Lecture Notes on Muscles, Endocrine System, Respiration, Circulation, and Digestion

Vocabulary flashcards based on lecture notes about muscles, endocrine system, respiration, circulation, and digestion.

Striated muscle

Type of muscle found in the heart, limbs, head, and torso.

Smooth muscle

Type of muscle found in the respiratory, circulatory, excretory, and digestive systems.

Actin & Myosin

Muscle protein types found in striated and smooth muscle.

Myofibrils, muscle fibers or cells, muscle bundles, and muscles

Major components of a whole muscle, from smallest to largest.

Sarcomere

The area between two Z discs (or Z lines), i.e., the smallest unit of contraction.

Cross-bridge formation

Occurs when myosin heads interact with actin filaments.

Detachment of the myosin head from actin

The effect of ATP binding to myosin.

Motor neuron

Sends nerve signals to skeletal muscle.

Connective tissue

The type of tissue that wraps around whole muscle groups and muscle bundles.

Acetylcholine

The neurotransmitter released by motor neurons at the motor endplate.

Motor unit

A motor neuron and the muscle fibers it innervates.

Muscle’s force output

Depends on the number of motor units activated each time frame.

T-tubule

Conducts a depolarization into the muscle cell, where it affects the sarcoplasmic reticulum.

Receptors for a particular hormone

Determines what cells will respond to a particular hormone in circulation.

Amine or peptide hormones

Hormones that bind to extracellular receptors specific to them.

Steroid or cholesterol-derived hormones (hydrophobic)

Class of hormones that binds to its receptor in the cytoplasm or nucleus of the cell.

Hypothalamus

Sits at the base of the forebrain, receives information from the nervous system, and initiates our endocrine system’s response.

Positive feedback

A system's end product feeds back into the system and amplifies the process.

Glucagon

Hormone released by the pancreas between meals to raise blood glucose by stimulating the breakdown of glycogen.

Insulin

Hormone promotes skeletal muscle and the liver to store energy via glycogen and fatty acid synthesis.

Negative feedback

Keeps circulating glucose at homeostatic, or healthy, levels.

Pancreas

Organ secretes glucagon and insulin and is key in regulating circulating energy levels.

Sympathetic nervous system

Activating this branch of your autonomic nervous system is crucial for a rapid stress response.

Adrenal gland

Gland sits atop the kidney and releases the primary hormones that govern the stress response.

Partial pressure

Differences in this property of gas drive its diffusion across a membrane from areas of higher concentration to lower concentrations.

Diaphragm

Muscle separates the abdominal and thoracic cavities and helps to inflate the lungs by creating a negative pressure in the thoracic cavity.

Bulk flow

Process allows multicellular organisms to transport substances to the site where diffusion occurs more efficiently.

Alveoli

Structures greatly increase the surface area of the lungs, ensuring that the gas exchange surface is maximized.

Red blood cell

Cell is hardly a cell at all given its lack of organelles; it travels slowly through the capillaries, where it exchanges the gases O2 and CO2.

Artery

Component of your circulatory system has 2x the smooth muscle as veins, contains elastin to allow for expansion/contraction.

Veins

Component of your circulatory system has one-way valves to ensure that blood always flows back toward the heart.

Capillary beds

Component of your circulatory system has the greatest surface area and, subsequently, the slowest rate of blood flow.

SA node or pacemaker

Specialized group of cells generates action potentials that initiate the heart’s contraction.

Left ventricle

Chamber of the heart produces the greatest amount of force before sending blood out to the systemic circuit of the CS.

Aorta

Artery connects to the heart and is the largest artery in the body.

Lymphatic system

System drains our body and has been dubbed “the body’s sewer system”.

Pulmonary vein

The only vein in the body that contains fully oxygenated blood.

Pulmonary valve

Ensures that deoxygenated blood does not return to the heart after being pumped by the right ventricle.

Systole

The heart beats rhythmically and has two phases, this phase can be heard when the ventricles contract.

Fats, carbohydrates, and proteins

Three major food macromolecules your GI tract is designed to digest.

Essential amino acids

Protein monomers that cannot be created by the body and need to be acquired via the diet.

Midgut

Region of our gut is responsible for almost all of the absorption of proteins and carbohydrates we eat.

Gall bladder

Digestive organ’s primary responsibility is to aid in the breakdown of fats, via bile or bile salts.

HCl

Acid creates an incredibly high acidity in the stomach (low pH) which helps denature protein and kill microbes.

Pepsin

High acidity of the stomach creates this active polypeptide, which starts the chemical process of protein digestion in our gut.

Bicarbonate

When the contents of the stomach first enter the small intestine (duodenum) the pancreas releases this molecule to neutralize the pH.