7VP MKehl Muscles Spring 2024 PDF

Vet Prep Structural and Functional Biology Dr. Melissa Kehl Muscles Courtesy of Dr. Terri Clark Learning objectives Describe the different types of muscles, where they are found and how they are innervated. Describe the muscle attachments including origins and insertions. Muscle Autonomic = involunt...

Vet Prep Structural and Functional Biology Dr. Melissa Kehl Muscles Courtesy of Dr. Terri Clark Learning objectives Describe the different types of muscles, where they are found and how they are innervated. Describe the muscle attachments including origins and insertions. Muscle Autonomic = involuntary Striated = having long, thin lines Visceral = related to organs Smooth Muscle slow, sustained contractions visceral, autonomic control in walls of GI tract, walls of arteries and veins, around glands Smooth Muscle visceral, autonomic In the wall of the heart Cardiac Muscle Skeletal Muscle Used for locomotion, movement of one body part relative to another, maintaining body posture Triceps brachii m. Accessory head Most skeletal muscles cross one or more joints and have actions on the joint(s) Muscle contraction – shortening of the muscle causes change in alignment of bones around a joint Long head Lateral head FYI Skeletal Muscle Bipennate muscle Muscle Attachments Muscle attachments can usually be classified as origins or insertions Muscle origin: Also known as the proximal attachment Usually, the part that is more fixed and moves the least Triceps brachii m. Biceps brachii m. Origin Origin Insertion Muscle insertion: Also known as the distal attachment Usually, the part that moves the most Insertion Thoracic Limb Muscle Examples Extrinsic Muscles – attach limb to axial skeleton Brachiocephalicus m. Origin – caudal skull Insertion – cranial humerus Action – extend shoulder Innervation – accessory nerve (CN XI) Intrinsic Muscles – within the limb lateral view cranial view Extensor Carpi radialis Origin – distal, cranial humerus Insertion – dorsal, metacarpal 2 and 3 Action – extend carpus Innervation – radial nerve Words in italics you are not responsible for….yet. Pelvic Limb Muscle Examples cranial Gracilis Origin – pelvic symphysis Insertion – tibia and caudal aspect of tarsal bone Action – adduct limb, extend hip and tarsus, flex stifle Innervation – obturator nerve stifle stifle Gastrocnemius medial view Origin – distal, caudal femur Insertion – caudal aspect of tarsal bone Action – extend tarsus, flex stifle Innervation – tibial nerve medial view Axial Muscles Axial muscles are the muscles of the trunk and neck Epaxial muscles Lie dorsal to the transverse processes of the vertebrae Extensors of the vertebral column Hypaxial muscles All other neck and trunk muscles – located ventral to the transverse processes of the vertebrae Flexors of the vertebral column The blue line is the Includes thoracic and abdominal wall muscles approximate location of the vertebral column Epaxial muscles Note that the limb muscles are not included – they are not axial muscles Hypaxial muscles Epaxial Muscle Example Iliocostalis – most lateral epaxial muscle, spans from ilium to cervical vertebrae 7 (C7), fixes vertebral column Hypaxial Muscle Example Rectus abdominus – runs from pubis to sternum, flexes vertebral column