Chapter 15 Review: Autonomic Nervous System and Senses

Flashcards for Autonomic Nervous System and Senses

Autonomic Nervous System

Contributes to homeostasis by responding to subconscious visceral sensations and exciting or inhibiting smooth muscle, cardiac muscle, and many glands. Not voluntary.

Autonomic motor neurons

Regulate visceral activities by exciting or inhibiting ongoing activities in their effector tissues.

Sympathetic Nervous System

Fight or Flight, Excitation

Sympathetic (Thoracolumbar)

Cell bodies of motor neurons are in lateral gray horns of T1-L2 where preganglionic neurons exit.

Sympathetic Trunk ganglia

Lie in a row on either side of the vertebral column. Postganglionic neurons innervate organs above the diaphragm.

Prevertebral Ganglia

Lies anterior to the vertebral column. Postganglionic neurons innervate organs below the diaphragm.

5 prevertebral ganglia

Celiac, aorticorenal, superior mesenteric, renal, and inferior mesenteric ganglia

Chromaffin cells

Secrete epinephrine and norepinephrine

Parasympathetic Nervous System

Rest and digest, Inhibition.

Parasympathetic (Craniosacral)

Cell bodies of motor neurons are in 4 cranial nerves (III, VII, IX, X) and lateral gray matter of S2-S4.

Terminal Ganglia

Four pairs of cranial parasympathetic ganglia innervate structures in the head.

Cholinergic

Synapses where ACh is used.

Nicotinic receptors

In dendrites and cell bodies of both sympathetic and parasympathetic postganglionic neurons. At NMJ. They always excite (depolarize) a cell

Muscarinic receptors

Located in plasma membranes of all effectors and sweat glands. They may inhibit (hyperpolarize) a cell

Adrenergic

Synapses where norepinephrine and noradrenalin are used.

Alpha 1 receptors

Excitation

Alpha 2 receptors

Inhibition

Beta 1 receptors

Excitation

Beta 2 receptors

Inhibition

Beta 3 receptors

Thermogenesis

Agonist

A substance that binds to and mimics the effect of the natural occurring neurotransmitter or hormone

Antagonist

A substance that binds and blocks the natural occurring neurotransmitter or hormone from binding

Autonomic tone

Regulated by the hypothalamus

Autonomic Reflex Arc

Receptor → Sensory Neuron → Integrating Center → Motor Neurons → Effector

Sensory modality

Touch, pain, vision

Somatic senses

Touch, pressure vibration, itch, and tickle, thermal sensations, pain sensations, and proprioception

Exteroreceptors

Located at or near the external surface of the body and respond to external stimuli.

Interoceptors

Located in blood vessels, organs, and muscles, and produce impulses which usually are not consciously perceived.

Proprioceptors

Located in muscles, tendons, joints, and the inner ear. They provide information about body position, muscle length, and movement of joints.

Nociceptors

Respond to painful stimuli.

Photoreceptors

Photons of light striking the retina of the eye.

Chemoreceptors

Detect chemical changes in the mouth (taste), nose (smell).

Osmoreceptors

Detect the osmotic pressure of body fluids.

Meissner corpuscles of touch

Located in hairless skin of fingertips, hands, eyelids, tip of tongue, lips, nipples, soles of feet, etc.

Hair root plexuses

Free nerve endings wrapped around hair follicles.

Type 1 cutaneous mechanoreceptors

Free nerve endings that make contact with merkel cells of the stratum basale

Encapsulated nerve endings

Dendrites enclosed in a connective tissue capsule that has a distinctive microscopic structure.

Mechanoreceptors

Detect touch, vibration, and pressure. Sensitive to deformation.

Thermoreceptors

Detect change in temp.

Cutaneous

Sensations arising from the skin surface

Tactile

Touch, pressure vibration, itch, and tickle.

Type 2 cutaneous mechanoreceptors

Encapsulated receptors located deep in the dermis, ligaments and tendons, hands and abundant in the soles. Sensitive to stretching of skin that occurs as digits or limbs are moved. Also crude touch

Meissner corpuscles of touch

Detect lower frequency vibrations

Pacinian lamellated corpuscle

Detect high frequency vibrations

Cold receptors

Located in the stratum basale of the epidermis. Temps between 50-95 degrees F.

Kinesthesia

The perception of body movements

First order neuron

somatic receptors to brainstem

Second order neuron

brainstem and spinal cord to thalamus.

Third order neuron

thalamus to cerebral cortex

Circadian rhythm

24 hr cycle

Stage 1 NREM sleep

Transition stage (1-7 min)

Stage 2 NREM sleep

Light sleep. First stage of true sleep, dream fragments.

Stage 3 NREM sleep

Moderately deep sleep. Difficult to wake the person (after about 20 min)

Stage 4 NREM sleep

Deepest sleep (sleepwalking occurs here)

Olfactory pathway

Olfactory nerve → olfactory bulb → olfactory tract → primary olfactory area

Facial (VII) nerve

Anterior ⅔ of tongue

Glossopharyngeal (IX) nerve

Posterior ⅓ of tongue

Vagus (X) nerve

Throat and epiglottis

Plasticity

The capability for change associated with learning

Amnesia

The lack or loss of memory.

Anterograde amnesia

Inability to form new memories

Retrograde amnesia

Inability to remember the past

Olfaction

Process of receiving smells

Olfactory receptor

Bipolar neuron with cilia

Five primary tastes

Sour, sweet, bitter, salty, and umami

Outer eye layer

Fibrous tunic, sclera (outer layer) & Cornea (transparent)

Vascular tunic

Ciliary body, iris, and choroid

Nervous tunic

Retina (inner)

Accessory structures of the eye

Extraocular muscles, Palpebra (upper and lower), Conjunctiva, Lacrimal glands

Ciliary muscle

Changes shape of lens to adapt to near and far vision

Optic disc

Where the optic nerve and retinal vessels enter and exit the eyeball

Glaucoma

Increase of pressure in aqueous humor flow

Pupil

Opening in the center of the iris

Vision

Normal image formation depends on refraction of light waves, accommodation of the lens, constriction of the pupil, and convergence of the two eyes

Refraction

Both the cornea and lens refract light rays

Convergence

Inward movement of the eyes so that both are directed at the object being viewed

Nearsightedness

Myopia

Farsightedness

Hyperopia

Rhodopsin

Single type of photopigment in rods

External ear

Auricle (elastic cartilage), Helix superior, Lobule inferior, Tympanic membrane

3 auditory ossicles

Stapes, Incus, Malleus

Eustachian tube

Bone and hyaline cartilage

Bony labyrinth

Semicircular canals, the vestibule, and the cochlea

Vestibule

Utricle and Saccule

Cataract

Opaque defect in the cornea or lens of the eye

Conjunctivitis

Inflammation of the conjunctival membrane (pink eye)

Inflammation of the ear drum

Myringitis

Otitis externa

Irritation of the skin in the ear canal

Meniere's disease

Disorder of the inner ear that can affect hearing and balance. Increased pressure in cochlea and semicircular canals.

Static equilibrium

object at rest

Dynamic equilibrium

Maintenance of balance during sudden movement.