ANHB2214 Lecture Notes - Lecture 1: Phonation, Olfactory Nerve, Olfactory Glands
29 May 2018
School
Course
Professor
ANHB4 TEST ONE NOTES
Cardiovascular System:
• Endothelium
o Epithelium lining the vascular system
o Simple squamous epithelium with flattened nuclei
o Selectively permeable layer
o Non-thrombogenic layer
o Functions
▪ Modulate blood flow and vascular resistance
▪ Work with immune cells
▪ Synthesize chemical messengers
▪ Oxidize lipoproteins
▪ Affect relaxation and contraction of smooth muscle cells in
tunica media
• Cardiac muscle
o Central nucleus
o Striations
o Intercalated discs → irregular arrangement
▪ Fascia adherens → holds muscle cells end to end
▪ Gap junctions → allows transmission of ions between cells
o Cardiac muscle is thicker in the ventricles than atria → have more
distance to pump blood
o 2 types of cardiac muscle cells
▪ Contractile cells
▪ Impulse generating/conducting cells
• The heart
o Muscular organ that contracts rhythmically, pumping blood
through the circulatory system
o Endocardium
▪ Homologous with tunica intima of blood vessels
▪ Single layer of squamous endothelial cells
▪ Rests on a thin subendothelial layer of loose connective
tissue
▪ Subendothelial cartilage → between endocardium and
myocardium → contains veins, nerves, Purkinje fibers
o Myocardium
▪ Thickest of the tunics
▪ Consists of cardiac muscle cells arranged in layers
o Epicardium
▪ Serous covering of the heart
▪ Forms visceral layer of pericardium
▪ Externally covered by simple squamous epithelium
supported by a thin layer of connective tissue
▪ Subepicardial layer contains veins, nerves and nerve
ganglia
find more resources at oneclass.com
find more resources at oneclass.com
▪ Adipose tissue that surrounds heart accumulates here
o Fibrous skeleton
▪ Composed of dense connective tissue with thick collagen
fibers
▪ Insertion point of cardiac muscle
▪ Septum
• Dense connective tissue
• Separating atria and ventricles
o Heart valves
▪ Stops backflow of blood during contraction of atria and
ventricles
▪ Either separate atria and ventricles or ventricles and blood
vessels
▪ Central core → fibrosa → strongest component joins with
fibrous skeleton
▪ Spongiosa → thin layer, elastic, dampens force of vibration
of heart beat
▪ Ventricularis → adjacent to ventricular space, continuous
with chordae tendinae, dense connective tissue
• Impulse generating system of the heart
o SA node
▪ Pacemaker of the heart
▪ Located close to superior vena cava, in right atrium
o Atrioventricular Bundle of His
▪ Purkinje cells
▪ Penetrate fibrous skeleton
▪ Divide into right and left atrioventricular bundles
o Impulse generating cardiac muscle cells have a greater diameter
than normal cardiac muscle cells
o Stimulus for ventricular contraction moves from apex to base
• Types of circulation
o Pulmonary circulation → right atrium and ventricle
o Systemic circulation → left atrium and ventricle
o Portal system
▪ Liver → hepatic portal system
▪ Pituitary gland → hypothalamic-hypophyseal portal system
• General structure of blood vessels
o Tunica intima
▪ Layer of endothelial cells lining the vessel’s interior surface
▪ Cells rest on a basal lamina
▪ Beneath endothelium → subendothelial layer → loose
connective tissue and smooth muscle arranged
longitudinally
o Tunica media
▪ Concentric layers of helically arranged smooth muscle cells
▪ Interposed amongst smooth muscle cells are elastic fibers,
collagen fibers and proteoglycans
▪ Media is separated from the intima by the internal elastic
lamina
find more resources at oneclass.com
find more resources at oneclass.com
▪ Media is separated from the adventitia by the external
elastic lamina
▪ Lamina is composed of elastin and has fenestrae to allow
substances to move through
o Tunica adventitia
▪ Consists of longitudinally oriented collagen and elastic
fibers
▪ Becomes continuous with the enveloping connective tissue
of the organ
• Vasa vasorum
o Branches of arteries → predominant in adventitia and outer media
o Provide metabolites to the adventitia/media in larger vessels
o Arise from the branches of the artery they supply or neighbouring
arteries
• Innervation of blood vessels
o Supplied by unmyelinated sympathetic nerve fibers
o Neurotransmitter → predominantly noradrenaline
o Gap junctions between smooth muscle cells propagate message
o Sensory nerve endings → baroreceptors and chemoreceptors
• Specific structures of blood vessels
o Capillaries
▪ Composed of a single layer of endothelial cells
▪ External surface rests on a basal lamina
▪ Gap junctions between endothelial cells
▪ Pericytes
• Tiny vessel surrounded by endothelium
• Wraps around capillaries
• Surrounded by basal lamina of endothelium
• Functions
o Can divide and turn into smooth muscle cells
o Inhibit growth of capillaries
▪ Thin layer of collagen fibers encompass capillaries
▪ 3 types of capillaries
• Continuous/somatic
o Lack of fenestrations in its wall
o Found in muscle tissue, connective tissue,
exocrine glands and nervous tissue
o Contains pinocytic vesicles to transport
macromolecules
• Fenestrated/visceral
o Large fenestrae closed by a thin diaphragm
o Continuous basal lamina
o Present in tissues where rapid interchanfe of
substances occurs between tissues and blood
→ kidneys and intestines
• Sinusoidal
o Large diameter which slows circulation of
blood
o Multiple fenestrae with no diaphragm
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Internal elastic lamina is not present: muscular arteries, make up most of the named arteries of the body. Internal elastic lamina not present: veins, capacitance vessels hold up to 70% of blood volume at rest, venules. Intima composed of endothelium: smallest type of vein, thin media layer, adventitia layer is the largest consists of connective tissue with collagen fibers, thin walls when compared to arteries, small/medium sized. Involved in the maintenance of electrolyte and water balance: zona fasciculate, cells are arranged in straight cords, middle layer, secretes glucocorticoids cortisol. Insulin causes the storage of excess glucose: d cells, contains somatostatin, somatostatin decreases glucagon release. If testosterone levels are too high, there is negative feedback to lh. Inhibin also has a negative feedbacks to lh: androgen binding protein produced under stimulus to fsh, duct systems. Infundibulum has projections fimbrae: ampulla longest portion where fertilization occurs.
