Respiratory, Nervous, Urinary, Itegumentary systems, eye and ear

Respiratory System

• Responsible for gas exchange (oxygen in, carbon dioxide out).

• Plays a crucial role in vocalization and olfactory senses.

Key Components

• Nose: Filters and warms incoming air.

• Pharynx: Common area in the back of the throat, passage for air and food.

• Larynx: Provides passage for air to the trachea and prevents food/water entry.

• Trachea: Connects the larynx to the bronchi; contains cartilage to maintain shape and prevent collapse.

• 

How cats purr and dogs smell.

• Cats: Produce sounds like purring through the larynx which regulates airflow.

• Dogs: Utilize the respiratory system for olfactory sensing; linked to their ability to smell.

Importance of Panting

• Purpose: Regulates body temperature and helps with:

  • Water elimination

  • pH balance (acid/base control)

  • Temperature regulation

Nervous System

• Coordinates body functions and responses to internal/external stimuli.

Neuron Diagram

1. Dendrite

2. Soma (cell body)

3. Axon

4. Node of Ranvier

5. Axon Terminal

6. Schwann Cell

7. Myelin Sheath

8. Nucleus

Central and Peripheral Nervous System

• Autonomic Nervous System: Operates involuntarily.

  • Sympathetic System: Involved in "fight or flight" responses (e.g., reacting to a loud noise).

  • Parasympathetic System: Promotes relaxation (e.g., a sleeping pet).

Responses Examples

• Sympathetic Examples:

  • Cat chased by a dog

  • Horse spooked by a noise

  • Aggressive response to stimuli

• Parasympathetic Examples:

  • Dog chewing a bone

  • Cat purring when petted

Urinary System

• Main function is waste removal and filtration from the blood.

• Proper functioning is vital; issues can arise from diseases, age, or toxins.

Nephron Function

1. Blood Filtration: Toxins are removed by nephrons in the kidneys.

2. Collection: Urine collects in a central channel after filtration.

3. Excretion: Urine exits the kidney via the ureter to the bladder.

Integumentary System

• The skin is the largest organ and comprises two layers:

  • Epidermis: The outer layer responsible for skin pigment.

  • Dermis: The inner layer containing hair follicles, glands, nerve endings, and blood vessels.

The Eye

• Retina: Connects to the optic nerve, processes visual information.

• Cornea: The outermost front part of the eye, plays a role in light refraction.

• Tapetum: Reflective layer allowing better vision in low light.

Visual Perception in Animals

• Rods: Highly sensitive to light; present in most domestic animals; allow limited color perception.

• Cones: Responsible for color vision, require more light than rods.

The Ear

• Essential for hearing and balance; animals hear different frequencies compared to humans.

Vestibular Sense

• Located in the inner ear, it helps maintain balance:

  • Comprises fluid-filled canals that send nerve impulses to the brain.

  • Disturbance can lead to balance issues, often due to infections.

References

• Sirois, M. (2021). Elsevier's Veterinary Assisting Textbook (3rd ed.). Elsevier.