GPHY

Sarcolemma

The cell membrane of muscle cells.

Sarcoplasm

The cytoplasm of muscle cells.

Sarcomere

The structural and functional unit of skeletal muscle.

Endomysium

Thin connective tissue surrounding individual muscle fibers.

Perimysium

Thick connective tissue surrounding bundles of muscle fibers.

Epimysium

Dense connective tissue surrounding the entire muscle.

Actin

Principal protein component of thin filaments in muscle.

Myosin

Protein that makes up the thick filaments in muscle.

Neuromuscular Junction

Connection between a neuron and a muscle fiber.

Prime mover (agonist)

Muscle chiefly responsible for a specific movement.

Antagonist

Muscle that opposes the action of the prime mover.

Synergists

Muscles that assist prime movers in performing actions.

Axial Muscles

Muscles of the head, neck, thoracic wall, diaphragm, and abdominal wall.

Appendicular Muscles

Muscles of the upper and lower extremities.

Myalgia

Muscular pain.

Myositis

Inflammation of muscular tissue.

Muscle Dystrophy

Progressive disorder leading to muscle weakness.

Muscle Atrophy

Degeneration of muscle fibers resulting in reduced muscle size.

Neurons

Active conducting elements of the nervous system that transmit electrical impulses between different parts of the body.

Neuroglia

Supporting elements in the nervous system that assist neurons in their functions.

Synapse

Points of connection between neurons where chemical transmitters are released to allow impulses to pass from one neuron to another.

Nerve Impulse

Localized reversal in the charge of a neuron's cell membrane, known as action potential, which allows for the transmission of electrical signals.

Myelin Sheath

Insulating material covering axons that speeds up the passage of nerve impulses through saltatory conduction.

Gray Matter

Area of the nervous system rich in nerve cell bodies, while white matter consists mainly of myelinated nerve fibers.

Cerebrum

Largest part of the brain responsible for advanced intellectual functions, sensory perception, and motor control.

Basal Ganglia

Paired masses of gray matter in the brain involved in motor function control and coordination.

Diencephalon

Part of the forebrain containing the thalamus and hypothalamus, crucial for sensory integration and various regulatory functions.

Cerebrospinal Fluid

Colorless fluid circulating within the brain's ventricles and spinal cord, providing a protective cushion and aiding in waste removal.

Foramen of Luschka and Magendie

Openings in the fourth ventricle allowing cerebrospinal fluid to flow into the subarachnoid space.

Spinal Cord

An elongated part of the central nervous system, extending from the foramen magnum to the lumbar vertebrae, with cervical and lumbar enlargements.

Cauda Equina

Bundle of lumbar and sacral spinal nerves descending along the filum terminale in the vertebral canal.

Spinal Nerve

A mixed nerve fiber bundle attached to the spinal cord, emerging through intervertebral foramina, with dorsal and ventral roots.

Cervical Plexus

Formed by the first four cervical nerves, supplying sensory fibers to the head and neck, including the phrenic nerve for the diaphragm.

Lumbar Plexus

Arising from L1-L4 spinal nerves, including the femoral nerve for the anterior thigh and obturator nerve for the medial thigh.

Thyroid Gland

Endocrine gland in the neck producing hormones like thyroxine and triiodothyronine, regulating metabolism and calcium homeostasis.

Adrenal Cortex

Outer part of the adrenal glands producing mineralocorticoids, glucocorticoids like cortisol, and androgens.

Oxytocin

Hormone stored in the posterior pituitary gland, contracting the uterus during delivery and stimulating milk ejection.

Blood

Liquid connective tissue with functions in transport, protection, and regulation, composed of plasma and formed elements like RBCs, WBCs, and platelets.

Hemoglobin (Hgb)

The amount of hemoglobin in blood, with normal levels of 14-16 gm in males and 12-14 gm in females.

Hematocrit (Hct)

The percentage of red blood cells in whole blood, with normal levels of 45-52% in males and 37-48% in females.

White Blood Cell (WBC)

Leukocytes that combat pathogens through phagocytosis and immune responses, with a range of 5,000-10,000 cells per microliter of blood.

Neutrophil

A type of granular leukocyte that is the most abundant white blood cell, with a multi-lobed nucleus and a key role in responding quickly to bacterial infections.

Lymphocyte

A type of white blood cell that produces antibodies, recirculates between blood and lymphatic fluid, and is essential in immune responses.

Monocyte

A type of white blood cell with a kidney-shaped nucleus that transforms into macrophages for phagocytosis, staying in the bloodstream for about 3 days.

Platelet

Cell fragments involved in hemostasis, picked up in the bloodstream to help seal blood vessel breaks, with a lifespan of 7 to 8 days.

Systolic Blood Pressure (SBP)

The highest arterial pressure during ventricular contraction, while Diastolic Blood Pressure (DBP) is the lowest arterial pressure during ventricular relaxation.

Aorta

The largest artery in the body, arising from the left ventricle of the heart and divided into ascending, arch, and abdominal parts.

Pulmonary Circulation

The circulation of blood between the heart and lungs, involving the pulmonary trunk, arteries, and veins for oxygen exchange.

Cardiac Cycle

All events associated with one heartbeat, consisting of alternating contraction and relaxation of atria and ventricles, forcing blood from areas of higher pressure to lower pressure.

Systole

Refers to the phase of contraction, either atrial or ventricular, following depolarization.

Diastole

Refers to the phase of dilatation following repolarization.

S1 - First Heart Sound

"Lubb" sound due to the closure of the atrioventricular valve when the ventricle contracts in systole.

S2 - Second Heart Sound

"Dupp" sound due to the closure of semilunar valves when the ventricle relaxes in diastole.

Electrocardiogram (ECG/EKG)

A composite record of action potentials produced by all heart muscle fibers during each heartbeat, recorded by an electrocardiograph.

P Wave

Represents atrial depolarization spreading from the SA node through the contractile fibers in both atria, with a small upward deflection.

QRS Complex

Represents rapid ventricular depolarization, with a Q-downward deflection, R-large upright, triangular wave, and S-downward wave.

T Wave

Represents ventricular repolarization occurring as the ventricles start to relax, with a dome-shaped upward deflection.