The immune system Block 4 Week 3 Flashcards
Betamethasone ?
- inhibit neutrophil apoptosis
- inhibit NF-Kappa B and other inflammatory transcription factors
- inhibit phospholipase A2 leading to decreased formation of arachidonic acid
- steroid medication
Indications:
- topically used to treat inflammatory conditions such as eczema
- as injection to treat rheumatic disorders, gastrointestinal disorders.
contraindications:
- if injected avoid live viruses
- topically: acne, fungal and viral lesions
side effects:
- increased risk of infection, mood altered, psychotic disorder
Prednisolone
- Prednisolone is available only on prescription as tablets and as a liquid you swallow
- It helps by reducing swelling (inflammation) and can also calm down your immune system
- Prednisolone is a steroid or corticosteroid medicine
Indication:
- used to treat endocrine , dermatological, rheumatic
Contraindications:
- avoid live virus
Describe chlorphenamine ?
- antihistamine medication
- over the counter
Describe hydrocortisone ?
- corticosteroid
- The medicine comes in different forms, including skin creams for the body and scalp, injections and tablets. The type of hydrocortisone you use will depend on your health problem.
- Skin: It works by calming down your body’s immune response to reduce pain, itching and swelling (inflammation).
-You may take hydrocortisone tablets if your body does not make enough cortisol – for example if you have Addison’s disease, or if you’ve had your adrenal glands taken out.
The tablets can also be prescribed for hypopituitarism, a rare condition affecting the pituitary gland.
- Hydrocortisone injections are used to treat swollen and painful joints in people with injuries and arthritis. They help to reduce pain and swelling (inflammation).
Describe Adrenaline? epinephrine ?
-inside epipens
- When injected, adrenaline rapidly reverses the effects of anaphylaxis by reducing throat swelling, opening the airways, and maintaining heart function and blood pressure.
Describe the scalp ?
- The scalp consists of the skin and subcutaneous tissue covering the neurocranium.
-It consists of five (5) layers from superficial to deep, namely (SCALP):
-skin
- dense connective tissue
-the epicranial aponeurosis
-loose connective tissue
- pericranium.
The scalp is highly vascular and is supplied by branches of both the internal and external carotid arteries. These branches anastomose freely with each other.
Describe the muscles of facial expression ?
MUSCLES OF FACIAL EXPRESSION:
-The muscles of facial expression are derived embryologically from the second pharyngeal arch (and
therefore supplied by its nerve – facial nerve, the seventh cranial nerve).
-These muscles are functionally
divided into groups that guard/control the main orifices of the face (orbit, nose, mouth).
-Each orifice has a sphincter, an opposing dilator, elevator, and depressor arrangement of muscles.
-The primary function of these muscles is to control the respective orifices, and facial expression is only a secondary effect of this control.
Orbicularis oculi: sphincter
Ocipitofrontalis and levator palpebrae superiors which are dilators/elevators
- Occipitofrontalis is a long and wide muscle of the scalp, spanning from the eyebrows to the superior nuchal lines of occipital bones
Muscles of the nostrils ?
- sphincter – compressor naris
- dilators/elevators – dilator naris, levator labii superioris alaeque nasi (near the eye to the top of the mouth), depressor septi
Muscles of the lips and cheeks ?
-sphincter – orbicularis oris
- dilators – levator labii superioris alaeque nasi, levator labii superioris (goes all the way from the near the eye to the top of the mouth), levator anguli oris,
zygomaticus major and minor, risorius, depressor anguli oris, depressor labii inferioris,
buccinator and mentalis.
Note that buccinator (Latin for trumpeter) is an accessory muscle of mastication as it returns food material
from the vestibule of the mouth (the cheek pouch) to between the teeth for chewing.
The INFRATEMPORAL FOSSA
The infratemporal fossa is an irregularly shaped three-dimensional space lying deep to the ramus of the
mandible. It contains the pterygoid muscles, and nerves to the mandibular teeth and tongue pass through
this clinically important region.
Identify the boundaries of the infratemporal fossa:
-laterally, the mandibular ramus
-medially, the lateral pterygoid plate
-anteriorly, the maxilla
-posteriorly, the tympanic plate, and the mastoid and styloid processes of the temporal bone
Identify the following contents of the infratemporal fossa
-the lateral and medial pterygoid muscles
-the maxillary artery
-the inferior alveolar and lingual nerve
The INFRATEMPORAL FOSSA
The infratemporal fossa is an irregularly shaped three-dimensional space lying deep to the ramus of the
mandible. It contains the pterygoid muscles, and nerves to the mandibular teeth and tongue pass through
this clinically important region.
Identify the boundaries of the infratemporal fossa:
-laterally, the mandibular ramus
-medially, the lateral pterygoid plate
-anteriorly, the maxilla
-posteriorly, the tympanic plate, and the mastoid and styloid processes of the temporal bone
Identify the following contents of the infratemporal fossa
-the lateral and medial pterygoid muscles
-the maxillary artery
-the inferior alveolar and lingual nerve
- The Lingual nerve (LN) is a branch of the mandibular division of the trigeminal nerve (V3) that is responsible for general somatic afferent (sensory) innervation.
The INFRATEMPORAL FOSSA
The infratemporal fossa is an irregularly shaped three-dimensional space lying deep to the ramus of the
mandible. It contains the pterygoid muscles, and nerves to the mandibular teeth and tongue pass through
this clinically important region.
Identify the boundaries of the infratemporal fossa:
-laterally, the mandibular ramus
-medially, the lateral pterygoid plate
-anteriorly, the maxilla
-posteriorly, the tympanic plate, and the mastoid and styloid processes of the temporal bone
Identify the following contents of the infratemporal fossa
-the lateral and medial pterygoid muscles
-the maxillary artery
-the inferior alveolar and lingual nerve
The INFRATEMPORAL FOSSA
The infratemporal fossa is an irregularly shaped three-dimensional space lying deep to the ramus of the
mandible. It contains the pterygoid muscles, and nerves to the mandibular teeth and tongue pass through
this clinically important region.
Identify the boundaries of the infratemporal fossa:
-laterally, the mandibular ramus
-medially, the lateral pterygoid plate
-anteriorly, the maxilla
-posteriorly, the tympanic plate, and the mastoid and styloid processes of the temporal bone
Identify the following contents of the infratemporal fossa
-the lateral and medial pterygoid muscles
-the maxillary artery
-the inferior alveolar and lingual nerve
Neurovascularture of the head and neck
-The head and neck are supplied with arterial blood via the common carotid arteries and branches of the
subclavian arteries.
- The cranial cavity and brain receive their blood supply via the internal carotid and
vertebral arteries while the external carotid arteries supply the face and upper neck.
-The veins draining the corresponding areas supplied by the arteries bear similar names to the arteries. All
these veins ultimately drain into the internal jugular vein. The internal jugular vein lies lateral to the
common carotid artery in the neck. The vagus nerve can be found lying posterior to these vascular
structures. All three of these structures (artery, vein, nerve) are enclosed within the carotid sheath.
-The hypoglossal nerve, the 12th cranial nerve, can be seen crossing lateral to the external carotid
artery (just superior to the carotid bifurcation) towards the tongue which it supplies with motor
fibres.
Neurovascularture of the head and neck
Identify the following structures:
-vertebral artery
-common carotid artery
- internal carotid artery
external carotid artery
- maxillary artery
-internal jugular vein
-hypoglossal nerve
- vagus nerve
-superior thyroid artery
-lingual artery
-facial artery
-superficial temporal artery
Neurovascularture of the head and neck
Identify the following structures:
-vertebral artery
-common carotid artery
-internal carotid artery
-external carotid artery
-maxillary artery
- internal jugular vein
-hypoglossal nerve
-vagus nerve
- superior thyroid artery
-lingual artery
- facial artery
-superficial temporal artery
Carotid sheath
The carotid sheath is an important landmark in head and neck anatomy and contains several vital neurovascular structures, including the carotid artery, jugular vein, vagus nerve, and sympathetic plexus. It extends upwards from the arch of the aorta and terminates at the skull base.
The carotid sheath is a condensation of the deep cervical fascia that surrounds the main neurovascular structures of the neck: the common and internal carotid artery, the internal jugular vein, and the vagus nerve (CN X).
Infratemporal fossa ?
Maxillary artery ?
- Branches off the external carotid.
- goes through the infratemporal fossa
- then into the pterygopalatine fossa
External jugular vein
- The external jugular vein crosses superiorly across the sternocleidomastoid
Hypoglossal nerve
- How you know its hypogglossal nerve: crosses internal and external common carotid laterally
Carotid sheath contents
Common carotid, azygous nerve, internal jugular vein
Internal and external carotid
Omohyoid muscle crosses over the structures in the carotid sheath
Facial artery
-Crosses the top of the of the submandibular gland to the masetter
Superficial temporal artery
Another branch of the external carotid
It goes behind the muscles and arises at the top of the zygomatic arch
Zygomatic bone and zygomatic arch
What are Myeloproliferative neoplasms ?
- Myeloproliferative neoplasms are a group of diseases in which the bone marrow makes too many red blood cells, white blood cells, or platelets. ALSO KNOWN AS BLOOD CANCER
There are 6 types of chronic myeloproliferative neoplasms:
1. Chronic myelogenous leukemia.
2. Polycythemia vera.
3. Primary myelofibrosis (also called chronic idiopathic myelofibrosis).
4.Essential thrombocythemia.
5.Chronic neutrophilic leukemia.
6. Chronic eosinophilic leukemia
Infratemporal fossa
The infratemporal fossa is the area behind the ramus which has been cut out so we can see inside the infratemporal fossa.
- The ramus of the mandible makes up the lateral wall of the infratemporal fossa.
- The back wall is the lateral pterygoid plate which is part of the sphenoid bone
- Maxillary artery is heading towards the pterygoid fossa of the skull
- The masseter muscle lies on top of it
Structures in infratemporal fossa
- Maxillary artery
- Medial pterygoid muscle
- Lateral pterygoid muscle
- Lingual nerve
- Inferior alveolar nerve (runs through the mandibular foramen to supply the teeth )
Depressor anguli oris
Branches of the external carotid artery ?
The major ECA branches are:
- the superior thyroid
-ascending pharyngeal
- lingual
- facial
- occipital
- posterior auricular
- superficial temporal
- maxillary arteries
Some Anatomists Like Freaking Out Poor Medical Students
Describe polycythemia vera ?
Also known as erythrocytosis.
Primary polycythemia is too much red blood cell. Its caused by genetic mutation. An example of polycythemia is polycythemia vera which is caused by a mutation in JAK2
- PV is rare. It’s usually caused by a change in the JAK2 gene, which causes the bone marrow cells to produce too many red blood cells.
The affected bone marrow cells can also develop into other cells found in the blood, which means that people with PV may also have abnormally high numbers of both platelets and white bloods cells.
Although caused by a genetic change, PV isn’t usually inherited. Most cases develop later in life. The average age at diagnosis is 60.
- Secondary polycythaemia is where an underlying condition causes more erythropoietin to be produced. This is a hormone produced by the kidneys that stimulates the bone marrow cells to produce red blood cells.
Health conditions that can cause secondary polycythaemia include:
chronic obstructive pulmonary disease (COPD) and sleep apnoea – these can cause an increase in erythropoietin, due to not enough oxygen reaching the body’s tissues
a problem with the kidneys – such as a kidney tumour or narrowing of the arteries supplying blood to the kidneys
-Relative polycythemia is an elevated hematocrit marked with a normal to high normal RBC mass and low normal to decreased plasma volume.[15] In spite of the absence of true erythrocytosis, patients with relative polycythemia are at a higher risk for thromboembolic complications
Describe Essential thrombocythemia ?
Essential thrombocythemia: Is a rare blood disease in which the bone marrow produces too little platelets.
- Primary myelofibrosis (also called chronic idiopathic myelofibrosis).
- Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis.
Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising.
Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain.
JAK 2 gene
What are hypersensitivity reactions ?
-Hypersensitivity reactions are an overreaction of the immune system to an antigen which would not normally trigger an immune response. The antigen may be something which would in most people be ignored – peanuts, for example, or it may originate from the body. In either case, the damage and clinical symptoms result from the body’s response to the substance rather than damage caused by the substance itself.
- The vulnerability of an individual to these reactions can have a genetic link. Overreaction to innocuous antigens are linked to changes in the CD regions of T-helper cell membranes, explaining why reactions like peanut allergies can commonly run in families. Overreaction to self-antigens is normally due to a failure in central tolerance, and this failure can also have genetically-inheritable features.
What happens when you are first exposed to a potential allergen ?
- As is the case for many immune reactions, hypersensitivity reactions require two separate interactions of the immune system with the antigen. The first time an antigen enters the body, it is picked up by antigen-presenting cells (such as macrophages or dendritic cells) and taken to the nearest lymph node, where it is presented to naïve T-cells. Cross-linking of the antigen with T-cells, as well as co-stimulatory molecules, can lead to activation of that T-cell and subsequent differentiation into “primed” Th1, Th2, or Th17 cells, which are specific to that antigen and can stimulate further immune responses if they meet the antigen again. It is this second meeting that could result in a hypersensitivity reaction.
What happens when you are first exposed to a potential allergen ?
- As is the case for many immune reactions, hypersensitivity reactions require two separate interactions of the immune system with the antigen. The first time an antigen enters the body, it is picked up by antigen-presenting cells (such as macrophages or dendritic cells) and taken to the nearest lymph node, where it is presented to naïve T-cells. Cross-linking of the antigen with T-cells, as well as co-stimulatory molecules, can lead to activation of that T-cell and subsequent differentiation into “primed” Th1, Th2, or Th17 cells, which are specific to that antigen and can stimulate further immune responses if they meet the antigen again. It is this second meeting that could result in a hypersensitivity reaction.
What are the different types of hypersensitivity reactions ?
- Type 1 (immediate) hypersensitivity
- Type 2 ( cell bound antigens)
- Type 3 ( immune complex disease)
- Type 4 (delayed) hypersensitivity
Describe Type 1 hypersensitivity reactions ?
- In Type 1 hypersensitivity reactions mast-cell activation is induced by secretion of IgE antibodies.
- Initial exposure to the antigen causes the priming of Th2 cells, and their release of IL-4 causes the B cells to switch their production of IgM to IgE antibodies which are antigen-specific. The IgE antibodies bind to mast cells and basophils, sensitising them to the antigen.
- When the antigen enters the body again, it cross links the IgE bound to the sensitised cells, causing the release of preformed mediators including histamine, leukotrienes and prostaglandins. This leads to widespread vasodilation, bronchoconstriction, and increased permeability of vascular endothelium.
- The reaction can be divided into two stages – immediate, in which release of pre-formed mediators causes the immune response, and the late-phase response 8-12 hours later, where cytokines released in the immediate stage activate basophils, eosinophils, and neutrophils even though the antigen is no longer present
- Allergic rhinitis is where an allergy to something like pollen, dust or mould irritates your nose and causes cold-like symptoms.
Symptoms of allergic rhinitis include sneezing, itchiness and a blocked or runny nose.
Examples of type 1 hypersensitivity reactions ?
- Allergic rhinitis
- Asthma
- systemic anaphylaxis
Consequences of type 1 hypersensitivity reactions ?
What are allergens ?
Atopy refers to the genetic tendency to develop allergic diseases such as allergic rhinitis, asthma and atopic dermatitis (eczema).
- Atopic eczema is a common skin condition that causes patches of skin that are itchy, cracked and sore.
IgE and mast cells
Immediate and late reaction ?