anatomy med test 2.2

brachial artery begins at the

inferior border of teres major and supplies the anterior arm. end at cubital fossa

branches of brachial artery

deep artery of arm to posterior compartment which gives off radial and ulnar collaterals

alos divides into radial and ulnar in the cubital fossa deep to bicepital aponeurosis

venous drainage of arm

basilic(medial) and cephalic(lateral) vein

basilic joins with brachial vein then empties into axillary but cephalic drains right into axillary vein

muscles of anterior compartment are all innervated by what nerve

musculocutaneous nerve (C5,C6,C7)

muscles include coracobrachialis, biceps brachii, brachialis

exception: small lateral part of brachialis receives radial nerve

proximal and distal attachment of coracobrachialis

P: coracoid process

D: middle third of medial humerus

nerve and action of coracobrachialis

N: musculocutaneous

A: flexes and adducts arm at the glenohumeral joint

proximal and distal attachment of biceps brachii

P: long head- supraglenoid tubercle

shorthead-tip of coracoid process

D: radial tuberosity and fascia of forearm via aponeurosis

nerve and action of biceps brachii

N: musculocutaneous

A: stabilizes anterior aspect of shoulder and weakly flexes arm

at elbow it flexes and supinates forearm

long head of biceps tendon

traverses the glenohumeral joint to attach to the superglenoid tubercle of scapula and labrum

rupture of long head of biceps brachii

often torn from supraglenoid attachment

when flexing elbow a bulge is noted "popeye sign"

brachialis muscle proximal and distal attachment

P: distal half of anterior surface of humerus

D: coronoid process and tuberosity of ulna

nerve and action of brachialis muscle

N: musculocutaneous and small lateral gets radial nerve

A: flexes forearm

course of musculocutaneous nerve

branches from lateral cord and passes through coracobrachialis

passes between biceps brachii and brachialis

emerges from lateral edge of biceps

after piercing deep fascia it emerges as the lateral cutaneous nerve of forearm, providing sensory innervation to lateral surface of forearm

biceps DTR

place thumb on biceps tendon in cubital fossa

positive sign confirms integrity of C6 spinal cord segment

posterior compartments of arm get innervation by

radial nerve

triceps, anconeus

proximal attachment of triceps

long head: infraglenoid tubercle of scap

lateral head: posterior surface of humerus superior to radial groove

medial head: posterior surface of the shaft of the humerus inferior to radial groove

distal attachment of triceps

three heads from a common tendon attaching to the olecranon of ulna

nerve and action of triceps

N: radial nerve (C6,C7,C8 mostly 7,8)

A: extends forearm at elbow

long head can adduct and extend the arm and resists glenohumeral dislocation

what spinal cord segment is tested by tapping triceps tendon

C7

aconeus proximal and distal attachments

P: lateral epicondyle of humerus

D: olecranon and posterior ulna

nerve and action of anconeus

N: radial nerve

A: elbow stabilizer

course of radial nerve in arm

originates from posterior cord

enters arm inferior to teres major muscle along with the deep artery of arm as they both pass through the triangular interval

lies in radial groove

innervates all extensors in arm and small lateral part of brachialis

cutaneous innervation via inferior lateral cutaneous nerve

also continues into forearm

radial nerve injury

in radial groove partial paralysis most likely only medial head affected

extensors paralyzed so seen as wrist drop

also called Saturday night palsy

boundaries of cubital fossa

superiorly: line connecting medial and lateral epicondyles

medially: pronator teres

laterally: brachioradialis

floor: brachialis and supinator muscles

roof: deep fascia and bicipital aponeurosis

contents of cubital fossa

biceps brachii tendon

brachial artery and veins

median nerve

Tendon artery nerve (lateral to medial TAN)

the radial nerves lies under

brachioradialis and divides into superficial and deep branches

supracondylar humeral fracture

may injure median vein and brachial artery

causes forearm compartment syndrome

elbow joint

hinge joint includes trochlea and capitulum of humerus articulating with trochlear notch of ulna and head of radius

ulnar collateral ligament reconstruction

tommy john surgery

palmaris longus, plantaris or other tendons used for graft

subluxation of radial head

pulled elbow or nurses maids elbow

arm pulled up while forearm is pronated

may tear anular ligament

ulnar nerve injury

ulnar nerve passes between the medial epicondyle of humerus and the olecranon of ulna. it passes underneath the tendinous arm that joints the 2 heads of flexor carpi ulnaris muscle (cubital tunnel)

results in localized pain, inflammation and impaired nerve function

carrying angle of elbow joint

10-15 degrees in men

greater than 15 in women

look at slide 46/47 arm and cubital fossa

components of plasma

cells and platelets: RBC, WBC, platelets

plasma: water, proteins, other solutes

hematocrit

relative volume of packed RBC

males: 40-54%

females: 35-45%

low reflects anemia

what percent of volume in the spun centrifuge will be WBC

1%

this is called the buddy coat

all plasma proteins are synthesized where

liver except gamma globulins

major plasma protein is

albumin (55%)

made in liver

repsonsible for colloid osmotic pressure

serves as carrier protein

Glubulins

immuno (y-globulins) (11%)

made by plasma cells

nonimmune globulins

A and B (27%)

made in liver

what percent of plasma proteins is fibrinogen

7%

erythrocytes

no nuclei

no organelles

biconcave disk

7.8um diameter

2.6um outer thickness

0.8um inner thickness

what does RBC shape do

maximizes surface area

shape in maintained by integral and peripheral proteins

flexible so it can squeeze through small places

membrane associated cytoskeletal proteins

spectrin, actin, tropomyosin which give membrane stability and elasticity

HbA

most prevalent in adult

two a and 2 b chains

glycosylation of HbA1c is used to assess serum glucose

HbA2

1.5-3% in adults

two a and 2 delta chains

HbF

fetal hemoglobin

two a and 2 gamma chains

sickle cell anemia

single point mutation of B-globulin chain of HbA

called HbS which aggregates under reduced oxygen tension and causes irreversible sickling

sickled RBCs are not flexible and therefore

clog capillaries causing ischemia and pain

hand-foot syndrome- swelling in hands and feet

proerythroblast

large spherical nucleus

basophilic cytoplasm

slide 16

basophilic erythroblast

stain intensely basophilic in cytoplasm bc of ribosomes

nuclei is smaller than pro and become more heterochromatic with each division

polychromatophilic erythroblast

as basophilic erythroblasts divide the cells are also accumulating hemoglobin which mixes with the basophilic ribosomes causing the cytoplasm to have acidophilia and basophilia (grey color)

last cell able to divide

Orthochromatophilic erythroblast (normoblast)

no longer bale to divide

small number of chromosomes

cytoplasm is predominantly acidophilic bc of large amounts of hemoglobin

can have extruding nucleus

Polychromatophilic Erythrocyte

reticulocyte

no nucleus

normally 1-2% of total RBCs

mitosis occurs in which pre RBCs

proerythroblasts, basophilic and polychromatophilic

cytoplasm starts out very basophilic bc

ribosomes involved in synthesis of hemoglobin

basophilia decreases and eosinophilia increases as

hemoglobin increases and ribosomes decrease by dilution effect of cell division

Erythropoietin

made by kidneys and regulate RBC production

look at slide 24 blood

three basic causes of anemias

blood loss

RBC destruction

decreased RBC production

microcytic anemia

iron deficiency

normocytic anemia

most common

may be decreased production of blood loss

macrocytic anemia

megaloblastic anemia due to B12 or folate deficiency

nitrous oxide abuse can deplete active form of B12

whippets

N2O abuse

megaloblastic anemia

degeneration of spinal cord which causes numbness and tingling in feet and ataxic gait

what cells in kidney secrete erythropoietin

peritubular interstitial cells

2 major groups of WBC

granulocytes and agranulocytes

Granulocytes

neutrophils

eosinophils

basophils

each contain specific and nonspecific granules

azurophilic granules are

lysosomes

agranulocytes

lymphocytes

monocytes

primary nonspecific granules

occur in all granulocytes

they are lysosomes

arise early in granulopoiesis

secondary specific granules

contents are specific to the type of granulocyte

tertiary granules

only described in neutrophils

basophils

0.5% of total leukocytes

bind IgE in circulation and release anticoagulant and vasoactive agents by degranulation

eosinophils

1-2% of total leukocytes

allergic reaction, parasites, chronic inflammation

modulate deleterious effects of inflammatory vasoactive substances by releasing arylsulfatase and histaminidase

found in large amounts in lamina propria

neutrophils

most common WBC

mature neutrophils have segmented nuclei

have 3 types of granules

neutrophil specific secondary granules

most numerous

contain type 4 collagenase, phospholipase, complement activators and lysozyme

azurophilic (primary) granules

less numerous

contain myeloperoxidase

two types of tertiary granules

contains phophatases

contains gelatinases and collagenases

4 neutrophil compartments

medullary formation compartment

medullary storage compartment

circulating compartment

marginating compartment

medullary formation compartment

mitotic compartment (3 days)

maturation compartment (4 days)

medullary storage compartment

acts as buffer

can release large numbers of neutrophils on demand

circulating compartment

suspended in plasma

marginating compartment

Sitting along the walls of capillaries where blood flow is reduced by vasoconstriction.

Expression of L-selectin involved in binding to endothelium

intense physical exertion or increased serum E will cause

transient neutrophilia by movement of neutrophils from the marginating to the circulating compartment

glucocorticoids cause demargination of neutrophils by

decreasing L-selectin production

p selectin

made by platelets but stored in Weibel-Palade bodies in endothelial cells

e selectin

made by endothelial cells

L selectin

made by neutrophils

the hematopoietic stem cell gives rise to two progenitor cells

1. common lymphoid progenitor

2. common myeloid progenitor

common myeloid gives rise to two progenitor cells

1. granulocyte/monocyte progenitor

2. megakaryocyte/erythrocyte progenitor

first recognizable precursor for granulopoiesis

myeloblast

Promyelocyte is the only cell to produce

azurophilic granules

myelocytes produce

specific granules and continue to divide

cell division from granulopoiesis stops when

by late myelocyte stage

metamyelocytes are first cells recognizable as

basophil, eosinophil or neutrophil by their granules

azurophilic granules (dark burgundy color) made only by

promyelocytes and diluted out by divisions

color of neutrophilic, eosinophilic, basophilic

N: salmon

E: red

B: blue

nucleus going through segmentation

indentation at myelocyte stage

U-shaped at band of stab

basophils and eosinophils bilobed

look at slides 43-46 blood

two types of agranulocytes

lymphocytes and monocytes

contain small numbers of non-specific granules called lysosomes