Introduction to Cardiac and Nervous System Flashcards
Heart
- 4 chambers
- Rhythmically contracting
- Unidirectional muscular pump
Arteries
Convey blood away from heart
Veins
Return blood to the heart
Capillaries
Site of nutrient/waste exchange
What branches is the arterial supply to the head and neck derived from?
- Common carotid aa.
- Subclavian aa.
Venous drainage from the head and neck is derived from the tributaries of the…
- Internal jugular v.
- Subclavian vv.
Anastomosis
Site where two or more arteries (or veins) merge/connect to supply the same region
Anastomotic networks
Provide a collateral/alternative) source of blood supply if one of the vessels in the network becomes damaged
General functions of the nervous system
- Integrating/coordinating incoming and outgoing signals
- Mediating higher cognitive function
CNS
Brain and spinal cord
PNS
Cranial nerves, spinal nerves, and ganglia
Somatic nervous system
Supplies the body wall voluntary
Autonomic nervous system
Supplies the viscera involuntary
Somatic motor component
Skeletal muscle contraction
Somatic sensory component
Touch, pain, temperature, proprioception, etc.
Autonomic motor component
Cardiac and smooth muscle, glands
Autonomic sensory component
Sensation from visceral organs
Axon
Transmits neural signals/ impulses away from the cell body
Dendrite
Carries neural signals/ impulses towards the cell body
Synapse
Region where neurons communicate with each other or effector organs
Neurotransmission
- At synapse
- Communcation between two neurons or between a neuron and an effector organ
What is a nerve
A bundle of axons coursing in the PNS
Neuronal cell bodies in CNS
- Grey matter
- Nucleus
Neuronal cell bodies in PNS
Ganglions
Bundle of axons in CNS
- White matter
- Fiber tract
Bundle of axons in PNS
Nerve
A nerve can…
Convey multiple fiber types with differing functions/targets
Spinal nerves
Mixed nerves that transmit both motor and sensory fibers
Spinal cord
Caudal portion of the CNS, extends inferiorly from brainstem
How many segments is the spinal cord made of?
31
Spinal cord segments are defined by its associated….
- Spinal nerve
- 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Vertebral column
- Extends from the skull to the tip of the coccyx
How many vertebrae is the vertebral column made of?
33
Where does the spinal cord sit in respect to a single vertebrae?
Vertebral canal
Where does the spinal nerve exit the vertebral column?
Intervertebral foramen
Dorsal root
Sensory fibers are conveyed to the spinal cord through here
Dorsal root ganglion
Cell bodies of sensory neurons
Dorsal and ventral primary rami
- Mixed nerves
- Convey both motor and sensory fibers
Cervical plexus
Supplies neck and head
Brachial plexus
Supplies upper extremities
Sympathetic innervation
Mediates fight or flight
Where does sympathetic innervation arise from?
Neurons in the thoracic and lumbar regions of the spinal cord
Functions of sympathetic innervation?
Mobilize resources of the body when demands are increased
Enteric division
Intrinsic nervous system of the gut
The enteric division is derived from…
The motor component of the autonomic nervous system
Parasympathetic division
Functions in the restoration or conservation of energy and resources
Where does parasympathetic innervation arise from?
Neurons of the cranial and sacral regions of the spinal cord
What innervation is a 2 neuron pathway?
Visceral motor innervation
What is in the middle of a 2 neuron pathway?
Intervening autonomic ganglion
Differences of the sympathetic and parasympathetic nervous division?
- Distinct CNS organs
- Distinct ganglia
Similarity of the parasympathetic nervous division?
Same target, just opposite actions
How does the sympathetic innervation assess structures in the head?
Through the sympathetic chain/trunk
Pre-ganglion neuron
- Located in CNS
- Project their axons to autonomic ganglia in PNS to synapse
Post-ganglionic neurons
- Project their axons to the target structure
- Examples are glands, smooth muscle, etc.
Steps in sympathetic division of autonomic nervous system
- Pre-ganglion sympathetic neurons in spinal cord (T1-L2)
- Sympathetic chain
- Post-ganglion sympathetic neurons in the superior cervical ganglion
- Periarterial plexuses
- Target structure in head
