Exam 2; Muscle, Cardiovascular, and Lymphatic System (PP) Flashcards
What are the characteristics, functions, locations, and component structures associated with skeletal muscle?
A. Consists of striated cells called myofibers.
B. Produces voluntary movement by attaching to bone.
What are the characteristics, functions, locations, and component structures associated with cardiac muscle?
A. Cardiac muscle is founds only in the walls of the heart.
B. Cardiac muscle is striated but involuntary.
C. Cells in cardiac muscle include myocytes, cardiomyocytes, and cardiocytes.
What are the characteristics, functions, locations, and component structures associated with smooth muscle?
A. No striations in smooth muscle since contractile proteins are not arranged the same way as others.
B. Contains cells called myocytes which are short and fusiform (tapered at ends)
C. Smooth muscle is involuntary.
Describe microscopic anatomy of skeletal muscle.
Describe the mechanism in which muscle contracts.
Skeletal muscle contracts only when stimulated by a somatic motor neuron. Nerve and muscle fiber meet at a complex of synapses called a neuromuscular junction. Each tip of the nerve fiber has a synaptic knob nestled into the sarcolemma. The synaptic knob contains NT acetylcholine which stimulates muscle fibers to contract. Acetylcholinesterase is the enzyme that breaks down Ach to terminate muscle fiber stimulation.
What is the association between skeletal muscle and connective tissue (ie: fascia)?
Describe microscopic anatomy of cardiac muscle.
Striated, short, stumpy, branched cells, intercalated discs with gap junctions. Typically mononucleated.
Describe microscopic anatomy of smooth muscle.
No striations, small, fusiform, cell with one nucleus, dense bodies link cytoskeleton and membrane. Involuntary control.
What is myology?
Myology is the study of the muscular system. The term muscular system only refers to skeletal muscle.
Describe the structure of a muscle fiber.
Muscle is organized into muscle fascicles all individually separated by CT called perimysium. Each fascicle have several muscle fibers separated by CT called endomysium. Each muscle fiber is an elongated cell with several nuclei. In each muscle fiber, there are myofibrils made of sarcomeres. Sarcomeres are the basic functional unit of muscle. Between myofibrils, there is lots of mitochondria, and smooth ER called sarcoplasmic reticulum here.
The sarcoplasm of like the cytoplasm of the muscle and contains glycogen and myoglobin.
What are the thick myofilaments made of?
Myosin protein.
What are the thin myofilaments made of?
Actin protein.
Fibrous and globular actin.
How are tropomyosin and troponin involved in muscle contraction?
Tropomyosin blocks the active site (myosin binding to globular actin) when muscle is relaxed. Troponin attaches to tropomyosin and binds calcium when excited.
What are the different striations within muscle?
A band- dark stripe of thick myofilaments that overlap thin myofilaments.
H band- central region of A band that is lighter due to lack of thin myofilaments.
I band- light stripe of thin myofilaments only.
Z disc- midline of I band. The region from Z disc to Z disc is called a sarcomere.
Which of the following muscles of facial expression is represented by ‘B’?
Orbicularis Oculi
Which of the following connective tissue layer covers an individual muscle cell?
Endomysium
Identify the muscle of mastication indicated by ‘A’?
Temporalis
What is the structural/ functional unit of skeletal muscle involved in contraction?
Sarcomere
Identify the muscle ‘B’.
Rectus Abdominus
Which muscle type exhibits intercalated discs?
Cardiac
Identify muscle ‘E’.
Erector spinae
Which labeled structure would be the suprahyoid muscles of the neck?
C
Which of these muscle types is not under the control of the autonomic nervous system (ANS)?
Skeletal
Which of the following muscle types exhibits rythmicity?
Smooth and cardiac muscle
Describe the 4 phases of contraction and relaxation of muscle.
- Excitation- Ach from motor neuron binds in sarcolemma. Na/K channels open when Ach is bound. Flow of ions leads to change in voltage of sarcolemma. This causes electrical excitation down T-tubules and interior of the cell.
- Excitation-contraction coupling- Electrical signals passing down t-tubules open calcium channels in sarcoplasmic reticulum. Calcium released into cytosol. Calcium binds to troponin on thin filaments which causes tropomyosin to shift position so that it is no longer blocking the active site for myosin heads.
- Contraction- Myosin head swings forward and binds to actin via ATP. Myosin head then pulls actin a short distance called the power stroke. Myosin head releases, binds new ATP, recocks, and repeats the process. Myofilaments just slide over each other which is called sliding filament theory of contraction.
- Relaxation- nerve signals stop arriving at neuromuscular junction. Myosin-actin bridges no longer form and the muscle relaxes.
What are the criteria used to name skeletal muscles?
Size- brevis=short
Shape- teres=round
Location- brachii=arm
Number of heads- biceps=two heads
Orientation of fibers- rectus=straight
Action= flexor- muscle that flexes.
Describe the origin, insertion, action, and innervations of the muscles of facial expression and mastication.
Frontalis- elevates the eyebrows.
Orbicularis oculi- closes eyes
Orbicularis oris- closes lips
Zygomaticus major/minor- raises corners of mouth for smile
Risorius- expresses horror
Occipitalis- retracts and tenses scalp
Depressor anguli oris- part of the lips
Most of these are innervated by cranial nerve VII (the facial nerve).
Describe the origin, insertion, action, and innervations of the muscles of extraocular muscles.
The orbicularis oculi, levator palpebrae superioris, and corrugator supercili move the eyelid and other tissues around the eye.
Describe the origin, insertion, action, and innervations of the neck muscles.
Digastric- depresses mandible
Sternohyoid- depresses hyoid
Sternothyroid- depresses larynx
Sternocleidomastoid- rotates head side to side
Scalenes- muscles around cervical vertebrae that flex the neck laterally
Describe the trunk muscles’ origin, insertion, action, and innervations.
Describe the origin, insertion, action, and innervations of the muscles acting on the scapula.
Anterior- pectoralis minor (attaches to coracoid process of scapula) and serratus anterior (attaches to anterior aspect of medial border of scapula)
Both PROTRACT scapula
Posterior- trapezius (attaches to spine of scapula), rhomboids (attach to medial border of scapula), and levator scapulae (attaches to superior aspect of the medial border of scapula and elevates it).
Describe the origin, insertion, action, and innervations of the muscles acting on the arm.
A. Pectoralis major flexes- adducts and medially rotates humerus
B. Deltoid- everything for arm
C. Teres major- extends and medially rotates humerus
D. Latissimus dorsi- extend and adduct arm
Describe the origin, insertion, action, and innervations of the muscles acting on the forearm.
A. Brachialis- prime mover of elbow flexion
B. Biceps brachii- supinates forearm an flex elbow
C. Brachiordialis- flexes elbow
D. Triceps brachii- extends elbow
E. Pronator teres and pronator quadratus- pronate forearm
Describe the origin, insertion, action, and innervations of the muscles acting on the wrist and hand.
A. Abductor pollicis brevis- base of thumb
B. Abductor digiti minimi- base of little finger.
Describe the origin, insertion, action, and innervations of the muscles acting on hips.
A. Iliacus and psoas major- powerful hip flexors
B. Gluteus medius and minimus- medially rotate and abduct hip
Describe the origin, insertion, action, and innervations of the muscles acting on the legs.
A. Quadriceps femoris- extend knee
What are the main functions of the circulatory system?
Transport of gases, nutrient, waste, hormones, and stem cells. Protection via clotting and inflammation, white blood cells, and antibodies. Regulation in balancing fluid levels, pH, and temperature.
What are the components of blood?
55% plasma
45% formed elements- RBC, WBC, and platelets
What is the shape and function of an erythrocyte?
Serves to transport oxygen to tissues and carbon dioxide to lungs. It is a discoid shape that lacks a nucleus and organelles.
What is hematocrit?
The percentage of blood volume composed of red blood cells. Ranges from 37-52%
Why are there different blood types?
Red blood cells have glycolipids antigens on surface. Blood plasma contains antibodies that react against foreign red blood cells.
What is the form and function of leukocytes?
These are the least abundant formed elements. Their job is to protect against pathogens. They are characterized by prominent nucleus and other organelles. There are agranulocytes (lymphocytes and monocytes) and granulocytes (neutrophils, eosinophils, and basophils).
What are neutrophils?
These are granulocytic white blood cells. Has a nucleus with 3-5 lobes in S or C shape. Functions in phagocytizing bacteria and secreting antimicrobial chemicals. Make up 60-70% of all WBCs.
What are eosinophils?
These are granulocytic white blood cells. Nucleus has two large lobes connected by a thin strand.
Functions in phagocytizing antigen-antibody complexes, allergens, and inflammatory chemicals. Secretes enzymes that destroy parasites. Makes up 2-4% of all WBCs.
What are basophils?
These are granulocytic white blood cells. Nucleus is large and irregularly shaped. Has coarse, abundant, and dark violet granules in cytoplasm. Functions include secrete histamine and heparin.
What are monocytes?
These are agranulocytic white blood cells. Kidney-shaped nucleus with sparse granules. Functions in phagocytizing pathogens, dead cells, can differentiate into macrophages. Makes up 3-8% of all white blood cells.
What are lymphocytes?
These are agranulocytic white blood cells. Has round nucleus. Functions in destroying cancer cells, cells with viral infection, and foreign cells. Secretes antibodies and serves in immune memory.
What are platelets?
Platelets are small fragments of megakaryocytes that aid in blood clotting. No nucleus but has lysosomes and mitochondria.
Describe the pulmonary and systemic circuits?
The pulmonary circuit carries blood to the lungs for gas exchange and returns it to the heart. The systemic circuit supplies blood to tissues in the body.
The right side of the heart receives deoxygenated blood from veins and sends it to lungs via the pulmonary trunk. Pulmonary veins return newly oxygenated blood to left side of the heart. The left side of the heart then pumps the blood to the aorta and pumps to rest of body. Blood returns to heart via veins that converge on the superior and inferior vena cava on the right side of the heart.
What is the position, shape, and size of the heart?
Located in the mediastinum right above the diaphragm. It is the size of your fist.
What is the peridcardium?
This is a double-walled sac that encloses the heart. It is made of dense irregular connective tissue. Two layers include pericardial sac and the epicardium. Between the two layers is pericardial fluid which allows the heart to beat without friction.
What are the three layers of the heart wall?
- Epicardium (visceral pericardium)- simple squamous epithelial. Serous membrane
- Myocardium- comprises bulk of heart wall and made of cardiac myocytes.
- Endocardium- thin inner wall that lines chamber. Made of simple squamous epithelium.
Describe the four chambers of the heart.
Left and right atria- receive blood returning to heart from great veins. Thin wall of separation called interatrial septum.
Left and right ventricles- pump blood to arteries. Thick walls separated by interventricular septum.
Describe the different valves of the heart.
Tricuspid valve- separates right atria from right ventricle. Has 3 cusps
Bicuspid/mitral valve- separates left atria from left ventricle. Has 2 cuss.
Operations of heart valves?
Describe blood flow through the heart.
How is blood supplied to heart tissue?
The left coronary artery branches off to the anterior interventricular branch the runs along the anterior interventricular septum. The circumflex branch continues around left side of coronary sulcus and supplies left atrium and posterior wall of left ventricle. The right coronary artery supplies right atrium and gives off into two branches, the right marginal branch and posterior intervertebral branch.
Describe the conduction system of the heart.
Cardiac myocytes depolarize at regular time intervals. First the sinoatrial node (SA) initiates each heartbeat and determines the rate. SA node is pacemaker of the heart. Electrical signal them spreads through the atria. The signal travels to atrioventricular (AV) node which passes electrical signal to the ventricles. Electrical signals pass through bundle of his that descend into the interventricular septum. The AV bundle branches off into Purkinje fibers near apex of heart. Signals then spread through the ventricular myocardium and distribute excitation to myocytes of the ventricles.
What are the three layers of arteries and veins?
- Tunica externa- outer most layer made of loose CT
- Tunica media- middle layer of smooth muscle and CT
- Tunica interna- inner most layer consisting of endothelium overlaying a basement membrane
In large and medium arteries, there is an internal elsatic lamina between interna and media layer. There is also an external elastic lamina between media and externa.
What are the three classes of arteries?
- Conducting/elastic arteries- the LARGEST arteries. Absorbs pressure and maintains it. Example is the aorta.
- Distributing/ muscular arteries- midsized arteries are smaller branches that distribute blood to specific organs. Example is the femoral artery.
3.Resistance/small arteries- Too variable in number and location to be given a specific name. Less than 0.1mm in diameter. The smallest of these arteries are called arterioles.
Metarterioles link arterioles to capillaries. Metarterioles have a circular cuff of smooth muscle called the pre-capillary sphincter. Can shunt blood flow.
What are the different baroreceptors and chemoreceptors in elastic arteries?
Carotid sinuses- baroreceptors in the internal carotid artery wall
Carotid bodies- chemoreceptors near the branch of the common carotid artery
Aortic bodies- chemoreceptors in the aortic arch.
What are the three types of capillaries?
- Continuous capillary-endothelial cells joined by tight junctions. Allow for the passage of small solutes.
- Fenestrated capillary- endothelial cells riddled with holes called filtration pores that allow for rapid passage of small molecules. Found in small intestine and kidneys
- Sinusoid/ discontinuous capillary- Irregular blood filled spaces in the liver, bone marrow, and spleen are called sinusoids. Endothelial cells are separated by wide gaps and no basal lamina. Large molecules can pass through these leaks. This is how formed elements enter the blood from bone marrow.
What are the five types of veins?
- Postcapillary venules- smallest veins that receive blood from capillaries. Has leaky walls that exchange fluid with surrounding tissue.
- Muscular venules- These receive blood from postcapillary veins and are up to 1mm in diameter.
- Medium veins- Up to 10mm in diameter and are usually named.
- Venous sinuses- veins with thin walls, large lumen, and no smooth muscle. An example includes the dural sinuses of the brain.
- Large veins- Diameter greater than 10 mm. Example includes the vena cava.
What is the skeletal muscle pump system?
This is the mechanism of blood propulsion back towards the heart via skeletal muscle contraction and relaxation.
What are the alternate circulatory routes besides the simple path?
- Portal system- sequence of two capillary beds that occur in kidneys, hypothalamus to pituitary connection, and intestines to the liver.
- Anastomosis- Where veins and arteries merge without capillaries. Vein could also dump into another vein or artery into artery
Be able to label the aorta and its major branches.
The ascending aorta arises from the left ventricle.
What are the arteries of the head and neck?
The common carotid artery supplies most blood to the head and neck. The right common carotid branches from the brachiocephalic trunk. Left common carotid branches off from the aortic arch. The vertebral arteries come from subclavian arteries and contribute to the blood supply of the brain.
All vertebral arteries converge to form a single median basilar artery along anterior aspect of brainstem. It supplies the cerebellum, pons, and inner ear.
The basilar artery and two internal carotid arteries converge on the cerebral arterial circle. This circle gives of anterior and posterior cerebral arteries.
What are the veins of the head and neck?
The dural venous sinuses between the layers of the dura mater receive blood that has passed through the brain. Most blood from dural sinuses flows into the internal jugular vein. All brain veins empty into the subclavian vein.
What are the main arteries of the thorax?
Thorax is supplied by arteries coming from the aorta, subclavian, and axillary artery. The thoracic aorta begins distally to the aortic arch and ends at the aortic hiatus in the diaphragm. Bronchial, esophageal, and mediastinal arteries supply structures of the chest.
What are the veins of the thorax?
Veins of the upper thorax include subclavian, brachiocephalic, and superior vena cava veins. The azygos system is the principal drainage of the thoracic organs. It includes the azygos vein which receives blood and empties into the superior vena cava.
What are the big arteries of the abdomen and pelvic areas?
The aorta descends through the diaphragm and branches off into the celiac trunk, which gives rise to vessels that supply the spleen, stomach, liver, superior mesenteric artery, renal arteries, varies and testicular arteries, and large intestine.
Distally, the aorta branches off into the two common iliac arteries. They supply the pelvic wall and viscera.
What are the main veins of the abdomen and pelvic region?
The inferior vena cava is made by the joining of the right and left common iliac veins.
What is the hepatic portal system?
Vessels that drain the digestive system organs all converge on the hepatic portal vein that leads to the liver. In the liver, blood from GIT is processed meaning nutrients and stored and detoxification of the blood occurs. From the liver, the blood travels to the inferior vena cava via the hepatic vein.
What are the main arteries of the upper limb?
Branches of the subclavian artery supply the arm, forearm, and hand. As it travels anterior to the humerus in the arm, it becomes the brachial artery, which branches off several more times. At the elbow, the brachial artery forks into the radial and ulnar arteries.
What are the main veins of the upper limb?
Superficial and deep veins of the upper arm lead to axillary and subclavian veins. Superficial veins include the dorsal venous arch and cephalic vein. Radial and ulnar veins come together to give rise to brachial veins. Brachial veins converge into the axillary vein. The Axillary becomes subclavian which becomes the brachiocephalic vein, which meets the internal jugular vein. The two brachiocephalic veins converge to form the superior vena cava which empties into the heart.
What are the main arteries of the lower limbs?
The aorta branches into common iliac arteries which divide into internal and external iliac arteries. The external iliac artery continues as the femoral artery to supply blood to the thigh. Near the knee, the femoral artery divides into the anterior and posterior tibial arteries which branch to supply the foot.
What are the main veins of the lower limb?
Dorsal venous arch on the foot. The great saphenous vein travels up the medial leg and thigh. Deep veins of the foot give rise to posterior and anterior tibial veins as well as the fibular vein. These all flow into the popliteal vein which continues as the femoral vein in the thigh. The external iliac vein is formed by the convergence of the femoral and great saphenous veins. It then meets the internal iliac vein where the common iliac vein is formed which drains into the inferior vena cava.
