Nervous System (CNS and PNS) Flashcards
Do sponges have a nervous system?
No
Describe the Cnidarians CNS. What are they?
- Have nerve nets- where neurons are spread apart
- Lack a brain
- Jellyfish
Describe the Annelids CNS. What are they?
- Well developed brain
- Ganglia in each segment
- Earthworms
Describe the Arthropods CNS. What are they?
- Brain
- Ventral nerve chord-double row of ganglia nervee chords on ventral and dorsal
- Segmental ganglia-in the thorax and abdomen provide nerves to the appendages, dorsal muscles, sense organs, and heart.
- Decentralized nervous system
- Crab
Describe the Cephalopods CNS. What are they?
- Ganglia in each arm
- Ganglia in body
- Brain
- Squid
Describe the Vertebrates CNS. What are they?
- Highly cephalized
- Hollow nerve chord on dorsal (back) side of body- the spine
- Animals
What are the four CNS protective barriers?
- Bone coverings
- Protective meninges
- Cerebrospinal fluid
- Blood-brain barrier
What is bone’s role in CNS protection?
- Brain is covered by skull
- Spinal cord is protected by vertebrae
What is meninges role in CNS protection? 3 types?
- The cranial meninges are layers of connective tissue continuous with the spinal meninges.
- Protect the brain and provide nutrients
- Dura mater-tough outer layer under the skull
- Arachnoid mater- spidery middle layer
- Pia mater- thin layer over the brain
What is cerebrospinal fluids role in CNS protection? 3 functions?
- Circulates through the internal cavities in the brain and spinal cord
- Mechanical- cushions the brain and protects from trauma
- Homeostatic- Removes waste products
- Circulation- Circulates nutrients
What is blood brain barrier’s role in CNS protection?
-a filtering mechanism of the capillaries that carry blood to the brain and spinal cord tissue
- The vascular endothelium around brain capillaries forms tight junctions with the nearby astrocytes.
- Blocks passage of certain substances
What are the three regions of the brain? How are they split up?
- Hindbrain- Controls most reflex responses; Regulates involuntary behaviours
- Midbrain-Coordinate visual, auditory, and sensory information
- Forebrain-Process olfactory (smell) information; Regulating body temp, reproduction, sleeping, eating; Learning and memory
What are the 3 basic functions (divisions) of the hindbrain?
-Medulla oblongata
Reflex centers regulating breathing, heart rate, diameter of blood vessels
Neural pathways between spinal cord and brain
-Pons
Control alertness, sleep and wake, regulates breathing
-Cerebellum Motor coordination (body posture, coordinates locomotion, integrates info from proprioceptors)n
What are the basic functions of the midbrain?
- Tectum- Optic lobes- Processes visual, auditory and touch information.
- Tegmentum- Reflex responses to visual, auditory and touch
Midbrain differences in animals.
- Humans- small
- Other animals are large
What are the basic functions of the forebrain?
- Cerebrum (Basal gangli, Amygdala, Hippocampus)
- Olfactory bulb
- Accessory olfactory bulb
- Hypothalamus
- Epithalamus
- Thalamus
What are the 3 basic functions of the forebrains cerebrum?
Cerebrum= Information processing
- Basal gangli- Movements
- Amygdala- Emotions
- Hippocampus- Memory
What are the basic functions of the forebrains olfactory bulb and accessory olfactory bulb? What secondary structure are these?
- Olfactory bulb- Sense of smell
- Accessory olfactory bulb- Direction of pheromones
- Telencephalo
What are the basic functions of the forebrains thalamus, hypothalamus and epithalamus? What secondary structure are these?
- Hypothalamus- Homeostatic regulation (e.g. body temp, feeding, repro, hunger, and thirst; circadian rhythms, sleep/wake cycles
- Epithalamus- Melatonin secretion. circadian rhythms, regulation of limbic system
- Thalamus- Integrates sensory information
- Diencephalon
What are the cerebrum’s lobes? 4 main and 11 cortical areas.
- *Frontal lobe**
- Primary motor cortex
- Premotor cortex
- Prefrontal cortex (thought)
- Broncas area (speech)
- *Parietal lobe**
- Somatosensory cortex
- Sensory association areas
- *Occipital lobe**
- Visual association areas
- Visual cortex
- *Temporal lobe**
- Olfactory cortex
- Limbic association areas
- Auditory cortex
What is the difference between the right and left hemispheres of the brain?
**Right** imagination holistic thinking intuition arts rhythm nonverbal cues feelings visualization daydreaming
**Left** logic sequencing linear thinking mathematics facts thinking in words
Who is Phineas Gage?
Got a rod driven through head. Destroyed his left frontal lobe
What are the 3 cranial sensory nerves? (PNS)
Olfactory (smell), Optic (vision), Vestibulocochlear (hearing)
What are the 5 cranial motor nerves? (PNS)
Oculomotor (eyeballs and pupills), Trochlear (eyeballs), Abducens (eyeballs), Accessory (head and pectoral region), and Hypoglossal (speech and food)
What are the cranial mixed nerves? (PNS)
Trigeminal (sense-face, motor-chewing), Facial (sense-taste, motor-blood pressure, swallowing and saliva), and Vagus (Sense-para NS, motor-swallow and vocalization)
What are the spinal nerve regions? How many spinal nerves?
- Cervical (neck)- C1-C8
- Thoracic (chest)- T1-T12
- Lumbar (lower back)- L1-L4
- Sacral (under lumbar)- S2-S4
- Coccygeal (tailbone)- Co1
- 31
What’s a dermatomes?
-An area of skin that is innervated by a single spinal nerve, indicated by the letters and number of a particular segmental nerve.
-Important dermatomes include:
C6/C7 - thumb and index
finger (“six-shooter”)
T4 - nipple line
T10 - umbilicus
L1-L5 - lower extremities
What are the parts of the Peripheral Nervous system?
- *Afferent (sensory)**
- cranial nerves
- *Efferent**
- -Motor division SNS-skeletal muscle- voluntary
- -Autonomic division-nonvoluntary
- Sympathetic nervous system and parasympathetic nervous systems deal with smooth muscle, cardiac muscle, exocrine glans, endocrine glands.
- Enteric nervous system deals with digestive organs
What is the ANS?
- Autonomic Nervous System
- Responds to subconscious visceral sensations
- Includes autonomic sensory neurons, integrating centers in the CNS, and autonomic motor neurons.
Compare the Somatic and Autonomic nervous systems.
- *Somatic**
- Voluntary and reflexive
- One neuron in pathway (from CNS to effector)
- Special sense, skin; proprioceptors
- Posterior root ganglia; sensory ganglia of cranial nerves
- Skeletal muscle fibers
- Excitation only
- Acetylcholine
- Thicker diameter, myelinated, fast conduction
- *Automatic**
- Involuntary control
- Two neurons in pathway: preganglionic neuron has preganglionic axon that projects to ganglionic neuron; ganglions neuron has postganglionic axon that projects to effector
- Visceral (internal organ) senses
- Posterior root ganglia, sensory ganglia or cranial nerves (sensory)
- Autonomic ganglia, intramural ganglia, sympathetic trunk ganglia, pre vertebral ganglia (motor)
- Cardiac muscle, smooth muscle, glands
- Excitation of inhibition of effectors
- Preganglionic axons release ACh and postganglionic axons release either ACh or norepinephrine (NE)
- Preganglionic are thin and myelinated; post ganglionic are thinner and unmyelinated; both have slow conduction
What is dual ANS innervation?
Body organs receive impulses from both sympathetic and parasympathetic neurons
What is sympathetic stimulation?
- Fight or flight response
- Comes from spinal nerves
Whats SLUDD? What are the parasympathetic nervous systems responses?
- Used to describe responses of parasympathetic nervous system
- Salivation, Lacrimation, Urination, Digestion, and Defecation
- Comes from the cranial nerves
Difference between SNS and PSNS?
SNS
-short preganglionic and long post ganglionic; NE; ganglion close to spine
PSNS
-Long preganglionic and short post; ACh; ganglion within organ
