Summary Course 1.4C Biological Psychology : The Human Body

1.4C The Human Body

1.4.1 Brain and Body

The Nervous system:

 Neurons → form nerves
 carry information to brain and respond
 86 billion neurons
 Nervous system covered by connective tissue

subarachnoid space: fluid filled→ cushion brain

cerebrospinal fluid: clear fluid→ blood plasma

 Cranial Nerves

General definition: connected from the brain – they control vital reflexes

Central Nervous system:

 brain and spinal cord

Peripheral Nervous System: (PNS)

 cranial nerves, spinal nerves, peripheral ganglia
 efferent: carry away to other parts (muscles/glands)
 afferent: sensory activated by external stimuli → axon directed towards Cns to
convey sensory information
 cranial nerves: peripheral nerve attached directly to the brain-parasymphatetic

1. Sympathetic Nervous System:

Location: ganglia in lumbar (lower back) & thoracic (chest) regions of spinal cord

Function: prepares the body for action, arousal, stress

Expends energy

Phrase: “fight or flight” response

2. Parasympathetic Nervous System:

Location: nerves in brain &sacral (lower back) region

Function: calms the body – both psychologically & physiologically

Conserves energy

Phrase: “rest & digest”

,Autonomic Nervous System (ANS): reflex loop, involuntary internal environment

symphatetic: higher heart rate, stress response

→ expenditure of energy from reserves

parasymphatetic: increase blood flow, poop, nap

→ psychological relaxation, conserves energy -rest and digest

Somatic nervous system: receive sensory information and control movements

→ regulates inetraction external environment

Motor neuron:



https://lh6.googleusercontent.com/1_SgIdjln2doJqMFa1kp83qmU24t-
1XDPjzqC7qf4t98eZfP-
1CaXMEq8Y1UbwMBoVs1Jq4EOJ2dxQmzWHVR4ZBAL6HpLFBtajLuUkBmnrqdVPtDn
9_eAVncD3SAjR92sDhWxC3k

Neurons: cell that transmits information in the brain

Structure of a neuron (Take-home assignment on Canvas)

A: dendites

B: nucleus

C: cell body

D: axon

E: branches

F: presynaptic terminals

Dendrites → Collection of information from other neurons

Cell body → Integration of incoming information and generation of outgoing signal to the
axon

Axon → Passing the signal over long distances

,Axon branches → Passing the signal in different directions

Terminal buttons/terminals → Here the signal is passed to the dendrites of other neurons or
other cells

Nucleus → Location of DNA (the genetic information)

 Myelin Sheath: fatty insulating material that allows action potential – protects the
axon & speeds up the transmission of the input

Extra Question: Is regenerative power only found in schwann’s cells?

So, less regenerative power for the CNS?

 located Spinal cord
 axon much longer

types of nerons:

sensory neurons: from senses to brain -afferent; carry msgs from sensory receptors (eg.
touch) to CNS/PNS

motor neurons: from brain to muscles/glands- efferent

3. Interneurons/Relays: connect sensory neurons and motor neurons

 efferent: carry information towards the CNS
 afferent: carry information away from the CNS




Synapse: contact to next neuron

 Membrane potential → voltage differential
 inactive 70
 Ion channels→ more than 300 different
 Action potential→ Iron channel open
 inside positive, outside negative
 Sodium Potasium pump
 billions of neurons make sense of information
 neurons develop dendrites and axons and establish synaptic connections

Dendrite: collection of information from other neurons

nucleus: location of DNA

soma: integration of incoming information and generate outgoing signals to axon

axon: pass signals over long distances

, axon terminal/button: pass signals to other neurons/cell

Early development of the brain:

 neural tube forms when embryo is about 2-3 weeks




after 11 weeks→ expanding Cerebral cortex




Telencephalon→ Cerebrum

Brainstem: Diencephalon, Mesencephalon, Metencephalon, Myelencephalon not Cerebellum




Cerebellum:

 Body control
 receives visual, auditory, somatosensory information
 coordinating and smoothing effects on movements

Pons

 sleep and arousal
 information from cerebral cortex to Cerebellum

Medulla oblangata:

 regulation cardiovascular system
 control movements

Thalamus:

sorts data

 most neural input into cerebral cortex

Hypothalamus:

 controls autonomic nervous system and endocrine
 organize behaviour→ feeding, fleeing, mating, fight
 produce hormones