thalamus, and Hypothalamus
Limbic and autonomic structures at base of brain that are modulatory in terms of autonomic nervous system.
Parasympathetic central regulation
Two central neurons (Modulatory and control)
and two peripheral neurons (pre-ganglionic and post-ganglionic)
Central regulation (afferent and efferent pathway)
If some sort of visceral distress (appendix is inflamed) sensory neurons bring signal through a peripheral nerve (that pain signal diverges into 4 neurons)
- one route is to the brainstem control centers plus the thalamus, hypothalamus, and emotion/motivation system. (synapses in dorsal horn and sends messages to visceral control centers (medulla, hypothalamus, and limbic lobe)
- 2nd route is to cortical (conscious) sensory areas which may be interpreted as referred pain. (synapses in dorsal horn and goes up to somatosensory areas of the brain. tells the brain it hurts to alert us about what is hurting).
- 3rd route loops back and terminates on the injured organ. The distress on the visceral organ initiates a reflex that shuts down that organ (if it is hurt the body doesn’t want to use it to protect it)
- 4th route is a divergent branch to motor cell bodies of the muscles of the abdominal wall right over the top of the organ (somatic body responds by splinting/contracting- trying to build a wall so nothing else can hurt the organ)
