nerves and vessels Flashcards
Label these major vessels
How is the nervous system divided
how are lymphatic vessels organised within the body
what do arteries and arterioles do
Deliver oxygen-rich blood and nutrients from heart to organs and tissues except pulmonary arteries which carry deoxygenated blood
which is the true anaotomical end arteries
centeral retinal artery
why is the central retinal artery the true anatomical end artery
no anastomosis
what is anastomosis
connection between two blood vessels
what are functional end arteries and why are they not true anatomical end arteries
coronary arteries but they have anastomosis
what do venules and veins do
take deoxygenated blood back to heart except pulmonary veins which carry oxygenated blood
what do capillaries do
Exchange of gases and transfer of nutrients between blood and tissues and Link arterioles to venules
what are the two atrioventricular valves
tricuspid and bicuspid valves
what are atrioventricular valves
separate atria from ventricles
what is the tricuspid valve
- three cusps that. tether valve to papilary muscle
- prevents blood backflow into right atrium
what is the bicuspid valve
- two cusps- anterior and prosterior leaflet
- have chordae tendineae
- prevents backflow into the left atrium
what are semilunar valves
where major arteries leave ventricles
what are the 2 semilunar valves
pulmonary and aortic
what is the pulmonary valve
- three half mooon shaped cusps
- prevents blood backlfow into right ventricle
what is the aortic valve
three cusps
prevent backflow into the left ventricle
how does blood flow through the body
- Deoxygenated blood enters right side of heart via superior, inferior vena cava (veins) → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk → pulmonary arteries → pulmonary arterioles → pulmonary capillaries → alveoli
- Oxygenated blood travels through pulmonary venules → pulmonary veins → left atrium → bicuspid/mitral valve → left ventricle → aortic valve → aorta → organs, tissues
- Deoxygenated blood returns to heart
what is is pressure like in systemic circulation
low
what happens in systemic circulation
right side of heart pumps deoxygenated blood through pulmonary circulation to collect oxygen
what is the flow of blood in systemic circulation
right atrium → right ventricle → pulmonary arteries → lungs
what is the pressure like in pulmonary circulation
high
what happens during pulmonary circulation
left side of heart pumps oxygenated blood to systemic circulation
what is the flow of blood during pulmonary circulation
pulmonary veins → left atrium → left ventricle → aorta → body
label this neurone
what is the role of a neurone
responsible for transmitting signals as electrical or chemical signals
what is the function of the cell body of a neurone
Holds nucleus. It is the site of protein synthesis, which occurs on small granules of rough endoplasmic reticulum
what happens when neuronal cell bodies group together in the CNS
its called a nucleus
what is a ganglion
when many neuronal cell bodies group together in the PNS
what are dendrites
elongated portions of the cell body. They extend outwards, receiving input from the environment and from other neurones. these processes originate from the soma and extend outwards
what are the functions of dendrites
They transmit signals received from other neurones to the soma.
what is an axon
The axon isa long, thin structure down which action potentials (the nerve impulse) areconducted. Whilst neurones have many dendrites, most cells only have one axon.
what is the mylein sheath made out of in the CNS
oligodendorcytes
t is the myelin sheath made out of in the PNS
schwann cells
what are nodes of ranvier
gaps in between the mylein sheath
what are features of axon terminals
where neurone sens chemical signals
many mitochondria
what are the layers of connective tissues within the axon
- Endoneurium– Surrounds the axon of an individual neurone.
- Perineurium– Surrounds a fascicle, which is a collection of neurones.
- Epineurium– Surrounds the entire nerve, which is formed by a collection of fascicles.
what is a unipolar neurone
the cell body is at one end of a single unbranched axon, and there are no dendrites.
the pseudounipolar neurone
They have one axon which is divided into two branches by the presence of the cell body. Sensory neurones are all pseudounipolar.
wat are bipolar neuroes
These neurones have two processes arising from a central cell body – typically one axon and one dendrite.
what are multipolar neurones
They have one axon and many dendrites, with a cell body displaced to one side of the axon. Motor neurones are a prime example of this.
what are the 3 functional classifications of nerves
sensory
motor
relay
what are sensory nerves
found in the PNS
small axons
psuedounipolar
what are motor nerves
large axons
multipolar
found in the pNS
what are relay nerves
central cell body
many dendrites
found in. theCNS
what are the 3 types of glial cells
astrocytes
oligodendrocytes
microglia
what are astrocystes
star-shaped glial cells in the brain and spinal chord
what is the functions of astrocytes
metabolic support- store glycogen
regulation of ionic environment- remove excess K+
neurotransmitter uptake
modulation of synaptic transmission- release ATP
promotion of myelination
what is the function of oligodendrocytes
insulate axons in the CNS
what do microglia do
These cells form theresident immune systemof the brain. They are activated in response to tissue damage and have the capability to recognise foreign antigens and initiate phagocytosis to remove foreign material.
what is a synapse
a gap that is present between two neurones
what is neurotransmission
Neurotransmission starts with the release of a readily available neurotransmitter from the presynaptic neurone, followed by its diffusion and binding to the postsynaptic receptors. Then the postsynaptic cell responds appropriately, whereas neurotransmitter is removed or deactivated to allow the entire cycle to occur again.
what does the somatic nervous system of the PNS do
is responsible for voluntary, conscious control of skeletal muscles (effector organ).
what does the autonomic nervous system of PNS do
The autonomic (visceral) nervous system control the visceral functions of the body and acts largely unconsciously.
The efferent arm of this system can be further subdivided into the parasympathetic (PSNS) and sympathetic (SNS) components, which control numerous smooth muscles and glands
what is the spinal cord
Thespinal cordis a tubular bundle of nervous tissue and supporting cells that extends from the brainstem to the lumbar vertebrae
what is a dermatome
An individual area of skin innervated by a single spinal nerve [primary ramus]; this being the area of skin responsible for sensory input to the dorsal root.
what is a myotome
An individual set of muscles innervated by a single spinal nerve [primary ramus]
Outline the basic mechanism of referred pain
The referred pain occurs because of multiple primary sensory neurons converging on a single ascending tract. When the painful stimuli arise in visceral receptors the brain is unable to distinguish visceral signals from the more common signals that arise from somatic receptors.
what is the role of the lymphatic system
It protects the body from invaders, maintains the fluid level in the body, and absorbs dietary fat from the intestine
It collects fluid lost from capillary beds and returns it back to the venous system
pathogens are trapped in lymphatic system
what are features of the lymphatic system
it is not a closed system
no pump like the heart
thin walls and low pressure
larger lymphatic vessels have valves to prevent backflow
what are the components of the lymphatic system
- lymph
- lymphocytes
- lymphatic vessels
- lymph nodes
- red bone marrow
- thymus gland
- spleen
- lymph nodules
- tonsils
- lymphatic fluid
what are lymphatic vessels
they are porous blind ended capillaries that converge to become larger vessels. they then drain into large veins at the root of the neck at the venous angle.
lymph vessels pass through lymph nodes which act as a filter
what are lymphatic capillaries
are endothelial tubes with small valves. there are more valves compared to veins however are thinner than veins. the larger lymphatic vessels have three layers: tunica intima, media and adventitia
what are lymph nodes
- secondary lymphatic organ
- all lymph passes through
- afferent to node
- efferent away
- filters that trap phagocytose matter
- detect and defend from foreign antigens
what is red bone marrow
- primary lymphatic organ
- site of T and B cell differentiation and B cell maturation
- active tissue that creates RBC (hemopoiesis)
- contains specialised blood vessels (sinusoids) where new cells are released
- yellow bone marrow: no hemopoiesis, consists of mainly fat cells
what is the thymus gland
primary lymphatic organ in the thorax
site of t cell maturation
what is the spleen
- secondary lymphatic organ
- largest lymphatic organ
- the white pulp is the lymphatic tissue
- the red pulp is erythrocytes, macrophages and immune cells
- it filters blood, reacts to blood borne antigens, removes old and defective erythrocytes and recycles iron from degraded haemoglobin
what is lymphatic fluid
- mostly clear
- comes from tissue in capillary bed
- contains WBC
- high protein conc
what is chyle
- special type of lymphatic fluid
- contains fats from intestinal absorption
- found in small intestine
- fluid is milky and opaque due to large chain fatty acids coated with protein and surrounded by cholesterol (called chylomicrons)
- lymph capillaries here are called lacteals
what is the cisterna chyli
- the pouch in the abdomen
- drains the abdominal organs, walls, pelvis, perineum and lower limbs
- cisterna chyli → thoracic duct → left subclavian vein
what is the thoracic duct
- largest lymphatic channel
- drains to left subclavian
- originates from cisterna chyli
- ascends from aortic hiatus in diaghram
- many valves- beaded appearance
where is the left/right bronchomedisastinal trunk
- lung
- bronchi
- mediastinal structures
- thoracic wall
where is the left/right subclivain trunk
upper limb
superficial regions of thoracic and abdominal wall
where is the left and right jugular trunk
head and neck
what are lymph node chains
- stay in clusters, connected by chains of lymph vessels
- primary nodes are the first node or group within a chain
- terminal nodes are the last nodes
- sentinel nodes are the first lymph node draining a cancer
what is the strucutre of a lymph node
- hilum which has blood vessels. efferent lymphatic
- afferent lymphatic penetrate the convex side and drain into the subcapsular and medullary sinus
what is a lymphoid follicle
- contain germinal centre
- separated by trabecular sinus
- contain: b cells, macrophages, t cells and plasma cells
what are features of superficial lymphatic vessels
- more numerous than veins in the subcutaneous tissue
- converge towards and follow venous drainage
- eventually drain into deep lymphatic vessels
what are features of superficial lymphatic nodes
- superficial to deep fascia
- associated with superficial veins
- drain to deep nodes
what are features of deep lymphatic vessels
accompany arteries
receive damage from internal organs
what are features of deep lymphatic nodes
- closely located to vasculature and organs
- name taken from neighboring structures
what are lymphatic nodules
- masses of lymphocytes and macrophages
- guard against pathogenic substances
- site for initial immune response
- Congregate in response to pathogens or are permanent
what is lymphoedema
- blockage or damage causes swelling in limbs
- caused from: trauma, coincidental surgical injury, deliberate surgical removal e.g. cancer, infection, radiation therapy.
what is lymphadenopathy
- swelling of lymph nodes
- caused by infection, skin wounds, metastases, primary malignancy
- infection of nodes: lymphadenitis
- infection of vessels: lymphangitis
what are the 3 major branches of the aortic arch
- Brachiocephalic artery– supplying the right side of the head & neck and the right upper limb.
- Left Common carotid artery– to the left side of the head & neck.
- Left Subclavian artery– to the left upper limb.
what are 4 structures in the superior vena cava
brachiocephalic veins
left superior intercotal vein
supreme intercostal vein
azygous vein
what does the brachiocephalic vein do
drain blood from the upper body
what does the left superior intercostal vein do
collectsblood from the left 2nd and 3rd intercostal vein. It drains into the left brachiocephalic vein.
what does the supreme intercostal vein do
drains the vein from first intercostal space directly into the brachiocephalic veins.
what does the azygos vein do
receiving blood from the right posterior intercostal veins. The left intercostal veins drain first into the hemiazygos and accessory hemiazygos veins before joining the azygos vein around T7-T9.
where is the vagus nerve
superior mediastinum
where is the vagus nerve
superior mediastinum
what are the two paths of the vagus neves
right and left
where is the right vagus nerve
runs parallel to the trachea and passes posteriorly to the superior vena cava and the right primary bronchus.
where is the left vagus nerve
enters the superior mediastinum between the left common carotid and the left subclavian arteries. It descends anteriorly to the aortic arch, before travellingposterior tothe leftbronchus.
what are features of cardiac nevres
originate from the superior, middle and inferior cardiac ganglion and form thesuperficial and deep cardiac plexusesin the superior mediastinum. The superior plexus sits between the aortic arch and right pulmonary artery. The deep plexus lies on the surface of the trachea at the point of bifurcation.
what are hemiazygos veins
It enters the mediastinum through the left crus of the diaphragm, ascending on the left side. At the level of T8, it turns to the right and combines withthe azygos vein
