Muscles and injection sites Flashcards
Define INTRINSIC MUSCLES
Muscles that lie within one area of the body only. They insert and attach in one specific area, e.g. the muscles of the head and skull
Define EXTRINSIC MUSCLES
Muscles that originate in one area of the body and insert in another, connecting the two parts e.g. the braciocephalicus muscle
Define a TENDON
Connects muscle to bone. Muscles are encased in fascia, and and the tendon is on the end of that fascia. Tendon is very tough as it has a lot of collagen
What are the different types of muscle contraction?
Concentric
Eccentric
Isometric
Define a LIGAMENT
Connects bone to bone. Very tough and fibrous - they also help to keep tendons in place
Describe concentric muscle contraction
When a muscle is actively shortening e.g. when lifting an object in a bicep curl - the arm is flexing and closing the angle of the joint
Describe eccentric muscle contraction
When the muscle is actively lengthening, but the lengthening is controlled, e.g. placing something down in a controlled way
Define FASCIA
A thin casing of connective tissue that surrounds organs, muscles and bone.
Describe isometric muscle contraction
Where the muscle is actively held at a fixed length e.g. carrying something out in front of you, your arm is neither raising or lowering and is stable
What is the name of the compound that muscles use for fuel?
Adenasine triphosphate
What are the three types of muscle tissue found in the body?
Skeletal
Cardiac
Smooth
Describe skeletal muscle
Any muscle that is connected to the skeleton - they attach to bones or skin and control conscious locomotion. The muscles are long and cylindrical, and have a striated appearance under the microscope, due to the regular arrangement of actin and myosin. The muscles have multiple nuclei
Describe smooth muscle
Occurs in the walls of hollow organs such as the intestine, stomach and urinary bladder, and around passages such as the respiratory tract
It is involuntary, has no striations, and only one nucleus per cell
Describe cardiac muscle
Found only in the heart. Involuntary. Contractions of this muscle pump blood around the body and maintain blood pressure. Striated, with one nucleus per cell. Distinguished by the presence of intercalculated discs.
What are voluntary muscles?
Ones that can be controlled consciously, or voluntarily, such as skeletal muscles
Define ACTIN
An abundant intracellular protein. Plays an important roll in muscle contractions, cell movements, controlling cell shape, and architecture. Works with myosin
Define MYOSIN
Works with actin. An intracellular protein that converts ATP to mechanical energy, thereby generating force and movement. Also plays a pivotal role in cell motility and muscle contraction
What stimulates a skeletal muscle to contract?
Nerve impulses to the muscle fibres. The number of nerves supplying a muscle or group depends on its function
What is a bundle of nerves called?
A motor unit
Define an AXON
The transmission lines of the nervous system. As bundles, they form nerves
Define INTERCALCULATED DISCS
Structures that connect adjacent cardiac cells. Bound together by desmosomes, and connected by gap junctions
Define DESMOSOMES
Intercellular junctions that mediate cell to cell adhesion. They do not allow the transfer of materials
Define GAP JUNCTIONS
Clusters of channels that form tunnels of aqueous connectivity between cells. They allow the transfer of materials
How many groups can the muscles of the head and skull be split into?
5
What are the 5 groups of muscles in the skull/head?
The muscles of expression
The muscles pf mastication
The muscles of the eye
The muscles of the tongue, pharynx and larynx
The extrinsic muscles of the head
Describe the muscles of expression
These intrinsic muscles control the mouth, eyes, and ears
Describe the muscles of mastication
There are 4 in total, and all are intrinsic to the head.
The temporal muscle, the masseter muscle, the digastricus and the lateral and medial pterygoid muscles
Describe the muscles of the eye
These are all intrinsic
Describe the muscles of the tongue, pharynx and larynx
Extrinsic, and help with mastication and deglutition.
What is an important point to remember about nervous tissue?
Once damaged, it cannot be repaired.
Define MASTICATION
The process of chewing
Define DEGLUTITION
The process of swallowing
Define the PHARYNX
Behind the mouth and in front of the oesophagus, the throat. Where the digestive and respiratory systems cross over
Define the LARYNX
A cartilaginous structure that opens and closes to control airflow through the trachea. Located near the top of the trachea, made up of cartilage and muscles. Includes the vocal cords.
Give an example of an extrinsic muscle of the head
The brachiocephalicus muscle
Describe the temporal muscle
One of the muscles of mastication. Helps to close the jaw
Describe the masseter muscle
One of the muscles of mastication. Helps to close the jaw
Describe the digastricus muscle
One of the muscles of mastication. Opens the jaw and aids with swallowing
Describe the medial and lateral pterygoids
One of the muscles of mastication. Move the jaw side to side. Not used much in carnivores, much more prominent in herbivores.
What are the two vertebral muscles?
Hypaxial muscles and epaxial muscles
Describe epaxial muscles
These sit above the vertebral column, running dorsally to the transverse processes. They attach to the pelvis, sacrum, vertebrae and ribs, and are varying lengths. They support the spine, the weight of the head, neck and tail, with the action of extending the vertebral column.
Is it better to inject into an overused or underused muscle?
Underused. They are less fibrous and tough and therefore less painful. Epaxial muscles are good sites for IM injection
Describe hypaxial muscles
Sit below the vertebral column, running ventrally to the transverse processes. Do not offer support to the head and neck. They act to bend the neck and flex the lumbar spine
What are intercostal muscles?
The muscles that run between adjacent ribs. Help to form the wall of the thoracic cavity, helping with breathing and respiration. There are both internal and external intercostals
What is the role of internal intercostal muscles?
Opposite function to external intercostal muscles. Help with expirations. They push the ribs apart.
What is the role of external intercostal muscles?
Opposite function to internal intercostals, they help with inspiration, and draw the ribs together
Define the DIAPHRAGM
The thin, domed shaped, unpaired muscle that sits below the lungs and heart. Attached to the sternum and the ventral surface of the lumbar vertebrae by a pair of thickened muscle bands called crura.
Define CRURA
Thickened muscle bands that connect the diaphragm to the ventral lumbar vertebrae and prevent the abdominal muscles entering the thoracic cavity
What are the three hiatuses in the diaphragm?
The post caval hiatus/caval foramen
The oesophageal hiatus
The aortic hiatus
What passes through the post caval hiatus/caval foramen in the diaphragm?
The caudal vena cava, which is a major vein
What passes through the oesophageal hiatus in the diaphragm?
The oesophagus and the vagus nerve
What passes through the aortic hiatus in the diaphragm?
The aorta (a major vein), the thoracic duct (part of the circulatory system) and the azygos and hemizygos veins
What is a hiatus hernia?
A largening of a hiatus. If this occurs in any of the hiatuses of the diaphragm, it can cause the contents of the abdominal cavity to be let into the thoracic cavity.
Not Good!
Define HIATUS
An opening, slit or gap that allows structures to pass through
Define FORAMEN
An opening or hole through tissue, usually bone
Define the VAGUS NERVE
The longest nerve of the autonomic nervous system. Controls involuntary bodily functions
Define the THORACIC DUCT
The primary channel for the return of lymph from most of the body (except the right thoracic limb, shoulder and cervical region)
Define the AZYGOS VEIN
A vein that transports deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava. It runs up the right side of the thoracic vertebral column
Define HEMIAZYGOS VEIN
The left sided equivalent of the azygos vein
What are the muscles of the forelimb?
The trapezius muscle, the latissimus dorsi, the brachiocephalicus muscle, the triceps brachii, the biceps brachii, and the supraspinatus and infraspinatus
Describe the trapezius muscle
A muscle of the forelimb. A trapezium shape, it elevates the shoulder and draws the forelimb forward
Describe the latissimus dorsi
A muscle of the forelimb. Draws the leg back and helps to hold the forelimb in place via synsarcosis
Define SYNSARCOSIS
The junction of two or more bones by means of attached muscles
Describe the brachiocephalicus muscle
A muscle of the forelimb. Acts to extend the shoulder and enables the head to move from side to side
Describe the triceps brachii
A muscle of the forelimb. Acts to extend the elbow and flexes the shoulder
Describe the biceps brachii
A muscle of the forelimb. Opposite effect of the triceps brachii. They contract the elbow, and extend the shoulder
Define RADIAL TUBEROSCITY
A medial eminence of the radius. Serves as an attachment point for the biceps brachii
Describe the supraspinatus and infraspinatus muscles
A muscle of the forelimb. Separated by the spinous process of the scapula. They extend the should and help to stabilise the shoulder joint.
What are the muscles of the hind limb?
The quadriceps femoris, the biceps femoris, the semitendinosus, the semimembranosus, and the gastrocnemius
Describe the quariceps femoris
A muscle of the hindlimb. Acts to extend the stifle. It sits on the craniolateral aspect of the thigh
Describe the biceps femoris
A muscle of the hindlimb. Acts to extend the stifle
Describe the semitendinosus muscle
A muscle of the hindlimb. Acts to extend the hip and the hock
Describe the semimembranosus muscle
A muscle of the hindlimb. Acts to extend the hip and the stifle
Describe the gastrocnemius muscle
A muscle of the hindlimb. Acts to extend the hock and flex the stifle
What are some of the muscles that are suitable for IM injection?
The lumbar epaxial muscles, the biceps femoris, the quadriceps femoris, the triceps
What is best practice for giving an IM injection?
- have the animal firmly restrained in a standing position
- stabilise the muscle
- push the needle into the muscle at a right angle
- pull the plunger back to ensure it is not in a blood vessel
- if it is not, inject slowly
- rub the injected area, and dispose of the sharp and the syringe
What is the total amount that can be given to a cat per IM injection site?
2ml per injection site
What is the total amount that can be given to a dog per IM injection site?
5ml per injection site
