Chapter 15 & 16 - ANS & Sensory, Motor & Integrative Systems

Question 1

(2) divisions of ANS

Answer 1

sympathetic

parasympathetic

Question 2

Structure of the Sympathetic Division

Answer 2

thorocolumbar (sympathetic) division- Preganglionic neurons originate from thoracic & lumbar levels of spinal cord (T1-L2).

**Sympathetic ganglia - **site of synapse between sympathetic pre & postganglionic

(2) types - sympathetic trunk & prevertebral (collateral) ganglia

Question 3

Preganglionic & postganglionic neurons

Answer 3

**preganglionic - **cell body in CNS, exits as cranial/spinal nerve

axon = type B fiber (small, myelinated)

**postganglionic - **in PNS (outside CNS), cell body & dendrites in **autonomic ganglia **

axon = small, unmyelinated type C fiber

Question 4

Sympathetic division

**sympathetic ganglia (2) **

Answer 4

**Sympathetic trunk (vertebral chain) ganglia. - **innervate organs above diaphragm

Prevertebral (collateral) ganglia: celiac, superior mesenteric, inferior mesenteric,
aorticorenal and renal.

innervate organs below diaphragm

Question 5

Once axons of sympathetic preganglionic neurons pass to **sympathetic trunk ganglia, **they may connect with postganglionic neurons in the following ways (4)

Answer 5

1) synapse with neurons in nearest gangliaon
2) axons ascend/descend to higher/lower ganglion, **sympathetic chains **
3) through sympathetic trunk ganglion to synapse with neurons in prevertebral ganglion
4) through **sympathetic trunk & prevertebral **to chromaffin cells of adrenal medulla

Question 6

A single sympathetic preganglionic fiber has many axon _______________ and may synapse with 20 or more postganglionic neurons.

Answer 6

branches (collaterals)

Question 7

sympathetic postganglionic axons typically terminate in several

Answer 7

visceral effectors

therefore effects are more widespread than parasympathetic stimulation

Question 8

Structure of the Parasympathetic Division

Answer 8

craniosacral divison - Preganglionic neurons originate from cranial
nerves III, VII, IX, X & sacral spinal nerves S2-S4

**parasympathetic ganglia - **preganglionic synapse with postganglionic in **terminal (intramural) ganglia **.

Question 9

Parasympathetic Presynaptic neuron usually synapses with 4-5 postsynaptic neurons all of which supply ?

Answer 9

a single visceral effector

Question 10

Autonomic Plexuses in Thorax, Abdomen & Pelvis

Answer 10

network of sympathetic & parasympathetic neurons

**thorax plexus - **heart

**pulmonary plexus - **bronchial tree

**celiac (solar) **plexus - largest. stomach, spleen, pancreas, liver, gallbladder & adrenal medulla

Question 11

Sympathetic response

Answer 11

fight or flight

↑ ATP, heart rate, BP, blood supply to skeletel/cardiac muscles, liver & fat, blood glucose

dilation of pupils, constriction of blood vessels

breakdown of glycogen & lipids

Question 12

Parasympathetic Responses

Answer 12

rest & digest

**conserve & restore energy **

↑ digestive & urinary function

↓ body functions supporting physical activity

Question 13

Sensation

Answer 13

conscious & subconscious awareness of changes in environment

Question 14

components of sensation

Answer 14

Stimulation of sensory receptor → transduction of stimulus → nerve impulses → integration of sensory input.

Question 15

Classification of Sensory Receptors

Answer 15

General senses

Special Senses

Question 16

1. General senses
2. Special senses

Answer 16

1) somatic & visceral
a. **somatic - **tactile, thermal, pain &proprioceptive sensations

b. Visceral- provide info about conditions within internal organs.

2) smell, taste, vision, hearing, equilibrium/balance

Question 17

Types of Sensory Receptors

Answer 17

free nerve endings

encapsulted nerve endings

seperate cells

Question 18

free nerve endings

Answer 18

pain & thermoreceptors

Question 19

encapsulated nerve endings

Answer 19

dendrites enclosed in CT capsule

pacinian corpuscles

Question 20

seperate cells

Answer 20

hair cells, photoreceptors & gustatory receptor cells

Question 21

Generator Potential and Receptor Potential

Answer 21

Generator potential: produced by free nerve, encapsulated **nerve **endings, and olfactory receptors. When it reaches threshold, triggers 1+ nerve impulses in axon of ** first-order sensory neuron. **

Receptor potential triggers release of neurotransmitters→ **postsynaptic potential → action potential. **

Question 22

Classification of Sensory Receptors Based on the Location

Answer 22

o Exteroceptors: external surface
o **Interoceptors: **internal environment (vessels, organs & muscles & NS)
o **Proprioceptors: **muscles, tendons, joints & nner ear

Question 23

Classification of Sensory Receptors based on the type of Stimulus

Answer 23

**mechanoreceptors - **mechanical stimuli (touch, proprioception)

thermoreceptors

**nociceptors - **pain

**photoreceptors - **light

**chemoreceptors - **chemicals in mouth, nose & body fluids

**Osmoreceptors **

Question 24

Adaptation of Sensory Receptors

Answer 24

**rapidly adapting receptors: ** detect pressure, touch and smell.

**slowly adapting receptors: **detect pain, body position & blood chemical composition

Question 25

**Somatic Sensations ** (4) modalities

Answer 25

sensory receptors in skin, muscles, tendons, joints & inner ear **1) tactile ** **2) thermal** **3) pain** **4) proprioceptive **

Question 26

** Tactile Sensations **include?

Answer 26

touch pressure vibration itch tickle

Question 27

Tactile receptors in skin

Answer 27

Meissner corpuscles hair root plexuses Merkel discs Ruffini corpuscles pacinian corpuscles free nerve endings.

Question 28

Meissner Corpuscles or Corpuscles of Touch

Answer 28

egg-shaped mass of **dendrites **enclosed by capsule of **CT** rapidly adapting - *dermal papillae of hairless skin * ***TOUCH & PRESSURE***

Question 29

Hair root plexuses

Answer 29

rapidly adapting- **touch ** in hairy skin free nerve endings wrapped around hair follicles detect movement on skin that disturbs hair

Question 30

Merkel Discs or Tactile Discs

Answer 30

type I cutaneous mechanoreceptors slowly adapting touch fingertips, hands, lips, external genitals

Question 31

Ruffini Corpuscles

Answer 31

type II cutaneous mechanoreceptors elongated, encapsulated receptors deep in dermis, ligaments & tendons hands & soles

Question 32

Pacinian or Lamellated Corpuscles

Answer 32

Large oval structure composed of a multilayered CT capsule that encloses a **dendrite (encapsulated)** fast adapting - **pressure** joints, tendons, muscles, peiosteum, mammary glands, external genitals, pancreas & urinary bladder

Question 33

Thermal Sensations

Answer 33

thermoreceptors **cold - **stratum basale: medium myelinated A fibers **warm - **dermis: small unmyelinated C

Question 34

Pain Sensations

Answer 34

protective nociceptors free nerve endings **fast: **acute, sharp/pricking **slow: **chronic, aching

Question 35

Refered pain

Answer 35

Pain is felt in or just deep to the skin that overlies the stimulated organ or in a surface area far from the stimulated organ

Question 36

Proprioceptive Sensations

Answer 36

proprioceptors slow adaptation weight discrimation (3) types: **muscle spindles, tendon organs & joint kinesthetic receptors **

Question 37

Proprioceptors: **muscle spindles**

Answer 37

parellel to & among skeletal muscle fibers measure muscle **length** consist of **intrafusal (inside) muscle fibers - **specialized with sensory nerve endings & gamma motor neurons **extrafusal (outside) muscle fibers - **surround muscle fiber supplied by alpha motor neurons

Question 38

Tendon Organs

Answer 38

at junction of tendon & muscle protect tendons from damage due to xs tension thin capsule of CT that encloses few tendon fascicles

Question 39

Joint Kinesthetic Receptors

Answer 39

Found within or around **articular capsules of synovial joints.** **Free nerve endings & Ruffini corpuscles** respond to pressure **pacinian corpuscles **respond to accel/deceleration of joints during movement

Question 40

Somatic Sensory Pathways 1. first order neurons 2. second order neuron 3. third order neuron

Answer 40

1. (somatic receptor →** brain stem/spinal cord** 2. brain stem/spinal cord → **thalamus** 3. thalamus → **primary somatosensory area**

Question 41

Major Somatic sensory pathways

Answer 41

o The **posterior column-medial lemniscus** pathway. o The **anterolateral** (**spinothalamic**) pathway. o The **trigeminothalamic** pathway. o The **anterior** and **posterior spinocerebellar** pathway.

Question 42

The Posterior Column-Medial Lemniscus Pathway

Answer 42

impulses for touch, pressure, vibration, conscius proprioception from **limbs, trunk, neck, & posterior head **to cerebral cortex

Question 43

The Anterolateral (spinothalamic) pathway

Answer 43

pain, cold , warmth, itch, & tickle from the **limbs**, **trunk**, **neck**, and **posterior** **head** to cerebral cortex.

Question 44

Trigeminothalamic Pathway

Answer 44

most somatic sensations from face, nasal/oral cavity & teeth to cerebral cortex

Question 45

Somatic Motor Pathways

Answer 45

**upper** motor neurons → **lower** motor neurons → skeletal muscles

Question 46

Neural circuits involving **basal ganglia and cerebellum** regulate activity of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ motor neurons.

Answer 46

upper

Question 47

Organization of the Upper Motor Neuron Pathways ## Footnote **direct motor pathway **

Answer 47

originates in cerebral cortex

Question 48

Direct Motor pathways (2)

Answer 48

**corticospinal - **limbs & trunk **corticobulbar - **skeletal muscles in head

Question 49

Indirect motor pathway-

Answer 49

originates in brain stem

Question 50

Indirect or Extrapyramidal Pathways (4)

Answer 50

Rubrospinal tract - Tectospinal tract - Vestibulospinal tract - Reticulospinal tract

Question 51

Modulation of Movement from the Cerebellum

Answer 51

**coordinates** and **smoothes** contractions of skeletal muscles during skilled movements & helps **maintain posture** and **balance**.

Question 52

Integrative Functions of the Cerebrum

Answer 52

wakefulness, sleep, learning, memory

Question 53

o The role of Reticular Activating System (RAS) in Awakening

Answer 53

neuronal axons from **reticular formation **through **thalamus **to **cerebral cortex** increased activity = awakening

Question 54

Sleep (2) components

Answer 54

state of altered consciousness 1) NREM 2) REM

Question 55

4 stages of sleep

Answer 55

1. relaxed 2. light sleep 3. moderately deep sleep 4. deepest sleep (sleepwalking)

Question 56

Learning

Answer 56

ability to acquire new info/skills through instruction/experience

Question 57

Memory

Answer 57

process by which information acquired through **learning **is stored and retrieved.

Question 58

Memory types (3)

Answer 58

immediate short-term long-term