Week 1 Flashcards
What are some of the common cuases of skin conditions?
Drugs Stress ingections Disease Genetics Allergies Systemic diseases
Define prevalence?
Total number of cases within the population at any time
Define incidence
Number of new cases described as a % of population who get the disease over a set period of time
Define illness behaviour
Concept that different people will react to the same thing differently due to perception influenced by their demographic and psycholical factors and their social situation.
What is the difference between an illness and disease?
Illness is the experience of discomfort and suffering, disease is a pathological condition
When you walk in a room you first will see how busy it is, then recognise faces. What is this phenomenom of the brain described as ?
Gestalt psychology, that the brain sees the whole picture first then interprets it
Raw reactions to things are controlled by neural pathways where in the brain?
Amygdala
Young man presents with skin disease following blaschkos lines. What does this indicate?
It is a prenatal disease
Blaschkos lines are how the skin was warped and stretched during foetal development so if it follows one of these lines you know it was prenatal
Give some examples of skin appendages
Hair
Nails
Glands
Mucosae
From when in the womb does the skin begin to develop? And until when?
4 weeks- periderm, basal layer, dermis estabilshed
16 weeks; epidermis layers formed keratin, granular, prickle cell, basal layer, dermis
26 weeks; skin appendages formed hair, melanocytes
What is a keratinocyte? Where do they originate in the skin?
Any cell that contains structural keratin e.g prickle cells
Originate from the basal membrane
Name the 4 layers of the epidermis from deep to superficial
Basal layer, prickle cell layer, granular layer, keratin layer
Name the 3 main layers of skin from superficial to deep
Epidermis
Dermis
Subcutaneous/ superficial fascia
What is the patholigcal process that causes patches of mucosa to appear white in the mouth
The mucosa and dermis have become thickened so you cant see the blood vessels anymore making it white
What layer of the skin would you find corneocytes? What is their function
The keratin layer of the epidermis
Composed of keratin and filaggrin that allows water to be retained
Describe the path of blood from the heart to the hand
Brachiocephalic -> axillary -> brachial -> radial/ ulnar -> deep/superficial palmar arches -> metacarpal and digital arteries
Man is bleed profusely from his right him around the biceps brachii, where would you pinch to cut of blood flow
Proximal to the bleeding
Subclavian artery
What is an end artery? Give an example of where you would find an end artery
Where only one artery supplies an area of the body. The hand
Where is the cubital fossa?
The elbow
What is the venous supply to the thumb? Medial or lateral supply?
Lateral supply by the cephalic vein
What vein runs medially in the upper limb?
The basilic vein
Which vein is venopuncture usually taken from ? What vessels does this bridge?
The median cubital vein
The cephalic vein and the basilic vein
Describe the arterial blood flow in the foot
Dorsalic pedis artery-> medial and lateral plantar arteries -> arcutate artery/ deep plantar arteries-> metatarsal and digital arteries
What is the general rule for the path of lympathics?
they follow the venous supply
Describe the venous path of blood beginning at the tibial vein to theheart
Tibial-> popliteal -> femoral -> external iliac vein -> common iliac vein -> IVC ->right atrium
What can cause venous ulceration?
Where there is a micronutrient deficiency in the blood so the skin becomes itchy, dry and inflamed
What is a vena comitantes? What is the function?
Where multiple veins will be wrapped in a bundle around an artery, so when the artery pulses it pushes blood in the veins back up to the heart
Where do the lymphatics of the upper limbs drain into? Where does this then drain?
Axillary lymph nodes
Subclavian lymphatics
Mans thumb gets infected, describe the path of the lymph nodes you expect to be enlarged
Cephalic nodes and apical axillary lymph nodes
Mans pinky gets infected, describe the path of the lymph nodes you expect to be enlarged
Basilic -> cubital nodes -> lateral axillary nodes
Describe the origin of the great saphenous vein and where it drains into
Arises from dorsal venous arch
Drains into the femoral vein
On medial aspect of the lower limb. Superficial vein
Describe the origin of the small saphenous vein and where it drains into
From dorsal venous arch
Drains into popliteal vein
On posterior midline of leg superficial vein
Name the cell type that produces pigment by converting tyrosine into melanin
What layer of skin are they in
Melanocytes
Basal layer
What is the function of langerhans cells
Interpresed in the epidermis antigen presenting cells
What is the function of merkel cells
Mechanoreceptors attached to the spinal cord that detect sensory information
What are the 3 phases of the life cycle of the hair follicle
What receptor stimulates this
Anagen (growing)
Catagen (involuting)
Telogen (resting)
Androgen receptor
Damage of what area of the nail will cause poorly differentiated nails
The nail matrix
What is the histology of a scar
Loss of skin appendages so the body fills the defect with collagen from fibroblasts
What is the function of the dermo-epidermal junction
Sticks the dermis and the epidermis together supporting the whole skin structure and allowing diffusion of blood across the layers
What is the condition vitiligo a problem with?
There is a loss of melanocytes resulting in patches of pigment in the skin
What is the problem with nelsons syndrome?
Hyperpigmentation due to excess secretion of ACTH and likely to gret adrenal tumours and mailgnant melanoma. Common to get in people with CUSHINGS
What embryological layer does the hair follicle originate from?
The mesoderm
What is the problem with alcopecia areata?
Autoimmune condition where hair is attacked by lymphocytes so falls out
What process can cause thickening of the nail?
Hyperkeratonosis
Why does bullous pemphigoid occur?
Due to a problem with the dermo-epidermal junction so causes blisters
What is the problem with epidermolysis bullosa?
Occurs in kids, can be life threatening, problem with dermo-epidermal junction
What is photoaging?
Where elastic fibre production fails in the dermis fails and becomes disordered. Natural aging process