AP Biology 2003-2004 The Nervous System AP Biology 2003-2004 Let’s go to the Video!

AP Biology 2003-2004

The The Nervous Nervous SystemSystem

AP Biology 2003-2004

Let’s go to the Video!

Regents Biology 2003-2004

OverviewOverview The Nervous System The Nervous System controlscontrols and and

coordinatescoordinates all the functions of all the functions of the body.the body.

The Nervous System consists of The Nervous System consists of two main sub-divisions:two main sub-divisions: Central Nervous System Central Nervous System

(CNS)(CNS) Peripheral Nervous System Peripheral Nervous System

(PNS)(PNS)• The Peripheral Nervous System is The Peripheral Nervous System is

divided into two sub-divisions:divided into two sub-divisions: Somatic- voluntarySomatic- voluntary Autonomic- involuntaryAutonomic- involuntary

Regents Biology 2003-2004 http://inside.salve.edu/walsh/cns_pns.jpg


Structure and Function of the Neuron Neuron is the scientific name for a Nerve Cell.

Neurons consist of 3 basic structures: Cyton, or cell body. Dendrites- receive messages,

impulses, and send them to the cell body.

Axons- send messages away from the cell body.

• Nerve impulses travel from one neuron to another across synapses, or spaces in between the cells.

• The “jumping across” the synapse is facilitated (helped) by chemicals called Neurotransmitters.


Parts of the Neuron Dendrites – Branched

parts of a neuron that receive impulses from other neurons.

Cyton- Contains cytoplasm and the nucleus. Impulses pass through here to the axon.

Axon- Single long fiber that carries impulses away from the cell body.

A Neuron


signaldirection

myelin coating

Myelin Sheath Axon coated with insulation

made of myelin cells (Fatty, protein substance) speeds signal 330 mph vs. 11 mph

Multiple Sclerosis immune system (T cells) attacks myelin coating loss of signal

Multiple Sclerosis immune system (T cells) attacks myelin coating loss of signal


Synapse

synapse

Junction between nerve cells 1st cell releases chemical to trigger

next cell where drugs affect nervous system


Types of NeuronsTypes of NeuronsNeurons can also be classified by the Neurons can also be classified by the

directiondirection that they send information: that they send information:･･ Sensory (or afferent) neuronsSensory (or afferent) neurons:: send send

information from sensory receptors information from sensory receptors (e.g., in skin, eyes, nose, tongue, (e.g., in skin, eyes, nose, tongue, ears) ears) TOWARDTOWARD the central nervous the central nervous system.system.

･･ Motor (or efferent) neuronsMotor (or efferent) neurons:: send send information information AWAYAWAY from the central from the central nervous system to muscles or glands.nervous system to muscles or glands.

･･ InterneuronsInterneurons:: send information send information BETWEENBETWEEN sensory neurons and motor sensory neurons and motor neurons. Most interneurons are neurons. Most interneurons are located in the central nervous system.located in the central nervous system.


ReflexesReflexes Stimulus-Stimulus- a change a change

in the environment.in the environment. Response/Reaction-Response/Reaction-

how the body reacts how the body reacts to a stimulus.to a stimulus.

ReflexReflex Arc-Arc- the the pathway that an pathway that an impulse follows to impulse follows to illicit a response to illicit a response to a stimulus.a stimulus.


Parts of the Central Nervous System

Brain Spinal cord

Regents Biology

What Protects the CNS?1. Skull and Vertebrae

2. 3 protective layers called meninges

3. Dura Mater (outer layer): consists of connective tissues, blood vessels, and nerves.

4. Arachnoid Layer (middle layer): elastic and weblike

5. Pia Mater (inner layer): contains nerves and blood vessels.

6. Cerebrospinal fluid a clear watery liquid separates the middle and inner layers Acts as shock absorber exchange of nutrients between blood and nervous system


The Brain

Coordinates body activities Made up of approximately 100 billion neurons Uses 20% of bodies oxygen and energy Divided into three major parts-

the Cerebrum the Cerebellum the Brain Stem (Medulla Oblongata, Pons)


Cerebrum Largest part of the brain Thinking Memory is stored Movements are controlled Impulses from the senses are

interpreted.

Regents Biology

Gray Matter vs. White Matter

Gray Matter – Absence of myelin in masses of neurons accounts for the gray matter of the brain – Cerebral Cortex

White Matter - Myelinated neurons gives neurons a white appearance – inner layer of cerebrum


Cerebrum specialization

frontal

temporal

Regions specialized for different functions Lobes

frontal speech,

control of emotions temporal

smell, hearing occipital

vision parietal

speech, tastereading

occipital

parietal

Regents Biology

Craniotomy

2003-2004


Brain Tumor Surgery

Regents Biology

Sub-Arachnoid Cyst Removal

2003-2004

Regents Biology

Cerebral Hemhorrage

2003-2004

Regents Biology

Subdural Hematoma

2003-2004

Regents Biology

Brain Worms!

2003-2004


Cerebellum Responsible for the

coordination of muscles and is the center of balance


Medulla Center of heart beat,

respiration, and other involuntary actions

Regents Biology

Other Structures inside the Brain

Thalamus – receives messages from sensory receptors; relays information to proper regions of cerebrum

Hypothalamus - Regulates hunger, thirst, fatigue, anger, etc… Control of pituitary for endocrine function

Regents Biology

Pons

Pituitary gland

Hypothalamus

Cerebrum

Medulla oblongata Spinal cord

Cerebellum

Pineal gland

Thalamus

Section 35-3


The Spinal Cord Extension of the brain stem Bundles of neurons that carry impulses

from all parts of the body to the brain and from the brain to all parts of your body


Research Visit the Glencoe Science Web site at tx.science.glencoe.com for more information about the nervous system. Make a brochure outlining recent medical advances.

The Peripheral Nervous System Your brain and spinal cord are connected to the rest of your body by the peripheral nervous system. The PNS is made up of 12 pairs of nerves from your brain called cranial nerves, and 31 pairs from your spinal cord called spinal nerves. Spinal nerves are made up of bundles of sensory and motor neurons bound together by connective tissue. For this reason, a single spinal nerve can have impulses going to and from the brain at the same time. Some nerves contain only sensory neurons, and some contain only motor neurons, but most nerves contain both types of neurons.

Somatic and Autonomic Systems The peripheral nervous system has two major divisions. The somatic system controls voluntary actions. It is made up of the cranial and spinal nerves that go from the central nervous system to your skeletal muscles. The autonomic system controls involuntary actions-those not under conscious control-such as your heart rate, breathing, digestion, and glandular functions. These two divisions, along with the central nervous system, make up your body's nervous system.


Peripheral Nervous System Connects body to brain & spinal cord 12 pairs of nerves from your brain

(cranial nerves) 31 pairs from your spinal cord (spinal

nerves) Bundles of sensory and motor neurons

held together by connective tissue Two divisions

Somatic Autonomic


Divisions of the PNS:

Somatic Nervous System Controls voluntary actions Made up of the cranial and spinal

nerves that go from the central nervous system to your skeletal muscles

Autonomic Nervous System Controls involuntary actions-those not

under conscious control-such as your heart rate, breathing, digestion, and glandular functions

Regents Biology 2003-2004http://www.christopherreeve.org/Research/Research.cfm?ID=178&c=21


Animals rely on two systems for regulation:

Nervous System is a system of nerve cells called neurons. It consists of a central nervous system (brain and spinal cord) and peripheral nerves. Typical responses are fast and short lasting.

Endocrine System is a system of ductless glands that secrete hormone into the blood. Hormones travel to target tissues.Typical responses are slow and long lasting.

Progesterone Estradiol


Human Endocrine Glands

Ductless glands transport hormones in the blood

Duct glands are exocrine glands that use tubes to carry the secretion(salivary, tears)


Pituitary gland and Hypothalamus serve to link the nervous system other glands and metabolic functions.


Thyroid and Parathyroid help regulate calcium metabolism

Feedback!


Goiter: Iodine deficiency and feedback causes the thyroid to enlarge

This people have a goiter, a condition that is easily preventable with iodized salt


Thyroid regulates metabolism

Graves disease: hyperthyroid

feedback


Pancreas helps regulate blood glucose

Insulin from Beta cells reduce blood sugar Glucagon from Alpha cells increase blood sugar

feedback


•Large amount of adrenaline pumped into the body to put us in a state of increased alertness •Blood is redirected away from the extremities to the large muscles of the body •The heart starts working harder to move the blood to the large muscle groups as quickly as it can •Increase in Respiratory Rate •Release of red blood cells •Release of sugar by liver •Increase in metabolic rate

THE FIGHT OR FLIGHT MECHANISM

alektorophobia


Gonads: Testes and Ovaries produce hormones that regulate secondary sex traits Male sex traits include

those changes that occur during puberty

Androgens include testosterone

feedback


Female sex traits include the menstrual cycle and the changes seen during puberty

LH and FSH from the pituitary

Estrogen and progesterone from the ovary

feedback


Identify the Glands

AP Biology 2003-2004 The Nervous System AP Biology 2003-2004 Let’s go to the Video!

Documents

Transcript of AP Biology 2003-2004 The Nervous System AP Biology 2003-2004 Let’s go to the Video!