Skeletal, Muscular, and Endocrine Systems Exam #3 Study Guide

These flashcards cover key vocabulary terms and concepts related to the skeletal, muscular, and endocrine systems, as outlined in the lecture notes.

Lamellae

Concentric mineralized circles made of bone matrix that makes up osteons.

Compact bone

Highly organized structure made of osteons.

Spongy bone

Lighter than compact bone but still designed for strength.

Diaphysis

Shaft of the bone that contains the medullary cavity with walls made of compact bone.

Epiphysis

Expanded end of long bone; composed of spongy bone containing red bone marrow.

Osteoblasts

Bone forming cells that secrete bone matrix and promote deposition of calcium salts.

Osteoclasts

Bone absorbing cells that break down bone, returning calcium and phosphate to blood.

Osteocytes

Bone cells located within lacunae.

Lacunae

Spaces between the concentric circles around the central canal of the osteon containing osteocytes.

Canaliculi

Tiny canals that connect lacunae with one another and the central canal.

Metaphysis

Located between the epiphysis and diaphysis; contains the epiphyseal plate that allows for bone growth.

Trabeculae

Thin plates that make up spongy bone.

Fibrocartilaginous callus

Forms between broken bones after a fracture.

Hematoma

A blood clot that forms 6 to 8 hours after a fracture.

Bony callus

Forms in 3 to 4 months during the bone repair process.

Endochondral ossification

Process of bone development from cartilage in a growing embryo.

Intramembranous ossification

Process that forms flat bones between sheets of fibrous connective tissue.

Hyaline cartilage

Type of cartilage found at the ends of long bones and in the respiratory system.

Fibrocartilage

Type of cartilage found in disks between vertebrae and in the knee.

Elastic cartilage

Type of cartilage found in ear flaps and the epiglottis.

Axial skeleton

Includes the skull, vertebral column, and ribs.

Appendicular skeleton

Includes the pectoral and pelvic girdles, and limb bones.

Insertion point

Attachment of muscle to bone that moves.

Origin point

Attachment to bone that is stationary.

Sarcoplasmic reticulum

Smooth endoplasmic reticulum of muscle fiber that stores calcium.

T tubules

Extensions of sarcolemma that convey impulses to muscle fibers.

Z line

Marks the end of sarcomeres.

A band

Contains both thick and thin myofilaments.

I band

Light colored region made of only thin myofilaments.

H zone

Central part of the A band containing only thick myofilaments.

Sarcomere

The basic unit of muscle contraction.

Summation

Increased muscle contraction that can lead to tetanus.

Tetanus

Maximal sustained contraction of muscle.

Sliding filament model

Describes how filaments slide past each other during contraction.

ATP

A molecule necessary for muscle contraction and breaking cross-bridges.

Creatine phosphate

A fast energy source for muscle contraction.

Fermentation

Anaerobic process producing ATP and lactate.

Oxygen debt

Heavy breathing after exercise to metabolize lactate.

Slow twitch fibers

Muscle fibers designed for endurance; resistant to fatigue.

Fast twitch fibers

Muscle fibers designed for strength and short bursts of energy.

Peptide hormones

Hormones made of peptides and proteins; act through second messengers.

Steroid hormones

Hormones that cross the plasma membrane and bind to receptor in the nucleus.

Antidiuretic hormone (ADH)

Hormone released to cause kidneys to reabsorb water.

Oxytocin

Hormone that causes uterine contractions during childbirth.

Thyroid releasing hormone (TRH)

Stimulates the anterior pituitary to secrete thyroid-stimulating hormone.

Epinephrine

Hormone involved in fight or flight response.

Glucagon

Hormone released when blood glucose levels are too low.

Insulin

Hormone released when blood glucose levels are too high.

Melatonin

Hormone that helps regulate the day/night cycle.

Prostaglandins

Produced by damaged tissues; can cause uterine contractions.

Leptin

Hormone produced by adipose tissue signaling satiety.

Erythropoietin

secreted by kidneys in response to low oxygen blood levels to stimulate red blood cell production

Growth hormone

Promotes skeletal and muscular growth.

Calcitonin

Helps lower blood calcium levels.

Parathyroid hormone

Promotes activity of osteoclasts (bone breakdown) to increase blood calcium levels.

Gonadotropic hormones

Stimulate production of gametes and sex hormones.