Week 1 Flashcards
Pharyngeal Arches
Also known as the aortic or branchial arches
- Develop in the 4th week as a seris of mesodermal outpiouchings on both sides of the developing pharynx
- 6 pairs
- Develop into the face, jaw and pharynx
- Nerve supply from cranial nerves, splanchnic mesoderm
- Structurally similar to skeletal muslce but usually covered in mucosa
Tension Lines of Skin
Kraissl lines, relaxed skin tension lines
-Cuts parralel cause less scarring
Langers lines
- Based on collagen orientation
- Based of dissection of cadavers
Types of Cartilage
Hyaline
- Most common, weakest
- Has perichondrium
- Ribs, nose. larynx, trachea
- Bone precursor
Fibro
- Strongest, no perichondrium
- Intervertebral discs, joint capsule, ligaments
Elastic
- Maintains shape, has perichondrium
- External ear, epiglottis, larymx
Muscle form type
Parrallel- Rectus abdominus
Unipennate- Tib posterior
Bipennate- (rectus femoris)
Multipennate- (Deltoid)
Types of Joints
Fibrous
- Solid with no joint cavity
- Bones bridged by fibres e.g. cranial sutures, syndesmosis
Cartilagenous
-Solid and no joint cavity
PRIMARY: Two bones bridged by hyaline cartilage (epiphyseal plates of long bones)
SECONDARY: Bone/Hyaline cartilage/fibrocartilage/Hyaline/Bone.
- Always in midline ie intervertebral discs, pubic symphysis
- Allow some movement
Synovial
- Joint cavity lined by synovial membrane
- Articular surfaces covered in hyaline cartilage (e.g knee, elbow, made for movement)
- PLANE (facet joint)
- Uni axial, bi axial or multi axial
- Simple/compound/complex
Hilton’s Law
The nerve supplying a muscle that extends across or acts at a joint also innervates that joint
Stability of Joints
- What factors maintain this
- When is the joint most stable
Bony
-Congruity of articular surfaces
Ligamentous
- Fibrous capsule (intrinsic)
- Collaterals
- Cruciates
- Accessory (AC joint)
Muscular
-More important in mobile joints ie popliteus, rotator uff
Other
-Fibrocartilage, menisci, labrum
Maximum stability is at the “close packed position”
Dermatomes/Axial lines
There is significant overlap between adjacent dermatomes that are CONSECUTIVE
- Pain and temp more than touch
- This is why dermatomal maps vary
Axial lines are the lines that separate adjacent dermatomes from NON-CONSECUTIVE spinal levels
- E.g. L4 and S2 meet on the calf
- They have no overlap
Myotome: Hip flexion
L2/3
Myotome: Hip extension
L4/5, S1 (same as abduction)
Myotome: Hip abduction
L4/5, S1 (same as extension)
Myotome: Hip adduction
L2/3/4 (hip flexion plus 4)
Myotome: Knee flexion
L5, S1
Myotome: Knee extesion
(kick) L2/3/4
Myotome: Ankle dorsiflexion
(toe high) L4/5
Myotome: Plantar flexion
S1/2 (tippy toe)
Myotome: Inversion
(toe inside) L4/5
Myotome: Eversion
(weird one) L5, S1
Myotome: Great toe ext
(Toe high plus one) L4/5, S1
Myotome: Shoulder Abduction
C4/5/6
Myotome: Elbow flexion
C5/6 (pick up sticks)
Myotome: Elbow extension
C7/8 (lay them straight)
Myotome: Wrist Flexion
C6/7/8
Myotome: Wrist Extension
C6/7
Myotome: Finger Abduction
C8 T1 (muscles of the hand)
Myotome: Finger Adduction
T1 (come together as one)
Myotome: Thumb Abduction
T1 (thumbs up)
Reflexes: Knee (patella)
(Kick) L2/3/4
Reflexes: Ankle (achilles)
S1/2 (tippy toe)
Reflexes: Plantar
(5 tippy toes) L5 S1/2
Reflexes: Triceps
C7/8 (lay them straight)
Reflexes: Biceps
C5/6 (pick up sticks)
Reflexes: Supinator (brachoradialis)
C5/6 (pick up sticks)
Reflexes: Finger
C8 (before the thumb)
Organisation of ANS
-Sympathetic vs Parasympathetic
Central/Peripheral
Somatic/Visceral
Symptathetic/Parasympathetic/Enteric
Sympathetic (Fight or flight)
-Short, pre-ganglionic neurons (acetylcholine) from Thoracolumbar cord at T1-L2–>
Postganglionic neurons (noradrenaline) to the rest of the body
-Adrenaline, dilate pupils, dilate bronchioles, ejaculation
Parasympathetic (Feed and Breed)
-Craniosacral outflow (CN III, VII, IX, X and S2-4)
-Direct Acetylcholine
Bradycardia, salivation, lacrimation, accomodation, miosis, erection
Spinal Nerve Organisation
31 pairs of spinal nerves
Posterior nerve roots are sensory (afferent/arrive), anterior are motor (efferent/exit)
-Dorsal root ganglion has the body of afferent sensory nerves
Anterior and posterior nerve joint to form the spinal nerve
- Dorsal rami smaller, sensory and motor nerves of the back
- Ventral Rami larger, anterior.lateral
Blood vessel types
Arteries -Endothelium, intima, media (muscle), adventitia Arterioles -Largest wall thickness to lumen ration -Rapid drop in BP before capillaries Capillaries -Single layer of endothelium with basement membrane Veins -Same layers as artery -Much less smooth muscle -More elastic
Lymphatics
Accompany veins (in the dermis) Drain to at least one LN before draining into a vein Seperated into "watershed" regions, can flow vertical and horizontal Anterior thorax, skin of glans penis and clitoris drain direct to deep LN
Fascia
Separating layers of collagen fiber e.g Deep fascia, retinaculum, septa
- Superfical fascia is loose
- Deep fascia is dense, non-elastic and gives attachement site for muscles
Vessels and nerves can pierce fixed fascia
-Will not pierce mobile fascia planes (two parralel sheets) as can kink
