The nervous system, structural/functional organization and the brain

what are the three main functions of the nervous system

sensory, integration, motor

what sensory functions does the NS provide

detects changes in environment (internally and externally)

what integration functions does the NS provide

processing and decision making (of sensory signals)

what motor functions does the NS provide

tells body what to do in response (to sensory signals)

what is the two functional divisions of the nervous system

sensory and motor function

what are the two structural organizations of nervous system

central nervous system and peripheral nervous system

what does the CNS consist of

spinal cord and brain

what does the PNS consist of

cranial and spinal nerves, ganglia, enteric plexuses in small intestine, and sensory receptors in skin

What does the CNS do?

receives, processes, stores, and transfers information

What does the PNS do?

receives stimuli from the CNS and and initiates response

what is the main job of the CNS

integration

what is the main job of the PNS

sensory and motor functions

what is the main idea of motor fucntions

carries commanded from CNS to effectors (tissues)

what is the main idea of sensory function

carries information to CNS

what are the 2 main divisions of the peripheral nervous system

somatic and autonomic nervous system

what are two subdivisions of the autonomic nervous system

the parasympathetic and sympathetic NS and enteric nervous system

What is the somatic nervous system?

voluntary control of skeletal muscles

What is the autonomic nervous system?

responsible for control of the bodily functions such as breathing, the heartbeat, and digestive processes (involuntary control)

What is the parasympathetic nervous system?

the division of the autonomic nervous system that calms the body, conserving its energy (rest and digest)

What is the sympathetic nervous system?

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations (fight or flight)

What is the enteric nervous system?

large network of neurons surrounding the digestive organs responsible for involuntary control of smooth muscle, glands, and endocrine cells of GI tract ( can work independently)

what nerves are involved in the parasympathetic nervous system

cranial nerves and parasympathetic nerves (located in sacral region S2-S4)

what nerves are involved in the sympathetic nervous system

sympathetic nerves ( located in thoracic region, T1-L1 segments)

What is a neuron?

Basic unit of the nervous system. (functional cell of NS)

What do neurons do?

send nervous signals to effectors, brain, and spinal cord

What is the axon?

carry electrical nervous signals away from cell body

What are dendrites?

receives signals from other neurons and helps direct signals to cell body

What is the myelin sheath?

A fatty insulation covering of the axon, speeds up electrical signals

What is the axon terminal?

end of axon, that sends signal to another neuron

what are the non nervous cells of the CNS

glial cells: oligodendrocyte, microglial cells, ependymal cells, astrocytes

what are the non nervous cells of the PNS

schwann cells and satellite cells

what is a oligodendrocyte

makes myelin sheath in CNS

What is a microglial cell?

Glial cells that defends the body against pathogens (CNS immune cells --> destory viruses and bacteria)

What is the ependymal cell?

cuboidal epithelial cells that line cavities (ventricles and central canal), that produce and circulate CSF

What are astrocytes?

large abundant cells located between blood capillaries and neuron that help regulate which substances can come in contact with neuron. they also provide structural support

What is a Schwann cell?

They wrap the axon with myelin sheath.

What is a satellite cell?

surround cell bodies in ganglia, provide support and protection, and regulate environment around neruon

What is multiple sclerosis?

autoimmune disease that effects the CNS

what can multiple sclerosis lead to?

demyelination, axon damage, and slowed/blocked nerve conduction

What is the brain

Control center of the body

what structural organization is brain apart of?

CNS

what are the three developmental regions in brain

midbrain, forebrain, and hindbrain

what does the forebrain consist of

cerebrum, and deeper grey matter (thalamus, hypothalamus, and basal nuclei)

What is the cerebrum?

The cerebrum is the part of the brain that controls memory, senses, consciousness, and reasoning.

what does the cerebrum consist of

white and grey matter

What is white matter?

myelinated axons

What is grey matter?

cell bodies

what divides the left and right hemispheres of the cerebrum

fissurs

What is the cortex?

outer layer of the brain

what is gyrus and sulcus

gyrus is the outer ridge of cortex, and sulcus is the inner grooves/depression (sulci connect gyri together)

what are the 5 main lobes of brain

frontal, temporal, parietal, occipital, and insula

where is the insula relative to the other lobes

deep to all lobes

what are the 4 tracts of brain

commissural tracts, projection tracts, arcuate fibers, and longitudinal fibers

what are commissural tracts

connect L and R hemispheres of cerebrum

what are projection tracts

carry sensory information form cerebrum to spinal cord (connect cerebrum and spinal cord). Also brings motor signals back up to cortex and deeper grey matter structures

what are arcuate fibers

short tracts connecting neighboring gyri (stay within same lobe)

what are longitudinal fibers

travel through hemispheres ( cross lobes but stay within same hemisphere)

what internal structures does the deeper grey matter include

thalamus, hypothalamus and basal nuclei

What is the thalamus?

sensory relay station (passes sensory signals to cerebrum)

What is the hypothalamus?

controls autonomic nervous system (motor control), and controls endocrine system

what is the basal nuceli

collection of cell bodies, pass voluntary motor signals from cerebrum to other areas of brain and spinal cord

where does parkison disease effect in the brain

basal nuclei

what does the forebrain and hindbrain make up

the brain stem

what 3 structures make up the brain stem

midbrain, pons, medulla oblongata

what is the midbrain responsible for

visual and auditory reflexes, and eye movement

where is the midbrain located

at top of brain stem

what does midbrain connect to

cerebellum

What are the pons responsible for?

regulates breathing and assist in sleep and arousal

where are pons located

between midbrain and medulla oblongata

what is the pons connected to

cerebellum

What is the medulla oblongata responsible for?

regulate HR, BP, and breathing

Where is the medulla oblongata located?

lower part of brain stem

what is the medulla oblongata connected to

cerebellum

how are the midbrain, pons, and medulla oblongata connected to cerebellum

through peduncles

what are peduncles

bundle of nerve fibers that connect major regions of brain

what does the superior cerebellar peduncle connect

cerebellum to midbrain

what does the middle cerebellar peduncle connect

cerebellum to pons

what does the inferior cerebellar peduncle connect

cerebellum to medulla oblongata

what is the cerebral peduncle

connects cerebrum to brainstem

what is the cerebellum

The cerebellum is the part of the brain associated with voluntary responses (motor actions) (known as little brain)

what separates the L and R hemispheres of the cerebellum

the vermis

What is the arbor vitae?

white matter of the cerebellum