Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
77 Cards in this Set
- Front
- Back
|
Structures of the body controlled by the ANS:
|
Glands, cardiac and smooth muscle
|
|
|
Example of a visceral reflex:
|
High BP detected by arterial stretch receptors --> signal transmitted to CNS --> efferent signals travel to the heart --> heart slows --> thus reducing BP.
|
|
|
Parasympathetic Division
|
Rest and Digest. Has calming effect on many body functions and assists in bodily maintenance.
|
|
|
Sympathetic Division
|
Fight or Flight. Prepares body for physical activity. Increases heart rate, BP, airflow, blood glucose levels, etc.
|
|
|
Somatic Pathways
|
1 neuron only - uses skeletal muscle as the effector.
|
|
|
Autonomic Motor Pathways
|
2 motor neurons - uses smooth muscle, cardiac muscle, and glands as the effector.
|
|
|
Enteric nervous system
|
Nervous system of the digestive tract. Isolated. Composed of 100s of millions of neurons found in the walls of the digestive tract (no components found in CNS). Has its own reflex arcs.
|
|
|
Norephinephrine receptors
|
Alpha adrenergic receptor - binding is Excitatory. Beta adrenergic receptors - binding is Inhibitory.
|
|
|
What two receptor types does ACh bind to?
|
Nicotinic - excitatory. Muscarinic - excitatory or inhibitory.
|
|
|
Nicotinic receptors
|
ACh receptor. Occur on all neuronal cell bodies in the ANS ganglia and at neuromuscular junctions (skeletal muscle).
|
|
|
Muscarinic receptors
|
ACh receptor. Glands, smooth muscles and cardiac muscle cells that receive cholinergic innervation. Either excitatory or inhibitory.
|
|
|
Dual innervation
|
Most organs receive nerve input from BOTH parasympathetic and sympathetic divisions, but not always equal.
|
|
|
Parasympathetic/Sympathetic - Antagonistic
|
Effects that oppose each other. Dual innervation of same effector cells: heart slowed down or speeded up. Innervation of different cells in same effector organ: Pupillary dilator muscle and constrictor pupillae change pupil size.
|
|
|
Parasympathetic/Sympathetic - Cooperative
|
Two divisions act on different effectors to produce a unified effect (salivation). Parasympathetic NS increases salivary serous cell secretion. Sympathetic NS increases salivary mucous cell secretion.
|
|
|
ANS Properties (3)
|
Carries out actions automatically. Visceral motor nervous system that controls glands, cardiac, and smooth muscle. Regulates unconscious processes that maintain homeostasis: BP, body temp., resp. airflow.
|
|
|
Visceral Reflexes
|
Unconscious, automatic responses to stimulation of glands, cardiac, or smooth muscle. Receptors detect internal stimuli. Afferent/sensory neurons connect to interneurons in the CNS. Efferent neurons carry motor signals to the effectors.
|
|
|
Visceral Reflexes and ANS
|
ANS is the efferent neuron of these reflex arcs. Glands, smooth, and cardiac muscle are the effectors. ANS modifies effector activity rather than turning it on or off.
|
|
|
Sympathetic and Parasympathetic effects depend on?
|
Neurotransmitters released. Receptors expressed by the target airflow, blood glucose levels, etc. (type of receptor)
|
|
|
Somatic vs. Autonomic Pathways (pre- and post-synaptic...)
|
ANS --> 2 neurons span the distance from CNS to effectors. Presynaptic neuronal cell body in CNS --preganglionic. Postsynaptic neuronal cell body in peripheral ganglion -- postganglionic.
|
|
|
Sympathetic NS - origin
|
Origin of preganglionic neurons in thoracolumbar --> gray matter of T1-L2. Produces a widespread effect on multiple organs.
|
|
|
Parasympathetic NS - origin
|
Origin of preganglionic neurons in craniosacral --> brainstem and S2-S4. Terminal ganglia are in target organs due to long preganglionic and short postganglionic fibers.
|
|
|
Transducers
|
Convert stimulus information into electrochemical activity.
|
|
|
Sensory receptors
|
Any structures specialized to detect a stimulus (simple nerve ending or complex sense organ)
|
|
|
Sensory information types that can be conveyed.
|
Type, Location, Intensity, Duration.
|
|
|
Classification of sensory receptors
|
1. Modality (type): chemoreceptors, thermoreceptors, nociceptors, mechanoreceptors and photoreceptors. 2. Origin of stimuli. 3. Distribution: general (somesthetic) sense -- widely distributed. Special senses -- limited to head.
|
|
|
Unencapsulated Nerve Endings
|
General Senses! Dendrites not wrapped in connective tissue. Free nerve endings include warm, cold, and pain. Tactile discs are associated with cells at base of epidermis. Hair receptors monitor the movement of hairs.
|
|
|
Encapsulated Nerve Endings - General Def.
|
Dendrites wrapped by glial cells or connective tissue.
|
|
|
Encapsulated Nerve Endings - Meissner (tactile) corpuscles
|
Used for light touch and texture.
|
|
|
Encapsulated Nerve Endings - Krause end bulb
|
Tactile corpuscles in mucous membranes
|
|
|
Encapsulated Nerve Endings - Pacinian (lamellated) corpuscles
|
Deep pressure, stretch, tickle, and vibration.
|
|
|
Encapsulated Nerve Endings - Ruffini corpuscles
|
Heavy touch, pressure, joint movements, and skin stretching.
|
|
|
Somesthetic (general sense) Projection Pathway - First-order
|
First-order neuron or afferent neuron: 1. from below head, enter the dorsal horn of spinal cord via spinal nerves. 2. from head, enter pons and medulla from cranial nerve. 3. touch, pressure and proprioception are carried on large, fast, myelinated axons. 4. heat and cold are carried on small, unmyelinated, slow fibers.
|
|
|
Somesthetic (general sense) Projection Pathway - Second-order
|
Second-order neuron: 1. transmission of signals to opposite side in spinal cord or medulla. 2. end in thalamus, except for proprioception (cerebellum).
|
|
|
Somesthetic (general sense) Projection Pathway - Third-order
|
Third-order neuron: 1. Extend from thalamus to primary somesthetic cortex of cerebrum.
|
|
|
Pain - part 1.
|
Nociceptors make us conscious of tissue injuries: forces us to care for minor inuuries to prevent serious problems.
|
|
|
Do olfactory receptors adapt quickly or slowly?
|
Quickly. Due to synaptic inhibition in the olfactory bulbs.
|
|
|
In which part of the body are there no pain receptors?
|
Found in all tissues except the brain.
|
|
|
Fast pain
|
Travels in myelinated fibers at 30 m/sec - sharp, localized, stabbing pain perceived with injury.
|
|
|
Slow pain
|
Travels in unmyelinated fibers at 2 m/sec - longer-lasting, dull, diffuse feeling.
|
|
|
What is the pinna (and function)?
|
Pinna (auricle) directs air vibrations down external auditory meatus.
|
|
|
Somatic pain
|
Arises from skin, muscles, and joints.
|
|
|
Explain how the semi-circular canals provide the brain with information about body position (equilibrium).
|
Crista ampullaris consists of hair cells buried in a mound of gelatinous membrane. Orientation of ducts causes different ducts to be stimulated by rotation in different planes.
|
|
|
What is the function of the ear ossicles and where are they located?
|
The ear ossicles amplify the sound vibrations. They are located in the middle ear. MIS - Malleus, Incus, Stapes.
|
|
|
Explain the relationship between K+ gates and cochlear hair cells.
|
Stereocilia bathed in high K+ concentration creating electrochemical gradient from tip to base. Movement of basilar membrane bends stereocilia. Bending pulls on tip links and opens ion channels. K+ flows in--depolarizing it and causing release of neurotransmitter stimulating sensory dendrites at its base.
|
|
|
Physiology of Hearing
|
1. Eardrum vibrates. 2. Vibration of eardrum causes vibration of ossicles. 3. Vibration of ossicles causes vibration in inner ear structures. 4. Cochlear membrane vibrations cause activation of hair cells (hearing receptors). 5. Tympanic reflex protects cochlea by muscle contraction in response to loud noises.
|
|
|
Visceral pain
|
Arises from stretch, chemical irritants, or ischemia of viscera (death of tissues).
|
|
|
Injured tissues
|
Release chemicals that stimulate pain fibers (i.e. bruise)
|
|
|
Projection Pathway for Pain
|
1. First-order neuron: cell bodies in dorsal root ganglion of spinal nerves or trigeminal ganglion (cranial nerve). 2. Second-order neurons transmit to other side and send fibers up spinothalamic tract to thalamus. 3. Third-order neurons reach cortex (Postcentral gyrus).
|
|
|
Describe the sequence of events from a sound wave entering the pinna all the way to being processed by the brain.
|
1. Eardrum vibrates. 2. Vibration of eardrum causes vibration of ossicles. 3. Vibration of ossicles causes vibration of inner ear structures. 4. Cochlear membrane vibrations cause activation of hair cells. 5. Ion channels depolarize.
|
|
|
Gustation
|
The sensation of taste resulting from the action of chemicals on the taste buds.
|
|
|
Lingual papillae (taste)
|
1. Filiform - no taste buds; important for texture. 2. Foliate - no taste buds. 3. Fungiform - at tips and sides of tongue. 4. Vallate - at rear of tongue; contains 1/2 of taste buds.
|
|
|
5 Primary Taste Sensations
|
Salty, sweet, sour, bitter, and umami.
|
|
|
Taste sensation locations
|
1. Sweet - concentrated on tip. 2. Salty & Sour on lateral margins. 3. Bitter at rear.
|
|
|
Project Pathways for Taste
|
Innervation of taste buds in cranial nerves VII, IX, and X. All fibers project to solitary nucleus in MEDULLA. Cells project to hypothalamus and amygdala to activate autonomic reflexes such as salivation, gagging, and vomiting. Cells project to thalamus and then postcentral gyrus of the cerebrum.
|
|
|
Name the three tunics of the eye and briefly describe their function.
|
1. Fibrous layer - sclera and cornea - protection. 2. Vascular layer - choroid, ciliary body, and iris - nutritive support. 3. Sensory layer - retina and optic nerve - receive and process light information.
|
|
|
What components are found in the inner ear?
|
Bony labyrinth, membranous labyrinth. (Passageways in temporal bone). Vestibular nerve, Cochlea, and Semicircular ducts.
|
|
|
What is found within the olfactory foramina of the cribriform plate?
|
Olfactory cells?: Neurons with 20 cilia called olfactory hairs. Binding sites for odor molecules in thin layer of mucus. Axons pass through cribriform plate. Cells survive about 60 days.
|
|
|
Name and describe the optical components.
|
1. Cornea - transparent covering. 2. Aqueous humor - clear serous fluid filling area between lens and cornea. 3. Lens - suspended by suspensory ligaments - changes shape to help focus light rays. 4. Vitreous humor - jelly filling to hold the retina in place.
|
|
|
What bone is the cribriform plate part of?
|
Ethmoid bone.
|
|
|
Describe the location and function of the conjunctiva and the lacrimal apparatus.
|
Conjunctiva lines the eyelids and eyeball - works together with Lacrimal apparatus to produce tears, wash away foreign substances.
|
|
|
Emmetropia
|
Harmonious/Normal response to distant objects (20 ft. away).
|
|
|
Hyperopia
|
Farsighted - eyeball too short. Focal plane is behind eyeball.
|
|
|
Fibrous Layer of Eye
|
Sclera and cornea - Protection
|
|
|
Vascular Layer of Eye
|
Choroid, ciliary body, and iris - Nutritive support
|
|
|
Myopia
|
Nearsighted - eyeball too long. Focal plane just inside eyeball.
|
|
|
Sensory Layer of Eye
|
Retina and optic nerve - receive and process light information.
|
|
|
Rods
|
Shades of gray. Night vision. Peripheral vision. Lots of neuronal convergence.
|
|
|
Cones
|
Color. Day vision. Private line to brain.
|
|
|
Color-blindness
|
Comes from mom.
|
|
|
Neural apparatus
|
Retina and Optic nerve
|
|
|
Lingual papillae - Filiform
|
No taste buds - important for texture.
|
|
|
Lingual papillae - Foliate
|
No taste buds.
|
|
|
Lingual papillae - Fungiform
|
At tips and sides of tongue
|
|
|
Lingual papillae - Vallate
|
At rear of tongue. Contains 1/2 of taste buds.
|
|
|
Where are sweet tastes concentrated?
|
On the tip of tongue.
|
|
|
Where are salty and sour tastes concentrated?
|
Lateral margins of tongue
|
|
|
Where are bitter tastes concentrated?
|
Rear of tongue.
|
