05 Muscles Flashcards
What are the four general functions of muscles? List them
- Movement 2. Maintenance of posture 3. Joint stabilisation 4. Heat generation
How do muscles generate heat and why is this important in the maintenance of body temperature?
Muscles generate heat as they contract; since skeletal muscle accounts for 40% of body mass, this is very important in maintaining body temperature
What are the four properties of muscle tissues?
- Contractility 2. Excitability 3. Extensibility 4. Elasticity
What does the property of muscles contractility allow?
The ability to shorten forcefully
What does the property of muscles excitability allow?
Responsiveness to stimulus
What does the property of muscles extensibility allow?
Ability to be stretched even beyond resting length
What does the property elasticity allow?
Ability to return to original length after stretching
What are the three types of muscles?
Skeletal, cardiac and smooth
Where are skeletal muscles located?
Mostly attached to bones / or skin for some facial muscles
Describe the shape of skeletal muscle cells.
Single, long, cylindrical and multinucleate cells with obvious striations
What is the speed of contraction of skeletal muscle?
Slow to fast
How is skeletal muscle contraction regulated?
Voluntary via the somatic nervous system
What is the effect of the nervous system on the skeletal muscle?
Excitation only
Does the skeletal muscle have a rhythmic contraction?
No babes
What type of respiration takes place in the skeletal muscle type?
Aerobic or anaerobic
What three key words should come to mind when describing skeletal muscle?
Skeletal, striated, voluntary
Where is the cardiac muscle located?
In the walls of the heart
How would you describe the cell shape and appearance of cardiac muscle?
Branching chains, uni-or bi-nucleate, striations present
What is the speed of contraction of cardiac muscle?
Slow
How is the cardiac muscle contraction regulated?
Involuntary control
What is the effect of nervous system stimulation on cardiac muscle?
Excitation or inhibition
Does the cardiac muscle have a rhythmic contraction?
Yes
What type of respiration occurs in cardiac muscles?
Aerobic
Where would you find smooth muscle?
Single unit muscle in walls of hollow visceral organs (except heart), multiunit muscle in intrinsic eye muscles, airways and large arteries
How would you describe the cell shape of smooth muscle cells?
Uninucleate with no striations
What is the speed of contraction of smooth muscle?
Very slow
How would you describe the regulation of contraction of smooth muscle?
Involuntary
What is the effect of the nervous system stimulation on the smooth muscle?
Excitation or inhibition
Is the contraction of smooth muscle cells rhythmic?
Yes in single unit muscle
How would you describe the respiration in smooth muscle?
Mainly aerobic
Roughly how many muscles in the human body?
Over 600
Muscles have points of ____ and _____. Fill in the gaps.
Origin and insertions
What is the origin of a muscle?
The point which does not move when the muscle contracts
What is the insertion of a muscle?
The point which does move when the muscle contracts
What type of muscle is this and give an example.
Parallel (strap-like). An example would be sternocleidomastoid
What type of muscle is this and give an example.
Circular - orbicularis oris
What type of muscle is this and give an example
Convergent and the pectoralis major
What type of muscle is this and give an example
Multipennate - deltoid
What type of muscle is this and give an example
Parallel: fusiform. Biceps brachii
What type of muscle is this and give an example
Bipennate - rectus femoris
What type of muscle is this and give an example
Unipennate and flexor pollicis longus
What does the anatomical term for motion adduct mean?
To move a structure towards the midline of the body
What does the anatomical term for motion abduct mean?
To move a structure away from the midline of the body
What does the anatomical term for motion extend mean?
Extend - to stretch limb segments away from one another
What does the anatomical term for motion flex mean?
To contract limb segments closer to one another
What does pronate and supinate mean?
pronate - to turn face down or palm down. supinate - to turn face up or palm up
What does dorsiflex and plantar flex mean?
Dorsiflex - to rotate the foot up. Plantarflex - to rotate the foot down
Skeletal muscle names are named according to various features. List some features that play a role in the naming of muscles.
Location, costal muscles to do with the ribs, shape deltoid is triangular , size- gluteus maximus, function adductor longus,
Why are the muscles that control facial expressions unsual?
They insert into skin or other muscles rather than bones
What are the facial muscles controlled by?
The cranial nerve (CN) VII, the facial nerve
What four pairs of muscles are involved in mastication?
Masseter, temporalis, medial pterygoid, lateral pterygoid
The muscles involved in mastication are enervated by which nerve?
cranial nerve 5 the trigeminal
Name three extrinsic tongue muscles
Genioglossus, hyoglossus and styloglossus
What are the extrinsic muscles of the tongue enervated by, nerve wise?
By the cn xii (12) the hypoglossal
Point to the following muscles and then compare your answer: Occipitofrontalis, temporalis, orbicularis oculi, zygomaticus, orbicularis oris, masseter, sternocleidomastoid, trapezius.
There ya go
Focusing on the muscles of the thorax and arm, what are the most superficial muscles of the thorax? Where do they run to?
The extrinsic shoulder muscles running from the ribs/vertebral column to the pectoral girdle
What is the most flexible joint in the body and what is special about it?
The shoulder joint is the most flexible and because of this, it is extremely complex
In the arm which muscles cause flexion and which muscles cause extension?
Flexion - anterior muscles. Extension - posterior muscles.
When do the posterior and anterior muscles separate and what do they separate from?
They separate from a large muscle mass as the long bones form during development (about week 8)
When do the lower limbs form/muscles separate
about 1-2 days behind the upper limbs
From the anterior side, point to the deltoid, pectroalis major, biceps brachii, rectus abdominis, external oblique and brachioradialis. Then look at the image on the back of this card
There ya go
List the following principal superficial muscles of the body from the posterior side. Trapezius, deltoid, triceps brachii, latissium dorsi, gluteus maximus. Then flip over homie.
There ya go
Point to the following muscles on the anterior side and then flip over. Sartorius, rectus femoris and tibialis anterior.
There x
Point to the following muscles of the body on the posterior side and flip over. you know the drill. Biceps femoris, Gastrocnemius (lateral and medial heads) and the calcaneal (achilles tendon)
x
What is the origin of the sternocleidomastoid?
The sternum and clavicle
What is the insertion of the sternocleidomastoid?
Mastoid process of temporal bone
What action does the sternocleidomastoid play a role in?
The flexion of the head and neck
What is the origin of the temporalis muscle?
The temporal fossa
What is the insertion of the temporalis muscle?
The mandible
What action does the temporalis muscle aid in?
The elevation and retraction of the mandible
What is the origin of the masseter muscle?
The zygomatic arch and the maxilla
What is the insertion of the masseter muscle?
The mandible
What action does the masseter aid in?
Elevates the mandible
There are three types of joints. What are these
Synarthroses. Amphiarthroses. Diarthroses/synovial joints
What are synarthroses?
Immoveable joints
What are amphiarthroses?
Slightly moveable joints
What are diarthroses or synovial joints?
Freely moveable joints
In synarthroses, the edges of bones are in ____ proximity and in some causes _____.
Close, interlock
What are the four major types of immoveable joints/ synarthroses?
- Sutures
- Gomphoses
- Synchondroses
- Synostoses
Sutures, a type of synathroses joint are located where?
Between the bones of the skull
Gomphoses, a type of synarthroses joint is located where?
Binding teeth to maxilla/mandible
Synchondroses, a type of synarthroses joint are located where and how would you describe this joint?
A rigid cartilagenous bridge between to articulating bones - e.g. cartilage connecting first pair of vertebrosternal ribs to sternum
Synostoses, a type of synarthroses joint can be described as? Where is it found?
A total rigid joint created when bones fuse completely - e.g. metopic suture which separates paired frontal bones at birth
Wha connects amphiarthroses?
Collagen fibres or cartilage
What are the two principle types of amphiarthroses?
Syndesmoses and symphyses
What is the difference between the two subgroups of amphiarthroses, the syndesmoses and the symphyses?
The syndesmoses are connected by ligament and the sympheses are separated by cartilage
Give an example of where the sub group of ampharthroses, the syndesmoses is found
The distal articulation between the tibia and fibula
Give an example of where the sub group of the amphiarthroses and symphyses is found
Intervertebral discs and pubic symphysis
What do the diarthroses/ synovial joints allow?
A wide range of movement
Where are diarthroses typically found?
At the end of long bones such as the femur, humerus, radius
What do diarthroses contain which makes them different to the synarthroses and amphiarthroses?
Diarthroses contain synovial fluid
List three functions of the synovial fluid found in diarthroses joints
- Lubricant
- Aids in nutrient distribution and waste disposal
- Shock absorption
How much synovial fluid is found, even in the larger joints such as the knee?
Less than 3ml
How are synovial joints stabilised?
By ligaments, muscles, tendons or by other bones
There are three types of articular motion, what are these?
- Linear (gliding)
- Angular
- Rotation
Describe the linear type of articular motion
A gliding motion, side to side across the surface.
Where can the linear gliding type of articular motion be found?
Intercarpal and intertarsal joints
Describe angular motion which is a type of articular motion
Angular is when the tip stays put but the angle changes.
Give an example of where angular motion occurs in the body
Flexion and extension of the elbow
How is flexion a type of angular motion?
You are decreasing the angle of a joint
How is extension a type of angular motion?
You are increasing the angle of a joint
How is abduction an example of angular motion?
Moving away from the midline
How is adduction an example of angular movement
Moving towards the midline
How is circumduction an example of angular motion?
You are moving a limb so it describes a cone with the distal end moving in a circle
Describe the rotation type of articular motion and give an example of where this occurs.
Obviously rotating haha, occurs between c1 and c2
What is protraction and retraction?
Moving the jaw forwards and backwards
What is elevation and depression?
Lifting the shoudlers up and down
What is the type of movement called opposition?
Touching thumb to the fingers
Why are these motions described separately to the other three categoreis of rotation, anguar and linear?: Pronation, dorsiflexion, protraction, retraction, elevation, depression, opposition?
These are types of movement that do not fit easily into the categories of angular, linear or rotation
List the six types of synovial/diarthroses joint
Plane joint, hinge joint, pivot joint, condyloid joint, saddle joint, ball and socket joint
Where is a plane joint - a type of synovial joint present?
Intercarpal in the hand
Where is the hinge joint present?
The elbow joint
Where can you find the pivot joint?
Proximal radioulnar joint
Where is the condyloid joint?
Metacarpophalangeal joint
Where is the saddle joint?
Carpometacarpal joint of the thumb
Where is the ball and socket joint?
Shoulder joint
Why does an electric shock cause you to grip?
Electric shock causes contraction of flexors and extensors but the anatomy of the hand is more geared towards flexion that extension. Flexors of the fingers are 62% stronger than extensors.
