Basic Life Processes

BASIC LIFE PROCESSES

Characteristics of a Cell

- Irritability- Conductivity- Contractility- Metabolism- Reproduction- Integration- Adaptation

NERVE CELLS- the basic structural unit of the

nervous system

- also called the “neuron”

- it is filled with cytoplasm, which is the living material forming the body of the cell.

- neurons vary in size.

The neuron

The nervous system is a complex communications

network controlling the body’s internal environment as well as its responses to its surroundings.

complex combination of billions of neurons

THREE TYPES OF NEURONSAfferent Neurons

- conduct nerve impulses from receptors to the brain or the spinal cord.

Internuncial or Associative Neurons

- responsible for what we commonly call thoughtEfferent Neurons

- conduct nerve impulses from the decision points to the effectors.

DIVISIONS OF NERVOUS SYSTEM

Central Nervous System

Peripheral Nervous System

The Central Nervous System

- The Central Nervous System includes the brain and the spinal cord.

- It is the decision-maker.

The Central Nervous System

Peripheral Nervous System

- It is composed of two parts

Autonomic nervous system Somatic system

Peripheral Nervous System

Autonomic nervous system - is a motor system supplying impulses to

most of the internal organs and smooth muscles of the body.

- composed of two principal divisions:Sympathetic and

Parasympathetic

The Brain - has an average weight of about three

pounds

- contains at least 15 billion nerve cells called neurons.

- composed of three principal sections:• Hindbrain• Midbrain• Forebrain

The Brain

The Principal Sections

Forebrain is composed of three parts: - Thalamus - Limbic System - Cortex

THALAMUS -switching pointLIMBIC SYSTEM - involved variety of complex human processesCORTEX - made up of four lobes which are separated by fissures

END!!!