anatomy & physiology (part 2) - fizziojoe...

Anatomy & Physiology (Part 2)


Overview

Endocrine SystemSkeletal SystemMuscle System

Nervous System


Endocrine System● A system of glands &

organs which produce hormones that biologically alter the function of the body


Endocrine System● The pituitary gland sits at the

base of the brain, just above the brain stem

● The parathyroid glands are located on the posterior of the thyroid gland

● The adrenal glands are on top of the kidneys

● The pancreas is found between the stomach and the small intestine


Endocrine System● The anterior pituitary stimulates

the thyroid gland to release thyroid hormones T3 and T4

● Increasing levels of these hormones in the blood result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland

● This is an example of a negative feedback loop


Skeletal System● Compact Bone

– Composed of many microscopic cylinders called osteons arranged closely together


Skeletal System● Spongy Bone

– Composed of many thread-like process called trabeculae which traverse the bone in many directions

– Marrow fills the spaces between the trabeculae


Skeletal System● Axial Skeleton (red)

– Composed of all the bones which make up the 'trunk' of the body

● Skull● Vertebrae● Ribs● Sternum


Skeletal System● Appendicular Skeleton

(green)– Composed of the appendages

● Arms● Legs

– Bones which attach the appendages to the axial skeleton (trunk)

● Pectoral Girdle– Scapula– Clavicle

● Pelvic Girdle– Os coxa


Skeletal System● Joints

– Structural & functional connections between bones● Sutures are fibrous joints found only in the skull● Cartilaginous joints are bones connected by cartilage, such as between vertebrae● Synovial joints are the only joints that have a space or “synovial cavity” in the joint


Muscle System● Functions to contract (shorten)● The body contains three types of muscle

tissue: – Skeletal muscle

● cells are long and cylindrical● multiple nuclei● small, dark nuclei are pushed to the periphery of

the cell.

– Smooth muscle● cells are short, tapered at each end, and have

only one nucleus each

– Cardiac muscle● cells are also cylindrical, but short● cytoplasm may branch● have one or two nuclei in the center of the cell


Muscle System● Skeletal muscle fiber (cell) is

surrounded by a plasma membrane called the sarcolemma, with a cytoplasm called the sarcoplasm

● Skeletal muscle fiber is composed of many fibrils packaged into orderly units.

● The orderly arrangement of the proteins in each unit in a fibril, shown as red and blue lines, gives the cell its striated appearance


Nervous System● Nervous system is excitable

– Responds rapidly to the slightest stimulus

● Composed of neurons and neuroglial cells

● Neurons produce nerve (electrical) impulses when stimulated

● Neuroglial cells surround and support the activity of neurons


Nervous System● Neurons

– Cell body

– Dendrites● Carry information to the

cell body

– Axon● Carries information from

the cell body to the next neuron


Nervous System● Central Nervous System

– Brain

– Spinal Cord

● Peripheral Nervous System– Spinal Nerves

– Cranial Nerves

● Autonomic Nervous System– A subset of the peripheral

nervous system that controls body functions automatically


Nervous System● Central Nervous

System– Brain

● Cerebral cortex– Frontal lobe (planning

and movement)– Parietal lobe (sensory

interpretations)– Temporal lobe (hearing)– Occipital lobe (sight)


Nervous System● Central Nervous

System– Spinal Cord

● Central gray matter (neuron cell bodies)

● Peripheral white matter (neuron axons)


Nervous System● Meninges

– Three connective tissue layers that surround the brain and spinal cord

● Dura mater● Arachnoid mater● Pia mater

– Protect the CNS from injury


Nervous System● Peripheral Nervous

System– Spinal Nerves

● Paired nerves which exit the spinal cord

● All 31 pair of spinal nerves help control organ functions, body movements, and help carry sensory information to the brain


Nervous System● Peripheral Nervous

System– Cranial Nerves

● Paired nerves which exit the cranium (skull)

● Some only help with organ functions and body movements

● Some only help carry sensory information back to the brain

● Some do both


Nervous System● Autonomic Nervous System

– A subset of the peripheral nervous system that helps control body functions without conscious thought

– In the autonomic nervous system, a preganglionic neuron (originating in the CNS) synapses to a neuron in a ganglion that, in turn, synapses on a target organ. Activation of the sympathetic nervous system causes release of norepinephrine on the target organ. Activation of the parasympathetic nervous system causes release of acetylcholine on the target organ.

anatomy & physiology (part 2) - fizziojoe...

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