Week 10 Day 2 Structure and Function of the Nervous System

The localization of sensory structures at the anterior end of an animal's body

cephalization

Vertebrates have 3 major anatomical divisions (3)

1. hindbrain

2. midbrain

3. forebrain

• Increased complexity is correlated with increased surface area of the cerebral cortex

• Animals with more complex brains have more folds & groves

• Simple animals have smooth brain

Basically, increases surface area

cerebral cortex folding

a group of neuronal cell bodies in the CNS that are involved in a particular function

nucleus

a group of neuronal cell bodies in the PNS that are involved in a particular functio

ganglion

structure in the PNS composed of multiple myelinated axons bound by connective tissue; carries information to or from the central nervous system

nerve

Brain tissue that consists of myelinated axons that are bundled together in large

numbers to form tracts.

white matter

Brain tissue that consists of neuronal cell bodies, dendrites, and some unmyelinated axons

gray matter

Several layers of protection cover the CNS to protect it (5)

1. scalp

2. skull

3. meninges

4. veins

5. cerebrospinal fluid

order of protective layers of the brain (3)

1. dura mater

2. arachnoid mater

3. pia matar

 Sense external environment and control

skeletal muscles

 Afferent sensory neurons receive stimuli

• heat, light, odors, sound, touch

 Transmit to CNS

Somatic nervous system

 Efferent motor neurons control skeletal

muscles

 Axons leave spinal cord and project

directly onto skeletal muscle

 Walk, hold a pencil, reflex responses

Somatic nervous system

 Regulates homeostasis & organ function

 Heart rate, blood pressure, glucose level

autonomic nervous system

 Mostly efferent motor neurons

 Involuntary

 Divided into 2 groups

autonomic nervous system

autonomic nervous system can be divided into what 2 groups

sympathetic and parasympathetic

• Increased heart rate

• Dilated airways

• Faster breathing

• Increased blood to skeletal muscles

• Inhibition of digestive activity

sympathetic

• Rest-and-digest response

• Increased digestion

• Slow heart rate

parasympathetic

which part of the brain controls of basic processes

hindbrain

• Receives sensory input from cerebral cortex, auditory visual areas

• Maintain balance, coordinate hand-eye movement

cerebellum

• Synchronize fine motor activity (texting!)

cerebellum

• Relay between cerebellum and other brain areas

• Cells that regulate rate and depth of breathin

pons

• Control of heart rate, breathing, blood pressure, digestion,

swallowing, vomiting

medulla oblongata

 Processes sensory inputs

 Vision, olfaction, audition

which part of brain

midbrain

 Sleep/wake cycle

 Alertness

 Respiration

which part of brain

brainstem

 Circulatory system

 Damage to brain stem is catastrophic, results in

coma or death

which part of brain

brainstem

DIENCEPHALON

 Relays sensory information to cerebrum

 Filters out information to allow us to pay attention to important cues only

which part of brain

thalamus

DIENCEPHALON

 Perception of pain

which part of brain

thalamus

DIENCEPHALON

 Homeostatic processes - digestion, reproduction, body temp, hunger, thirst

 Circadian rhythms

which part of brain

hypothalamus

DIENCEPHALON

 Food and water intake

 Integration of olfactory inputs

which part of brain

epithalamus

cerebrum is split into 2 halves, these halves are called

hemispheres

Hemispheres connected by __ __

corpus callosum

Understanding language, producing speech

left or right hemisphere

left

Nonverbal memories, facial recognition, interpreting emotion

left or right hemisphere

right

 Surface layer of gray matter that covers cerebrum

cerebral cortex

 Contains about 10% of all neurons in the brain

cerebral cortex

 4 lobes, named for the bones the cover each region

cerebral cortex

Voluntary movement, decision making, impulse control, making plans, judgment, short term memory, conscious thought and social awareness

which lobe

frontal lobe

 Somatosensory cortex

 Receive and interpret sensory input

which lobe

parietal lobe

 Spatial awareness

which lobe

parietal lobe

Visual perception, color recognition

which lobe

occipital lobe

Language, hearing, some memory

which lobe

temporal lobe

Clusters of neuronal cell bodies in the vertebrate forebrain that surround the

thalamus and lie beneath the cerebral cortex; involved in planning and learning

movements.

basal nuclei (people with Parkinson’s disease have a hard time with movements)

In the vertebrate forebrain, the areas involved in the formation and expression of

emotions; also plays a role in learning, memory, and the perception of smells.

 Contains olfactory bulbs, amygdala, hippocampus

limbic system

The process by which new information is acquired

learning

he ability to retain, retrieve & use information previously learned

memory

• Lasts minutes to hours

• Caused by a single stimulus

short term memory

Stimulus activates pathways which enhance transmission of signal between pre and post synaptic cells

short term memory

• Days to weeks (or years)

• Repeated stimuli

long term memory

Required synthesis of new proteins & formation of more synaptic connections

long term memory

An imaging method that relies on the use of magnetic fields and radio waves to

visualize the internal structure of an organism’s body

MAGNETIC RESONANCE IMAGING (MRI)

 Allows doctors to examine structure & activity level of the brain without anesthesia or surgery

 Provide information about abnormal tissue such as brain tumor

MAGNETIC RESONANCE IMAGING (MRI)

Functional MRI (fMRI) uses __ flow and __ delivery to show what __

are active

blood, oxygen, neurons

Can be used to show what neurons are active when a person performs intellectual or motor tasks

MRI

 Infection that occurs in the meninges (membranes covering the brain

meningitis

 Fluid accumulates compressing brain tissue, results in loss of oxygen and neuronal death

 Caused by bacteria &/or viruses

meningitis

Symptoms:

 Severe headaches, fever, seizures, stiff neck

 Can lead to death in hours

 Affects about 25,000 people/year (USA

meningitis

Loss of memory & cognitive function

ALZHEIMER’S

Build up of beta-amyloid protein plaques & neurofibrillary tangles

ALZHEIMER’S

 Normally after age 65

 No current prevention or cure

 About 4-5 million people (USA)

ALZHEIMER’S

 2050 expected 16 million

 Approximate cost/year $100 billion

ALZHEIMER’S