Nervous System

Name 2 systems that allow organs and tissues communicate with each other and coordinate the maintenance of homeostasis

Endocrine and nervous

Endocrine system:

glands that produce hormones, affects most cells, difficult to make quick changes, effects longer lasting.

Reticular formation function

motor control, sleep/consciousness, cardiovascular function, pain perception.

Meninges are made of

fibrous connective tissue

Nervous system functions

receives info, processes info, and causes action using nerves, brain, and spinal cord

Nervous system is divided into two divisions

central and peripheral

Sensory division functions

receives information and transmits it to the CNS via AFFERENT NEURONS

Motor division functions

sends signals from the CNS to muscles, glands, organs, etc… via EFFERENT NEURONS

Central nervous system includes:

brain and spinal cord

Peripheral nervous tissue includes

Nerves and ganglions

Nerves are

bundles of nerve fibers (axons) wrapped in fibrous tissue

Ganglion are

concentrated areas of somas of neurons

visceral sensory division function

carries signals from the viscera of the thoracic and abdominal cavities.

both sensory division and motor division have these subsections

visceral and somatic

somatic sensory division function

carries signals from the skin, muscles, bones, joints.

visceral motor division function:

carries signals to glands, cardiac muscle, smooth muscle. Involuntary control (visceral reflexes)

What are visceral reflexes?

involuntary control or the visceral motor division, send signals to glands and muscles.

somatic motor division function:

carries signals to skeletal muscles

What are somatic reflexes?

involuntary skeletal muscle contraction

visceral refers to

organs and systems

somatic refers to

skin, muscles, joints, bones

Gyri

folds of brain tissue

Sulci

grooves in brain tissue

Afferent

towards CNS

Efferent

away from CNS

Neurons only direct signals

one direction

Autonomic nervous system

coordinated activities of the visceral sensory and motor divisions

The autonomic nervous system is important for

regulating the functions of many organ systems

Sympathetic division function

stimulates and prepares body for activity

Parasympathetic division function:

slows down many body functions, decreases activity

Cerebrum includes folds and grooves called

gyri and sulci

Parts of the brainstem

Diencephalon, Midbrain, pons, medulla oblongata, reticular formation.

Central sulcus

separates frontal lobe from parietal lobe

Lateral Sulcus

separates temporal lobe from frontal and parietal lobes above it

Parieto-occipital sulcus

separates parietal lobe from occipital lobe

Precentral gyrus

gyrus located anterior to central sulcus – important for initiating motor signals (to skeletal muscles)

postcentral gyrus

gyrus located posterior to central sulcus – important for processing somatic sensory information

Frontal lobe function

voluntary motor function, memory, mood, emotion, planning

Parietal lobe function

sensory reception, taste, some visual processing

Temporal lobe function

hearing, smell, learning, memory, some vision processing, emotion

Occipital lobe function

vision

Reticular Formation

network of nuclei scattered throughout brainstem.

Grey matter consists of

neuronal dendrites, soma, and synapses

White matter consists of

of bundles of myelinated axons (TRACTS)

the Cerebral cortex is made out of

gray matter

Cerebral cortex function:

carries out higher level brain functions that separate humans from lower primates, many areas have specialized functions.

Decussate means

the tracts of spinal cord and visual nerves crossover

corpus callosum

thick bundle of nerve fibers linking hemispheres of cerebrum

Thalamus

a relay center that receives information and directs it to appropriate areas of the cerebrum

Hypothalamus

major control center of the autonomic nervous system and endocrine systems. Very important for relaying messages to the pituitary gland

Thalamus/hypothalamus are components of the

diencephalon

Pituitary gland

Executes many endocrine actions of the autonomic nervous system

Midbrain

connects the cerebrum and cerebellum, pons, and medulla oblongata, helps coordinate some visual and auditory reflexes.

Pons

conducts signals between cerebrum and cerebellum. Sends sensory messages to thalamus.

Medulla oblongata

conducts motor signals from cerebrum to spinal cord and sensory signals from spinal cord to all other parts of the brain. Contains regions which control cardiovascular and respiratory systems as well as reflexes like coughing, sneezing

The brainstem includes

the midbrain, pons, medulla oblongata, and reticular formation

Cerebellum has an outer layer of

grey matter

Cerebellum has an inner layer of

white matter

The inner white matter of the cerebellum is called

Arbor Vitae

Cerebellum has an important role in

processing sensory information received from many parts of the body

Damage to the cerebellum can

impair motor coordination, impaired interpretation of visual and auditory info, and timekeeping

the cerebellum has additional roles in

emotion, behavior, speech, and sensory processing

the brain is surrounded by 3 layers of tissue called

meninges

Meninges function:

protecting the brain

Cerebrospinal fluid, along with meninges, helps

protect the brain

Outermost layer of meninges;

Dura mater

Dura mater is divided into

Periosteal layer and meningeal layers

the falx cerebri separates

right and left hemispheres of cerebrum

the tentorium cerebelli separates

the cerebellum from the cerebrum

middle layer of meninges

Arachnoid mater

Arachnoid mater function

cushions the brain

Space between dura mater and arachnoid mater

subdural space

space between arachnoid mater and pia mater

subarachnoid space

What is found in the subarachnoid space

Cerebral spinal fluid

Innermost layer of the meninges

Pia mater

The pia mater is attached to the brain and follows

contours of gyri and sulci

Cerebral Spinal fluid is found

within ventricles and in the subarachnoid space

What produces cerebral spinal fluid

Choroid plexuses

Choroid plexuses are found

within ventricles and ependymal cells lining ventricles.

Functions of CSF

Buoyancy, protection, chemical stability

How does the CSF chemically stabilize

CSF is eventually reabsorbed into the bloodstream allowing metabolic wastes to be easily removed from the nervous system

CSF circulates the brain via

4 ventricles

CSF eventually reaches the subarachnoid space via

the lateral and median apertures

In the subarachnoid space, CSF is resorbed into the bloodstream by

arachnoid granulations (villi)

Arachnoid granulations are

extensions of the arachnoid mater

Functions of the Spinal cord

Conduction, locomotion, reflexes

The longitudinal fissure separates

the left and right hemispheres

The cerebellum has the same number of neurons as

the cerebrum

Folia are

folds

White matter consists of

bundles of myelinated axons called Tracts

Grey matter consists of

neuronal dendrites, soma, and synapses

The two types of proprioception are

conscious and unconscious

Two layers of dura mater

periosteal and meningeal

The choroid plexus is

granule tissue made of ependymal cells

Where is most of the cerebral spinal fluid resorbed?

Superior sagittal sinusth

The spinal cord carries out locomotion by

generating repetitive motor signals that coordinate walking

the spinal cord extends fromthe foramen magnum to the first lubar vertebrae

Spinal cord gives rise to how many spinal nerves?

31 pairs

Distal end of the spinal cord is called

Medullary Cone

the spinal nerves that continue to travel down the vertebral column and exit intervertebral foramina of lumbar and sacral vertebrae

Cauda equina