Body Logistics ESA 1 Flashcards
(163 cards)
1
Q
What does one find in artery walls that is absent from veins?
A
2 elastic lamina:
Internal elastic lamina (just outside Tunica intima)
External elastic lamina (just outside of tunica media)
2
Q
What are the layers of an artery wall?
A
Tunica Intima: Edothelium, subendothelium
-Internal elastic lamina-
Tunica media
-external elastic lamina-
Tunica adventitia: cont. vasa vasorum, nerves and lymphatics
3
Q
What are capacitance vessels, and which are they?
A
Capacitance vessels means that the volume they hold can increase without the internal pressure increasing. (very lax)
It is the case of Veins.
Capacitance is inversely proportionate to elasticity. Indeed, an elastic wall will increase the pressure when volume increases as it will be wanting to pull back.
4
Q
Which type of vessels are said to be conducting?
A
large, elastic arteries
5
Q
Which tyoe of vessels are said to be distributing?
A
Medium, muscular arteries
6
Q
Which vessels are said to be resistance vessels:
A
arterioles and metaarterioles (as they can contract or dilute changing blood flow)
7
Q
Which type of vessels are said to be exchange vessels?
A
capillaries
8
Q
Which vessels are said to be capacitators?
A
Large and medium veins
9
Q
What is the humoral immune response mediated by?
A
Antibodies produced by effector B cells (called plasmocytes once they start producing antibodies)
10
Q
What is the cell-mediated immune response?
A
It is mediated by cytotoxic T cells.
11
Q
T cells are more likely to defend us from a pathogen that had infected inside a cell or outside?
A
Inside (ie. viruses etc.)
12
Q
What does ipsilateral mean?
A
on the same side
13
Q
What does contralateral mean?
A
on opposite sides
14
Q
What movements occur in the sagittal plane?
A
flexion/extension
15
Q
Which movements occur in the coronal plane?
A
Adduction/abduction
16
Q
What is circumduction?
A
It is a combination of flexion, extension, adduction and abduction.
17
Q
What are pronation and suppination?
A
Suppination = palms facing upwards (ie to hold soup) Pronation = palms facing down
18
Q
What is osteomalacia? Cause, symptoms,
A
Osteomalacia is loss of MINERAL BONE. The lack of mineralisation is caused by vitamin D deficiency (affecting collagen structure)
- symptoms: pain, tiredness, weakness
- who is most at risk? darker skinned individuals
19
Q
What is osteoporosis? Cause, symptoms, who is affected most
A
Osteoporosis is a lack of total bone resulting from more degradatin than deposition of bone. (ie osteoclasts are more active than osteoblasts)
- cause: low oestrogen levels increase OC activity, elderly people have lower osteoblast activity.
- symptoms: none, but will be more susceptible to ractures
20
Q
What is osteoarthritis?
A
Osteoarthritis is a degenerative joint disease.
- loss of cartilage, so narrowed joint space
- bone remodelling occurs leading to bony spurs
- inflammation
- symptoms: pain and swelling are worse post-activity, ROM is decreased
21
Q
What is Rhumatoid arthritis?
A
Rhumatoid arthritis is an autoimmune disease in which antibodies are directed against the synovial membrane, thus causing inflammation.
- Symptoms: red, hot, pain, swelling, loss of function
22
Q
What is Pethes disease?
A
It is a chilhood hip disorder caused by avascular necrosis of the head of the femur.
- Cause: insufficient blood supply to the growth plate causes bone to soften and break down
- Symptoms: hip and groin pain + limp
23
Q
What is SCFE (bone associated disease)?
A
SCFE is
- slipped capital femoral epiphysis
- a hip affecting adolescent disease
- causes: minor trauma, inflammation, radiation
- symptoms: hip pain, abnormal gait
- who? adolescents
24
Q
What is osteogenesis imperfecta?
A
It is a autosomal dominant disease affecting collagen Type I.
- symptoms: frequent fractures, blue sclerae
25
Name 6 functions of the liver, and an example of each.
- Anabolism: plasma protein synthesis, foetal haematopoiesis
- Catabolism/detox: drugs, hormones (oestrogen, progesterone, insulin, glucagon), haemoglobin
- Storage: vitamins A,B12,D,K; iron, Glycogen
- Filtering: Kupffer cells! they are specialised macrophages that look after RBC degradation.
- Exocrine: bile
- Endocrine: Angiotensinogen, thrombopoietin, IGF1, (+ modifies to activate Vitamin C, thyroxine)
26
What is the first reaction of the body to an antigen? What cells is this mediated by?
An inflammatory response. it is an innate, non-specific response.
This response is mediated essentially by macrophages and neutrophiles.
27
What is the major difference between a neutrophile and a macrophage?
Neutrophils DIE after pathogen ingestion. (ie pus!)
| Dont die afetr ingestion, they can ingest and ingest again.
28
Inn which situation do NK cells act, and what do they do?
NK cells killo ur own cells if they are infected by a virus or are cancerous. They trigger apoptosis.
29
What do mast cells secrete, and what does this substance do?
Mast cells secrete Histamine.
| - Histamine increases vasopermeability and vasodilation
30
What is fever mediated by?
Pyrogen chemicals that are released by the hypothalamus mediate fever.
31
Where are T cells made and where do they mature?
T cells are made in the bon marrow and mature im the thymus
32
Where are B cells made and where do they mature?
B cells are made in the bone marrow and mature in the bone marrow.
33
What are pericytes and where can they be found?
They are found in the basement membrane of capillaries and the can differentiate into muscle cells, or fibroblasts.
34
3 roles of bile
1. Emulsify fats
2. Neutralise acidic pH of the stomach contents
3. Give stool its colour
35
4 roles of colon bacteria
1. Physical barrier to infection
2. Competition against pathogenic bacteria
3. Help with polysaccharide digestion
4. Metabolism, they help produce Vitamin K! (and certain NTs)
36
5 ways the colonic wall is protected against invasion?
1. IgAs
2. Mucus
3. Tight junctions
4. ++ cell turnover
5. ++ lymphoid tissue (Peyers patches in ileum but also other places)
37
what sort of muscle has no myoglobin?
smooth muscle!
38
which muscle types are striated? and why are they striated?
Skeletal and cardiac, the strations come from the sarcomeres
39
What are the types of regeneration that occur in each miscle tyoe?
1. Skeletal muscle: no regenration as such, but satellite cells can
2. Cardiac Muscle: no regenration at all. If damage, fibroblasts lay diwn scar tissue.
3. Smooth muscle: mitotic activity for regeneration
40
Which muscle type had intercalated disks?
Cardiac muscle does, and it takes the place of Z bands that are seen in skeletal muscle.
41
Which muscle types have T tubules, and how do they differ in structure and position between muscle types?
Skeletal muscle has T-tubules, they form a triad as either side they have sarcoplasmic reticulum. They are positionned at the junction overlap of A and I bands of the sarcomere.
Cardiac muscle also had t-tubules but they form diads. only one side has sarcoplasmic reticulum cisternae close by. They are positionned at the Z line.
42
how many cell types does hyaline cartilage have?
1, chondrocytes, either in isogenous groups or single
43
How many tyoes does elastic cartilage have?
1, chondrocytes
44
How many cells tyoes does fibrous cartilage have?
2, chondrocytes and fibroblasts
45
Which cartilage types have pericondrium?
hyaline and elastic
46
what are the functions of hyaline cartilage?
resistance to pressure loads, and provide a model for endochondral ossification
47
examples of hyaline cartilage
articular surfaces
| epiphyseal plates
48
Function of elastic cartilage
Resilience and elasticity
49
what are the functions of fibrous cartilage
shock absorbtion and resistance to shearing forces
50
examples of elastic cartilage
pinna of the ear
epiglottis
auditory meatus
eustachian tube
51
examples of fibrous cartilage
```
menisci
pubic symphysis
intervertebral disks
sternoclavicular joint
temporomandibular joint
```
52
what are the characteristics of haematoxylin staining?
stains dark blue, especially strongly the nuclei
53
what are the characteristics of eosin staining
it stains pink, especially strongly extracellular matrix, but difficult to see nuclei
54
what are the benefits of H and E staining?
Gives dark purple staining, with nuclei obvious.
55
What is gout? Cause, symptoms, commonly affected sites, type and shape of deposits
Gout is an attack of inflammatory arthritis.
- cause: elevated uric acid in the blood which will cristalise and cristals deposit in joints, tendons and surrounding tissues
- why can urate be elevated? underexcretion of urate 90% cases (or overproduction)
- red, hot, tender, swollen
- pain onset very sudden, <12hrs
- affects BIG TOE
- what are the cristals made of? monosodium urate, they are needle shaped
- goutnis very responsive to NSAIDS, to such an extent that they can confirm diagnosis
- alcohol agravates gout
- crystals show up yellow when parallel to polarised light microscopy compensator rays
56
What are the cristal deposits in gout made of?
monosodium urate
57
what joint does gout most commonly affect?
big toe
58
what joint does pseudogout most commonly affect?
Knee
59
What are pseudogout cristals made of.
Calcium pyrophosphate
60
What shape are the cristals in pseudogout?
rod, or rhomboid shape
61
what shaoe are the cristals in gout?
needle, or spindle shaped
62
What does confocal kicroscopy enable the visualisation of?
live specimen
63
Parasympathetic and sympathetic systems are subdivisions of the...
Autonomic nervous system
64
the central nervous system had 2 components, these are:
brain + spinal cord
65
What doe the somatic nervous system look after?
Conscious, volountary perception and movement
66
the brain can be subdivided into 3 functional parts, which are these and what do they do?
1. Cerebral hemispheres: for complex activities
2. Brainstem: regulation of heart rate, respiratory rate, sleep
3. Cerebellum: motor control: juggling, coordination
67
what is the equivalent of a PNS ganglion in the CNS?
A nucleus
68
What is the equivalent of a PNS nerve in the CNS?
Tracts
69
a spinal nerve has 2 components, what are they?
1 dorsal root
1 ventral root
(each root is a collection of rootlets)
70
What sort of infomation do dorsal roots vehicle?
sensory axons
71
What sort of information do ventral roots vehicle?
Motor axons
72
what is the grey matter composed of, and what function occur here?
The grey matter = neurones
| It is in the grey matter that PROCESSING takes place
73
How many pairs of nerves emerge from the spinal cord?
30 PAIRS
74
What are ganglions PNS and nuclei CNS?
they are collections of cell bodies
75
What are tracts CNS?
The are bundles of nerve fibres
76
Where is the grey matter positionned in the spinal cord?
centrally (butterfly shape)
77
Which of dorsal or ventral roots have ganglia? What does this imply?
Dorsal roots have ganglia.
These ganglia contain the cell bodies of the afferent sensory neurons. Indeed these sensory neurons are PSEUDOUNIPOLAR, meaninqg that the infomration does not have to pass through the cell body before arriving in the dorsal horn = faster
78
What is a pseudo-unipolar neuron and where can we find them?
These are neurons where the infomration can bypas the cell hody, making information travel faster. Only 1 process leaves the cell body.
These types of neurons are fout in dorsal roots, they are the sensory afferent neurones.
79
What are interneurones and where can we find them?
Interneurones conenct sensory neurones to motor neurones, responsible for complex processing of this information.
We can find them EXCLUSIVELY in the CNS.
80
Axons arrange in bundles, what name do these bundles have and what surrounds them?
Bundles of axons are called fascicles.
| Each fascicles is surrounded by perineurium
81
Axons arrange in bundles, but what surrounds each fibre in the bundle?
endoneurium
82
axins arrange in bundles, and bundles arrange in fascicles, but what surrounds these fascicles?
epineurium
83
Why do some motor neurons have to be very long?
because they go all the way from the spinal cord to the muscle. so if its a muscle in thenfoot, the axon will need to be very long.
84
3 types of glial cells of the CNS?
- Oligodendrocytes (myelinate many axons)
- Astrocytes (form blood brain barrier, they send out orocesses to capillaries and stimulate the endothelial cells to make tight junctions between them. They are also CNS vacuum cleaners as they collect NTs that are diffusing out of the synaptic cleft)
- Microglia: extend very fine processes looking for toxins or anything that could cause damage. if activated, focusses all its processes towards the site of toxin and transforms into a mcrophage.
85
What are the equivalent of oligodendrocytes in the CNS?
Schwann cells. but Schwann cells only myelinate 1 single axon.
86
What do oligodendrocytes do?
they myelinate many axons, making transmission faster
87
What do astrocytes do? (2 roles)
Astrocytes contact capillary endothelial cells and stimulate them to make tight junctions. This enables the blood brain barrier to exist.
Astrocytes also act as synaptic cleft vacuum cleaners. indeed, released NTs can diffuse out of the cleft potentially activating other nearby cells. Astrocytes hoover up these excess NTs.
88
What do microglial cells do?
The emit very thin processes around them that search for toxins or other that could cause damage. if they find anything, they concentrate their axins to this site and become macrophages.
89
What are the 4 main cardiac valves, what do they seperate, and how many cusps do they each have?
1. Tricuspide: between rV and rA, 3 cusps
2. Mitral: between lV and lA, 2 cusps
3. Aortic: between lV and aorta, 3 cusps
4. Pulmonary: between rV and pulmonary artery, 3 cusps
90
What is systole?
The contraction phase of the heart
91
What is diastole?
Relaxation and refill phases
92
What is bridging (context: heart)
It is the compression of a coronary artery during systole = narrowing that reverses durin diastole
93
Normal blood distribution in %
65% veins
20% lungs and heart
10% peripheral arteries
5% capillaries
94
What is an anatomical end artery (+ example)?
It is an artery that has no collateral circulation. If it is blocked the tissue will no longer recieve blood at all.
= absolute end
Eg. Central retina artery
95
What is a functional end artery?
It is an artery that does have collateral circulation, but this circulation would not be sufficient in case of artery occlusion for tissue needs.
Eg. renal arteries, coronary arteries, splenic arteries and cerebral arteries
96
Which artery is an anatomical end artery?
Central retinal artery
97
What arteries are examples of functional end arteries?
Renal arteries
Splenic artery
Coronary arteries
Cerebral artery
98
What is the cinduction velocity of the SA node?
0.5 m/sec
99
What is the conduction velocity of the AV node?
0.05 m/sec
100
Why is it important that the AV node's conduction velocity is slower (10x) than the SA node? (2 reasons)
It enables the transmission delay to the ventricules that
1. Allows time for fill atrial depolarisation and emptying into the ventricule
2. Limits the frequency of impulses travelling through AV, thus limiting atrial fibrillation to be transmitted to ventricules.
101
What is the conduction velocity through the L and R bundles branches?
2 m/sec
102
What are Purkinje fibres and what is their conduction velocity?
They connect with ventricular myocytes, ie the last transmission fibers before actual cell to cell conduction. The conduction velocity is 4 m/s.
103
Which vessels are said to be auxillary pumps, and what does this mean?
elastic arteries. This denomination refers to the fact that after each heart beat, these arteries are strethced out by the blood volume, and then between beats, they will squeeze the blood along by the elastic fibres recoiling, enabling the downstream flow to be continuous and not pulsatile.
104
How much fluid to lymphatics drain away for interstitium every day?
3L
105
Hwere do lympathics return liquid to venous blood?
Junction between internal jugular vein and subclavian veins
106
What layers constitute the capillary wall?
Single endothelial layer + basement membrane
107
What are oericytes?
they form a branching contractile network on the outer surface of the endothelium of capillaries and venules and are capable of differenciation into: fibroblasts of muscle cells during angiogenesis, tumour growth and wound healing.
108
Which cells are said to be phagocytes? (3)
1. Neutrophils
2. Macrophages (APCs)
3. B cells (APCs)
109
What 2 pathways can happens after pathogen ingestion by a phagocyte?
1. The phagosome fuses with a lysosome (contains hydrolytic enzymes) and digestion of material occurs.
2. activated phagocytes produce Reactive Oxygen Intermediates ROIs. these ROIs have apotent antimicrobial activity.
110
What is opsonisation?
it is the marking of a pathogen for destruction by a phagocyte.
It involves the binding of an opsonin, IgG or C3b, to a receptor on the pathogen's membrane.
111
What is the complement system?
It is a group of serum proteins that activate
a) Inflammation
b) Cell destroyal
c) Opsonisation
Complement can be activated by different molecules categorised into 2 pathways:
a) Classical pathway: C1 is activated when it bind to an antigen-antibody complex
b) Alternative pathway: C3b is activated when it reacts with antigens (eg. bacterial wall)
112
What are the two pathways of complement activation?
1. Classical pathway, activated when C1 binds to antigen-antibody complex
2. Alternative pathway, actuvated when C3b binds to an antigen.
113
What is the complement's classical pathway?
It is activated by C1 binding to an antigen-antibody complex
114
What is the alternative pathway to complement activation?
Alternative pathway is activated when C3b binds to an antigen-antibody complex.
115
What are the 3 possible outcomes of complement activation? And by which complement "particle" are they mediated?
1. Inflammation - mediated by C3a and C5a
2. Opsonisation - mediated by C3b
3. Membrane attack complex - mediated by C5b and others that form in pathogen membrane.
116
What is oedema?
It is accumulation of watery fluid in the interstitium.
Oedema is pitting.
Oedema can result from heart failure for example.Venous blood dams up because the rV is not coping with venous return. So venous oressure rises, causing outflow into the interstitium.
Odedema is sensitive to diuretics.
117
What is lymphoedema?
Lymphoedema is swelling, especially in subcutaneous tissues, as a result of obstructed lymphatics or lymph nodes. Large amounts of lymph accumulate in interstitium.
The most common cause of lymph oedema is a parasite called filariasis. It is a worm that blocks lymphatics.
Lymphoedema does NOT pit. Indded, fibroblasts lay down pocket forming fibres so fluid cannot move away if you apply pressure to skin.
Lymphoedema does not respond to diuretics.
Lymphoedema is NO BETTER in the morning!
118
Which form of iron is found is the blood?
Ferrous oxide
119
Which form of iron should not be found in the body?
Ferric oxide
120
What pathological process happens to iron if the is severe hypertension?
Capillaries can burst, and ferrous oxide exits the vessel. iron changes ferric oxide, and changes colour.
Its new colour is responsible for skin staining = hemosiderin (found inside cells, never in blood)
Macrophages will get rid of ferric oxide
121
What are the 4 basic tissue types?
1. Connective
2. Muscular
3. Nervous
3. Epithelial
122
What is the neurotransmitter of the somatic system?
Acetylcholine
123
Where do sympathetic presynaptic nerves originate from?
From Thoracic and lumbar levels of the spinal cord
124
Where do parasympathetic presynaptic nerves originate from?
Cranial and sacral levels of the spinal cord
125
Where are sympathetic ganglia located?
Very close to the spinal cord, in a paravertebral chain
126
Where are parasympathetic ganglions located?
Very close to the effector organs
127
What are the sympathetic NTs?
Acetylcholine at gangliar level
| Noradrenaline at effector level
128
What are the parasympathetic NTs?
At gangliar level: ACh
| At effector level: ACh
129
What are the receptor of the sympathetic system?
At gangliar level: nAChr (nicotinic, so ion channel)
| At effector level: acdrenoceptors
130
What are the receptors of the parasympathetic system?
At gangliar level: nAChR (nicotinic, so ion channel)
| At effector level: mAChR (muscarinic, so GPCR)
131
3 types of lateral domain junctions
1. Desmosomes
2. Tight junctions
2. GAP junctions
132
Characteristics of tight junctions, and example
1. Form a seal ie. impenetrable, forcing species through cells as opposed to between them
Eg. intestinal epithelium
133
Characteristics of desmosomes and example
- found on lateral domain
- desmosomes are associated with intermediate filaments that interlock cells
- found near tight junctions that they strengthen
- they are stretch and twist resistant
Eg. skin, its what enables skin to stay intact when rub or scratch
134
Characteristics of GAP junctions and example
- on lateral domain of cells
- enable direct communication of adjacent cells via a "channel"
- channel is formed by 6+6 connexons
Eg. help synchronise myocardial contraction, GAP junctions are found in the intercalated disks
135
2 types of basal domain junctions
1. Hemidesmosomes
| 2. Focal adhesions
136
What are hemidesmosomes?
Hemidesmosomes are a tyle of anchorage junction that links cell to the underlying basement membrane.
- hemidesomsomes are a half desmosome (dont link to other cell, so can only have half.
- associated with intermediate filaments
- found in tissues subject to abrasion, Eg. skin, oral cavity
- involve INTEGRINS
137
What are focal adhesions?
- They are anchorage junctions enabling cells to be attached to the underlying basement membrane
- They anchor ACTIN FILAMENTS to the basement membrane
- They play a big role in cell movement
Eg. cell migration in wound repair
- They involve INTEGRINS
138
What are integrins and in which type of junctions (2) are they involved?
Integrins are transmembrane proteins.
- they function mechanically by attaching the cytoskeleton to the extracellular matrix
- they function biochemically by sensing whether adhesion had occured and signal transduction
- They are involved in Hemidesmosomes and Focal adhesions, noth type of basal domain junctions
139
What are ells that do not have a luminal, free, surface called?
epitheloid
eg. leydig cells of testis, lutein cells of ovary, islets of Langerhaans in the pancreas, parenchyma of the adrenal gland
140
What sort of special covering can the apical domain have?
1. Microvilli - cytoplasmic processes that extend form cell surface and contain actin. ie. form a brushborder increasing surface area but not volume
Eg. intestine, kidney tubules
2. Stereocilia - particulary long non-motile microvilli limited to epididymis and sensory hairs in the ear
3. Cilia - these are motile cytoplasmic processes that contain microtubules. they beat in synchrony with a rapid forward movement called effective stroke and a slower return called recovery stroke.
Eg. tracheobrinchiak tree, oviducts
141
Name the 6 types of connective tissue
```
lymphatic
adipose
cartilage
bone
blood
haematopoietic
```
142
What are the 3 basic components of connective tissue?
1. Ground substance: proteoglycans (ie. core proteins + GAGs)
2. Cells
3. Fibres: collagen, reticular, elastin
143
What are the 3 sorts of fibre that compose the fibrous element of connective tissue?
1. Collagen
2. Reticular
3. Elastin
144
Connective tissue proper (or general) can be on 2 different types...?
1. Loose - many cells, lots of ground substance, sparse collagen
2. Dense - few cells, little ground substance, lots of collagen
145
Dense connective tissue can be subdivided into...
Regular and irregular depedning on whether colagen bundles are arranged in parallel or multiple directions
146
What are the characteristics of dense connective tissue?
Dense connective tissue has
- few cells
- little gorund substance
- lots of collagen
- withstands stress
147
Characteristics of Loose connective tissue, and most common locations
- many cells
- lots of ground substance
- sparse colagen
- important role in transport by diffusiom
- most commonly found under epithelia, associated with the epithelium of glands, around small blood vessels
148
What is hyaluronic acid and in which tissue does it play an important role?
Hyaluronic acid is a special sort of GAG. it binds to proteoglycans by a protein link. They form giant hydrophilic macromolecules. Hyaluronic acid is found in the ground substance of cartilage! It reists compression well by attracting water, without compromising flexibility.
149
Which tyoe of cell secretes the ground substance of connective tissue?
fibroblasts
150
What are mast cells, what do they secrete?
Mast cells' cytoplasm comtanis abundant granules.
These granules contain
- Histamine: increase blood vessel permeability
- Heparin: anticoagulant
These granules are released when IgEs on mast cell surface bind to allergens.
Mast cells are found near blood vessels but are completely absent from CNS to avoid oedema.
151
types of collagen and their caracteristics
1. Type I: 90% of all collagen, fibrils form FIBRES, and FIBRE BUNDLES. Eg. tendons, organ capsules, skin dermis
2. Type II: fibrils do NOT form fibres. Eg. Hyalin and Elastic cartilage
3. Type III: RETICULIN. Fibrils form FIBRES around muscle and nerve cells + more.
4. Type IV: unique form present in basal lamina of basement membrane
152
What is Marfan's syndrome?
Abnormal fibrilin gene (fibrilin is associated with elastin)
Autosomal dominant.
++ tall, arachnodactyly, ++ joint dislocation, at risk of aortic rupture.
153
Where can brown fat be found ni an adult?
Scapular, sternum, axillae, upper chest, neck
154
What are the main differences between white and brown fat?
White fat has one droplet of fat per cell.
Brown fat has many lipid droplets per cell.
White fat droplet displaces cytoplasm and nucleus to cell periphery.
Brown fat cell maintain a central nucleus.
White fat is an insulator and a fuel reserve.
Brown fat is a heat generator.
155
What is ghrelin's main function?
Increases appetite
156
What is leptin's general function?
decreases appetite
157
Which are the 3 locations where neurocrine secretion occurs?
1. Hypothalamus
2. Posterior pituitary
3. Adrenal medulla
158
What sort of product does the adrenal cortex produce?
1. Glucocorticoids
| 2. Mineralocorticoids
159
What sort of product does the adrenal medulla produce, and what are the producing cells called?
Chromaffin cells of the adrenal medulla (considered as postsynaptic neurons because they are modified neurons innervated by a pre-ganglionic symapthetic nerve) produce Noradrenaline and adrenaline that they release into the blood.
= neurocrine secretion
160
What are the hormones released by neurocrine secretion into the posterior pituitary?
OT and ADH (oxytocin and vasopressine)
161
Are pre-ganglionic neurons myelinated or unmyelinated?
myelinated
162
What are chromaffin cells?
They arebmodified neurons in the adrenal medulla that produce adrenaline and noradrenaline under sympathetic stimulation.
163
What does the pineal gland produce?
melatonin
- melatonin is involved in controlling the circadian rhythm.
- light exposure inhibits melatonin release
- the othway is from retina to HT to pineal gland
- melatonin inhibits release og gonadotropins LH and FSH
