Anatomy Flashcards
Torso/Trunk
The main central part of the body including the thorax, abdomen, and pelvis.
Not including the neck, head, or the upper or lower limbs.
Thorax
The upper part of the torso from the bottom of the neck to the diaphragm (an internal muscular sheet that separates the thorax from the abdomen).
The thorax houses the lungs and heart and is surrounded by the ribs.
The term ‘chest’ refers to the front of the thorax only.
Abdomen
The central part of the torso between the diaphragm and top of the pelvic bones.
The abdomen contains most of the organs of digestion including the stomach, intestine, and liver.
In everyday conversation, people often refer to the entirety of the abdomen as the ‘stomach’.
Pelvis
The lowest part of the torso, between the abdomen and the start of the lower limbs.
The pelvis contains the last part of the digestive tract, the bladder, and reproductive organs.
The bony ‘ring’ of the pelvic region is also called the pelvis, so the term ‘pelvis’ is used to describe both the entirety of the pelvic region (including organs and blood vessels etc.) and the bone of the pelvic region.
Back
A poorly descriptive term.
Anatomically, the ‘back’ refers to the entire posterior surface of the torso.
Arm
The upper part of the upper limb (from the torso to the elbow).
This is where the biceps muscle is located.
Forearm
The middle part of the upper limb (from the elbow to the wrist).
Thigh
The upper part of the lower limb (from the pelvis to the knee).
Leg
The middle part of the lower limb (from the knee to the ankle)
anatomical position
A person is standing up with their feet flat on the floor, facing forward, arms by their sides with their palms facing forwards
Diagram page 9
Superior
Above
Example; The brain is superior to the heart
Inferior
Below
Example; the pelvis is inferior to the pelvis
Anterior/ Ventral
Front (in front of)
Example; The nose is anterior to the ears
Posterior/dorsal
Back (behind)
Example; the spine is posterior to the sternum
Medial
Closer to the centre line
Example; the big toe is medial to the little toe
Lateral
Further away from the centre line
Example; The thumb is lateral to the palm
Proximal
Closer to the origin
Example; The elbow is proximal to the wrist (wrist is the origin here)
Distal
Further away from the origin
Example; the toes are distal to the knee (origin is the knee here)
Ipsilateral
The same side of the body
Example; The right arm and left leg are contralateral to each other.
Deep
Further away from the surface
Example; The heart is deep to the sternum.
Superficial
Closer to the surface
Example; The skin is superficial to the muscle
Supine (position)
Lying down, flat on back, facing up
Example; With the patient supine, they are facing the ceiling.
Prone (position)
With the patient prone, they are facing the floor
Cranial
Towards the head
Example; the brain is cranial to the spina cord
Caudal
Towards the tail
Example; The pelvis is caudal to the abdomen.
Rostral
Towards the face
Example; The frontal lobe of the brain is rostral to the occipital lobe.
Coronal (/frontal)
face-on’. A coronal incision cuts a structure into an anterior and a posterior part.
Diagram page 12
Sagittal
‘side-on’.
A midline sagittal incision cuts a structure into a left and a right side.
Parasagittal
a cut in the sagittal plane but parallel to the midline (i.e. off to one side or the other)
Axial (also called transverse or horizontal)
end-on
An axial incision cuts a structure into a superior and an inferior part.
The skeleton (diagram page 13)
bony scaffolding of the body
Axial part of skeleton
central, or core, parts: the skull, vertebral column, ribs, and sternum
Appendicular part of skeleton
the bones of the limbs, including the shoulder blades
(scapulae), collarbones (clavicles) and the pelvic girdle
A joint
formed where two bones meet; the two bones articulate with each other
Not all joints move
How are joints classified?
according to their histological structure and their biomechanical structure
‘histological’ refers to the cellular and structural composition of tissue
Three different histology all types of joints (diagrams page 15-16)
Synovial
Fibrous
Cartilaginous (primary Cartilaginous and secondary Cartilaginous)
Synovial joints
Most common type of joint
A very narrow synovial cavity separates the articular surfaces of the bones.
The cavity contains lubricating synovial fluid, which is enclosed in a joint capsule.
The joint capsule has two layers: an outer fibrous capsule, and an inner synovial membrane.
The articular surfaces are covered with articular ‘hyaline’ cartilage
Synovial joints usually allow a great deal of movement.
Examples of synovial joints
Shoulder joint
Knee joint
Wrist joint
Fibrous joint
connect two bones together via strong fibrous tissue
There is no cavity and no fluid
There is usually very little (if any) movement at fibrous joints.
Examples of fibrous joints
the joints between the individual bones of the skull (called ‘sutures’).
Cartilaginous joints
like fibrous joints, but the articular surfaces are separated by cartilage instead of fibrous tissue
There are two types; primary and secondary
Primary cartilaginous joints
are connected to each other by hyaline cartilage, which allows some flexibility
Examples of Primary cartilaginous joints
where the ribs meet the sternum
Secondary cartilaginous joints
are connected to each other by fibrocartilage, plus a layer of hyaline cartilage covers the articular surfaces of the bones.
They are flexible but strong and can support a lot of weight.
Examples of Secondary cartilaginous joints
the intervertebral discs (between the vertebrae in the spine)
How are synovial joints biochemically classified?
Synovial joints permit movements in different planes and to different degrees, depending on the shape of the articular surfaces and other factors such as surrounding ligaments and muscles
6 types of synovial joints (diagram on page 18)
Ball and socket
Hinge
Pivot
Saddle
Condyloid
Plane
Ball and socket joint
the end of one bone is shaped like a ball and the end of the other bone is shaped like a bowl that the ball fits inside
These joints are mobile and allow a significant range of movement in all directions, including rotation
How mobile and stable these joints are depends on the fit between the ball and socket - the better the fit, the more stable the joint but the less mobile it is
With a poorer fit comes better mobility but less stability and greater risk of dislocation
Examples
Hip
Jaw
Shoulder
Hinge joint
they allow a significant range of movement, but only in one plane
Examples
In the fingers
Elbow
Knee
Pivot joint
It allows rotational movement only
Example
found at the top of the spine where the first and second vertebrae articulate with each other
The first vertebrae (C1, the atlas) at the base of the skull pivots around the peg of the second vertebrae (C2, the axis)
Allows us to turn our head left and right
Saddle joint
joints are shaped like a rider sitting in a saddle, and permit movement in two planes
Examples
the joint at the base of the thumb, where the metacarpal of the thumb articulates with one of the small carpal bones (the carpometacarpal joint of the thumb)
Condyloid joint
like a ball and socket joint, but the joint surfaces are oval- shaped.
They have a good range of movement but only in two planes
Examples
the wrist joint
The metacarpophalangeal joints of the fingers (the knuckles)
Plane joint
the articular surfaces are almost flat and glide against each other.
The range of movement is usually limited and dictated by the neighbouring bones and surrounding ligaments.
Examples
the joints between the small bones of the wrist
the acromioclavicular joint at the top of the shoulder
Ligament
A band of fibrous connective tissue that attaches bone to bone.
Ligaments stabilise joints and limit their movement.
They can stretch and, over time, can be stretched to allow greater joint mobility.
double- jointed
People who have ligaments that are stretchy enough to allow their joints a greater degree of mobility (‘hypermobility’)
A sprain
occurs when a ligament is overstretched and injured.
The most often sprained ligaments are those of the ankle, caused by ‘going over’ on the ankle (forced, excessive inversion).
Over-stretched and torn ligaments are painful. They may not return to their original shape.
When joints dislocate the ligaments may be stretched so much that they become permanently lax, leading to joint instability and in some cases, recurrent dislocation.
Flexion
Bending (decreasing the angle between the two parts)
Extension
Straightening (increasing the angle between the two parts
Lateral flexion
Unique to the vertebral column: bending sideways.
Abduction
Movement away from the midline
Adduction
Movement towards the midline
Internal rotation
Rotating (around an axis) towards the midline (also known as medial rotation)
External rotation
Rotating (around an axis) away from the midline (also known as lateral rotation)
Pronation
Unique to the forearm: internal rotation of the radius, so that the palm faces posteriorly (our forearm and hand are prone when we type using a keyboard)
Supination
Unique to the forearm: external rotation of the radius, so that the palm faces anteriorly (i.e. the anatomical position)
Opposition
Unique to the thumb and little finger: flexion and rotation of the thumb or little finger so that each one can reach the other
Circumduction
Combination of flexion, extension, abduction, and adduction such that the appendage traces a circular or conical pattern.
Dorsiflexion
Unique to the ankle: the foot and toes move superiorly towards the shin (pointing the foot and toes ‘up’)
Plantarflexion
Unique to the ankle: the foot and toes move inferiorly (pointing the foot and toes ‘down’).
Inversion
Unique to the foot and ankle: medial flexion so that the sole of the foot faces medially
Eversion
Unique to the foot and ankle: lateral flexion so that the sole of the foot faces laterally
Protraction
Unique to the scapula and mandible: moving the scapula or mandible anteriorly (e.g. moving our upper limb out in front of us to push open a door
Retraction
Unique to the scapula and mandible: moving the scapula or mandible posteriorly (e.g. ‘squaring’ the shoulders)
Elevation
Unique to the scapula and mandible: moving the scapula or mandible superiorly (e.g. shrugging the shoulders, closing the mouth)
Depression
Unique to the scapula and mandible: moving the scapula or mandible inferiorly (e.g. returning the shoulders after elevation, opening the mouth).
How are muscles classified?
Histologically according to their cellular and structural composition
Three different types of muscle
Skeletal
Smooth
Cardiac
Skeletal muscle
found throughout the body
Skeletal muscles provide support for the body and move the joints and some soft tissues.
They are under voluntary control (i.e. we can consciously control them).
The muscle fibres are described as striated as they have a striped appearance under a microscope.
Examples
the eyeball
tongue
Smooth muscle
located in the walls of blood vessels and internal organs
Smooth muscle is involuntarily controlled by the autonomic nervous system – we cannot consciously control its activity.
Smooth muscle fibres are not striated.
Examples
Intestine
Cardiac muscle
Unique to the heart
It is involuntarily controlled. Cardiac muscle cells contract in response to electrical impulses that are spontaneously generated by specialised cells within the heart. The autonomic nervous system influences these specialised cells and can speed up or slow down the heart rate.
Cardiac muscle fibres are striated.
Tendons
Attach skeletal muscles to bone or soft tissues
What are tendons composed of?
Strong connective tissue
Aponeuroses
Thin, flat sheets formed by tendons
Found in the scalp and abdominal wall
Tendons can also be…
Rounded
‘Belly’
The muscle between the tendons
How are joints moved?
muscles or tendons must cross the joints
When a muscle contracts, one of its attachments moves whilst the other attachment does not.
The bone or part that does not move is called the origin, and the bone or part that does move is called the insertion.
Brevis
Means short