THE BIOLOGICAL PERSPECTIVE

1
THE BIOLOGICAL PERSPECTIVE

• THE NERVOUS SYSTEM

2
Nervous System
Central Nervous System Transmits and receives
messages to and from the PNS
Peripheral Nervous System Carries messages to
and From the CNS
Autonomic nervous system Carries messages from
the CNS to internal muscles, organs and glands
Brain Organizes, Integrates and Interpret
s Neural messages
Spinal Cord Connects brain and peripheral nervo
us system
Somatic nervous system Carries messages between
the CNS and the body
3
AUTONOMIC NERVOUS SYSTEM
Sympathetic Nervous System Controls our
response to a Situation when we need a Fight
or Flight response
Parasympathetic Nervous System Is responsible
for our return to normal after the
situation that led us to defend ourselves or run
away
4
The Human Brain

• Contains 10,000 different types of neurons
• Contains 100 billion neurons
• Each neuron communicates with 5,000-200,000 other
  neurons to make one trillion neuronal connections

5
Neural Circuits

• The brain contains nerve cells grouped together
  into bodies
• These bodies interconnect with other regions in
  the brain
• Individual neurons, collections of neurons and
  their interconnections make up a circuit

6
BRAIN STRUCTURE

• The brain can be divided into three major
  regions
• Hindbrain includes the cerebellum and two
  structures found in the lower part of the
  brainstem the medulla and the pons
• Midbrain is the segment of the brainstem that
  lies between the hindbrain and the forebrain
• Forebrain is the largest and most complex
  region of the brain, encompassing a variety of
  structures, including the thalamus, hypothalamus,
  limbic system and cerebrum

7
HINDBRAIN

• Brainstem the oldest part and central core of
  the brain, beginning where the spinal cord swells
  as it enters the skull -
• responsible for automatic survival functions
• Medulla - base of the brainstem controls
  unconscious but vital functions such as
  circulating blood, breathing, maintaining muscle
  tone, and regulating reflexes

8
HINDBRAIN

• Pons a bridge of fibers that connects the
  brainstem with the cerebellum it also contains
  several clusters of cell bodies involved with
  sleep and arousal.
• Cerebellum (little brain) critical to the
  coordination of movement and to the sense of
  equilibrium or physical balance. There is some
  evidence that it plays a role in emotional
  development and modulates sensations of anger and
  pleasure.

9

• Pons involved in the regulation of sleep,
  arousal and movement
• Medulla controls vital functions such as
  breathing
• Reticular Formation- a network of neurons that
  regulates alertness and muscle movement
• Cerebellum (little brain) controls subconscious
  movements of the skeletal muscles that maintain
  balance and posture

10
Reticular Formation

• Runs through both the hindbrain and the midbrain
  at the central core of the brainstem
• Contributes to the modulation of muscle reflexes,
  breathing and pain perception
• Best known for its role in the regulation of
  sleep and arousal

11
Hindbrain Midbrain
12
MIDBRAIN

• Contains an area that is concerned with
  integrating sensory processes, such as vision and
  hearing
• An important system of dopamine-releasing neurons
  that projects into various higher brain centers
  originates here

13
The Diencephalon

• Consists of the thalamus and hypothalamus
• The thalamus has a role in emotion and memory
• The thalamus is an interpretation center for
  pain, temperature, light touch and pressure.
• The hypothalamus main function is homeostasis,
  or maintaining the bodys equilibrium.

14
THALAMUS

• Thalamus the structure in the forebrain through
  which all sensory information (except smell) must
  pass to get to the cerebral cortex
• The thalamus also appears to play an active role
  in integrating information from various senses

15
HYPOTHALAMUS

• Hypothalamus
• neural structure lying below (hypo) the thalamus
  directs several maintenance activities
• eating
• drinking
• body temperature
• helps govern the endocrine system via the
  pituitary gland
• is linked to emotion

16
HYPOTHALAMUS

• Hypothalamus is a structure found near the base
  of the forebrain that is involved in the
  regulation of basic biological needs
• One function is to control the autonomic nervous
  system
• Responsible for regulating basic biological
  needs hunger, thirst, temperature control

17
HYPOTHALAMUS

• When researchers lesion the lateral areas (the
  sides) of the hypothalamus, animals lose interest
  in eating
• When electrical stimulation is used to activate
  the lateral hypothalamus, animals eat constantly
  and gain weight rapidly

18
(No Transcript)
19
(No Transcript)