BIO 180 - Human Anatomy and Physiology I - Unit V Notes

Function of the sympathetic nervous system

Fight of flight, increases heart rate and breathing, dilates eyes, reduces mucus and saliva, constricts arteries

Function of the parasympathetic nervous system

Rest and digest, lower breathing and heart rate, increase gut motility,

Preganglionic neurons

Originate from the brain or spine and travel to the ganglia where the synapse with postganglionic neurons

What are ganglion neurons

Collections of neural bodies called ganglion act as a relay station and transmit signal to postganglionic fibers

What are postganglionic neurons

Fibers from the ganglion to the effector organ

What ganglion makes of the sympathetic division

3 cervical 10-12 thoracic 4-5 lumber 4-5 sacral and 1 coccygeal

How do signal travel in the sympathetic chain?

Into the white ramus to the sympathetic chain ganglion and then through either the sympathetic nerve (heart and lungs) or a spinal nerve

What are the sympathetic nerves for

Heart and nerves

What does thoracic ventral room damage mean

No sympathetic motor function to the same side/neck

What does cervical ventral root damage mean

Muscles paralysis but sympathetic function intact

What does cervical/thoracic ganglia damage mean

No sympathetic to the face but motor and sensory intact.

Signs of horners syndrome

Flush face, no sweat, pupil constriction

What does the collateral chain ganglia do

Intervates tissues and organs in the abdominopelvic cavity. Liver, stomach, spleen, pancreas, small and large intestines, rectum, adrenal and kidneys, bladder, sex organs

What are the 3 major ganglia of the collateral ganglia

Celiac, inferior and superior mesentaric

What does the celiac ganglia innervate?

Stomach, liver, gallbladder, spleen, pancreas

What does the superior mesenteric ganglia innervate?

Small intestine and part of large intestine

What does the inferior mesenteric ganglia innervate?

The rest of the large intestine, kidneys, bladder, and sex organs

What hormones do the adrenal medullas secrete

Epinephrine and norepinephrine

What are the characteristics of adrenal activation

Increased alertness

Energy and euphoria

Increase in cardiac and respiratory

Elevation in muscle tone

Fat reserves activated

What are varicosities

String of pearls surround target tissue and are full of NTs to release in tissue

ACh synapse

Cholinergic

Stimulate sweat glands and arteriole dilation

NE synapse

Adrenergic

Arteriole vasoconstriction

NE is reabsorbed by varicosities and recycled or broken down by the enzyme

MOA monoamine oxidase

What does NO nitrous oxide do

Offers immediate vasodilation

Function of the parasympathetic division

Times of rest, rest and digest

What CNs turn into the parasympathetic nervous system

3 ocularmotor

7 facial

9 glossopharyngeal

10 vagus

4 ganglia of the parasympathetic nervous system and nerves

Ciliary

Pterygopalatine

Submandibular

Otic

Pelvic nerves

What nerves are associated with the sympathetic nervous system

Sympathetic nerves

Splanchnic nerves: greater, lesser, least, and lumbar

What nerves are associated with the parasympathetic nervous system

Pelvic nerves

What does the parasympathetic system activate

Conserve energy

Digestive function

Hormone secretion

Defecation/urination

Regular cardiovascular and respiratory function

Sexual arousal

NTs of the parasympathetic nervous system

All release ACh

Nicotine receptors always excited

Muscarinic receptors can be excitatory or inhibitory

What is automatic tone

Background activity of the nervous system balances the sympathetic and parasympathetic

Define biofeedback

Visual and auditory stimuli identify changes and used to control blood pressure heart rate, circulation, skin temp, brain waves etc

What is short term memory

Recall quickly

What is long term memory secondary

Effort to recall

What is tertiary long term memory

Part of your consciousness usually associated with emotion

What are fact memories

Information

What are skill memories

Learned motor behaviors

Which parts of the brain like memory and emotion and associate memories

Amygdaloid and hippocampus

What are memory engrams

Single circuits for single memories

General senses

Touch, pain, temp, pressure, vibration, and proprioception

Special senses

Olfactory, vision, Gustation, equilibrium, and hearing

Sensation

Feeling something physically

Perception

Awareness and understanding of the sensation

Receptor specificity

The selective nature a receptor has for a certain sense

Receptive fields

A area cover by a single receptor

Tonic receptors

Slow adapting receptors nociceptors

Phasic receptors

Fast adapting receptors like thermoreceptors

Peripheral adaptation

Occurs when receptor activity changes

Central adaptation

Occurs when awareness of the stimulus decreases

Phantom pain

Feeling pain in an organ that is no longer a part of the body

Referred pain

Pain spread to areas not associated directly with the pain

Exteroreceptors

External environment

Interoreceptors

Visceral organs

Proprioreceptors

Body position Tension and state of muscle contraction

Receptors in joint capsules

What are muscle spindles

Trigger stretch reflexes

Golgi tendon organs

Junction of muscle and tendon

nociceptors

Pain

Located in the skin joint bones and blood vessels

Data travels in the spinothalamic tract

3 types of nociceptors

Temperature pain

Mechanical damage broken

Chemicals burns

Thermoreceptors

Temperature

Free nerve ending in the dermis muscles liver and hypothalamus

3x greater that warm receptors

Travels with pain in CNS to reticular formation, thalamus and primary somatosensory cortex.

Mechanoreceptors

Movement and contact respond to stretch compression and twisting

3 classes of mechanoreceptors

Tactile recp touch pressure and vibration

Barorecp- pressure changes

Propriorecp- positions of the body

Free nerve ending

No protection, touch and pressure, in epidermis only sensory in cornea

Root hair plexus

Notice movement of the hair follicle but these adapt quickly

Tactile disc (Merkel)

Fine touch/pressure, myelinated

Located in the germinativum of epidermis

Tactile corpuscles (meissners)

Fine touch/pressure and low frequency vibration, adapt quickly, surrounded by modified Schwann cells

Found in the papillary dermis of lips, eyelids, fingertips, nipples, and external genitalia.

Chemoreceptors

Chemicals/viscera

Taste smell bodily fluids

Photoreceptors

Detect light

Osmoreceptors

Fluid pressure

Pacinian corpuscles lamellated

Deep pressure, high frequency vibration, in deep reticular dermis of the fingers, mammary glands, and external genitalia,

Also in fasciae, joint capsules, mesentaries, pancreas, urethra, and bladder

Baroreceptors

Free nerve ending that detect changes in pressure and adapt quickly

Blood pressure, lung expansion, digestive and urinary function, pressure in tissues

Bulbous corpuscles Ruffini

Pressure and distortion of skin

Found In reticular dermis

Tonic and show little adaptation

Motor homunculus

Represents the cortical area responsible for motor control of different body parts

Sensory homunculus

Represents the cortical area responsible for sensory processing of different body parts

Sensory motor tract

Posterior columns

Spinothalamic tract

Spinocerebellar

Motor tract

Corticospinal

Corticobulbar

Medial pathways

Lateral pathways

Posterior columns

Fasciculis gracilis and cutaneous

Carries fine touch vibration and propioception

Spinothalamic tracts

Anterior (crude touch and pressure)

Lateral (pain and temperature)

Responsible for phantom and referred pain

Spinocerebellar

Carries proprioception information to the cerebellum

Posterior Does not crossover

Anterior crosses before

Corticospinal

AKA pyramidal system

3 pairs of tract

Corticobulbar

Lateral Corticospinal

Anterior Corticospinal

Medial pathways

Control gross movements to trunk and proximal limb muscles

Vestibulospinal

Tectospinal

Reticulospinal

Lateral pathways

Movements of the distal limb muscles for precise movements

Posterior columns pathway

Crossover occurs in the medulla and travels as the medial lemniscus

What is crossover site called

Decussation

First order neurons

From sensation to CNS

Second order neurons

Interneuron within the CNS crossover to the other side relay to thalamus

Third order neuron

Synapse in the thalamus to the cerebral cortex

vestibulospinal tracts

Form vestibular nuclei

Subconscious balance and muscle tone

No crossing

Tectospinal tract

From tectum

Subconscious responses to auditory and visual stimuli

Reticulospinal tracts

From reticular formation

Subconscious control of reflexes

No crossing

Lateral pathways

Rubrospinal tracts- red nuclei subconscious control of upper extremities for tone and movement