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The hypothenar muscles include the abductor digiti minimi    , flexor digiti minimi brevis    , and the opponens digiti minimi    . These muscles form the hypothenar eminence    , the rounded contour of the little finger, and as such, they all act on the little finger. Finally, the intermediate muscles act on all the fingers and include the lumbrical    , the palmar interossei    , and the dorsal interossei    .

Intrinsic muscles of the hand

This multipart figure shows the intrinsic muscles of the hand with the major muscle groups labeled.
The intrinsic muscles of the hand both originate and insert within the hand. These muscles provide the fine motor control of the fingers by flexing, extending, abducting, and adducting the more distal finger and thumb segments.
Intrinsic Muscles of the Hand
Muscle Movement Target Target motion direction Prime mover Origin Insertion
Thenar muscles Moves thumb toward body Thumb Abduction Abductor pollicis brevis Flexor retinaculum; and nearby carpals Lateral base of proximal phalanx of thumb
Thenar muscles Moves thumb across palm to touch other fingers Thumb Opposition Opponens pollicis Flexor retinaculum; trapezium Anterior of first metacarpal
Thenar muscles Flexes thumb Thumb Flexion Flexor pollicis brevis Flexor retinaculum; trapezium Lateral base of proximal phalanx of thumb
Thenar muscles Moves thumb away from body Thumb Adduction Adductor pollicis Capitate bone; bases of metacarpals 2–4; front of metacarpal 3 Medial base of proximal phalanx of thumb
Hypothenar muscles Moves little finger toward body Little finger Abduction Abductor digiti minimi Pisiform bone Medial side of proximal phalanx of little finger
Hypothenar muscles Flexes little finger Little finger Flexion Flexor digiti minimi brevis Hamate bone; flexor retinaculum Medial side of proximal phalanx of little finger
Hypothenar muscles Moves little finger across palm to touch thumb Little finger Opposition Opponens digiti minimi Hamate bone; flexor retinaculum Medial side of fifth metacarpal
Intermediate muscles Flexes each finger at metacarpo-phalangeal joints; extends each finger at interphalangeal joints Fingers Flexion Lumbricals Palm (lateral sides of tendons in flexor digitorum profundus) Fingers 2–5 (lateral edges of extensional expansions on first phalanges)
Intermediate muscles Adducts and flexes each finger at metacarpo-phalangeal joints; extends each finger at interphalangeal joints Fingers Adduction; flexion; extension Palmar interossei Side of each metacarpal that faces metacarpal 3 (absent from metacarpal 3) Extensor expansion on first phalanx of each finger (except finger 3) on side facing finger 3
Intermediate muscles Abducts and flexes the three middle fingers at metacarpo-phalangeal joints; extends the three middle fingers at interphalangeal joints Fingers Abduction; flexion; extension Dorsal interossei Sides of metacarpals Both sides of finger 3; for each other finger, extensor expansion over first phalanx on side opposite finger 3

Chapter review

The clavicle and scapula make up the pectoral girdle, which provides a stable origin for the muscles that move the humerus. The muscles that position and stabilize the pectoral girdle are located on the thorax. The anterior thoracic muscles are the subclavius, pectoralis minor, and the serratus anterior. The posterior thoracic muscles are the trapezius, levator scapulae, rhomboid major, and rhomboid minor. Nine muscles cross the shoulder joint to move the humerus. The ones that originate on the axial skeleton are the pectoralis major and the latissimus dorsi. The deltoid, subscapularis, supraspinatus, infraspinatus, teres major, teres minor, and coracobrachialis originate on the scapula.

The forearm flexors include the biceps brachii, brachialis, and brachioradialis. The extensors are the triceps brachii and anconeus. The pronators are the pronator teres and the pronator quadratus. The supinator is the only one that turns the forearm anteriorly.

The extrinsic muscles of the hands originate along the forearm and insert into the hand in order to facilitate crude movements of the wrists, hands, and fingers. The superficial anterior compartment of the forearm produces flexion. These muscles are the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and the flexor digitorum superficialis. The deep anterior compartment produces flexion as well. These are the flexor pollicis longus and the flexor digitorum profundus. The rest of the compartments produce extension. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris are the muscles found in the superficial posterior compartment. The deep posterior compartment includes the abductor longus, extensor pollicis brevis, extensor pollicis longus, and the extensor indicis.

Finally, the intrinsic muscles of the hands allow our fingers to make precise movements, such as typing and writing. They both originate and insert within the hand. The thenar muscles, which are located on the lateral part of the palm, are the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and adductor pollicis. The hypothenar muscles, which are located on the medial part of the palm, are the abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. The intermediate muscles, located in the middle of the palm, are the lumbricals, palmar interossei, and dorsal interossei.

Questions & Answers

what are membranous epithelial tissues
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they are the lining and covering epithelial tissues which cover body surfaces and line cavities... they're grouped into simple and stratified according to the number of layers and squamous, cuboidal and columnar according to their shape
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Nuella
the study of tissues is called
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histology
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microscopic or histology anatomy
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it is the pressure exerted by mixture of gases...
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because to know the mechanisms of our body
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head thorax abdomen and many kind of...
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Tariq
Human body can be divided into different regions on the basis of: 1. Systems: e.g. digestive system, respiratory system, excretory system etc.. 2. Parts: e.g. head, thorax, neck, upper limbs, lower limbs etc..
AMEL
we have 9 region in d human body
ZAINAB
what is systematic anatomy?
nsofor Reply
it is the anatomy or study of a certain body system for example the digestive system. or respiratory system.
Summer
It is a group of structure that work together to perform a unique function..
RAPHERA
describe the division of anatomy and physiology
Vissa Reply
the what and the how
Josh
anatomy is the structure. physiology is the function.
Gavin
what is homeostasis?
nsofor
the balance if everything in your body
Kare
is the tendency of the body to maintain the internal environment
Flora
It is the ability of systems and living organisms to adjust its internal environment
RAPHERA
how does a saggital plane look like and a frontal plane
susan Reply
saggital plane divides left and right.. frontal plane divides front and back.. I'm trying to upload a picture but idk how.
Pipiena
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Angella
The sagittal plane is a vertical plane that divides the body into left and right anteriorly whilst the frontal plane divides the body into the posterior(back) and anterior(front) parts. They're all perpendicular to the transverse plane.
Sirius
what is a neurones?
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how many systems are there in human
Angella
It is a cell that specialized to conduct nerve impulse
RAPHERA
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Ovulation is release of mature ovum from ovary
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The study of how e body systems or structures function and interrelate with each other
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large carbohydrates and proteins which is known as acid mucopolysacchrides
adam
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What causes the banding pattern seen in the muscle fibril under the electron microscope
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Ribosome
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nop they are produced by cells of Nucleolus
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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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