The Nervous System
What is it? What does it do?
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Structures
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Brain
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Spinal Cord
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Nerves
Function : Sensory process and response center
Components
Central Nervous System
Peripheral Nervous System
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Brain and spinal cord
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Nerves
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Processes Info
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2 Divisions (sensory and motor)
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Sends Responses
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Has Meninges and CSF
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Grey matter and white matter
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Motor split further into ANS and
SNS
Cells and Tissues
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Neuron is the functional unit
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Nervous tissue: Grey and white matter
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Structures of importance
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Cell body
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Dendrite
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Axons
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Myelin Sheaths
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Axon Terminal
The Brain
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Know these lobes and their functions
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Frontal
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Parietal
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Occipital
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Temporal
Know these structures and their functions:
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Cerebrum
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Thalamus
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Hypothalamus
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Cerebellum
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Brain stem
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Amygdala
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Pituitary gland
Peripheral Nervous System
Autonomic NS
Somatic NS
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Involuntary function Control
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Voluntary function control
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Controlled by Effectors (CNS)
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Controlled by Effectors (CNS)
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Split into two sections
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Sympathetic and parasympathetic
Terms to know
•
Action potential
•
Resting potential
•
Synapse
•
Neurotransmitters
•
Threshold
•
Sensory neurons
•
Motor neurons
•
Interneurons
•
Reflex arc
How Information Travels
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Neurons carry messages via electrochemical signals
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Sodium – Potassium pumps
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Resting potential into action potential
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Signal Passageway
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Signal at dendrites
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Action potential through the axon to axon terminal
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In synapse, neurotransmitters are released
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Neurotransmitters will trigger action potential in other neuron
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Enzymes in synapse inactivate the neurotransmitters
Sensory Organs
What are they? What do they do?
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Organs that perceive your surroundings
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Contain sensory receptors
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Give the senses:
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Sight (Primary)
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Sound (Primary)
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Taste
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Touch
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Smell
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Balance
What Are They?
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How Hearing works
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Split into 3 Parts
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Outer – Collects soundwaves
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Auricle
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External auditory canal
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Tympanic membrane
Middle – transport soundwaves deeper
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Malleus, incus, stapes
Inner – converts soundwaves into electrical signals
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Bony labyrinth
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Membranous labyrinth
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Cochlea
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Semicircular canals
Sight and the Eye
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How Sight Works
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Structures of the Eye
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Sclera
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Cornea
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Retina
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Optic nerve
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Lens
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Choroid
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Iris
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Pupil
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Aqueous/Vitreous Humor
Minor Senses
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Touch
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Cutaneous Receptors
Taste
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Taste hairs
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5 basic taste sensations
Balance
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Static equilibrium – utricle & saccule
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Dynamic Equilibrium – semicircular canals
Smell
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Accommodation
Endocrine System
What to know?
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Hormones – chemical messengers
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Structures - Glands
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Hypothalamus – connection between Nervous and Endocrine systems
Hormones
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Usually controlled by Negative feedback
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Travel to Target cells
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Two Exit pathways
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Broken down in Liver
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Removed from body via Kidneys
2 Basic types
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Steroidal
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Hormone receptor centers
Non-Steroidal
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Second Messengers
Pituitary Gland
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Two Lobes
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Located in the brain
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Anterior Lobe
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Human Growth Hormone
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Other Control Hormones for the Endocrine system
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TSH
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ACTH
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gonadotrophins
Posterior Lobe
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Antidiuretic Hormone (for urinary system)
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Oxytocin (smooth muscle contraction)
Pineal Gland
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Located in the brain
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Hormones:
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Melatonin
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Effects circadian rhythms
Thyroid & Parathyroid
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Located around the trachea
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Hormones
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Thyroid
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Thyroxine
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Triiodothyronine
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Calcitonin
Parathyroid
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Parathyroid Hormone (antagonist to calcitonin)
Adrenal Glands
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Located on top of the Kidneys
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2 Layered Structure
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
Adrenal medulla
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Medulla cortex
Hormones:
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Epinephrine
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Norepinephrine
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Cortisol
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Aldosterone
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Adrenal Androgens
Gonads
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Male
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
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Hormones – testosterone (androgens)
Structures - Testes
Female Hormones
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Hormones – Estrogen and progesterone
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Structures - Ovaries
Pancreas
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Works in both Digestive and Endocrine

Endocrine Function
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Cells: Islets of Langerhans
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Insulin
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Glucagon