Equine Muscular System Flashcards
Head
What are the two main muscle groups in the head?
Mimetic (facial expression)
Masticatory (chewing)
Head
What do the major mimetic muscles control?
Eyelids, mouth and muzzle, cheeks and ears
Head
Which muscles close the eyelids?
Orbicular muscles of the eye
Head
Which muscles close the lips of the mouth?
Orbicular muscles of the mouth
Head
Which muscles control the ears?
Auricular muscles
Head
Which is the major masticatory muscle?
The masseter
Head
Which muscle opens the mouth?
Digastric muscle
Neck
What movement do the muscles in the lower portion of the neck allow?
Lowering the head
Neck
What is the name of the muscle which runs from the sternum to the head?
Sternocephalic muscle
Neck
Which muscle runs from the upper arm (brachium) to the head?
Brachiocephalic muscle
Neck
What motion does the Brachiocephalic muscle cause when the limb is loaded?
Lowering the head
Neck
What movement does the Brachiocephalic muscle cause when the horse is in motion?
Extension of the shoulder joint leading to protraction of the limb
Neck
Which two muscles form the boundaries of the jugular groove?
Sternocephalic and Brachiocephalic
Neck
What is the function of the Jugular Vein and where does it run?
Drains the blood from the head and neck to the heart
Jugular groove
Neck
What is the purpose of the muscles in the upper half of the neck?
Provide movement and stability to the neck and proximal forelimb
Neck
Which muscle runs from the withers to the back of the head and top 4 cervical vertebrae?
Splenius muscle
Neck
What effect does contracting splenius have on the horse?
Raises the head and exerts a cranial pull on the withers, stabilising the back
Neck
Which muscle runs from the upper thoracic vertebrae to the occipital process on the back of the skull?
Semispinalis Capitis muscle
Neck
What effect does contracting the semispinalis capitis have?
Raises the head and moves it from side to side
Thoracic Girdle and Back
What is the purpose of the muscles in the thoracic girdle?
Connect forelimbs to trunk (no direct skeletal link)
Transfer weight of trunk to forelimbs and move forelimbs
Thoracic Girdle and Back
Which muscle runs from the cervical part of the neck and anterior ribs to the inner side of the scapula?
Serratus Ventralis muscle
Thoracic Girdle and Back
What is the purpose of the Serratus Ventralis muscle?
Attaches forelimbs to trunk
Enables forward and backward movement of the forelimbs
