Anatomy π« Flashcards
What are bones?
Calcified connective tissue.
How many bones are found in the body?
206
What are the functions of bones?
1) Support body & shapes it (framework for the body)
2) Protection of certain organs e.g. skull protects brain.
3) gives attachment to muscles & joints
4) Long bones provide levers for muscles to move joints
5) Formation of blood cells in red marrow.
6) Store & provide body with minerals; Calcium & phosphorus in emergencies.
What are bones classified according to?
According to:
A. Position.
B. Development.
C. Structure.
D. Shape.
Classification of bones according to position
Axial and appendicular
What is the axial skeleton?
skull, vertebral column & thoracic cage.
What is the appendicular skeleton?
Bones of upper and lower limbs
Describe the vertebral column
has 32-33 vertebrae, divided into:
1) Cervical (neck): 7 cervical vertebrae.
2) Thoracic (chest): 12 thoracic vertebrae.
3) Lumbar (low back): 5 lumbar vertebrae.
4) Sacrum: 5 fused sacral vertebrae.
5) Coccyx (tail): 3-4 fused coccygeal vertebra
What is the function of the thoracic cage?
It protects heart & lungs & allows breathing
What does the thoracic cage consist of?
1) Sternum: anteriorly.
2) Ribs: 12 pairs laterally.
3) 12 Thoracic vertebrae: posteriorly.
Compare between the upper limb and lower limb
What are bones classified into according to ossification?
Intramembranous and intra-cartilaginous bones
What is the mechanism of formation of intramembranous bones?
The condensed mesenchymal tissue β undergoes bone formation directly
What are examples of intramembranous bones?
ο shaft of clavicle
ο skull cap
ο Bones of face.
What is the mechanism of formation of intra-cartilaginous bones?
- The condensed mesenchymal tissue β chondrification first to form a cartilaginous model
- Then bone is deposited in this model
What are examples of intra-cartilaginous bones?
All bones of limbs except shaft of clavicle.
Compare between cancellous (spongy) bones and compact bones
What are bones classified into according to structure?
Cancellous (spongy) and compact
What are bones classified into according to shape and give examples for each one?
What are the parts of a long bone?
A long bone consists of 2 ends & a shaft.
What is (epiphysis)?
The end of long bone.
What is the epiphyseal Cartilage?
- a hyaline cartilaginous plate
- It is the site of growth in length of bone.
What is the diaphysis and what is it composed of?
- The shaft of long bone
- Composed of:
ο² a cylinder of compact bone with a cavity
ο² Medullary cavity contains bone marrow.
ο² Bone marrow occupies the marrow cavity in long & short bones & cancellous bone in flat & irregular bones:
β’ At birth, marrow is red & hematopoietic.
β’ At 7 years of age, yellow marrow begins to appear in distal bones of limbs.
What is the metaphysis?
Wide expanded end of shaft close to epiphyseal cartilage.
What is the periosteum and what is its function?
- A fibrous membrane covering Shaft.
- responsible for growth of bone in thickness
What is the blood supply of long bones?
Nutrient artery: Passes through nutrient canal
Periosteal arteries
Metaphyseal arteries
Epiphyseal arteries
NB. The epiphyseal plate is avascular (= doesn`t have blood supply) & is supplied by diffusion.
What are the blood supply of short bones?
Via periosteal vessels.
β A 67-year-old woman presented to the emergency department with 4-month history of worsening lower back pain.
β There was no history of trauma or falls.
β She completed her investigations with serology and radiology.
β Based on the mentioned history and investigations, the patient was diagnosed with severe osteoporosis.
What are the main cells responsible for bone formation and resorption?
- osteoblast cell is responsible for bone formation
- while osteoclast is responsible for bone resorption
What are the two main hormones responsible for calcium deposition and removal from bones?
- calcitonin is responsible for calcium deposition in bone
- while parathormone is responsible for mobilization of calcium from bone
What are contractile fibers responsible for?
Contractile fibers responsible for movement, controlled by nervous stimuli.
What are the sites of skeletal muscles?
- Attached to bone.
- Around joints.
- 40-50% of body mass.
What are the sites of smooth muscles?
- Wall of internal viscera (longitudinally & circularly) to produce peristalsis.
- In blood vessels to control the lumen caliber.
- In storage organs to produce expulsion of contents.
What are the sites of cardiac muscles?
In myocardium.
Compare between skeletal, smooth and cardiac fibers according to contraction and striation
What are the nerve supply and control of skeletal muscle fibers?
Somatic mixed nerve (motor & sensory).
What is the nerve supply and control of smooth muscle fibers?
- Autonomic nerves
- Also, controlled hormonally
- And by local stretch action.
What is the nerve supply and control of cardiac muscle fibers?
- Autonomic nerves
- conducting system: spontaneous rhythmic contraction
What is the shape of the muscle cell in skeletal muscle fibers?
Multi nucleated
What is the shape of muscle cell in smooth muscle fibers?
Spindle-shaped with single nucleus.
What is the shape of muscle cells in cardiac muscle fibers?
Spiral, Branch & unite together (one syncytium).
What are the attachments of a skeletal muscle?
2 attachments:
1) Origin: is the more fixed attachment.
2) Insertion: is the more mobile attachment.
What are the functions of skeletal muscles?
1) Produce movement.
2) Maintain posture.
3) Stabilize joints.
4) Generate heat.
What are skeletal muscles classified into according to fascile arrangement?
1- Fusiform
2- Parallel
3- Convergent
4- Unipennate
5- Bipennate
6- Multipennate
7- Circular
What are skeletal muscles classified according to the action of muscles?
1- Prime movers
2- Antagonists
3- Synergists
4- Fixators (stabilizers)
What is the function of prime movers? and give an example.
- Responsible for initiation of movement.
Example: brachialis in elbow flexion.
What is the function of antagonists? and give an example.
- oppose action of prime movers.
Example: triceps antagonizes elbow flexion produced by
brachialis.
What are the functions of synergists? and give an example.
- Act with each other to perform with more efficient contraction.
Example: Biceps helps brachialis muscle.
What are the functions of fixators? and give an example.
- Stabilize the joint on which the prime mover acts.
Example: rotator cuff muscles stabilize the humerus which is the origin of brachialis
What are skeletal muscles classified into according to the number of joints the act upon?
Uni-articular: Brachialis
Bi-articular: Sartorius
Multi-articular: Flexors and extensors of the digits
What is Lou Gehrigβs disease?
Is a fatal neurologic disease that attacks the neurons responsible for controlling voluntary muscles.
What are the earliest symptoms of Lou Gehrigβs disease?
The earliest symptoms may include cramping, twitching, and muscle weakness,
What happens to muscles with Lou Gehrigβs disease with time?
The muscles gradually atrophy, and patients lose the ability to swallow, speak and finally to breath.
What is fascia and what are its types?
-Connective tissue lying between skin & underlying muscles & bones.
-Superficial fascia, Deep fascia
What are the characters of superficial fascia?
1) Mixture of loose areolar & fatty tissue that lies between skin & deep fascia.
2) Dense in the scalp, the palm of the hand, sole of foot & back of the neck.
3) Thinnest with no fat: over penis, scrotum, eyelid, auricle of the ear
4) May contain (fat, cutaneous vessels, nerves, lymphatics, and glands)
What is the function of superficial fascia?
1) Bad conductor to heat so keeping body temperature constant.
2) Fills up hollows & rounds off irregularities so gives rounded appearance & smooth
outline particularly in females.
3) Facilitates skin movement over underlying structures.
4) Acts as a medium for cutaneous vessels, nerves & lymphatics.
What are the definition of deep fascia?
-Membranous layer of connective tissue that is denser & lies deep to superficial fascia.
-It is present in the neck, upper & lower limbs.
What are the types of deep fascia?
-Investing fascia: covers surface of the muscle.
-Inter-muscular septa: lie between muscles.
-Retinacula: localized transverse thickenings of deep fascia around wrist and ankle joints to hold long tendons in place.
-aponeurosis: thicker parts of deep fascia in the palm of hand and sole of foot and scalp
-sheaths for neuromuscular bundles: As femoral and carotid sheathes.
-tendons: Fibrous bands that connect muscles to bones or cartilage or connecting abdominal viscera.
-Ligaments: Fibrous bands like tendons that connect bones to bones or cartilage or are folds of the peritoneum serving to support visceral structures.
-Raphe: The line of union of symmetrical muscles through interdigitation of their tendentious ends.
What does CVS consist of?
Consists of: heart, blood vessels & blood.
What does CVS transport? and what does blood transport?
ο It transports blood to and from the tissues.
ο Blood transports O2 & nutrition to tissues for metabolism & transports CO2 & wastes from tissues to lung & kidney for elimination
What is the site of the heart?
-in the middle of the thorax above the diaphragm.
-extending slightly to the left.
What is the size of the heart?
about the size of an individualβs closed fist.
What are the general features of the heart?
-It is surrounded by a thin membrane called pericardium
- It is divided into 4 chambers
-Interatrial septum separates 2 atria
- An interventricular septum separates 2 ventricles
There are 2 types of valves: Atrioventricular and semilunar
What are the chambers of the heart? and what are the structures associated with atria?
It is divided into 4 chambers:-
1) The upper 2 champers are right & left atria, each atrium has an ear-like projection called the auricle
2) The lower 2 champers are right & left ventricles
What are the types of Valves?
There are 2 types of valves:
1) Valves ( ) atria & ventricles βcuspid valvesβ or βatrioventricular valvesβ
2) Valves at the base of large vessels leaving the ventricles βSemilunar valvesβ
where and when does blood flow through vessels?
blood passes from the heart in arteries, through tissues in capillaries & back to the heart in veins
What are the types of circulations?
Systemic, pulmonary, and portal
Systemic circulation
ο Oxygenated blood is pumped from the left ventricle to the aorta where it is distributed to various parts of the body through arteries, arterioles, and finally the capillaries in the tissues.
ο Deoxygenated blood from the capillaries passes into small veins then large veins and finally returns to the right atrium via the superior and the inferior vena cava
Pulmonary circulation
ο Deoxygenated blood passes from the right atrium into the right ventricle.
ο Then pumped to the pulmonary trunk then to lungs through two pulmonary arteries, arterioles and finally capillaries around the alveoli; where carbon dioxide is eliminated and the blood is oxygenated.
ο Oxygenated blood from the capillaries passes into venules, veins, then to the left atrium via four pulmonary veins.
ο Then passes from the left atrium into the left ventricle.
Portal circulation
Circulation of the blood between two sets of capillaries.
-One in the digestive tract: Venous blood from the stomach, intestines, pancreas, and spleen does not return directly to the heart, but it drains into the liver via the portal vein.
-One in the liver: In the liver, the portal vein breaks up finally into the 2nd set of capillaries (liver sinusoids), which drain into the heart via the hepatic veins and inferior vena cava
What are blood vessels?
The channels through which the blood is moved.
What are the types of blood vessels?
arteries, veins, and capillaries.
What are arteries?
Vessels or tubes carry blood away from the heart & distribute it to various tissues by their branches
What are the types of arteries?
-arterial anastomosis
-end arteries
-wavy(tortuous arteries)
What is the definition of arterial anastomoses?
The terminal branches of arteries communicate with those of adjacent arteries.
What are the sites of arterial anastomosis?
ο Around joints of limbs.
ο In hand & foot.
ο At the base of the brain.
ο In abdomen ( ) stomach & intestine
What is the importance of arterial anastomosis?
Provides a collateral circulation if an artery becomes occluded to maintain blood flow to the area
What is the definition of end arteries?
arteries whose terminal branches do not anastomose adjacent arteries
What are the sites of end arteries?
ο Retinal
ο Renal, splenic.
ο Cerebral, coronary, and pulmonary arteries.
What is the importance of end arteries?
Their occlusion disrupts blood supply to their organs; resulting in ischemia and infarction
What is the definition of wavy arteries?
arteries which have wavy course mostly as they supply expansile or moving organs
What are the examples of wavy arteries?
ο facial artery
ο Lingual artery
ο Uterine artery
ο Splenic artery
What are veins?
Vessels or tubes carrying blood towards the heart & they have tributaries
Wat are the types of veins?
Pulmonary and systemic
Pulmonary veins
Return oxygenated blood from lung to left atrium
Systemic veins
-Return deoxygenated blood from body to right atrium In limbs & neck, veins have valves to ensure unidirectional flow of blood.
-Divided into 3 sets:
1) Superficial veins: in the superficial fascia
2) Deep veins: accompany arteries
3) Dural sinuses: inside skull ( ) 2 dural layers
Compare between arteries and veins?
-DIRECTION of carrying of the blood (away-to)
-TYPE of carried blood (oxy-de) βexcept pulmonaryβ
-WALLS (rich in SM and EF - poor) (thick wall and narrow lumen - reverse)
-presence of VALVES (no-yes)
-BRANCHES or TRIBUTARIES (branch - tributaries)
What are the types of connections between arteries and veins?
1-capillaries
2-AV Shunts
3-blood sinusoids
capillaries
-Simple vascular endothelial networks between arterioles & venules in tissues
-Their walls are very thin to allow the exchange of oxygen, nutrients & wastes between blood & tissue.
-Cartilage, cornea & epidermis of skin are devoid of (without) capillaries
What is the definition of AV Shunts?
Direct communications ( ) arterioles & venules proximal to capillaries so, blood passes directly from arterial to the venous side without passing in capillaries
What are the sites of AV shunts?
ο The dermis of the skin (to regulate body temperature)
ο The auricle of ear, Tip of the Tongue, Nose, Lips Intestine (to regulate the rate of absorption)
ο The erectile tissue of sex organs (to regulate erection)
What are blood sinusoids?
Wide tubular spaces lined incompletely with phagocytic cells
What are the sites of blood sinusoids?
liver, spleen & bone marrow
What is the definition of the lymphatic system?
considered a part of both the circulatory & immune systems.
What are the components of the lymphatic system?
-lymph
-lymphatic vessels
-lymphoid tissue
What is the function of the lymphatic system?
ο drainage of extracellular tissue fluid to the blood stream, this fluid is called lymph (clear water)
ο removal of cellular debris & microorganisms
What are the components of the lymphatic system?
-lymph capillaries
-lymph vessels
-lymph ducts
-lymph nodes
-lymphoid tissues
Lymph cappilaries
ο network of fine blind end capillaries
ο drain lymph from extracellular spaces of tissues
What are lacteals?
lacteals are a special type of lymph capillaries that receive absorbed fat from the small intestine.
Lymph vessels
ο lymph capillaries join to form thin-walled lymph vessels
ο have numerous valves allowing lymph to pass in one direction
ο lymph within vessels passes in stations of lymph nodes
ο lymphatics carry lymph to lymph node are called afferent lymphatics
ο lymphatics that carry lymph away from L N are called efferent lymphatics
ο areas with no lymphatics: teeth, bone marrow, cornea & CNS
Lymph ducts
lymphatic vessels unite to form lymph duct
-right lymph duct:
ο drains lymph from the right side of head, neck, thorax & right upper limb
ο it end in junction ( ) right subclavian & right internal jugular v.
-thoracic duct:
ο drains rest of body
ο begins in the abdomen as cisterna chyli & ascends through the thorax
ο it ends in junction ( ) left subclavian & left internal jugular v.
What is the definition of lymph nodes?
small oval bodies of lymphatic tissue along lymph vessels through which lymph is filtered on its way to the venous system
What are the important groups of lymph nodes?
ο axillary: for upper limb & breast
ο cervical: for head & neck
ο mediastinal: for thorax
ο iliac: for the pelvis
ο aortic: for abdomen
What is the function of lymph nodes?
ο filtering station as they prevent microorganisms & foreign bodies in lymph from entering the blood.
ο formation of lymphocytes
ο formation of antibodies
What are lymphoid tissues?
β collection of lymphoid tissue other than lymph nodes eg: palatine tonsils, adenoid, thymus & spleen
What is the function of lymphoid tissues?
defense mechanism for the body.
What is the definition of jointsΨ
Articulation between two or more bones.
What are Joints classified according to?
- According to the nature of tissue between the articulating bones
- According to mobility
What are bones classified into according to the nature of tissue between the articulating bones?
ο² Fibrous.
ο² Cartilaginous.
ο² Synovial.
What are joints classified into according to mobility?
ο² no mobility.
ο² Limited mobility.
ο² Freely mobile.
What are the characteristics of fibrous joints (Synarthroses)?
ο Articulating bones are separated by fibrous tissue.
ο Produce no mobility.
Compare between the types of fibrous joints
What are the characteristics of cartilaginous joints (Amphiarthroses)?
ο Bones are united by cartilage.
ο Limited mobility.
Compare between the types of cartilaginous joints
What are the characteristics of synovial joints?
ο Freely mobile joints.
ο Characterized by presence of joint cavity.
ο Articular surfaces are covered by hyaline cartilage.
ο Bones are surrounded by fibrous capsule.
ο Presence of synovial membrane and synovial fluid
What the what is the synovial membrane line and what is its function?
ο² Lines the inner surface of capsule and covers non articular parts of bones.
ο² Its function is to produce and absorbe the synovial fluid.
What are the functions of the synovial fluid?
1) Allow free mobility of joints.
2) Lubrication of articular cartilage.
3) Provides nutrition of articular cartilage and structures inside joint cavity.
What are the structures inside joints?
What are the types of synovial joints according to the number of axes?
1) No axis joints.
2) Uni-axial joints
3) Bi-axial joints.
4) Poly axial joints.
What are the types of synovial joints according to the shape of articulating bones?
1) Plane joints.
2) Hinge joints.
3) Pivot joints
4) Saddle joints
5) Ellipsoid joints.
6) Ball & socket joint.
What are uni-axial joints?
- Hinge joints (Ginglymus)
- Pivot joints (Trachoid)
Hinge joints (Ginglymus)
Pivot joints (Trachoid)
What are bi-axial joints?
- Ellipsoid joints (Condyloid)
- Saddle joints (Sellar)
Ellipsoid joints (Condyloid)
Saddle joints (Sellar)
What are poly-axial joints?
Ball and socket (spheroidal and cotyloid)
Ball and socket (spheroidal and cotyloid)
What are non-axial joints?
Plane joints
Plane joints
What are the factors that are responsible for stability and the strength of joints?
1) Shape of articulating bones.
2) Muscle around joints.
3) Ligaments related to joints.
What is the extent of the scalp?
In front: Supraorbital margin (Eyebrows).
Behind: Highest nuchal lines.
Laterally: Temporal line and superior temporal line.
β The area from the superior temporal lines downwards to the zygomatic arch is called the temple.
What are the layers of the scalp?
S: SKIN
C: CT
A: APONEUROSIS (EPICRANIAL)
L: LOOSE AREOLAR TISSUE
P: PERIOCRANIUM
The skin of the calp
It is rich in hair follicles and sebaceous glands.
CT of the scalp
ο It is rich in fat and fibrous septa that connect the skin to the underlying aponeurosis.
ο Numerous arteries and veins, that freely anastomose, are found in this layer and thus scalp wound leads to marked bleeding.
EPICRANIAL aponeurosis of the scalp
ο It is a fibrous band attached:
ο² anteriorly (through the frontal bellies of the occipitofrontalis muscle) to the skin over the superciliary arches.
ο² posteriorly (through the occipital bellies of the
occipitofrontalis muscle) to the highest nuchal lines and a part of the aponeurosis extends between the occipital bellies to be attached to the external occipital protuberance.
ο² on each side, the aponeurosis is attached to the superior temporal line.
Loose areolar tissue of the scalp
ο It is the 4th layer.
ο It lies between the aponeurosis and the pericranium.
ο Allows the forward and backward movements of the first three layers of the scalp over the skull.
ο Contains emissaryβs veins.
ο It extends anteriorly to the eyelid beneath orbicularis oculi.
ο Bleeding in it may appear in upper eyelids causing (black eye)
Periosteum of the scalp
ο It is adherent to the skull bones.
ο At the suture lines, it becomes continuous with the endosteum.
What is the muscle of the scalp?
Occipito-frontalis
What are the bellies of the occipital-frontalis?
Frontal and occipital
What is the origin of the frontal bellies?
the skin of the forehead and the eyebrows
What is the insertion of the frontal bellies of the occipital frontalis?
the epicranial aponeurosis.
What Is the nerve that suppliers the frontal bellies of the occipital-frontals?
The temporal branch of the facial nerve
What is the function of the frontal bellies?
transversely corrugates the skin of the forehead (expression of surprise).
What is the origin of the occipital bellies og the occipital-frontal is?
from the highest nuchal lines
What is the insertion of the occipital bellies of the occipital-frontalis?
the epicranial aponeurosis.
What is the nerve that supplies the occipital bellies of the occipital-frontalis?
the posterior auricular branch of the facial nerve.
What is the function of the occipital bellies of the occipital-frontalis?
draw the scalp backward
What is the arterial supply of the scalp?
The scalp is supplied by 5 arteries on each side:
ο² 2 in front of the auricle
ο² 2 behind it.
ο² 1 in the middle part of the scalp
What are the arteries in front of the scalp?
β Supratrochlear artery and Supraorbital artery:
ο² They are branches of the ophthalmic artery which is a branch from the internal carotid artery.
ο² They accompany the corresponding nerves.
What are the arteries in the middle of the scalp?
β Superficial temporal artery:
ο² One of the two terminal branches of the external carotid artery inside the parotid gland at the level of the neck of the mandible.
ο² It emerges from the upper border of the parotid gland to enter the scalp where it divides into terminal anterior and posterior branches.
ο² It gives the transverse facial artery which emerges from the anterior border of the parotid to share in the arterial supply of the face.
What are the arteries in the posterior of the scalp?
Posterior auricular artery
-Arises from the posterior aspect of the external carotid artery
-passes backward along the upper border of the posterior belly of digastric
-supply the skin of the scalp behind the auricle.
Occipital artery
-Arises from the posterior aspect of the external carotid artery
-passes backward along the lower border of the posterior belly of the digastric.
-supplies the back of the scalp.
What are the veins of the scalp?
Superficial veins: -
1-Supraorbital vein & Supratrochlear vein:
ο² Both unite to form the facial vein.
2- Superficial temporal vein:
ο² Unites with the maxillary vein to form the retromandibular vein.
ο² The anterior facial vein unites with the anterior division of the retromandibular vein to form the common facial vein.
3-Posterior auricular vein:
ο² Unites with the posterior division of the retromandibular
vein to form the external jugular vein.
4-Occipital vein:
ο² Drains into the suboccipital venous plexus.
Deep veins: emissary veins.
What is the lymph drainage of the scalp?
β The forehead and the anterior part of the face: ο² drain into the submandibular lymph nodes.
β The lateral part of the scalp drains into the pre-auricular lymph nodes.
β The posterior part of the scalp drains into the mastoid (occipital) lymph nodes.
What is the cause of the gaping of scalp cut wounds?
The contraction tone of the frontal belly and the 2 occipital bellies of the occipital-frontalis
What is the cause of profuse hemorrhage in scalp cut wounds?
The extensive anastomosis between the arteries
can infection spread from scalp through the emissary veins to inside the cranial cavity?
Yes
How are scalp wounds sutured? And why?
Cut wounds of the scalp are sutured by thick silk thread due to the presence of the aponeurosis and the thickness of the scalp
What are the nerves that supply the scalp?
A) In front of the auricle: 4 sensory branches from the trigeminal nerve & 1 motor branch from the facial nerve
- supratrochlear
- supraorbital
- zygomaticotemporal
- auriculotemporal
- temporal
B) Behind the auricle: 4 sensory branches from the cervical nerves & 1 motor branch from the facial nerve
- great auricular
- lesser occipital
- great occipital
- third occipital
- posterior auricular
What is the origin of the supratrochlear nerve?
One of the two terminal branches of the frontal nerve which is a branch from the ophthalmic division of the trigeminal nerve
What is the course of the supratrochlear nerve?
Comes out of the orbit one finger breadth from the midline.
What is the supply of the supratrochlear nerve?
the medial 1/3 of the upper eyelid and the skin of the forehead above the root of the nose.
What is the origin of the supraorbital nerve?
The other terminal branch of the frontal nerve.
What is the course of the supraorbital nerve?
Comes out of the orbit through the supraorbital foramen two fingers breadth from the midline
What is the supply of the supraorbital nerve?
the middle 1/3 of the upper eyelid and the skin of the scalp as far back as the lambdoid suture.
What is the origin of the zygomaticotemporal nerve?
One of the two terminal branches of the zygomatic nerve which is a branch from the maxillary division of the trigeminal nerve.
What is the course of the zygomaticotemporal nerve?
Comes out of the orbit from the zygomaticotemporal foramen.
What is the supply of the zygomaticotemporal nerve?
the skin of the temporal region and a small area of the scalp above the temporal region.
What is the origin of the auriculotemporal nerve?
A branch from the posterior division of the mandibular branch of the trigeminal nerve.
What is the course of the auriculotemporal nerve?
Appears in the scalp just in front of the auricle.
What is the supply of the auriculotemporal nerve?
the skin of the scalp above the auricle & the upper 2/3 of the outer surface of the auricle and a part of the external auditory tube and ear drum.
What is the origin of the temporal nerve?
Facial nerve
What is the supply of the temporal nerve?
the frontal belly of the occipito frontalis.
What is the origin of the great auricular nerve?
Arises from the ventral rami of C2&3
What is the course of the great auricular nerve?
Appears at the middle of the posterior border of the sternomastoid then passes upwards and forwards superficial to the muscle. It divides into two branches that pass in front and behind the auricle
What is the supply of the great auricular nerve?
the skin over the angle of the mandible, a small area of the scalp behind the auricle, lower 1/3 of the outer and the lower 2/3 of the inner surfaces of the auricle as well as the capsule of the parotid gland
What is the origin of the lesser occipital nerve?
Arises from the ventral ramus of C2
What is the course of the lesser occipital nerve?
Appears at the middle of the posterior border of the sternomastoid then passes upwards and backwards.
What is the supply of the lesser occipital nerve?
the skin of the scalp behind the auricle and the upper 1/3 of the inner surface of the auricle.
What is the origin of the great occipital nerve?
Arises from the dorsal ramus of C2.
What is the course of the great occipital nerve?
Appears near the external occipital protuberance
What is the supply of the great occipital nerve?
a large area of the skin of the back of the scalp.
What is the origin of the third occipital nerve?
Arises from the dorsal ramus of C3.
What is the course of the third occipital nerve?
Appears in the back of the scalp below the greater occipital nerve.
What is the supply of the third occipital nerve?
an area of the skin of the back of the scalp as well as the back of the neck.
What is the origin of the Posterior auricular nerve?
Facial nerve
What is the supply of the posterior auricular nerve?
the occipital belly of the occipito frontalis.
What is the extent of the face?
β The superior orbital margin (eyebrows) to the chin.
β Laterally to the external auditory meatus.
NB: The forehead is common to both scalp and face
What are the layers of the face?
β Skin.
β Muscles
What are the muscles of the face characterized by?
- They surround the openings of the face.
- They originate from the bones of the skull.
- They are inserted in the skin; they are the muscles of expression.
- They develop from the 2nd pharyngeal arch.
- They are supplied from the facial nerve.
What are the openings of te. Face?
- Orbit 2. Nose 3. Mouth 4. Ear
What are the muscles of the face?
- Orbicularis occuli
- Orbicularis oris
- Buucinator
- platysma
What are the parts of the orbicularis oculi?
Orbital, palpebral and lacrimal parts
What is the origin of the orbital part of the orbicularis oculi?
the upper part of the medial palpebral ligament
What are the insertions of the orbital part of the orbicularis oculi?
the lower part of the medial palpebral ligament.
What is the nerve that supplies the orbital, palpebral and lacrimal parts of tne orbicularis oculi?
Temporal and upper zygomatic branches of the facial nerve.
What is the action of the orbital part of the orbicularis oculi?
firm closure of the eye.
What is the origin of the palpebral part of the orbicularis oculi?
upper and lower parts of the medial palpebral ligament
What is the insertion of the palpebral part of the orbicularis oculi?
lateral palpebral raphe.
What is the action of the palpebral part of the orbicularis oculi?
gentle closure of the eye.
What is the origin of the lacrimal part of the orbicularis oculi?
lacrimal bone and the fascia covering the lacrimal sac.
What is the insertion on the lacrimal part of the orbicularis oculi?
the tarsi of the lids.
What is the function of the lacrimal part of the orbicularis oculi?
dilates the lacrimal sac to drain tears
What are the parts of the Buccinator?
Upper, lower and middle fibers
What is the origin of the upper fibers?
From the maxilla opposite the upper molars.
What is the insertion of the upper fibers?
Upper lip
What is the nerve that supplies the fibres of the buccinator?
Buccal branch of the facial nerve.
What is the action of the buccinator?
presses the cheek to the gums, to prevent the accumulation of food in the vestibule of the mouth.
What does the paralysis of the buccinator lead to?
Its paralysis leads to the accumulation of food in the vestibule of the mouth and the dripping of saliva.
What is the origin of the lower fibres of the buccinator?
From the mandible opposite the lower molars.
What is the insertion of the lower fibre of the buccinator?
Lower lip
What is the origin of the middle fibres of the buccinator?
From the Pterygomandibular ligament.
What is the insertion of the middle fibre of the buccinator?
decussate before passing to lips
What is the origin of orbicularis oris?
maxilla above incisor teeth
What is the insertion of the orbicularis oris?
the skin of the lip.
What is the nerve supply for the orbicularis oris?
Buccal branch of the facial nerve.
What is the function of the orbiculas oris?
Compresses the lips together to close the mouth.
What is the origin of the platysma?
the upper part of pectoral and deltoid fascia
What is the insertion of the platysma?
the base of the mandible, the skin of the lower face, and the lip
What is the function of the platysma?
releases pressure of skin on the subjacent veins, depress mandible, pulls the angle of the mouth downwards.
From where does the facial nerve leave the skull?
The facial nerve leaves the skull through the stylomastoid foramen to enter the parotid gland through its posteromedial surface.
Where does the facial nerve branch?
Inside the parotid
What are the branches of the facial nerve?
Temporal
Zygomatic
Buccal
Mandibular
Cervical
What does the temporal branch supply?
Supplies the frontal belly of occipitofrontalis and the upper part of orbicularis oculi.
What does the zygomatic branch supply?
- Upper zygomatic: Supplies the lower part of orbicularis oculi.
- Lower zygomatic: Supplies the nasal muscles.
What does the buccal branch supply?
Supplies the buccinator, orbicularis oris, and other muscles of the mouth except those of the lower lip.
What does the mandibular branch supply?
Supplies the muscles of the lower lip.
What does the cervical branch supply?
Supplies the platysma
What does the trigeminal nerve supply?
β supplies all the skin of the face EXCEPT the skin over the angle of the mandible which is supplied by the great auricular nerve.
Whata are the divisions of the trigeminal nerve?
ophthalmic division
maxillary division
mandibular division
What are the branches of the ophthalmic division? And what do they supply?
- Supratrochlear nerve: Supplies the medial 1/3 of the upper eyelid.
- Supraorbital nerve: Supplies the middle 1/3 of the upper eyelid.
- Palpebral of lacrimal: Supplies the lateral 1/3 of the upper eyelid.
- External nasal nerve: Supplies the lower 1/2 of the dorsum of the nose.
- Infratrochlear nerve: Supplies the upper 1/2 of the dorsum of the nose and the adjoining part of the lower eyelid.
What are the branches of the maxillary division?
- Zygomaticofacial nerve: Supplies the skin over the bony cheek.
- Infraorbital nerve (the continuation of the maxillary nerve):
ο² Palpebral branch: Supplies the skin of the lower eyelid.
ο² Nasal branch: Supplies the skin of the side of the nose.
ο² Labial branch: Supplies the skin of the upper lip.
What are the branches of the mandibular division?
- Buccal nerve: Supplies the skin of the cheek.
- Mental nerve: Supplies the skin of the lower lip
Do the wounds of the face heal fast?
Yes
What are the arteries of the face?
1)The facial artery:
ο² It arises from the anterior aspect of the external carotid artery.
ο² It turns around the lower border of the mandible at the inferior angle of the masseter to reach the face.
ο² In the face, it takes a tortuous course, passes upwards till a point 1 cm behind the angle of the mouth, then continues upwards on the side of the nose till the medial
the angle of the eye.
2) Supraorbital and Supratrochlear:
ο² branches of the ophthalmic artery which is a branch of the internal carotid artery.
3) Transverse facial and zygomaticorbital arteries Which are branches of the superficial temporal artery.
4) Small twigs accompanying nerves supplying the face.
What are the veins of the face?
1) Anterior facial vein:
ο² formed by the union of supratrochlear & supraorbital veins at the medial angle of the eye.
2) Posterior facial vein (retromandibular vein):
ο² formed by the union of the superficial temporal vein with the maxillary vein. It ends by dividing into anterior and posterior divisions.
3) Common facial vein:
ο² formed by the union of the anterior facial with the anterior division of the posterior facial veins.
4) External Jugular vein:
ο² formed by the union of the posterior division of retromandibular with posterior auricular veins
5) Deep facial vein:
ο² connect the anterior facial vein with the pyrgotid plexus.
Communications of the anterior facial vein
a) At its beginning:
ο² it receives the ophthalmic veins which are connected to the cavernous sinus through the superior orbital fissure.
b) Along its course:
ο² it receives veins corresponding to the branches of the facial artery.
c) While crossing the buccinator:
ο² it is connected with the pterygoid venous plexus through the deep facial vein that passes deep to the ramus of the mandible.
ο² The pterygoid venous plexus is connected to the cavernous sinus through emissary veins passing through the foramen ovale.
Infection in the triangular area of the face between the two anterior facial veins (Dangerous area of the face) can lead to cavernous sinus thrombosis in two ways:
Anterior facial vein β ophthalmic veins β cavernous sinus.
Anterior facial vein β deep facial vein β pterygoid venous plexus β emissary veins through foramen ovale β cavernous sinus.
Lymph drainage in the face
Upper region
ο preauricular lymph nodes (parotid):
ο² the greater part of the forehead, lateral 1β2 of the eyelid, conjunctiva, lateral part of the cheek, and parotid area:
Middle region
ο submandibular lymph nodes:
ο² median part of the forehead, external nose, upper lip, lateral part of the lower lip.
ο² medial 1β2 of the eyelid, the medial part of the cheek, the greater part of the lower jaw.
Lower region
ο submental lymph nodes:
ο² the central part of the lower lip, chin.
Trigeminal neuralgia
pain in the region of distribution of maxillary and mandibular branches of the trigeminal nerve.
β Infranucleur lesions of the facial nerve (eg, bellβs palsy)
the whole face is paralyzed, Affected side is motionless.
ο² Loss of wrinkles.
ο² The eye cannot be closed.
ο² In smiling the mouth is drawn to the normal side.
ο² During mastication, food accumulates in the vestibule of the mouth.
β Supranuclear lesions of the facial nerve
ο² only the lower part of the face is paralyzed.
ο² The upper part (frontalis &part of orbicularis oculi) escapes due to its bilateral innervation
Characters of face wounds
β Face wounds bleed profusely, heal rapidly, and are sutured with thin threads
Dangerous area of the face
infections from face mainly from upper lip & nose can go
to cavernous sinus through ophthalmic vein and deep facial vein.
What are the branches of the aortic arch?
β The brachiocephalic artery that gives:
ο² Rt subclavian artery
ο² Rt common carotid artery
β Lt common carotid artery
β Lt subclavian artery
What is the origin of the common carotid artery?
ο The right common carotid artery arises from the brachiocephalic art.
ο The left common carotid artery arises from the arch of the aorta.
What is the course of the common carotid artery?
ο Enters the neck behind the corresponding sternoclavicular joint.
ο Then runs upwards and backwards within the carotid sheath.
ο Lies partly undercover of sternomastoid muscle
What is the termination of the common carotid artery?
-Opposite the upper border of the thyroid cartilage and the intervertebral disc between the 3rd and 4th cervical vertebrae.
-It ends by dividing into 2 terminal branches.
What are the branches of the common carotid artery?
Only 2 terminal branches: Which are External and internal carotid arteries.
What is the carotid sinus?
The carotid sinus is a dilatation in the terminal part of CCA and beginning of ICA.
What is the origin of the external carotid artery?
ο It is one of two terminal branches of the common carotid artery
ο At the level of the upper border of the thyroid cartilage and the intervertebral disc between the 3rd and 4th cervical vertebrae
What is the course of the external carotid artery?
ο Ascends upward in neck
ο Divided by the posterior belly of the digastric muscle into 3 parts.
ο Enters the parotid gland
What is the termination of the external carotid artery?
ο Behind the neck of the mandible within the parotid gland.
ο divides into two terminal branches:
ο² The maxillary and the superficial temporal.
What are the branches of the external carotid artery and what do they supply?
3 from the front:
ο² Superior thyroid artery: the 1st branch, supplies the thyroid gland
ο² Lingual artery: supplies the tongue.
ο² Facial artery: supplies the face.
2 from the back:
ο² Posterior auricular artery: supplies the scalp
ο² Occipital artery: supplies the scalp.
1 from medial aspect:
ο² Ascending pharyngeal artery: 2nd branch, supplies the pharynx
2 terminal branches:
ο² Superficial temporal artery: supplies the face and scalp. ο² Maxillary artery: supplies the head and teeth.
What are the pulse points in our bodies?
Carotid pulse:
β Carotid arteries are felt on the side of the neck, in front of the sternomastoid muscle, just below the angle of the mandible.
Facial pulse:
β The facial artery is felt against the base of the mandible.
Superficial temporal pulse:
β The superficial temporal artery is felt in front of the ear against the zygomatic arch.
What is the origin of the internal carotid artery?
ο It is one of two terminal branches of the common carotid artery.
ο At the level of the upper border of the thyroid cartilage and the intervertebral disc between the 3rd and 4th cervical vertebrae.
What is the course of the internal carotid artery?
ο Runs inside the carotid sheath.
ο It enters the cranial cavity through the carotid canal in the petrous part of the temporal bone.
What is the termination of the internal carotid artery?
Divides into anterior & middle cerebral arteries.
What are the branches of the internal carotid artery?
ο It has no branches in the neck.
ο Has branches supply the brain and the eye.
What is the beginning of the external jugular vein?
Union of the posterior division of the retromandibular vein with the posterior auricular vein
What is the course of the external jugular vein?
ο Descends in the superficial fascia superficial to the sternomastoid muscle
ο It pierces the deep fascia of the neck just above the clavicle.
What is the termination of the external jugular vein?
In the subclavian vein
What are the tributaries of the external jugular vein?
SS TC AJ
1) Suprascapular vein
2) Transverse cervical vein
3) Anterior jugular vein
What is the beginning of the internal jugular vein?
Direct continuation of the sigmoid sinus at the jugular foramen.
What is the course of the internal jaguar vein?
ο Runs downwards through the neck within the whole length of the carotid sheath (with internal and common carotid arteries and the last 4 cranial nerves).
ο Lies undercover of sternomastoid muscle
What is the termination of the internal jugular vein?
It joins the subclavian vein to form the brachiocephalic
What are the tributaries of the internal jaguar vein?
1- Superior thyroid vein
2- Middle thyroid vein
3- Common facial vein
4- Lingual vein
5- Pharyngeal veins
6- inferior petrosal venous sinus
What is the medical importance of the internal jaguar vein?
it is used for insertion of central venous catheter
What is the nervous system composed of?
The nervous system is formed of 2 types of cells and their processes:
ο½ Nerve cells: called neurons.
ο½ Supporting cells: called glial cells or neuroglial cells or neuroglia.
What is the structure of the cell body (soma)?
consists of the nucleus and cytoplasm.
ο½ The nucleus is usually central and contains nucleolus.
ο½ The cytoplasm contains organelles & inclusions
What are the processes of the nerve cell?
single axon and dendrites.
Compare between axon and dendrites Acc to:
Length
Function
ο¨ It is the largest process of the nerve cell
ο¨ Through which the nerve cell communicates with other nerve cells
ο¨ Short and highly branched processes
ο¨ Receive impulses from other neurons and transmit them toward the cell body
What are neurons classified according to?
the number of their processes into 3 types:
1) Unipolar Neurons: they have one process:
a. True unipolar neurons
b. Pseudounipolar neurons
2) Bipolar Neurons: 2 processes, one axon, and one dendrite. located in the sense organs (olfactory epithelium of nose, retina)
3) Multipolar Neurons: one axon and several dendrites. They form most of the nerve cells in the nervous system
What are synapses?
Sites of communication between nerve cells or between a nerve cell and muscle or gland.
What is the structure of the synapse?
- Presynaptic element: axon terminal containing synaptic vesicles.
- Synaptic cleft: 20-nm space.
- Postsynaptic element: usually dendrite.
What are the types of synapses?
1) Axodendritic synapse: between axon and dendrite.
2) Axonaxonic synapse: between axon and axon.
3) Axosomatic synapse: between axon and cell body.
4) Neuromuscular junction: between axon and muscle fiber
What are the types of neuroglia cells
A. CENTRAL NEUROGLIA: in the central nervous system(CNS)
B. PERIPHERAL NEUROGLIA: in the peripheral nervous system
What are examples of central neuroglia?
a. Astrocytes: for support and protection.
b. Oligodendrocytes: for the formation of myelin.
c. Microglia: for phagocytosis and defense against infection.
d. Ependymal cells: lining ventricles of the brain
What are examples of peripheral neuroglia?
a. Schwann cells: formation of myelin
b. Satellite cells: surrounding nerve cells
What are the divisions of the NS?
1) Central nervous system (C.N.S): Brain Spinal cord
2) Peripheral somatic nervous system
3) Peripheral autonomic nervous system
What are the divisions of the brain?
1) Cerebrum: formed of:
a. Two cerebral hemispheres: contain higher motor and sensory centers.
b. Diencephalon: formed mainly of thalamus and hypothalamus
2) Cerebellum: for coordination of muscles movements and maintaining equilibrium.
3) Brain stem: formed of the midbrain, pons, and medulla oblongata.
What is another division of the brain?
Forebrain: two cerebral hemispheres and diencephalon
midbrain: midbrain
hindbrain: cerebellum, pons, and medulla
What are the ventricles of the brain?
ο½ Lateral ventricle in each cerebral hemisphere
ο½ 3rd ventricle in the diencephalon
ο½ 4th ventricle in the hindbrain
What is the length of the spinal cord?
Length: 45 cm in the male and 42 cm in the female.
What is the location of the spinal cord?
in the upper two-thirds of the vertebral canal.
Where does the spinal cord begin?
as the continuation of the medulla oblongata.
Where does the spinal cord end?
It ends at:
o In the newborn: at the level of the third lumbar vertebra (L3).
o In the adult: at the level of the lower border of (L1).
What is the number of spinal cord segments?
31 segment
What is the distribution of spinal nerves?
Distribution: the 31 pairs of the spinal nerves are distributed as follows:
ο½ 8 cervical ο½ 12 thoracic ο½ 5 lumbar ο½ 5 sacral ο½ 1 coccygeal
How are spinal nerves formed?
- Each spinal nerve arises by 2 roots
- The 2 roots unite at the intervertebral foramen to form spinal nerve trunk
What does the ventral root contain?
ο¨ Axons of anterior horn cells supply skeletal muscles.
ο¨ Axons of lateral horn cells (autonomic) supply smooth muscles.
What is attached to the dorsal root?
The spinal ganglion is attached to it; so it is called dorsal root ganglion.
What is the dorsal root formed from?
It is formed of processes of pseudounipolar cells of the spinal ganglion
Ventral root
Motor (efferent)
Dorsal root
Sensory (afferent)
What are the branches of spinal nerves?
Anterior (Ventral) Primary Ramus
Posterior (Dorsal) Primary Ramus
What are the characters of ventral primary rami?
ο¨ Large in size.
ο¨ Run anteriorly
ο¨ May join each other to form plexuses
ο¨ Connected to the sympathetic chain
What are the characters of dorsal primary rami?
ο¨ Smaller in size
ο¨ Run backward supply muscles & skin of the back.
ο¨ Does not share in the formation of plexuses.
ο¨ Not connected to the sympathetic chain
What is attached to the sympathetic ganglion?
Ventral ramus is attached to sympathetic ganglion by 2 rami communicantes: white ramus (myelinated) and gray ramus (unmyelinated)
What is the number of cranial nerves and from where do they arise?
ο½ Consists of 12 pairs (I to XII).
ο½ All arise from the brainstem except The first (I, olfactory), which arises from the nose, and the second (II, optic), which arises from the retina
What do both of the autonomic systems consist of?
Each system is formed of 3 components:
ο¨ Preganglionic fibers: arise from a nucleus in the brain stem or spinal cord.
These fibers relay in the autonomic ganglia.
ο¨ Autonomic ganglia: sympathetic, or parasympathetic.
ο¨ Postganglionic fibers: arise from the ganglia to supply the organs.
Peripheral somatic nervous system
ο¨ Cranial nerves: 12 pairs, from brain .
ο¨ Spinal nerves: 31 pairs, from spinal cord .
ο¨ Associated ganglia: spinal & cranial ganglia
Peripheral autonomic nervous system
ο¨ Sympathetic part: thoracolumbar part .
ο¨ Parasympathetic part: craniosacral part .
ο¨ Associated ganglia: autonomic ganglia
What are the sympathetic and parasympathetic nerves?
