Skip this Video
Download Presentation
Nerves & Hormones

Loading in 2 Seconds...

play fullscreen
1 / 28

Nerves & Hormones - PowerPoint PPT Presentation

  • Uploaded on

Nerves & Hormones. Nervous System:. Central Nervous System: (The center of integration and control) 1. The brain 2. The spinal cord Peripheral Nervous System: The nervous system outside of the brain and spinal cord. Basic Nerve cell Structure: Neurons. Dendrites Cell body

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Nerves & Hormones' - twila

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript



Nervous System:
  • Central Nervous System:
  • (The center of integration and control)
  • 1. The brain
  • 2. The spinal cord
  • Peripheral Nervous System:
  • The nervous system outside of the brain and spinal cord
Basic Nerve cell Structure: Neurons
  • Dendrites
  • Cell body
  • Axon
  • Axon terminal
3 main types of Neurons:

sensory neuron

motor neuron

relay neuron

Online video

Online animation

The Action Potential

Activation gates

of the Na+ channels are open, but the K+ channels

remain closed. Na+ ions rush into the cell, and

the interior of the cell becomes more positive.

Na+ close and potassium channels

open. K+ ions leave the cell and

the loss of positive charge causes

the inside of the cell to become

more negative than the outside.

A stimulus opens some Na+ channels.

If the Na+ influx achieves threshold potential,

then additional Na+ gates open, triggering an action potential.

Na+ channels are closed,

but the slower K+ remain open. Within a

millisecond, the resting state is restored.

Both Na+ & K+ channels are closed, and the

membrane’s resting potential is maintained.

Synaptic Transmission


Explain how a nerve impulse passes along the membrane of a neuron
  • resting membrane is polarized;
  • interior is –70 mV/negative relative to outside;
  • more sodium ions outside than inside;
  • more potassium ions inside than outside;
  • disturbance of membrane opens sodium ion channels;
  • sodium ions rush to inside of cell;
  • causing depolarization;
  • sodium ion channels shut;
  • potassium ion channels open;
  • potassium ions rush out;
  • helping to restore polarized state of membrane;
  • sodium-potassium pumps maintain polarity;
  • process repeated along the length of neuron / sodium ions diffuse between region with an action potential and the region at resting potential; [8 max]
Endocrine System:
  • Major endocrine glands.
  • (Male on the left, female on the right.)
  • Pineal gland
  • Pituitary gland
  • Thyroid gland
  • Thymus
  • Adrenal gland
  • Pancreas
  • Ovary
  • Testes
  • Organic substances
  • Produced in small quantities
  • Produced in one part of an organism (an endocrine gland)
  • Transported by the blood system
  • To a target organ or tissue where it has a profound effect
  • Homeostasis involves maintaining the internal environment
  • (tissue fluid, blood) between limits.
  • Examples:
    • Blood pH
    • Blood carbon dioxide levels
    • blood glucose concentration
    • body temperature
    • water balance
Homeostasis: Thermoregulation

Thermoregulation is an example of homeostatic mechanism.

Homeostasis: Thermoregulation in endotherms

The body must balance its heat budget

  • by conduction from warm air surrounding the body
  • by the body’s metabolic activity which generates heat e.g. when muscle move
  • by conduction and radiation to cold air (or water)
  • by evaporation of sweat from the body surface (c.f. properties of water)
  • Humans can also affect their body temperature by changing their behavioure.g. wearing different clothes, seeking shade

Heat is gained:

Heat is lost: