9. The functional unit of a muscle is the (A) actin. (B) myosin. (C) Z line. (D)
ID: 303400 • Letter: 9
Question
9. The functional unit of a muscle is the (A) actin. (B) myosin. (C) Z line. (D) sarcomere. Muscle fibers that have many mitochondria and contain myoglobin are (A) fast-twitch muscles. (B) skeletal muscles. (C) smooth muscles. (D) slow-twitch muscles. Specialized cells that help you obtain information from your environment are called (A) neurons. (B) dendrites. (C) axons. (D) nodes. 10. Which of the following is not part of a simple reflex? (A) sensory neuron (B) interneuron (C) brain 12. (D) motor neuron The small gap between two nerve cells is called a(n) (A) threshold. (B) synapse. (C) action potential. 13. (D) node. The portion of the brain that controls body temperature, thirst, appetite, and water balance is the 14. (A) medulla oblongata. (B) pons. (C) cerebellum. (D) hypothalamus.Explanation / Answer
9- sarcomere
The functional unit of muscle is Sarcomere. Sarcomere consists of muscle fibers made up of multinucleated cells enclosed by a special membrane called sarcolemma. Many sarcomeres join to form a myofibril. Sarcomere is further made up of actin and myosin which are also responsible for muscle contraction and relaxation.
10- skeletal muscle
Skeletal muscles are made up of multinuclear cells called myocytes. These cells contain a special type of protein called myoglobin, which has more oxygen storing capacity than hemoglobin. Under a microscope these cells appear straited,because of presence of actin and myosin which help in muscle contraction. The energy for muscle contraction and relaxation comes from mitochondria of myocytes in form of ATP.there are two types of skeletal muscles in our body
11— Neurons
A neuron is a special type of cell which send messages from parts of body to brain and back in form of electrical and chemical signals. The network of neurons makes our nervous system. Neurons are present in every part of our body.
Structure of a neuron….
A neuron consists of following parts
12- Brain
Simple reflex is an autonomous response to stimulus. In simple reflex there is involvoment of only three kinds if nerve cells I.e sensory nerve cell, interneuron and motor neuron.
13- Synapse
Synapse or synaptic cleft is gap between two nerve cells. The cell which send a signal is called pre synaptic cell and the cell which is going to receive the signal is called post synaptic cell.
14- hypothylamus
Hypothylamus is part of brain that controls body temperature,thrist appetite and water balance mainly by regulating hormones in our body.ADH is the hormone from hypothalamus that controls water balance.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.